April 5, 2023 – COVID-19 can harm the makeup of microbes in the gut, which play a significant role in the body’s immune system and overall health, new research shows.
The vast combination of healthy bacteria, fungi, and viruses that live in our gut – known collectively as the microbiome – plays a crucial role in preventing infection, aiding in digestion, and helping your body to mount natural defenses against disease.
A study from the University of Chicago Medicine has found COVID appears to adversely affect the gut microbiome specifically, and in a number of different ways. Researchers determined the composition of the microbiome in the guts of COVID patients can potentially show how severe an infection is.
The researchers found that metabolites produced by gut microbiota, which are essential for metabolism in the body, played a particularly important role.
Patients who had lower levels of a metabolite called desaminotyrosine, as well as secondary bile acids, were more likely to have progressive lung failure. The researchers also found that desaminotyrosine and secondary bile acids may positively affect immune responses, noting that more research might show that probiotics could help COVID patients produce more gut metabolites and recover from life-threatening respiratory distress.
The findings echo other research that has linked COVID to changes in the body’s microbiome and more severe illness.
Research from the Chinese University of Hong Kong found that microbiomes in the gut can not only become inflamed due to COVID infection, but stay that way even after the patient initially recovers. That means COVID symptoms can remain – or one can become at higher risk for other illnesses, as the immune system can be affected by this problem.
This may help explain how long COVID develops after infection with the virus. The findings have widespread significance, the researchers said, as they observed 76% of patients develop long COVID. (Long COVID is defined as at least one persistent symptom for 4 weeks after clearing the virus.)
A study from Brigham and Women’s Hospital in Boston and Harvard Medical School also found the “richness” of protective gut microbiota appears to be reduced in patients with COVID.
“There is evidence that during COVID-19 infection, there is a significant reduction in the diversity of the bacteria,” said Joshua LaBaer, MD, PhD, executive director of Arizona State University’s Biodesign Institute and leader of ASU’s COVID-19’s research efforts and the ASU Biodesign Clinical Testing Lab in Tempe.
“Reduced diversity in the microbiome is often a sign of illness. In healthy people, the usual bacteria in the gut compete for resources that make it difficult for pathogenic bacteria to grow. But if diversity is lost, people are more prone to get an infection, both in the gut and also in the blood.”
LaBaer, who was not involved in the new studies, said how microbiome diversity is lost in COVID is not fully understood. But “there is evidence that that gut lining shows signs that resemble inflammatory bowel disease, with shortening of the gut, inflammation, and greater permeability," he said.
Can COVID Permanently Change Your Microbiome?
Since your microbiome is so critical to protecting the body against illness, researchers are trying to answer this question.
A new study from the University of Luxembourg found that patients who didn't have COVID symptoms or had mild to moderate symptoms were more at risk for bacterial infections. The patients also showed a greater amount of genes that cause a resistance to antibiotics. The research team is now studying whether these changes could be permanent.
“It’s highly likely that observed changes to infective competence last a long time,” said senior study author Paul Wilmes, PhD, a professor of systems ecology, head of the Systems Ecology Group, and deputy director of the Luxembourg Centre for Systems Biomedicine at the University of Luxembourg in Esch-sur-Alzette.
Whether you have had COVID-19 or not, the virus is now part of our lives, so it’s a smart idea to make your microbiome as strong as possible, experts say.
“In general, to maintain a healthy microbiome, eat a diverse diet, meaning that you should avoid eating the same things all the time,” said LaBaer. “A diet rich in foods that are not heavily processed, as well as some probiotic foods, will also encourage a more diverse gut microbiome.”
In short: the more diverse your gut bacteria are, the more ground they can cover when it comes to fighting off illness.
Foods rich in fiber, as well as fermented foods, are especially key for improving your gut microbiome function. According to data from Mayo Clinic, great additions to your diet include:
- Asparagus
- Artichokes
- Bananas
- Garlic
- Oatmeal
- Onions
- Wheat
- Barley
- Beans
- Berries
- Buttermilk
- Kefir
- Miso
- Kimchi
- Yogurt with live cultures
- Sourdough
- Sauerkraut
- Flax
- Chicory root
- Rye
- Leafy greens
- Tempeh
- Kombucha
