How do my symptoms affect my diet?

It is unknown if over-the-counter vitamins and mineral supplements are helpful, harmful or have no effect in treating symptoms of COVID-19.Vitamin D is important for a properly functioning immune system and so plays a role in preventing COVID-19. Recommendations for Vitamin D are that all adults should take a 10ug (400IU) supplement during the winter (Oct-Mar), and for at risk adults to take the same supplement all year. More than this can weaken bones and harm kidneys, so take advice from your healthcare professional for higher doses.

Arginine or glycine supplementation may be a new nutritional strategy to reduce deleterious effects of bacterial infection in alveolar function (Ferrara, De Rosa and Vitiello, 2020).

Probiotics are live microorganisms which when consumed in large enough amounts give a health benefit to the person consuming them (Food and Agriculture Organization of the United Nations and World Health Organization, 2006). The big question is do probiotics help recovery from COVID-19?

Currently the evidence is weak. Research into the effects of probiotics only applies to the specific strain (type of good bacteria) used. Just because one type of bacteria has an effect it doesn’t mean all types of bacteria will have the same effect. As yet, there is no evidence that any probiotic will have a specific effect on recovery from COVID-19 (Ayseli et al., 2020).

There is still emerging evidence to use probiotics in recovering from COVID-19. Dysbiosis is closely associated with changes in the dynamics of the immune system – even immunomodulation by signalling pathways of intestinal and immune cells. This route involves intestinal purine metabolism, possibly one of the explanations for the benefits achieved with the use of probiotics. Thus, curiosity and interest in nutritional therapies to promote the reduction of purine intake have increased, whether using probiotics or by dietary restriction advice on source foods, and consequently control of serum uric acid concentrations. This behaviour can positively influence the health of individuals with viral infections (Morais et al., 2020).

Probiotics are microorganisms with the ability to modulate the intestinal and systemic immune response and could be used in bacterial and viral respiratory infections to improve their outcomes. An important factor that affects both gut microbiota and the immune system is diet, being a trigger factor for low-grade systemic inflammation and oxidative stress. An unbalanced state of the microbiome, called dysbiosis, is characterised by overgrowth of pathobionts, loss of commensals, and lower diversity. Lactobacillus, for instance, can maintain the ecological balance of the host intestinal microbiota by reinforcing intestinal flora and inhibiting harmful bacteria.

L. gasseri PA3 has demonstrated an ability to reduce purines in foods and beverages. Purines are essential to viral RNA synthesis. Reducing purine availability might slow down virus replication, holding down viral infections.

L. gasseri’s potential to modulate proinflammatory cytokines interferon and interferon-stimulated genes was upregulated. L. gasseri SBT2055 boosted the immune responses in healthy vaccinated subjects that received a trivalent influenza vaccine. This lactobacillus strain stimulated humoral immunity and total immunity.

IgG and IgA levels in plasma and IgA production in saliva were also higher in the probiotic-treated group, as L. gasseri helped to block proinflammatory cytokine production. Therefore, this information might suggest the actions of this lactobacillus strain in COVID-19, improving the innate and adaptive immune systems, and further studies should address this hypothesis (Morais et al., 2020; Zhao et al., 2020).

There is a wide range of products containing probiotics available and many are claimed to improve the health of the gut or generally support immunity (e.g. kefir, boza, kimchi, and sauerkraut). There is some evidence to support this idea but not enough to enable health professionals to recommend any particular food or supplement (Ayseli et al., 2020). Nevertheless, they are generally accepted as safe. These foods can be used in moderation as part of a healthy Mediterranean type diet.

You can watch our Q&A session with topic experts where they discuss the use of supplements.

It can help to keep a diary of your symptoms. This will help you to learn what works best to manage your symptoms. It can also help health care professional understand the pattern of your symptoms. There are many ways to keep a diary by using an app or keeping a paper copy.

You can watch a video about how to use a food diary and its benefits by our expert, Hannah Hunter: “Is there a link between food and my symptoms?”.