As the world continues to live through another day of COVID 19, the medical world continues to report new findings attempting to explain the symptoms of COVID 19. A common adjective used to describe COVID 19 disease has been ‘weird’. This virus seems to have taken on a multitude of superpowers to affect a wide variety of body systems. This collection includes the ability to dysregulate the immune cells of the GI tract, contributing to dysfunction in this organ system.
While the respiratory systems takes the brunt of the attack, studies show that about 12% of those with COVID 19 experience GI symptoms such as vomiting and diarrhea. Live virus shedding from the stool has also been identified in many patients (2) and actual virus identified in the lining of the GI tract (3). Besides the wide-ranging effects of the disease already mentioned, the involvement of the GI tract comes as little surprise given the ACE2 receptors found on the cells (epithelium) lining the GI tract. These receptors provide the entry point for the virus to our cells across multiple body systems.
Besides the acute GI effects of COVID 19, other studies indicate some ongoing GI effects in those with Post-COVID or Long Hauler syndrome. These patients continue to suffer a variety of symptoms, primarily centered around fatigue, for weeks to months afterwards. Knowing that other viruses prior to COVID 19 have been linked with the development of Irritable Bowel Syndrome symptoms should prepare us to look for similar effects post-COVID. We do see some ongoing GI symptoms in patients diagnosed with Long Hauler that resemble irritable bowel syndrome.
Rather than dismissing the connection as many have done with other viral induced IBS cases in the past, these researchers are looking for the biochemical and immunological connections between virus and symptoms. The primary connection appears to be effects on collections of immune B and T cells called germinal centers. These are meeting places for our B and T cells to talk to each other about the infectious assault and to coordinate their work. Without this interaction, the immune response is less robust and may falter in defending us.
In the GI tract these germinal centers form what are called Peyer’s Patches in the end of the small intestine. Normally these patches allow the immune system to monitor what passes through the small intestine and respond to the microbes and antigen by making IgA antibody. With these patches acting as sentries and sending out their antibodies, we can keep the bad bacteria in check and keep our microbiome (bacteria living in our gut) balanced and helpful.
In this evaluation of 9 patients who died from COVID 19, the researchers looked for viruses in the GI tissues and evaluated the changes in the immune systems visible at time of death. While they found viruses in the epithelial cells which had ACE2 receptors, the immune cells and tissues showed little to no actual virus particles. Instead, in the immune cells, the germinal centers where B and T cells would normally interact and coordinate the immune defenses, were greatly depleted.
Applying what we know of the function of these germinal centers (Peyer’s Patches), this likely explains the resulting dysbiosis, or imbalance of bacteria in the gut post COVID, that we see clinically. In those patients suffering from Post-COVID GI symptoms, often gut bacteria become disbalanced allowing bad bacteria to overgrow the good. This makes sense if the Peyer’s Patches can no longer function adequately to keep the bacteria in check via IgA antibodies.
As we wait for further research to uncover more connections, those of us in functional medicine will continue to utilize available tools to rebalance gut bacteria. We guide patients on fiber intake that feeds good bacteria. We user herbs that encourage good bacteria or discourage bad bacteria. We supplement gut flora with probiotics and fermented foods. We encourage nutrients like vitamin A that augment IgA antibody production. Last, but not least, we work to turn down the inflammation and immune dysfunction which lead to these gut imbalances. All of this is part of helping our patients live healthier more abundant lives.
Trevelin Silvia C., Pickering Suzanne, Todd Katrina, Bishop Cynthia, Pitcher Michael, Garrido Mesa Jose, Montorsi Lucia, Spada Filomena, Petrov Nedyalko, Green Anna, Shankar-Hari Manu, Neil Stuart J.D., Spencer Jo. Disrupted Peyer’s Patch Microanatomy in COVID-19 Including Germinal Centre Atrophy Independent of Local Virus. Frontiers in Immunology. v13, 2022. https://www.frontiersin.org/article/10.3389/fimmu.2022.838328 DOI=10.3389/fimmu.2022.838328
- Parasa, Sravanthi et al. “Prevalence of Gastrointestinal Symptoms and Fecal Viral Shedding in Patients With Coronavirus Disease 2019: A Systematic Review and Meta-analysis.” JAMA network open vol. 3,6 e2011335. 1 Jun. 2020, doi:10.1001/jamanetworkopen.2020.11335
- Wölfel, Roman et al. “Virological assessment of hospitalized patients with COVID-2019.” Nature vol. 581,7809 (2020): 465-469. doi:10.1038/s41586-020-2196-x
- Gaebler, Christian et al. “Evolution of antibody immunity to SARS-CoV-2.” Nature vol. 591,7851 (2021): 639-644. doi:10.1038/s41586-021-03207-w
Sanctuary Functional Medicine, under the direction of Dr Eric Potter, IFMCP MD, provides functional medicine services to Nashville, Middle Tennessee and beyond. We frequently treat patients from Kentucky, Alabama, Mississippi, Georgia, Ohio, Indiana, and more... offering the hope of healthier more abundant lives to those with chronic illness.