A research team from the University of California, Irvine's Joe C. Wen School of Population & Public Health announced on Apr. 15 that it has identified a key biological link explaining why people with metabolic dysfunction–associated steatotic liver disease (MASLD), commonly known as fatty liver disease, experience worse outcomes from certain foodborne infections.
The findings are important because MASLD is the most common chronic liver disease worldwide and often occurs alongside conditions like obesity and type 2 diabetes. The study, published in Gut Microbes, reveals how disruptions in the gut-liver connection can make infections more severe for these patients—a growing concern as cases of foodborne illness rise globally.
In experiments conducted on mice, researchers found that those with MASLD suffered greater liver damage and inflammation after being exposed to Vibrio vulnificus, a bacterium often linked to seafood consumption. The affected mice showed increased intestinal permeability and immune changes that allowed harmful bacteria to move more easily from the gut to the liver through what scientists call the gut–liver axis. These animals also displayed higher levels of iron-related proteins that promote bacterial growth and developed early signs of cirrhosis faster than healthy mice exposed to the same pathogen.
Restoring a healthy gut microbiome after infection improved outcomes for MASLD mice, reducing both liver damage and inflammation. "These results suggest that the gut microbiome isn't just a bystander – it's a modifiable factor that could be targeted to reduce infection severity," said first author Punnag Saha, Ph.D., a former graduate student researcher in Chatterjee's Lab. "Therapies such as microbiome restoration may hold promise for protecting high-risk patients."
Non-cholera vibriosis—caused by bacteria including Vibrio vulnificus—affects about half a million people globally each year. Cases are increasing due to climate change and environmental shifts; people with chronic liver diseases like MASLD face up to five times higher risk of severe infection compared with others.
The research provides new insight into why patients with MASLD are particularly vulnerable during outbreaks of foodborne illness and suggests future strategies could focus on prevention or interventions targeting the microbiome.
