The UK Phyto-V Covid Nutritional intervention Study

 IRAS (Ethics) Number: 282517EudraCT: 2020-001532-10-1: MHRA notified April 21

Read full paper published in the international Journal – COVID

Summary: This was the World’s largest nutritional intervention study involving men and women with symptomatic early and long covid infection. It  established that boosting the diet with natural phytochemical rich concentrated foods, in combination with  a specifically designed lactobacillus probiotic and an inulin prebiotic  reduced the severity of symptoms, improve gut health, speed up recovery and prevented late complications of a covid-19 infection.

This non-commercial intervention was designed and conducted  by a team of clinical and academic nutritionalist, chest physicians, research pharmacist, consultants and scientists from Bedfordshire and Addenbrooke’s Cambridge University Hospitals. It was conducted in two parts:

The first analysis.
This involved the 126 patients with symptomatic covid, look at the impact of  a 5 blend of lactobacillus probiotics combined with a purified inulin prebiotic made from chicory. Patients had an  average duration of symptoms of 108 days. They were given 30 days of yourgutplus (a pre and probiotic capsule) within the ongoing UK national Phyto-v study. Symptoms were recorded using the validated Cough Symptom Score, the Subjective Well-Being questionnaire and the Chandler fatigue questionnaire. The group was analysed as a whole and then subdivided into 40 (32%) in an early phase of infection (average symptoms 10 days before baseline) and the 86 (68%) in a chronic phase (average symptoms 120 days before trial baseline).

A final analysis of the results showed that cough, fatigue and subjective well-being scores significantly improved over the 30 days in both the early and chronic phase cohorts. Participants who were more likely to have gut dysbiosis at trial entry, such as sedentary, hospitalised, older males with GI symptoms, had a statistically significantly better response to the probiotics. Gut symptoms improved in 25 of 31 (82%) who reported them at baseline. Two (1.5%) patients reported mild increased bloating and diarrhoea.

This aspect of the study was  completed and  published in early December 2021: Read a summary of the results

The second analysis
This looked the difference in clinical outcomes between 151 participants were blindly randominsed either to a placebo or to the nutritional capsule containing phytochemical rich foods. 

This study involved 147 participants with symptomatic COVID-19, randomised to receive a placebo (P) or a phytochemical-rich concentrated food capsule (PC) in addition to a pre/probiotic lactobacillus capsule known as Yourgutplus+®.

Participants taking the PC had an almost two-fold reduction in mean fatigue scores compared to placebo [p=0.02], a three-fold reduction in cough score and more than a double improvement in overall well-being scores [p=0.02]. Two (1.5%) participants reported mild, increased bloating which they felt was attributable to the capsules, although GI symptoms improved in 25 of 31 participants (82%) who reported them at baseline. Sedentary, older, previously hospitalised men with GI symptoms had a statistically significantly improvement among those given the probiotic.

Such a rapid improvement observed in the majority of participants, who had been suffering for an average of 108 days, was clinically relevant and welcomed, especially among those more likely to have pre-existing gut dysbiosis. Recruitment has also completed and the data was externally audited and statistically analysed independently via the biostatistics team at The University of Bedfordshire.

This aspect of the study was published in Summer 2022: Read a summary of the results

Further studies
One evaluating whether this probiotic/prebiotic blend reformulated with Vitamin D3 could enhance antibody titres post covid vaccine. This has been submitted to the UK ethics committee and with hopefully start in early 2022. This study was designed to assess and quantify the positive impact of regular exercise on antibody titres. A second study is planned to evaluate whether phyto-v could help patients with peripheral neuropathy


See some of the media coverage for the study



Since the completion of the academic study, the manufacturers, who supplied the supplements for the trial, have now made them available to buy. As, they are classed as nutritional interventions and not drugs, they cannot be prescribed by doctors under current rules


The UK Phyto-V Study –  Background 

On the 31 December 2019, the World Health Organization (WHO) was informed of a cluster of cases of pneumonia of unknown origin detected in Wuhan City, China. The infection spread to the rest of the world, and on the 11th of March 2020, the WHO declared that COVID-19 was a pandemic.  

Covid-19 is an enveloped, positive-sense single-stranded RNA (ssRNA) virus belonging to the Coronaviridae family which causes upper respiratory tract and gastrointestinal infections in mammals, bats and birds. In humans, it mainly causes common cold, but complications include severe adult respiratory distress due to pneumonia.

In the current pandemic, most cases recover fully but about a small number require  intensive care hospital care.   Why one person gets a severe infection and other not is not entirely understood and genetic variabilities in both the host and virus are likely to be important [Wu]. Data collected from hospitals across the World showed that people with pre-existing health conditions or who are overweight are more vulnerable to catching covid-19 infection, developing the complications of infection. Pre-existing chronic conditions which weaken cardiac or pulmonary function reserve have an influence on whether an effective individual is able to sustain the viral insult. 

Gut Health: This is very relevant to covid because  as emerging evidence from clinical studies and experience from managing patients with Covid-19 (Covid) unfolds, the links between severity of symptoms, mortality and gut microbial dysbiosis has become increasingly apparent 1,2,3,4,5 .  Depleted healthy strains of commensal bacteria such as Lactobacillus have been reported in the majority of patients with Covid  expressing gastrointestinal (GI) symptoms and especially those with persistent ongoing problems, coined long or chronic Covid 6,5,7,8,9,10,11 .   The authors of these studies postulated microfloral dysbiosis contributes to symptoms via increased gut inflammation, impaired gut wall integrity which correspondingly leads to systemic inflammatory dysfunction, reduced immune surveillance leading to greater non-gut symptoms as well 4, 6, 8,5,11, 12 .

In this situation, overgrowth of less favourable gut bacteria have been found in the systemic circulation and even within pulmonary aspirates taken from the lung airways. this contributes to  an increased inflammatory response, causing cough and breathlessness  13, 14, 15, 16,17 . Excess inflammatory cytokines and pulmonary exudates are a feature of acute respiratory distress syndrome (ARDS) following a viral infection, hence the recently coined term  cytokine storm 13 14, 15, 16, 17 .  The link between bowel dysbiosis and lung hyperinflammation has also been well documented in other chronic respiratory diseases including asthma and chronic bronchitis 18,  19, 20 

Probiotic supplements: In addition to dietary and behavioural measures, supplementary capsules are a convenient way to increase total intake of pro and prebiotics, as well as a way to spread their intake throughout the day. The most widely researched  probiotics include lactic acid producing bacteria such as species of Lactobacillus, the colonisation of which is enhanced by concomitant intake with prebiotic soluble fibres such as inulin 21, 22.   Numerous interventional studies in humans and animals have shown they can help improve mircrofloral biodiversity, correct GI symptoms such as bloating and diarrhoea and improve Immune efficiency 23, 24, 25, 26, 27, 28.  Many of these studies, albeit most needing further confirmation, have shown they help modify a range of chronic diseases ranging from obesity, inflammatory bowel disease, diabetes, cardiovascular disease, hypertension, anxiety, depression, osteoporosis and dementia 21, 28, 29,  30, 31,  32,  33, 34, 35, 36 , 37. More relevant to this study,  intervention studies have shown regular intake of live probiotics, particularly Lactobacilli strains, shortened the incidence duration and severity of upper respiratory tract infections in several studies 38, 39, 40, 41, 42, 43. This includes a summary of interventional studies published in the Cochrane Database which concluded that probiotics did reduce the number of symptomatic upper respiratory tract infections 43 . Another meta-analysis of small RCTs suggests that probiotics decreased the need for invasive mechanical ventilation due to development ARDS following viral pneumonia 44 .

How do probiotic bacteria help?: The reported mechanism of action of probiotic bacteria is multifactorial 45, 46 . They encourage gut colonisation of anti-inflammatory strains which then out space pro-inflammatory (Firmicutes) bacteria. They encourage the fermentation of otherwise poorly-digestible dietary carbohydrates into short-chain fatty acids (SCFA) such as butyrate. These have an important impact upon mucosal physiology as they are an idea source of energy for gut cells so help improve gut health and hence gut wall integrity 47, 48, 49, 50.  Probiotic bacteria also help the breakdown of polyphenols into more ready absorbed and more bioactive varieties 51, 52. Higher serum levels of polyphenols and other phytochemicals are linked to lower systemic inflammation, a lower risks of chronic degenerative disease 49, 55, 52, 53, 55, 56, 57 and cancer 53, 54 .

As well as their positive influence on immune balance, probiotics have been found to have a range of other potential mechanisms of actions45, 46 . They can enhance intracellular oxidative enzyme capacity and can help scavenge excess superoxide anions among patients with Covid58.  This mechanism, in laboratory studies, was attributed to their ability to reduce oxidative stress via upregulating superoxide transferase and other anti-oxidant enzymes60 . Excess oxidative stress is a linked to more aggressive  pulmonary pathogenicity following Covid pneumonia61,62.  Probiotics help increase vitamin D absorption and bioactivity 63, 64, 65, 66, 67, 68.  Low vitamin D is associated with higher levels of unregulated hyperinflammatory cytokine production and ultimately more severe respiratory Covid related symptoms 69, 70, 71, 72 .  Finally, there are reports of direct anti-viral actions of lactic acid producing bacteria such as lactobacillus via the production of antiviral inhibitory metabolites following induction of the expression of genes involved in antiviral immunity 73, 74, 75, 76, 77.

The Kings app study has reported that individuals who have more symptoms initially, including bowel problems, were more at risk of long Covid 78 . In addition, people who took regular probiotics had a 14% lower risk of symptomatic Covid 79 .  Many clinical trials are underway globally examining the role of pro and prebiotics in both prevention and treatment of Covid and some have reported benefits 1, 8, 58, 80, 81, 82, 83, 84. Considering this background of evidence, this study aimed to examine whether their administration could reduce the severity and longevity of symptomatic Covid infection, particularly those with ongoing symptom, via their gut health promoting, immunomodulatory and anti-inflammatory and direct actions.

Phytochemical rich foods

Regular intake of natural phytochemicals in fruit, herbs and vegetables,  are linked to a reduced risk of chronic degenerative diseases and more recently their role in mitigating some symptomatic effects of viral infections is being explored [Thomas, Shen, Uchide, Powanada, Bailey, Powanda]. There are a number of properties of these foods which could be utilised to help the fight against covid:

Improving gut health: Some polyphenols such as plant lignans found in nuts, resveratrol in red wine, ellagitannin found in tea as well as celery, pomegranate and turmeric act as prebiotics to healthy bacteria which improve gut health and integrity which reduces the absorption of proinflammatory toxins into the systemic circulation [Powanda]. 

Reducing Chronic excess inflammation: In addition to their positive effect on gut health, curminoids in turmeric, ellagic acid, quercetin and resveratrol found in tea, grapes, polygonum cuspidatum root and pomegranate, dampens down excess tissue chronic inflammation, by reducing COX–2 activation of prostaglandins via modulation of the function of NF-kappaB NF‐κB, [Blacklock, Zakkar Handler, Thomas, Funk]. This mechanism explaining why they have been shown to reduce inflammatory associated pain in joints, a symptom common amoung people with long covid [ref Powanada, powdnada]. Yet unlike aspirin, ibuprofen, which can damage the gastric mucosa, polyphenol rich foods have been shown to protect it [Al-howiriny]. Resveratrol influences regulation of angiotensin-converting enzyme 2 (ACE2),  another factor relevant for viral-induced excessive inflammatory exudate and lung parenchyma injury [Rossi, Martinez, Nencioni]. Unlike steroids and other immune suppressants, the ability of phytochemicals to downregulation of pro-inflammatory cytokines has not lead to a reduced viral Immunosurveillance [Rossi, Filardo, Campagna, Tang, Lee, Critchfield]. Resveratrol, has been reported to increase anti-viral cytotoxic T lymphocytes (CTLs) and natural killer (NK) immune cells. [Rossi, Filardo, Campagna ]. Likewise, apigenin, derived from camomile, has shown to induce anti-HIV activity in T-cell lines transfected with HIV [Tang, Lee, Critchfield].

Enhancing appropriate oxidative pathways: Phytochemicals have been shown to promote a natural adaptive response to tissue oxidative stress via ability to facilitate activation of the transcription factor NF‐E2–related factor 2 (Nrf2) [Uchide]. This enhances an appropriate antioxidant response to damaging reactive oxidative species a relevant as tissue damage post covid has been linked excess oxidative damage [Stivala, Davidosn, Juge, Dinkova‐Kostova. Yet, unlike direct anti-oxidants such as vitamins A & E, there is no evidence they over deplete ROS levels causing a situation coined anti-oxidative stress as they do not slow the degradation of antioxidant enzymes after a tissue insult has diminished, [Poljsak, Ristow, Eder, Teixeira, Avery, Peternelj, Lotito].

Foods such as pomegranate are also usually rich in nitrates which, in the presence of vitamin C, citrus bioflavonoids and other polyphenols, are converted to nitric oxide (NO) [Lundberg]. NO has smooth muscle vasodilatory properties which helps to lower blood pressure and enhance tissue oxygenation, both relevant factors after a covid pneumonia [Bailey, Bondon, D’Angelo].

On top of these protective mechanism on immunity and normal tissue, phytochemicals have recently been discovered to have direct anti-viral properties [Li, Lin, Ge, Wu, Lau, Yu, Chaing, Li, Lin, Ge]. Ellagic Acid, quercetin and resveratrol, have inhibited viral penetration and replication in vitro cells exposed to HIV, influenza and hepatitis by inhibition of viral gene expression, viral protein synthesis and downregulation of cellular transcription and signaling pathways [Filardo, Filardo, Marinella, Palamara, Ramdani, Calland, Park, [Neu, Su, Sundararajan, Yang,  Wu, Song]. Curcuminoids have inhibited grow of a range of RNA and DNA viruses including hepatitis,  influenza, and human papilloma and other virus by competitively suppressing sterol regulatory element binding protein pathways require by the virus for cell penetration  [Kim Anggakusuma, Jassim Maher]. A combination curcuminoids and ellagic acid has been demonstrated synergy in their ability to generate ROS mediated apoptosis in HPV infected HeLa cells [Kumar]. Apigenin, found in chamomille, has slowed viral replication by suppressing internal ribosomal entry site (IRES) mediated translational activity and by modulating cellular c-Jun N-terminal kinase (JNK) pathways [Lv, Qian]. The three main citrus bioflavonoids hesperetin, naringin and catechin have demonstrated inhibitory effects on replication and infectivity influenza and SARS-CoV infected cells virus [Ryu, Kaul, Mycol Lin, Paredes].  Emodin found in aloe vera and Polygonum cuspidatum root have inhibited replication of the H5N1 virus responsible for the last pandemic in 2013  via galectin-3 up-regulation, which in turn reduces RNA-dependent protein kinase and 2’5′,-oligoadenylate synthetase expression [Sun, Lin, [Syed] [Iljazovic],,  [Kahlon, Radha] Li 2014]Li 2014].

The combination of probiotic bacteria, inulin and phytochemicals appears particularly advantageous as there is evidence of synergy between them. Some phytochemicals particularly the polyphenols act as prebiotics, which helps support colonisation of gut probiotic bacteria, via a number of mechanisms [Powanda, ref]. Resveratrol and emodin in aloe vera and  polygonum cuspidatum root, for example, enhance the formation of a protective biofilm over bacteria such as Lactobacillus paracasei  facilitating adhesion, aggregation and colony formation [Al Azzaz]. Cucuminoids, being poorly absorbed in the small bowel, pass into the large gut where they promote the local synthesis of sulfur containing anti-oxidant enzymes which protect probiotic bacteria from oxidative damage [Narciza]. In return, probiotic bacteria help the breakdown of polyphenols into more readily absorbed and more bioactive varieties [Morrison, Koh, Gross]. Inulin, a soluble fermentable polysaccharide found in chicory roots, also passes into the large bowel where it functions as a carbon source for growth favoured by anti-inflammatory commensal bacteria over pro-inflammatory strains [Carlon].

The optimal health benefits of a diverse phytochemical, prebiotic and probiotic rich diet are likely to be result of long term intake. There are some data, however, to suggest that, even short-term intervention, can rapidly alter the composition of the gut microbiota [Conlon, David] in healthy volunteers. It is unknown whether same impact could be achieved in people suffering from covid or whether the multiple biochemical properties reported in earlier studies could be achieved humans, to level which could reduce symptoms and shorten the lime to recovery, hence the rationale for this clinical study.

These healthy natural chemicals, especially the polyphenol groups are naturally responsible for the colour, taste and aroma of foods.  Their regular intake in fruits, herbs and vegetables has been linked with multiple health benefits particularly reducing chronic degenerative disease and reducing excess chronic inflammation [Thomas,Powanada, Bailey, Thomas, Thomas]. Numerous laboratory experiments have shown they favourably effect multiple biological pathways in the body, can indirectly via enhancing bacterial gut health, especially if combined with probiotic bacteria and are reported to have direct anti-viral properties [Chaing, Li, Lin, Ge, Wu, Lau, Yu]. If these benefits are extrapolated to humans, boosting their intake could potentially reduce the chance of catching the virus, suffering from their adverse effects or spreading it to other people. Phtyochemicals have several properties which could help fight covid:

Reducing excess inflammation: Fresh vegetables, fruit, herbs and spices have been shown to reduce COX–2 activation of prostaglandins via modulation of the function of NF‐κB, [Blacklock, Zakkar].  Polyphenols in  turmeric and celery can dampens down excess inflammation via de-activation of NF-kappaB which could overwise increases chemokines, cyclooxygenase 2 and RANK levels [Handler, Thomas]. Consistent with these findings, tissue inflammatory cell influx, have been shown to be inhibited by turmeric extract supplementation [Funk]. Likewise they have been shown to reduce inflammatory associated pain in joints [Powanada, powdnada]. Yet unlike aspirin and ibuprofen, which can damage the gastric mucosa, polyphenol rich foods have been shown to protect it [Al-howiriny].

Reducing excess oxidative stress:  As well as reducing inflammation, polyphenols can help reduce excess oxidative stress within tissues. Their antioxidant enhancing properties stem from an ability facilitate activation of the transcription factor NF‐E2–related factor 2 (Nrf2), which enhances an appropriate antioxidant response to damaging reactive oxidative species [Stivala, Davidosn, Juge, Dinkova‐Kostova). ROS are generated at higher levels in obesity, after eating unhealthy foods such as burnt meat and processes sugar or disease such as diabetes and obesity (Wang, Marseglia). Polyphenols also promote the natural adaptive to ROS when needed yet do not affect the degradation of antioxidant enzymes after exercise so the time cells spend with optimal oxidative balance is greatly extended [Poljsak, Ristow, Eder, Teixeira, Avery, Peternelj, Lotito]. There is a suggestion that polyphenols could enhance intracellular oxidative enzyme capacity can help scavenge excess superoxide anions and potentially help red [Uchide].

Although some phytochemicals could have weak direct anti-oxidant properties, in the past, this aspect has been overstated. In fact, many people previously referred to them only as anti-oxidants which is misleading and diminishes the importance of their, other biochemical properties. Unlike direct anti-oxidant vitamins A & E (highlighted below), they do not over deplete ROS levels causing anti-oxidative stress, instead they improve antioxidant efficiency and capacity when needed.

Tissue oxygenation: Polyphenol rich foods such as celery, pomegranate, beetroot and other leafy green vegetables are rich in nitrates which, in the presence of vitamin C and polyphenols, are converted to nitric oxide (NO) [Lundberg].These have been shown to help to improve muscle oxygenation, increase the time to fatigue [Bailey, Bondon, D’Angelo].

Anti-viral potential of polyphenol rich foods: Numerous in vitro experiments have demonstrated significant anti-viral properties of phytochemical rich plants including SARS-associated coronavirus [Li, Lin, Ge, Wu, Lau, Yu]. Clinical studies are lacking which many believe is due to the difficulties and cost of human studies using plants which cannot be intellectually protected commercial so are of little interest to big pharma [Kotwal]. Furthermore, as foods have multiple different phytochemicals, vitamins, minerals, prebiotic fibres its more difficult to establish whether it’s one candidate polyphenol or a combination of all which provides the therapeutic effect  [Lin].

Developing the nutritional intervention for the Phyto-V study

It is important to emphasise a well-balanced diet rich in fruit vegetables, herbs and spices but concentrating certain polyphenol rich whole foods into a supplements is a convenient way to boost their intake especially for individuals who may not have particularly varied diet or have a poor appetite. Although they are safe, very unlikely to do harm, they may to financial burden on families and their popularity remains strong so its important to collect robust evidence of their potential benefits [Thomas K].

The phytochemicals particularly the polyphenol group, which show promise and are found in common foods include: The flavanone polyphenol hesperetin found in citrus fruits; the anthraquinone derivative aloe emodin found in Aloe Vera; Quertin, a flavonoid found in, onions, apple, pomegranate and citrus fruits; Apigenin a polyphenol found in parsley, chamomile, tea and fruit; curcumin curcuminoids found in  turmeric; ellagic acid found in  pomegranate. Rational for their inclusion in this supplement are now explained further:

Pomegranate, particularly the ground seeds are rich in anthocyanins, flavonoids, gallic acid, ellagic acid, quercetin, and ellagitannins. In a laboratory study the antiviral (HRV) property and mechanism of action of ellagic acid were evaluated measuring real-time reverse transcription-PCR levels using HeLa cells. The 50% inhibitory effect on RNA replication of natural ellagic acid was twice that of ribavirin. It also mainly protected cells after viral inoculation virus inoculation which the authors suggested that ellagic acid inhibits virus replication by targeting on cellular molecules, rather than virus molecules [Park].  Similar in vitro experiments have demonstrated similar findings for pomegranate and tea polyphenols, ellagic acid epigallocatechin-3-gallate in extracts and whole foods, in hepatitis C infected cells [Calland], HIV,  influenza A and B infected cells both by slowing viral replication and reducing penetration through the cell wall [Neu, Su, Sundararajan, Yang].

Curcuminoids (Turmeric):  circumoids has been identified as a potential inhibitor of hepatitis C virus replication, potentially by competitively suppressing sterol regulatory element binding protein pathways [Kim] and more recently its negative effect on HCV cell penetration has been demonstrated [Anggakusuma]. Other studies have shown curcumin to inhibit proliferation of Human Papilloma virus [Maher] as well as parainfluenza virus type 3 (PIV-3), feline infectious peritonitis virus (FIPV), vesicular stomatitis virus (VSV), herpes simplex virus (HSV), flock house virus (FHV), and respiratory syncytial virus (RSV), VSV and FIPV/FHV [Jassim]. What’s more a study demonstrated considerable synergy between curcuminoids and ellagic acid in pomegranate and tea in their ability to generate ROS mediated apoptosis in HPV infected HeLa cells The combination of Curcumin and Ellagic acid at various concentrations showed better effects than either of the foods when used alone.  [Kumar]

Apigenin ( Chamomile, parsley, celery, citrus fruits) rich foods have demonstrated many health benefit including [Aherne, Shulka,]. It is a particularly commonly consumed drink in Germany, consumed as single ingredient chamomille tea is, prepared from the dried flowers from Matricaria chamomilla [McKay] In terms of viral effects, apigenin extracts have shown to induce anti-HIV activity in T-cell lines transfected with HIV-I and HIV-1 (IIIB) infected MT-4 cells, respectively, by integrase inhibitory activity [Tang, Lee, Critchfield]. Apigenin has been shown to slow viral replication by suppressing  internal ribosomal entry site (IRES) mediated translational activity and by modulating cellular c-Jun N-terminal kinase (JNK) pathways [Lv, Qian].

Quercetin (Onions, pomegranate, citrus fruit): Quercetin displayed antiviral activity against different influenza virus strains, including H1N1and H3N2 [Song]. The inhibitory effect of quercetin was particularly enhanced when the virus was pre-incubated with quercetin, or the cell was infected with the virus in the presence of quercetin. This suggested that quercetin could inhibited virus infection and cell entry and reduced complications associated with the (H1N1) virus infection  [Wu].

Hesperetin (Citrous fruit). Citrus fruits an some vegetables contain several naturally occurring dietary bioflavonoids including hesperetin, naringin, and catechin which have demonstrated inhibitory effects on various viruses including herpes simplex virus type 1 (HSV-1), polio-virus type 1, parainfluenza virus type 3 (Pf-3), and respiratory syncytial virus (RSV) in different mechanisms.  Hesperetin had no effect on infectivity but it reduced intracellular replication [Lin]. Catechin inhibited the infectivity but not the replication [Kaul, Mycol]. Oxidation of citrus is important because it breaks down the hesperetin skeleton which has been shown to decrease its antiviral activity [Paredes]. Some bioflavonoids have demonstrated specific replication inhibition effects on SARS-CoV infected cells [Ryu].


Manufacturing, safety and quality assurance

The phytochemical rich foods supplement and probiotics and placebo have been made specifically for this trial by one of the more established UK manufacturers. Both have been certified FSSC 22000 (ISO 22000) and all operations confirm to Good Manufacturing Practice (GMP), UK and International law. They are also certified Organic by the Organic Food Federation.  They have an inhouse Research and Development which measure and confirm the quality and polyphenol content of each batch for this study. Every batch is also tested for biological contamination, TBC, yeast, mould, E.Coli and Salmonella for safety. They also measure, Lead, Arsenic, Cadmium, Mercury and pesticides abiding by international threshold guidance and law.

In terms of safety, millions of people around the world consume probiotics daily for perceived health benefits. There are rare instances of excess bacterial overgrowth with prolonged excessing use and diarrhoea with especially E.coli [Rao] but the risk of adverse effects with Lactobacillus use was estimated in a French study to be at about one case per 10 million people over a century of probiotic consumption [Bernardeau]. Moreover, the risk of lactobacillemia was considered as ‘unequivocally negligible’, at <1 case per million individuals [Borriello]. Further evidence for safety was derived from a retrospective study that showed that increased probiotic consumption of Lactobacillus rhamnosus GG in Finland did not lead to increased cases of Lactobacillus bacteremia [Salminen] Furthermore, clinical studies where certain probiotics have been safely administered to immunocompromised patients (for example, patients with HIV infection), premature infants, elderly and patients with Crohn’s disease without any side-effects provide further evidence of poor opportunistic pathogenicity [Bernardeau 2008]. The numbers of opportunistic infections that result from probiotic supplements are negligible. For example, probiotics have been administered to thousands of new born infants, including some who were premature without a single case of sepsis [AlFaleh]. They have been used in trials involving patients severely ill in intensive care and a recent meta-analysis of 13 RCT involving potentially immunocompromised patients on chemotherapy reported a significant reduction in diarrhoea and an improvement in other symptom [NIH].  For these reasons, the common probiotic species such the Lactobacillus used in this trial are very unlikely to cause harm and this is support by many international academic bodies [World, Gibson].

There has never been a statistically valid study, which has shown that polyphenol rich foods cause harm – and that applies to whole foods or dried concentrated versions in capsules although caution is required when it comes to chemicals removed from foods then concentrated [Thomas, Thomas]. The supplement used in study is using foods at quantities which can obtained from diet. They are concentrated using techniques which removes the sugar, water and fibre yet concentrates the natural polyphenols [Aggarwal].

No Vitamin A, E or direct anti-oxidants – It is very important to differentiate polyphenol rich whole food supplements with direct antioxidant chemical extracts such as Vitamins A and E. They have very different properties and risks yet they are often grouped together as “supplements”, “vitamins” or “antioxidants” in the media [Sayin, Le Gal]. Polyphenols promote a natural adaptive increase in anti-oxidant enzymes [Stivala, Davidson, Juge,], unlike direct antioxidants such as vitamin A and E which can actually block this process so can increase oxidative damage leading to increase impede tissue repair [Teixeira, Avery, Poljsak, Eder, Ristow, Gomez-Cabera, Peternelj]. Polyphenols also enhance an enzyme called keap 1 which signals nrf2 to reduce the anti-oxidant levels when the oxidative environment diminished. Vitamin A & E anti-oxidants which have the opposite [Eder, Ristow]. Combined with their ability to neutralize ROS by directly donating a hydrogen atom this can result in the mopping up of too many ROS that can lead to a state called anti-oxidative stress [Poljsak].  This can also cause tissue damage as our cells do need a certain level of ROS for normal functions such as regulating vascular tone, monitoring of oxygen tension and normal response to pathogen attack [Poljsak, Ristow, Schulz, Son].

In terms of cancer,  numerous cohort studies linked higher intake of polyphenol rich foods with a lower cancer risk and lower risk of relapse [Wang, Bradbury, Block, Buck]. The UK Pomi-T randomised controlled study which evaluated a capsule containing dried whole polyphenol rich foods (turmeric, green tea, broccoli and pomegranate) reported a statistically significant effect on markers of progression in men with early prostate cancer [Thomas, Thomas].

Turmeric is recognized as safe by the FDA as a food additive. Serious adverse effects have not been reported in humans, even in those taking high doses of curcumin. A dose escalation trial in 24 adults found that single oral dosages up to 12g were safe, and adverse effects were not dose-related [Lao]. In a phase I trial in Taiwan, curcumin supplementation up to 8g/day for three months was reported to be well-tolerated [Cheng]. In another clinical trial in the UK, curcumin supplementation ranging from 0.45-3.6 g/day for four months was generally well-tolerated by people with advanced colorectal cancer, although two participants experienced diarrhoea and another reported nausea [Sharama]. There is no evidence that dietary consumption of turmeric as a spice adversely affects pregnancy or lactation, although the safety of curcumin supplements in pregnancy and lactation has not been established. Curcumin has been found to inhibit platelet aggregation in vitro [Shah], suggesting a potential for curcumin supplementation to increase the risk of bleeding in people taking anti-platelet medications, but no reports have been documented in humans. Clinical studies have reported minimal or no adverse events even with intake over 3g/day [Thomas, Shah, Sharma, Loa].

Pomegranate fruit, the juice or it’s dried concentrated extracts have no safety issues reported for pomegranate juice extract apart from rare food allergies. The Johns Hopkins study above reported a 14% of diarrhoea if doses were over 3g a day, but only 2% if below this dose. There are some potential drug inactions because like many fruit juices, pomegranate is a weak inhibitor of cytochrome P450 (CYP2C9). There is, therefore, a small potential risk of reducing the metabolism, and thereby increasing serum levels of warfarin and other coumadins, anti-hypertensives such as captopril, ramipril or anti-convulsants such a carbimazole ( Men on warfarin had no interference of their INR or blood pressure in a previous similar study [Thomas].

Within the low concentrations used in this interventions the risk of toxicities from Aloe vera extract are very small, especially for a short intervention but could include diarrhoea [Guo]. Chamomile and citrus are particularly safe and they consumed by millions for people every day.

Trial Design and methodology

This is a double blind placebo controlled randomised trial run from the research unit at Bedford Hospital. Participants are given a written information sheet explaining the details via email. On day 2, if  the patients subsequently agrees to enter the study, via a telephone consultation, he/she will be randomised to either a phytochemical rich food supplement containing extracts of several phytochemical rich foods or placebo (1:1 randomisation). In addition they will be given a capsule containing a lactobacillus probiotic bacterial blend. The probiotic arm of the trial is not blinded and these have been donated to the study by YourGutplus+ . These were delivered to all participants, in boxes containing 60 tablets.

During these telephone consultations the trials team will discuss healthy living advice such as exercising regularly out doors in the fresh air. Participants will be telephoned a regular intervals by the trials nurse who will annotate the  body temperature taken by the participant themselves ( if they do have a thermometer, one will be sent them).  The trials nurse will complete a formal cough scale, a Subjective wellness score, a formal fatigue score and record any symptoms using the NCI common toxicity checklist. The nurse will also speak to the other household members who have consented to enter the study, if they have developed any symptoms and invite them to enter the study

End points: The primary end point will be time to recovery from start of the study in terms of pyrexia, cough or any other relevant symptom. The secondary  end points look at the profile of patient who gets more or less benefit from the intervention

Acknowledgements: The scientific committee are very grateful to the designers and manufacture’s  of Yourgutplus+ for suppling this probiotic free of charge for this study.



  1. Kurian SJ, Unnikrishnan MK, Miraj SS, Bagchi D, Banerjee M, et al. (2021) Probiotics in Prevention and Treatment of Covid-19: Current Perspective andFuture Arch Med Res 52: 582-594.
  2. Lin L, Jiang X, Zhang Z, Huang S, Zhang Z, et (2020) Gastrointestinal symptoms of 95 cases with SARS-CoV-2 infection. Gut 69: 997-1001.
  3. Olaimat A, Aolymat A, Al-Holy M, Ayyash M, Abu Ghoush M, et al. (2020) The potential application of probiotics and prebiotics for the prevention andtreatment of Covid-19. Sci Food 4:
  4. Dhar D, Mohanty A (2020) Gut microbiota and Covid-19-possible link and Virus Res 285: 198018.
  5. Chen Y, Gu S, Chen Y, Lu H, Shi D, et al. (2021) Six-month follow-up of gut microbiota richness in patients with Covid-19.
  6. Gu S, Chen Y, Wu Z, Chen Y, Gao H, et (2019) Alterations of the Gut Microbiota in Patients With Coronavirus Disease or H1N1 Influenza. Clin Infect Dis71: 2669-2678.
  7. Ng SC, Tilg H (2020) Covid-19 and the gastrointestinal tract: more than meets the eye. Gut 69: 973-974.
  8. Yeoh YK, Zuo T, Lui GC, Zhang F, Liu Q, et al. (2021) Gut microbiota composition reflects disease severity and dysfunctional immune responses inpatients with COVID-19. Gut 70: 698-706.
  9. Wan Y, Li J, Shen L, Zou Y, Hou L, et al. (2020) Enteric involvement in hospitalised patients with COVID-19 outside Lancet GastroenterolHepatol 5: 534-535.
  10. Wang L, Zhu L, Qin S (2019) Gut Microbiota Modulation on Intestinal Mucosal Adaptive J Immunol Res 2019: 4735040.
  11. Budden K, Gellatly S, Wood D, Cooper M, Morrison M, et al. (2017) Emerging pathogenic links between microbiota and the gut-lung axis. Nat RevMicrobiol 15: 55-63.
  12. Dumas A, Bernard L, Poquet Y, Lugo-Villarino G, Neyrolles O (2018) The role of the lung microbiota and the gut-lung axis in respiratory infectious Cell Microbiol 20: e12966.
  13. Enaud R, Prevel R, Ciarlo E (2020) The gut-lung axis in health and respiratory diseases: a place for inter-organ and inter-kingdom Front Cell Infect Microbiol 10: 9.
  14. Dickson RP (2017) The microbiome and critical illness. Lancet Respir Med 4: 59-72.
  15. Fanos V, Pintus M, Pintus R, Marcialis M (2020) Lung microbiota in the acute respiratory disease: from coronavirus to metabolomics. Journal of Pediatricand Neonatal Individualized Medicine 9:
  16. Ver Heul A, Planer J, Kau A (2019) The human microbiota and Clin Rev Allergy Immunol 57: 350-363.
  17. Namasivayam S, Sher A, Glickman MS, Wipperman MF (2018) The microbiome and tuberculosis: early evidence for cross talk. mBio 9: e01418-e01420.
  18. Mammen M, Sethi S (2016) COPD and the microbiome. Respirology 21: 590-599.
  19. Macfarlane S, Cleary S, Bahrami B, Reynolds N, Macfarlane GT (2013) Synbiotic consumption changes the metabolism and composition of the gutmicrobiota in older people and modifies inflammatory processes: a double-blind, placebo Aliment Pharmacol Ther 38: 804-816.
  20. Carlson JL, Erickson JM, Lloyd BB, Slavin JL (2018) Health EffectsMa C, Gu J, Hou P, Zhang L, Bai Y, et al. (2020) Incidence, clinical characteristics, and prognostic factor of patients with Covid-19: a systematic reviewand meta-analysis. MedRxiv 03.17.20037572.and Sources of Prebiotic Dietary Fiber. Curr Dev Nutr 2: nzy005.
  21. Smyk W, Janik MK, Portincasa P, Milkiewicz P, Lammert F, et (2020) COVID-19: Focus on the lungs but do not forget the gastrointestinal tract. Eur J Clin Invest 50: e13276.
  22. Nobaek S, Johansson M, Molin G, Ahrne S, Jeppsson B (2000) Alteration of intestinal microflora is associated with reduction in abdominal bloating andpain in patients with irritable bowel Am J Gastroenterol 95: 1231-1238.
  23. Azad MAK, Sarker M, Wan D (2018) Immunomodulatory effects of probiotics on cytokine Biomed Res Int.
  24. Morshedi M, Hashemi R, Moazzen S, Sahebkar A, Hosseinifard ES (2019) Immunomodulatory and anti-inflammatory effects of probiotics in multiple sclerosis: a systematic review. J Neuroinflammation 16:
  25. Gill HS, Rutherfurd KJ, Cross ML (2001) Dietary probiotic supplementation enhances natural killer cell activity in the elderly: an investigation of age-related immunological changes. J Clin Immunol 21: 264-271.
  26. Livingston M, Loach D, Wilson M, Tannock GW, Baird M (2019) Gut commensal Lactobacillus stimulates an immunoregulatory response. Immunol CellBiol 88: 99-102.
  27. Dehghan P, Gargari B, Jafar-Abadi M, Aliasgharzadeh A (2014) Inulin controls inflammation and metabolic endotoxemia in women with type 2 diabetes mellitus: a randomized-controlled clinical trial. Int J Food Sci Nutr 65: 117-123.
  28. Hempel S, Newberry S, Ruelaz A, Wang Z, Miles JNV, et al. (2011) Safety of probiotics used to reduce risk and prevent or treat disease. Evid RepTechnol Assess 1-645.

  29. Turnbaugh P, Hamady M, Yatsunenko T, Cantarel BL, Duncan A, et
    (2009) A core gut microbiome in obese and lean twins. Nature 457: 480-484.
  30. Dabke K, Hendrick G, Devkota S (2019) The gut microbiome and metabolic J Clin Invest 129: 4050-4057.
  31. Foster JA, McVey Neufeld KA (2013) Gut-brain axis: how the microbiome influences anxiety and depression. Trends Neurosci 36: 305-312.
  32. Nishida A, Inoue R, Inatomi O, Bamba S, Naito Y, et al. (2018) Gut microbiota in the pathogenesis of inflammatory bowel disease. Clin J Gastroenterol11: 1-10.
  33. Gurung M, Li Z, You H, Rodrigues R, Jump DB, et al. (2020) Role of gut microbiota in type 2 diabetes pathophysiology. EBioMedicine 51:
  34. Tang W, Kitai T, Hazen S (2017) Gut microbiota in cardiovascular
  35. health and disease. Circ Res 120: 1183-1196.
  36. Meijnikman A, Gerdes V, Nieuwdorp M, Herrema H (2018) Evaluating causality of gut microbiota in obesity and diabetes in humans. Endocr Rev 39:133-153.
  37. Jiang C, Li G, Huang P (2017) The gut microbiota and Alzheimer’s J Alzheimers Dis 58: 1-15.
  38. Fujita R, Iimuro S, Shinozaki T, Sakamaki K, Uemura Y, et al. (2013) Decreased duration of acute upper respiratory tract infections with daily intake of fermented milk: a multicenter, double‐blinded, randomized comparative study in users of day care facilities for the elderly Am JInfect Control 41: 1231‐1235.
  39. Rerksuppaphol S, Rerksuppaphol L (2012) Randomized controlled trial of probiotics to reduce common cold in Pediatr Int 54: 682‐687.
  40. Waki N, Matsumoto M, Fukui Y, Suganuma H (2014) Effects of probiotic Lactobacillus brevis KB290 on incidence of influenza infection amongschoolchildren: an open-label pilot study. Lett Appl Microbiol 59: 565-
  41. Kang EJ, Kim SY, Hwang IH, Ji YJ (2013) The effect of probiotics on prevention of common cold: a meta-analysis of randomized controlled trial Korean J Fam Med 34: 2-10.
  42. Eguchi K, Fujitani N, Nakagawa H (2019) Prevention of respiratory syncytial virus infection with probiotic lactic acid bacterium Lactobacillus gasseri Sci Rep 9: 4812.
  43. Hao Q, Dong B, Wu T (2015) Probiotics for preventing acute upper respiratory tract Cochrane Database Syst Rev CD006895.
  44. Su M, Jia Y, Li Y, Zhou D, Jia J (2020) Probiotics for the prevention of ventilator-associated pneumonia: a meta-analysis of randomized controlled Respir Care 65: 673-685.
  45. Hemarajata P, Versalovic J (2013) Effects of probiotics on gut microbiota: mechanisms of intestinal immunomodulation and TherapAdv Gastroenterol 6: 39-51.
  46. Plaza-Diaz J, Ruiz-Ojeda FJ, Gil-Campos M, Gil A (2019) Mechanisms
  47. of action of probiotics. Adv Nutr 10: S49-S66.
  48. Thomas C, Versalovic J (2010) Probiotics-host communication: modulation of signalling pathways in the intestine. Gut Microbes 1: 148-163.
  49. Al Faleh K, Anabrees J. Probiotics for prevention of necrotizing enterocolitis in preterm infants. Cochrane Database Syst Rev 2014:Cd005496
  50. Aherne SA, O’Brien NM. Dietary flavonols: chemistry, food content and metabolism.  Nutrition. 2002;18:75–81.
  51. Anggakusuma, Colpitts CC, Schang LM, et al. Turmeric curcumin inhibits entry of all hepatitis C virus genotypes into human liver cells. Gut. 2013 Gut. 2014 Jul;63(7):1137-49
  52. Avery NG, Kaiser JL, Sharman MJ et al  Effects of vitamin E supplementation on recovery from repeated bouts of resistance exercise. J Strength Cond Res. 2003 Nov;17(4):801-9.
  53. Berggren A, Lazou Ahren I, Larsson N, Onning G. Randomised, double‐blind and placebo‐controlled study using new probiotic lactobacilli for strengthening the body immune defence against viral infections. European Journal of Nutrition 2010 Aug 28
  54. Bernardeau M, Vernoux JP, Henri-Dubernet S, Gueguen M. Safety assessment of dairy microorganisms: the Lactobacillus genus. Int J Food Microbiol. 2008;126:278–285.
  55. Bernardeau M, Guguen M, Vernoux JP. Beneficial lactobacilli in food and feed: long-term use, biodiversity and proposals for specific and realistic safety assessments. FEMS Microbiol Rev. 2006;30:487–513.
  56. Block G, Patterson B, Subar A (1992) Fruit vegetables and cancer prevention a review of the epidemiological evidence. ‎Nutr Cancer 18: 1-29.
  57. Borriello SP, Hammes WP, Holzapfel W, Marteau P, Schrezenmeir J, Vaara M, et al. Safety of probiotics that contain lactobacilli or bifidobacteria. Clin Infect Dis. 2003;36:775–780.
  58. Bradbury KE, Appleby PN, Key TJ (2014) Fruit, vegetable and fiber intake in relation to cancer risk findings from the European Prospective investigation into Cancer and Nutrition (EPIC). Am J Clin Nutr 100: 394-398.
  59. Calland N, Albecka A, Belouzard S, Wychowski C, Duverlie G, Descamps V, et al. (-)-Epigallocatechin-3-gallate is a new inhibitor of hepatitis C virus entry. Hepatology. 2012;55:720–9.
  60. Cheng AL, Hsu CH, Lin JK, et al. Phase I clinical trial of curcumin, a chemopreventive agent, in patients with high-risk or pre-malignant lesions. Anticancer Res. 2001;21(4B):2895-2900.
  61. Choi C, Kim JK, Choi SH, et al. Identification of steroid hormones in pomegranate (Punica granatum) using HPLC and GC mass spectrometry. Food Chemistry 2006; 96: 562–571.
  62. Critchfield JW, Butera ST and Folks TM. Inhibition of HIV Activation in Latently Infected Cells by Flavonoid Compounds. AIDS Research and Human Retroviruses 1996, 12, 39–46Davies KJ. Oxidative stress: the paradox of aerobic life.Biochem Soc Symp. 1995; 61():1-31.
  63. Doron S, Snydman DR Risk and safety of probiotics.. Clin Infect Dis. 2015,15; 60 Suppl 2:S129-34.
  64. Fujita R, Iimuro S, Shinozaki T, et al. Decreased duration of acute upper respiratory tract infections with daily intake of fermented milk: a multicenter, double‐blinded, randomized comparative study in users of day care facilities for the elderly population. American Journal of Infection Control 2013;41(12):1231‐5.
  65. Ge H, Wang YF, Xu J, Anti-influenza agents from Traditional Chinese Medicine.Nat Prod Rep. 2010; 27(12):1758-80.
  66. Gill HS, Rutherfurd KJ, Cross ML. Dietary probiotic supplementation enhances natural killer cell activity in the elderly: an investigation of age-related immunological changes. J Clin Immunol. 2001;21:264–271.
  67. Gibson GR, Hutkins R, Sanders et al. Expert consensus document: The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of prebiotics. Nat Rev Gastroenterol Hepatol 2017;14:491-502.
  68. Guo X, Mei N et al. Aloe vera: A review of toxicity and adverse clinical effectsJ Environ Sci Health C Environ Carcinog Ecotoxicol 2019; 2; 34(2): 77–96
  69. Hao Q, Dong B, Wu T et al Probiotics for preventing acute upper respiratory tract infections: A cochrane metanalysis (2015)
  70. Hu F, Wang YB, Liang J, et al: Carotenoids and breast Cancer risk: a meta-analysis and meta-regression. Breast Cancer Res Treat 131(1):239-253, 2012
  71. Iljazovic E, Zulcic-Nakic V, Latifagic A, Sahimpasic A, Omeragic F and Avdic S. (2006). 245 ORAL Efficacy in treatment of cervical HRHPV infection by combination of interferon, Aloe vera and propolis gel associated with different cervical lesion. Eur. J. Surg. Oncol. 32 S73–S139. 10.1016/S0748-7983(06)70680-1.
  72. Jassim SAA, Naji MA. Novel antiviral agents: a medicinal plant perspective. Journal of Applied Microbiology. 2003;95(3):412–427. [PubMed] [Google Scholar]
  73. Kahlon J., Kemp M., Carpenter R., McAnalley B., McDaniel H., Shannon W. (1991a). Inhibition of AIDS virus replication by acemannan in vitro. Mol. Biother. 3 127–135.
  74. Kaul TN, Middleton E Jr, Ogra P et al Antiviral effect of flavonoids on human viruses. J Med Virol. 1985, 15(1):71-9.
  75. Kotwal G. Natural anti-virals against human viruses, Virol Mycol 2014, 3:2 DOI: 10.4172/2161-0517.1000e107
  76. Kim K, Kim KH, Kim HY, et al . Curcumin inhibits hepatitis C virus replication via suppressing the Akt-SREBP-1 pathway. FEBS Lett. 2010;584:707–12.
  77. Kumar D, Basu S, Parija L et al Curcumin and Ellagic acid synergistically induce ROS generation, DNA damage, p53 accumulation and apoptosis in HeLa cervical carcinoma cells.Biomed Pharmacother. 2016;81:31-37. doi: 10.1016/j.biopha.2016.03.037.
  78. Lao CD, Ruffin MT 4th, Normolle D. Dose escalation of a curcuminoid formulation. BMC Complement Altern Med. 2006 Mar 17;6:10.
  79. Lau KM, Lee KM, Koon CM, Cheung CS, Lau CP, Ho HM, et al. Immunomodulatory and anti-SARS activities of Houttuynia cordata. J Ethnopharmacol. 2008;118:79–85.
  80. Lee JS, Kim HJ and Lee YS. A New Anti-HIV Flavonoid Glucuronide from Chrysanthemum Morifolium. Planta Medica 2003, 69, 859–861
  81. Li SY, Chen C, Zhang HQ, Guo HY, Wang H, Wang L, et al. Identification of natural compounds with antiviral activities against SARS-associated coronavirus. Antivir Res. 2005;67:18–23
  82. Lin CW, Tsai FJ, Tsai CH, Lai CC, Wan L, Ho TY, et al. Anti-SARS coronavirus 3C-like protease effects of plant-derived phenolic compounds. Antivir Res. 2005;68:36–42.
  83. Lin L, Hsu W, Lin C, et al Antiviral Natural Products and Herbal MedicinesJ Tradit Complement Med. 2014 Jan-Mar; 4(1): 24–35.  doi: 10.4103/2225-4110.124335
  84. Lin CW, Tsai FJ, Tsai CHAnti-SARS coronavirus 3C-like protease effects of Isatis indigotica root and plant-derived phenolic compounds. Antiviral Res. 2005 Oct;68(1):36-42.
  85. Li S, Yang T, Lai C et al Antiviral activity of aloe-emodin against influenza A virus via galectin-3 up-regulation. Eur J Pharmacol. 2014 Sep 5;738:125-32. doi: 10.1016/j.ejphar.2014.05.028..
  86. Lo P, Tsai Y, Lin S, et al Risk of asthma exacerbation associated with nonsteroidal anti-inflammatory drugs in childhood asthma: A nationwide population-based cohort study Medicine (Baltimore) 2016 ; 95(41).
  87. Lu D et al Probiotics in preventing and treating chemotherapy-induced diarrhea: a meta-analysis of 13 RCT.Asia Pac J Clin Nutr. 2019;28(4):701-710. doi: 10.6133/apjcn.201912_28(4).0005.
  88. Lv, X.; Qiu, M.; Chen, D, et al. Apigenin Inhibits Enterovirus 71 Replication Through Suppressing Viral IRES Activity and Modulating Cellular JNK Pathway. Antiviral Research 2014, 109, 30–41.
  89. McKay DL, Blumberg JB. A review of the bioactivity and potential health benefits of chamomile tea (Matricaria recutita L.) Phytother Res. 2006;20:519–530. [PubMed] [Google Scholar]
  90. Maher DM, Bell MC, O’Donnell EA et al Curcumin suppresses human papillomavirus oncoproteins, restores p53, Rb, and PTPN13 proteins and inhibits benzo[a]pyrene-induced upregulation of HPV E7. Mol Carcinog. 2011; 50(1):47-57.
  91. Meijvis SC, Hardeman H, Remmelts HH, et al. Dexamethasone and length of hospital stay in patients with community-acquired pneumonia: a randomised, double-blind, placebo-controlled trial. Lancet. 2011 Jun 11; 377(9782):2023-30.
  92. Mycol V, Kotwal GJ and Longum P. Natural Antivirals against Human Viruses with Bitter melon. Virol. Mycol. 2014;3:3–5.[Google Scholar] [Ref list]
  93. National Institute of Health – Probiotics fact sheet for professionals
  94. Neurath AR, Strick N, Li YY, Debnath AK (2004) Punicagranatum (Pomegranate) juice provides an HIV-1 entry inhibitor and candidate topical microbicide. BMC Infect Dis 4: 41.
  95. Paredes A1, Alzuru M, Mendez J et al Anti-Sindbis activity of flavanones hesperetin and naringenin. Biol Pharm Bull. 2003;26(1):108-9.
  96. Park S, Hwon M, Yoo J et al Antiviral activity and possible mode of action of ellagic acid identified in Lagerstroemia speciosa leaves toward human rhinoviruses. BMC Complement Altern Med. 2014; 26;14:171. doi: 10.1186/1472-6882-14-171.
  97. Peternelj TT, & Coombes JS (2011). Antioxidant Supplementation during Exercise Training: Beneficial or Detrimental? Sports medicine (Auckland, N.Z.), 41 (12), 1043-69.
  98. Pierce JP, Natarajan L, Caan BJ, , et al. (2007) Influence of a diet very high in vegetables, fruit, and fiber and low in fat on prognosis following treatment for breast cancer the Women’s Healthy Eating and Living (WHEL) randomized trial. JAMA 298: 289-298.
  99. Pierce, J. P., L. Natarajan, Caan BJ, et al: Influence of a Diet Very High in Vegetables, Fruit, and Fiber and Low in Fat on Prognosis Following Treatment for Breast Cancer:
  100. Poljsak B Milisav I, Lampe T et al Strategies for reducing or preventing the generation of oxidative stress. Oxidative Medicine and Cellular Longevity. 2011:9
  101. Powanda MC, Whitehouse MW, Rainsford KD. Celery Seed and Related Extracts with Antiarthritic, Antiulcer, and Antimicrobial Activities. Prog Drug Res. 2015;70:133-53.
  102. Powanda MC and Rainsford KD. A toxicological investigation of a celery seed extract having anti-inflammatory activity. Inflammopharmacology. 2011; 19(4):227-33. Epub 2010 Jun 22.
  103. Qian, S.; Fan, W.; Qian, P.; Zhang, D.; Wei, Y.; Chen, H.; Li, X. Apigenin Restricts FMDV Infection and Inhibits Viral IRES Driven Translational Activity. Viruses 2015, 7, 1613–26.
  104. Rao S, Rehman S, Yu S Brain fogginess, gas and bloating: a link between SIBO, probiotics and metabolic acidosis Clinical and Translational Gastroenterology. 2018  9 (6)  p 162.
  105. Radha M. H., Laxmipriya N. P. (2015). Evaluation of biological properties and clinical effectiveness of Aloe vera: a systematic review. J. Tradit. Complement. Med. 5 21–26. 10.1016/j.jtcme.2014.10.006.
  106. Reddy, M.K.; Alexander-Lindo, R.L.; Nair, M.G. Relative inhibition of lipid peroxidation, cyclooxygenase enzymes, and human tumor cell proliferation by natural food colors. J. Agric. Food Chem. 2005, 53, 9268–9273.
  107. Rerksuppaphol S, Rerksuppaphol L. Randomized controlled trial of probiotics to reduce common cold in schoolchildren. Pediatrics International 2012;54(5):682‐7.
  108. Ryu YB, Jeong HJ, Kim JH, et al. Biflavonoids displaying SARS-CoV 3CL (pro) inhibition. Bioorg Med Chem. 2010;18:7940–7.
  109. Salminen MK, Tynkkynen S, Rautelin H, Saxelin M, Vaara M, Ruutu P, et al.  Lactobacillus bacteremia during a rapid increase in probiotic use of Lactobacillus rhamnosus GG in Finland. Clin Infect Dis. 2002;35:1155–1160.
  110. Hempel S, Newberry S, Ruelaz A, et al of probiotics used to reduce risk and prevent or treat disease.Evid Rep Technol Assess (Full Rep). 2011 Apr; (200):1-645
  111. Sanders M, Akkermans L, Haller D et al Safety assessment of probiotics for human use. Gut Microbes. 2010, 1(3): 164–185.
  112. Sharma RA, Steward WP, Gescher AJ. Pharmacokinetics and pharmacodynamics of curcumin. Adv Exp Med Biol. 2007;595:453-70.
  113. Shah BH, et al (1999). Inhibitory effect of curcumin, on platelet-activating factor through inhibition of thromboxane formation and Ca2+ signaling. Biochem Pharmacol., 58(7): 1167–72.
  114. Shen CL, Smith BJ, Lo DF et al Dietary polyphenols and mechanisms of osteoarthritis Phytother Res. 2010;24(2):182-5.
  115. Shukla S and Gupta S. Apigenin: A Promising Molecule for Cancer PreventionPharm Res. 2010 Jun; 27(6): 962–978: 10.1007/s11095-010-0089-7
  116. Song J, Park K, Kwon D et al Anti-human rhinovirus 2 activity and mode of action of quercetin-7-glucoside from Lagerstroemia speciosa. J Med Food. 2013 Apr;16(4):274-9. doi: 10.1089/jmf.2012.2290.
  117. Srivastava KC, Bordia A and Verma SK (1995). Curcumin, a major component of food spice turmeric (Curcuma longa) inhibits aggregation and alters eicosanoid metabolism in human blood platelets. Prostaglandins Leukot Essent Fatty Acids, 52(4): 223-227.
  118. Sun Z, Yu C, Wang W et al Aloe Polysaccharides Inhibit Influenza A Virus Infection—A Promising Natural Anti-flu Drug Front Microbiol. 2018; 9: 2338.  doi: 10.3389/fmicb.2018.02338
  119. Su X, Sangster MY, D’Souza DH (2010) In vitro effects of pomegranate juice and pomegranate polyphenols on foodborne viral surrogates. Foodborne Pathog Dis 7: 1473-1479.
  120. Sundararajan A, Ganapathy R, Huan L, Dunlap JR, Webby RJ, et al. (2010) Influenza virus variation in susceptibility to inactivation by pomegranate polyphenols is determined by envelope glycoproteins. Antiviral Res 88: 1-9.
  121. Syed T. A., Cheema K. M., Ahmad S. A., Holt A. H., Jr. (1996). Aloe vera extract 0.5% in hydrophilic cream versus Aloe vera gel for the management of genital herpes in males. A placebo-controlled, double-blind, comparative study. J. Eur. Acad. Dermatol. Venereol. 7 294–5.
  122. Tang, R.; Chen, K.; Cosentino, M etal. Apigenin-7-O-β-D-Glucopyranoside, an Anti-HIV Principle from Kummerowia Striata. Bioorganic and Medicinal Chemistry Letters 1994, 4, 455–458.
  123. Tannenbaum SR, Wishnok JS, Leaf CD. “Inhibition of nitrosamine formation by ascorbic acid”. The American Journal of Clinical Nutrition. 1991, 53 247–250.
  124. Teixeira V, Valente H, Casal S, et al Antioxidants do not prevent post exercise peroxidation and may delay muscle recovery. Medicine & Science in Sports & Exercise: 2009. 41( 9); 1752-60.
  125. Thomas KJ, Coleman P et al. Use of complementary or alternative medicine in a general population in Great Britain. Results from the National Omnibus Survey. Journal of Public Health 2004; 26:152–57.
  126. Thomas KJ, Nicholl JP, Coleman P. Use and expenditure on complementary medicine in England: a population based survey. Complementary Therapies in Medicine 2001; 9:2–11.
  127. Thomas R, Yang D, Zollaman C. Phytochemicals in Cancer Management. Current Research in Compl and Alt therapy.  2017, 105 (01), pp 2-8.
  128. Thomas R,  Butler E, Macchi F and Williams M. Phytochemicals in cancer prevention and management? BJMP 2015, 8 (2), pp 1-9.
  129. Thomas R, Williams M, Sharma H, et al. A double-blind, placebo-controlled randomised trial evaluating the effect of a polyphenol-rich whole food supplement on PSA progression in men with prostate cancer–the U.K. NCRN Pomi-T study. Prostate Cancer Prostatic Dis. 2014 17(2):180.
  130. Thomas R, Williams M, Sharma H, Chaudry A, Bellamy P. A double-blind, placebo-controlled randomised trial evaluating the effect of a polyphenol-rich whole food supplement on PSA progression in men with prostate cancer–the U.K. NCRN Pomi-T study. Prostate Cancer Prostatic Dis. 2014 17(2):180.
  131. Tisoncik J, Korth M, Simmons C et al. Into the Eye of the Cytokine Storm Microbiol Mol Biol Rev. 2012 Mar; 76(1): 16–32. doi: 10.1128/MMBR.05015-11
  132. Uchide N, Toyoda H Antioxidant therapy as a potential approach to severe influenza-associated complications. Molecules. 2011. 28; 16(3):2032-52.
  133. Wang X, Ouyang Y, Liu J et al,  Fruit and vegetable consumption and mortality from all causes, cardiovascular disease, and cancer: systematic review and dose-response meta-analysis of prospective cohort studies. BMJ. 2014 Jul 29; 349; 4490.
  134. Welliver R, Monto AS, Carewicz O et al. Effectiveness of oseltamivir in preventing influenza in household contacts: a randomized controlled trial. JAMA. 2001; 285: 748-754
  135. WHO report – Health and Nutritional Properties of Probiotics in Food including Powder Milk with Live Lactic Acid Bacteria. 2001. [2009].
  136. World Health Organization. [Last accessed on 2020, 1.4.2020]. Available from: .
  137. World Gastroenterology Organisation. Probiotics and prebiotics . 2017.
  138. Wu W, Li R, Xianglian Li X, et al  Quercetin as an Antiviral Agent Inhibits Influenza A Virus (IAV) Entry. Viruses. 2016 Jan; 8(1): 6.
  139. Yang ZF, Bai LP, Huang WB et al. Comparison of in vitro antiviral activity of tea polyphenols against influenza A and B viruses and structure-activity relationship analysis. Fitoterapia. 2014; 93:47-53
  140. Yagi A, Byung P (2015). Immune modulation of Aloe vera: acemannan and gut microbiota modulator. J. Gastroenterol. Hepatol. Res. 4 1707–1721. 10.17554/j.issn.2224-3992.2015.04.525.
  141. Yao X, Ye F, Zhang M et al.In vitro antiviral activity and projection of optimized dosing design of hydroxychloroquine for the treatment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Clin Infect Dis. 2020; (published online March 2020) DOI:10.1093/cid/ciaa237
  142. Yu MS, Lee J, Lee JM, Kim Y, Chin YW, Jee JG, et al. Identification of myricetin and scutellarein as novel chemical inhibitors of the SARS coronavirus helicase, nsP13. Bioorg Med Chem Lett. 2012;22:4049–54.
  143. Zhou Y, Fu B, Zheng X et al.  Pathogenic T cells and inflammatory monocytes incite inflammatory storm in severe COVID-19 patients PERSPECTIVE IMMUNOLOGY
  144. Zhou Y, Fu B, Zheng X et al Pathogenic T cells and inflammatory monocytes incite inflammatory storm in severe COVID-19 patients  (2020). National Science Review, nwaa041,