A pattern I have seen in my practice that I have yet to see talked about is the possibility of post-viral SIBO infection after Covid-19. SIBO stands for small intestinal bacterial overgrowth and the disease is exactly that: overgrowth of pathogenic bacteria in the first part of the intestinal tract.
Typical symptoms of SIBO are early fullness when eating, excessive upper intestinal gas and bloating, belching, GERD, and constipation or diarrhea depending on the types of bugs present. In the last few years, I have seen this pattern of symptoms come on soon after my patients recover from Covid-19 infection (or are exposed to the spike protein through vaccination). While I don’t have any proof that Covid-19 was the cause of these infections, research does strongly support the fact that Covid-19 causes immunosuppression.
A study published in Frontiers Immunology Journal found that patients hospitalized for Covid-19 had severely decreased expression of adaptive immunity-related genes, especially those related to T/B cell arms and HLA molecules. They also found that those patients developed long-term secondary infections (1). Another study published in 2023 found that Covid-19 damages the CD8+ T cell response, which is an effect that is similar to the immune system damage caused by HIV and hepatitis C (2).
This drop in immune function can make us more susceptible to contagious diseases, but it also allows for opportunistic infections to flourish. Opportunistic infections are pathogens that often already live inside our body when we are healthy, but then flare up significantly when our immune function is suppressed. And we have seen plenty of opportunistic infections develop after Covid-19 and spike protein exposure. Some of the most common ones supported by research are shingles (reactivation of the chicken pox virus) (3), Epstein Barr Virus (mononucleosis) (4), candida (5), and cytomegalovirus (6).
While there is a lack of definitive research supporting a connection between Covid-19 and SIBO, I believe there is a significant correlation between these two diseases for many patients. SIBO bacteria are already known to be opportunistic — we all have small amounts of pathogenic bacteria in our small intestine even when we are healthy. It is the job of our immune system to keep these bacteria in check, and if the immune system becomes depressed it only makes sense that these pathogenic bacteria will flourish. Often this overgrowth will happen in the large intestine as well, creating a combination of both SIBO and large intestine dysbiosis for many patients.
I believe as conventional medicine becomes more adept at testing for and identifying SIBO, we will subsequently get more research supporting the link between immunosuppression and SIBO infections. But for now, many of us naturopathic doctors and trained SIBO professionals will continue to test for and treat those suffering from this condition, no matter what the underlying cause.
Dr. Katie Nuckolls is a naturopathic physician and owner of Thrive GI: Natural Digestive Medicine in Vancouver, Washington. She currently sees patients that live in Washington and Oregon using telemedicine. For more information, visit our contact page or schedule a free 15-minute consultation online.
- https://www.frontiersin.org/articles/10.3389/fimmu.2021.755579/full
- https://www.infectioncontroltoday.com/view/covid-19-study-suggests-long-term-damage-immune-system
- https://pubmed.ncbi.nlm.nih.gov/35470920/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10292739/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8918595/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9910675/