Health & Wellbeing

COVID-19 severity linked to gut bacteria in first-of-its-kind study

COVID-19 severity linked to gu...
An observational study suggests certain microbiome imbalances correspond with the severity of COVID-19 and persistent symptoms of the disease
An observational study suggests certain microbiome imbalances correspond with the severity of COVID-19 and persistent symptoms of the disease
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An observational study suggests certain microbiome imbalances correspond with the severity of COVID-19 and persistent symptoms of the disease
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An observational study suggests certain microbiome imbalances correspond with the severity of COVID-19 and persistent symptoms of the disease

A first-of-its-kind study has investigated the relationship between COVID-19 severity and the gut microbiome. The observational research suggests specific microbial patterns correlate with disease severity and those bacterial imbalances may account for some cases of “long COVID”.

A growing body of study is finding a relationship between our immune system and the massive population of bacteria living in our intestines, known as our gut microbiome. These links suggest our microbiome may influence, or be influenced by, inflammatory activity in the body. And this relationship could play a role in everything from depression and obesity to Alzheimer’s.

In light of these recent microbiome discoveries it is reasonable to wonder what kind of influence gut bacteria has on perhaps the greatest acute health crisis of our time, COVID-19. A handful of preliminary studies published in late 2020 suggested patients suffering from COVID-19 may present with novel gut microbiome signatures.

One study found COVID-19 patients presented with unique microbial compositions compared to patients with influenza and healthy controls. Another small pilot study, investigating a cohort of just 15, suggested there may be signs microbiome alterations correlate with COVID-19 severity.

This new study, published in the BMJ journal Gut, offers the most detailed investigation to date into the relationship between COVID-19 severity, the gut microbiome, and general inflammatory biomarkers. The research looked at blood and stool samples from 100 COVID-19 patients admitted to hospital, compared to 78 healthy control subjects.

The study found significant microbial differences between COVID-19 patients and controls. Species including Bifidobacterium adolescentis, Faecalibacterium prausnitzii and Eubacterium rectale, which have previously been shown to play a role in immune system activity, were all seen in notably lower volumes in COVID-19 patients. COVID-19 patients also displayed unusually higher volumes of bacterial species including Ruminococcus gnavus, Ruminococcus torques, and Bacteroides dorie.

“Moreover, this perturbed composition exhibited stratification with disease severity concordant with elevated concentrations of inflammatory cytokines and blood markers such as C creative protein, lactate dehydrogenase, aspartate aminotransferase and gamma-glutamyl transferase,” the researchers report in the study.

A smaller subset of COVID-19 patients in the study were followed for up to a month after recovery and discharge from hospital, revealing the disrupted microbiome signatures seemed to persist beyond the phase of acute disease. One hypothesis raised by the researchers suggests microbiome disruptions could play a role in the enduring symptoms many COVID-19 patients suffer from in the months following infection.

It is important to note these findings are very preliminary and cannot offer insight into causality. It’s unclear, for example, whether these particular COVID-19 patients had irregular microbiome signatures before viral infection. And it is unclear whether these microbiome signatures directly influence the severity of the disease, or are merely a consequence of it.

“… the observed gut microbiota composition could simply be a response to patients’ health and immune states rather than a direct involvement in disease severity, as such it may not be directly applicable to predicting disease susceptibility in non-COVID-19 subjects,” the researchers note in the new study.

Perhaps the most interesting hypothesis to come out of this preliminary study is the proposition that some kind of personalized microbiome therapy could be a useful treatment for patients following the acute phase of COVID-19. A great deal of work is still needed, however, before any kind of real-world clinical application arises from this field of investigation.

“The dysbiotic gut microbiota that persists after disease resolution could be a factor in developing persistent symptoms and/or multi system inflammation syndromes that occur in some patients after clearing the virus,” the researchers conclude. “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.”

The new study was published in the journal Gut.

Source: BMJ via EurekAlert

7 comments
Austin Milby
Wouldn’t they need to do the same tests on covid patients who didn’t go to the hospital and recovered quickly? It also seems like those hospitalized could just be effected by the hospital stay itself. Without doing the same tests on short term stay at home patients they can’t have complete test results.
Chris Coles
Might also be why taking oral vitamin C can cause diarrhoea; where the dysbiotic gut microbiota react against it. Then again, history of sailing ships on long sea voyages, shows that a lack of vitamin C can have drastically negative health effects such as scurvy, which causes bleeding gums and bleeding under the skin , and why there are very credible reports of the advantages of using intravenous vitamin C in large doses to treat COVID infections.
bahbah
Might have been useful to state in the article that 80% of the immune system is in the gut, and the prognosis of Covid depends on the immune response. Inflammation levels are also determined by the biome. Though we must wait for more research results, it is becoming increasingly clear that we must eat for optimal biome composition and the biome will look after us.
David Jackson
"It also seems like those hospitalized could just be effected by the hospital stay itself."
Are you suggesting, that when a patient is ingesting, one should "brown bag it"?
That would definitely work for me. Both Arby's and Burger King use brown bags.
Graeme S
The old saying is well served and maybe should again be forefront in what we do to our bodies, " You are what you eat"
And instead of trying to manipulate our gut microbe world, maybe a healthy diet, not purchased at the fast food outlets, and re look at what was eaten over the last couple of hundred years and see if today we have taken that for gospel and continued in similar traditions of eating, and today our gut world is wrong. For me that came about when my wife started a new way (to us) of eating that has seen her shed 22kg and myself 6 kg, with little effort just changing what we eat, no strange food, no diet fads, no extra money, just deleted a lot of what we were eating that was a carry over from our parents, which in turn was a carry over from their parents, the 3 veg and meat English way of eating.
ljaques
I'd love to see a huge (million+)study on this performed on covid+nonreactive, covid+minorreactive, and covid+critical patients to get a much better handle on it than 15 patients. // RE: Vit C diarrhoea, mine presented only when there were rose hips in the tablets at 2-3g/day levels. Ascorbic acid crystals or Vit C or C-complex were tolerated up to 10g without digestive troubles.
Norman Kozlarek
Enduring 2nd COVID case, worse than the 1st. Infection post surgery led to massive antibiotic introduction which culminated in such intense abdominal pain that I passed out and suffered head trauma. At ER tested positive for COVID but also e-coli, C-diff, diverticulitis, micro perfs, and colitis. 9 months later, COVID positive again. Seeking answers.