Increasing evidence suggests that alterations in the gut microbiota are associated with the development, severity, and sequelae of COVID-19 infection.
Certain Gut Bacteria Can Inactivate COVID-19 Virus
In a new study published in Cell Host & Microbe, researchers evaluated the impact of gut microbiota composition on respiratory viral infections through animal experiments. The results showed that segmented filamentous bacteria (SFB) in the gut could protect mice from viral influenza, respiratory syncytial virus (RSV), and the COVID-19 virus.Studies have indicated that SFB, whether naturally present or acquired, can combat viral infections with the help of alveolar macrophages in the lungs.
Gut-Lung Axis
While the functions of the gut and lungs are different, they share common structural features, as they both develop from the same embryonic tissue. Both the gut and lungs are covered with mucous membranes. These membranes secrete mucin and collectively form a mucosal immune system that defends against pathogens.As research on COVID-19 progresses, some researchers have noted the bidirectional and complex relationship of the gut-lung axis. Microbiota-derived metabolic pathways can function distally and play a vital role in anti-inflammatory responses in the airways.
The SFB are unlikely to be the only kind of gut microbe capable of affecting the immune cells in the lungs, said Dr. Andrew Gewirtz, a co-senior study author, in a press release.
Dr. Richard Plemper, a co-senior author of the paper, said that among the thousands of microbial species inhabiting the mouse gut, a common commensal microbe significantly impacted respiratory virus infections. He further stated that if these findings apply to human infections, they could have substantial implications for the risk assessment of disease progression in patients.
Viral Respiratory Tract Infection Affects the Gut Microbiota
An analysis of fecal samples from 102 patients with severe COVID-19 infection following ICU admission found that decreased concentrations of gut microbiome metabolite—secondary bile acids and desaminotyrosine—were associated with an increased risk of respiratory failure and mortality.Enhancing Gut Health to Build Robust Immunity
The intestinal tract, the largest immune organ in the human body, plays a crucial role in establishing and maintaining a robust immune system, and gut immunity is closely linked to our diet.The study covered 2,884 frontline health care workers from six different countries, investigating their dietary habits and the severity of COVID-19 infection. The results showed that participants who followed either a plant-based or pescatarian diet (where a person doesn’t eat meat but eats fish) had a 59 percent lower odds of developing moderate to severe COVID-19 than those who did not.