A recent study suggests that "profiling" the gut microbiome (the environment where bacteria, viruses, and fungi live in the intestines) will help to determine who might develop post-acute COVID-19 syndrome, or "long Covid."  

Lingering Symptoms and the Gut

A significant number of people who were infected with COVID-19 reported persistent complications and symptoms as long as six months after "recovery." The most commonly noted issues were fatigue, muscle weakness, and insomnia. 

With about 75% of the immune system living in the gut, any disruption to the microbiome can lead to a difficult and long recovery, especially from a severe infection that attacks major organs. The researchers suggest that this may have a role in long COVID even though it's not completely clear what the cause is or why only some patients will develop it. More and more research is indicating that a damaged gut microbiome plays a major role in how severe COVID-19 infection is.