From The Scientist, 31 August 2021:
hen SARS-CoV-2 first began rampaging around the world, it was thought to primarily affect the respiratory system. It soon became clear that the virus had more far-reaching effects, including on the gastrointestinal system and its bacterial symbionts.
This came as no surprise to Siew Ng, a gastroenterologist in the Center for Gut Microbiota Research at the Chinese University of Hong Kong. “We previously had found quite a lot of impaired gut microbiome in different conditions, including people with infectious disease,” says Ng. COVID-19 patients were no different. “In quite a substantial proportion of people, they also have gut manifestations, such as diarrhea, such as abdominal pain.”
One early study suggested that nearly 20 percent of patients with confirmed SARS-CoV-2 infection had gastrointestinal symptoms. That same study found that COVID-19–infected people shed viral RNA in their feces—another clue that the virus was getting into the gut.
Since then, researchers have identified patterns in the makeup of gut bacteria—a state called ‘dysbiosis’ in which there is loss of diversity and beneficial bacteria but an increase in bad bacteria—that are associated with poorer outcomes and slower recovery from COVID-19. It’s early days for this line of research, but its proponents say that changes in the gut microbiome could potentially flag patients at risk of worse outcomes from COVID-19, or that its makeup could even be altered to help patients avoid severe disease. Read more.