It is hardly news that one important way by which the new coronavirus strain (called SARS-CoV-2) affects people’s health is by weakening the respiratory tract, from the nose to the lungs.
But as scientists become more familiar with the virus, they are also finding out that the body’s immune and digestive systems might be also affected.
Why it is worth taking the gut microbiota into account in the fight against COVID-19
The idea that bodily organs and tissues opened to the outside are connected is not new. For instance, the lungs and gut microbiota influence each other and that relationship may keep your lungs healthy.
In this case, scientists have reported the presence of SARS-CoV-2 in the stool samples of people who have the virus. Furthermore, some COVID-19 patients showed an altered gut microbiota composition with decreased beneficial bacteria, which included Lactobacillus and Bifidobacterium.
“[Although] there is no way our gut microbiome could exert direct protection against COVID-19, we have very good evidence that there is a very close relationship between the microbiota and the immune system. A balanced healthy microbiota promotes immune homeostasis*, hence avoiding hyper-reactivity [of a person’s immune system],” acknowledged INRAE Research Director Joël Doré via email.
A healthy gut microbiome could prevent immune overreactions to COVID-19
Considering the gastrointestinal manifestations of the COVID-19 infection and the gut microbiota’s role in the body’s immune response to viral infections, scientists suspect that a healthy gut microbiome might help prevent pro-inflammatory immune reactions in the lungs and other vital organs infected by COVID-19.
“Taking care of our gut health and especially nurturing a highly diverse microbiota through a dietary intake rich in a wide range of plant sources, fruits, vegetables, grains and nuts will favor a robust immune system and indirectly increase our ability to fight viral attacks in every organ, including the lungs,” highlighted Joël Doré.
How might probiotics and prebiotics fare in fighting the current coronavirus pandemic?
Within diet, probiotics and prebiotics may play an important role in regulating the functioning of the immune system’s response via the gut microbiota, which in turn influences the immune system.
While probiotics have been shown to reduce flu-like respiratory tract infections, China’s National Health Commission and National Administration of Traditional Chinese Medicine suggested the use of probiotics in patients with severe COVID-19 to prevent secondary bacterial infection.
Joël Doré acknowledged: “In addition to a diverse protective commensal microbiota, certain strains of probiotics are known to exert activities that empower the immune system. They have their place in a preventive arsenal, together with appropriate nutrition and gut-barrier reinforcing, anti-inflammatory and anti-oxidant strategies.”
Like probiotics, fermentable dietary fiber could also optimize immune defense against viral infections, as revealed by a mice study in which a day diet high in soluble fiber led to a reduced lung viral load and increased survival.
Although what you eat won’t stop you getting infected with COVID-19, looking after your gut microbiota with a well balanced diet that includes probiotics and prebiotics when necessary for supporting digestive wellbeing will help keep your immune system in good shape.
*Gut immune homeostasis is the state in which our immune system protects us from pathogens while remaining harmless against our microbiota, food and other environmental components.
The second article in this series covers the role of diet and nutrients in supporting a healthy immune system for fighting COVID-19.
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