1. Poor Gut Health

Contracting a virus with an already pre-existing gut imbalance (known or otherwise) leaves you open potentially for poorer immune regulation and a more inflammatory condition. 

2. Virus Affects

For those with the worst health outcomes that required hospitalization, it appears that the inflammation or byproduct of the virus actually altered their gut bacteria for the worse.

3. Rebalancing the Gut

The altering of the gut microbiome allowed for more pathogenic strains of bacteria to grow, which may also cause a further inflammatory condition and worse immune response in the future (if not resolved).