A common gut fungus, Fusarium foetens, has emerged as a promising treatment for metabolic-dysfunction-associated fatty liver disease (MAFLD), which currently affects over 25% of adults globally.

Published on May 1, 2025, in the journal Science, the research reveals that F. foetens significantly reduces liver fat, inflammation, and scarring in mice, suggesting its potential as a future treatment for humans.

The study also found a disparity in gut fungal diversity between urban and rural populations, with urban residents exhibiting poorer diversity, potentially linked to lifestyle factors.

Future research plans include human clinical trials to assess the safety and efficacy of F. foetens, as well as exploring other gut fungi for their potential metabolic benefits.

This research signifies a shift in understanding gut-liver interactions, suggesting that future treatments for fatty liver disease may involve precision-engineered microbes rather than traditional medications.

Dr. Changtao Jiang from Peking University highlights the urgent need for new therapeutic approaches, as there is only one FDA-approved drug for MAFLD that has limited effectiveness.

In studies involving mice on a high-fat diet, F. foetens administration led to reduced liver weight, inflammation, and fibrosis, indicating its therapeutic potential.

Gut fungi, often referred to as the 'dark matter' of the microbiome, have been largely overlooked compared to gut bacteria due to challenges in studying them, such as difficulties in culturing and contamination.

MAFLD can progress to metabolic-dysfunction-associated steatohepatitis (MASH), which leads to liver inflammation and fibrosis, and currently, only one FDA-approved drug exists for MASH, which is not universally effective.

The benefits of F. foetens are attributed to its metabolites, which disrupt the production of harmful ceramide fats, although researchers caution that mouse biology may differ from humans.

The treatment appears to lower the activity of ceramide synthase (CerS), an enzyme involved in fat production, providing insight into its mechanism against fatty liver disease.

Jiang's team analyzed fecal samples from 100 individuals across five regions in China, successfully isolating F. foetens as a dominant and gut-adapted species.