Although COVID-19 is primarily a respiratory illness, there is mounting evidence suggesting that the GI tract is involved in this disease. Scientists are investigating whether the gut microbiome is linked to disease severity in patients with COVID-19, and whether perturbations in microbiome composition, if any, resolve with clearance of the SARS-CoV-2 virus.
The gut, which regulates immune response, is one of the largest and most essential organs in the body. COVID-19 patients have been found to have poorer gut microbiome compositions compared with those without the disease. Dr John Whyte, chief medical officer at WebMD hosts this fascinating interview. There is a lot of scientific information in the article. For easier understanding you can also watch the video interview with Professor Siew Ng. Dr Ng, from the Chinese University of Hong Kong. In this two-hospital cohort study, they obtained blood, stool and patient records from 100 patients with laboratory-confirmed SARS-CoV-2 infection. Serial stool samples were collected from 27 of the 100 patients up to 30 days after clearance of SARS-CoV-2. Gut microbiome compositions were characterised by shotgun sequencing total DNA extracted from stools. Concentrations of inflammatory cytokines and blood markers were measured from plasma. What is already known on this subject? SARS-CoV-2 primarily infects the respiratory tract, however, pathophysiology of COVID-19 can be attributed to aberrant immune responses in clearing the virus. We know that the human gut is one of the largest organs in our body that actually regulates our immune response. In fact, it helps protect us against different infections, including SARS-CoV-2. Each one of us has trillions of bacteria in our guts, and they play a lot of roles. And it's like an organ on its own. It controls our immune system; it controls how we work our metabolic system, how our brain functions, the hormones in our body. What are the new findings? Composition of the gut microbiota in patients with COVID-19 is concordant with disease severity and magnitude of plasma concentrations of several inflammatory cytokines, chemokines and blood markers of tissue damage. Gut microbiome composition was significantly altered in patients with COVID-19 compared with non-COVID-19 individuals irrespective of whether patients had received medication. Doctors have found that patients with COVID-19 have very different composition of the gut microbiome to those without disease. But what's more important, what is missing in those with COVID-19, are the good bacteria that help generate a very good immune response. Several gut bacterias with known immunomodulatory potential such as Faecalibacterium prausnitzii, Eubacterium rectale and bifidobacteria were underrepresented in patients and remained low in samples collected up to 30 days after disease resolution. It's likely that some of the gut bacteria that are good in helping us to prevent such an immune response are actually missing. During the third wave of COVID in Hong Kong, scientists found patients with and without disease, and scientists were able to follow them up over a period of time to look at what's happening to the gut microbiota. Dysbiosis — abnormal gut microbiome — may account for long-term COVID-19 symptoms. In studies, elderly patients and those with chronic conditions were more likely to have dysbiosis, which might explain their increased risk for severe disease. In fact, at the Chinese University of Hong Kong, doctors have other centers using stool to test for SARS-CoV-2. They have now tested close to 6000 children. And have found positivity of 0.2%, which is much higher than nasopharyngeal or deep-throat saliva because it's noninvasive. And we now know that SARS-CoV-2 is not just a lung disease because many people (about 30%-40%) get gut manifestation and gut symptoms as well. How might it impact on clinical practice in the foreseeable future? These findings suggest that depletion of immunomodulatory gut microorganisms contributes to severe COVID-19 disease. COVID-19 is not just a lung disease. Anywhere from 30% to 40% have gut manifestations too. Stool samples are now being used to test for COVID-19. The dysbiotic gut microbiota that persists after disease resolution could be a factor in developing persistent symptoms and/or multisystem inflammation syndromes that occur in some patients after clearing the virus. What's fascinating is that when scientists tested about 1000 healthy people in Hong Kong, we found that 40% actually had dysbiosis, abnormal gut microbiome. These are the people who are at higher risk of having the infection: diabetics, the elderly, the obese, those with chronic disease, or those who have abnormal gut microbiome. And this may, in fact, explain why they are more susceptible but, more importantly, why when they are infected, they have worse outcomes. Epidemiology studies have shown that. So, if we have that as a clue, one day doctors may be able to test them to identify the type of outcome that they may have and the type of treatment. In the future, doctors believe that the gut microbiome also affects the vaccine response. They are seeing this data with flu vaccine, that some people may generate longer-term immunity and antibody while others don't. The personalized way will be with a simple stool test — we know that COVID will be here for a long time — and we might be able to personalize to see which type of people may respond better to the vaccine. During the COVID pandemic, Dr Ng personal advice is threefold: First is that we know that our diet influences our gut microbiome. So the easiest thing for our citizens to do is to have a very healthy diet. What that means is less processed food, less food additives, emulsifiers — these are known to cause inflammatory response to our bacteria. And increase fiber intake and exercise, because ample data show that this generates really good bacteria in the gut. Bolstering of beneficial gut species depleted in COVID-19 could serve as a novel avenue to mitigate severe disease, underscoring importance of managing patients’ gut microbiota during and after COVID-19. We well know that taking probiotics are generally safe, it depends on what your role is in doing it. Select probiotics carefully; they are not all created equal. The difference between probiotics is probiotics are live bacteria. They are known to generate a beneficial effect on our body. Prebiotics are purely food components. For example, asparagus has prebiotics in it, the byproduct. They help to induce the growth of the good bacteria. Both are generally safe. For example, in people who are known to have dysbiosis, chronic disease, and in the elderly, doctors have found that the good bacteria definitely are much lower than those of children. In this cohort, it's important to talk to your doctor to make sure there are no contraindications for you in taking a specific probiotic. Thank you doctor Ng and doctor Whyte for this important article and interview. We have we have known since ancient times that the digestive system rules your health (see fun facts). Doctor Ng talks about the diversity of the microbiome for promoting health. The microbiome is the community of microorganisms of GI tract . There are more cells in your microbiome than in your body. To create a healthy population in your microbiome you need to feed them the right food. Here is such a food "FLORASSIST Prebiotic Chewable". You can order it through my Fullscript account Fullscript Link here. If you have an account simply put the name in the search bar to order, otherwise set up your own account to receive a 10% discount and free shipping for $50 or more. Our gut microbiome is going to have a huge, long impact on our future partly because of the hygiene hypothesis. We know that when you lack a lot of the good bacteria in your gut, you're more likely to get immune-mediated diseases, such as multiple sclerosis, cancers, auto immune and rheumatic disease. We now know that our gut microbiome is a central organ that really influences many of the outcomes.
Fun Fact: Our “modern” probiotics are a “new” twist on ancient wisdom. Academics say that fermented milk products may have been used to treat digestive illnesses during the Roman times and that one version of the Old Testament attributes Abraham’s long life (supposedly 175 years) to his “consumption of sour milk.” Later, in 1907, Russian microbiologist Elie Metchnikoff recorded an association between Bulgarians’ consumption of large amounts of fermented dairy products and their good health and longevity. Travel the world and you’ll find that nearly every culture’s diet includes some form of fermented food and has been doing so for a long, long time. This is especially amazing considering that the microbiome and its importance to our health wasn’t really recognized by the scientific community until the late 1990s.