Hepatoprotective potential of Bacteroides eggerthii on fatty liver disease: a mouse model study

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as nonalcoholic fatty liver disease (NAFLD), is a significant global health burden, with increasing evidence pointing to gut microbiota as a modifiable contributor to disease pathogenesis. Yet, the causality of gut microbiota in liver health is not fully established. Method: In this pre-clinical study, we assessed the hepatoprotective potential of Bacteroides eggerthii (B. eggerthii), a gut commensal bacterium, in a high-fat diet (HFD)-induced mouse model of MASLD. Results: Our in vivo experiments showed that mice given with HFD exhibited prominent metabolic abnormalities, intestinal dysbiosis, liver steatosis, and drivers of pathological changes in the livers (autophagic dysregulation and lipid peroxidation). Oral supplementation with a strain of B. eggerthii that was isolated from the fecal specimen of a healthy subject improved the perturbation of fecal microbiota and mitigated lipid peroxidation and lobular inflammation in the liver of MASLD mice, without ameliorating hyperlipidemic conditions and hepatic steatosis. Conclusion: Our results indicate that B. eggerthii may potentially protect against diet-induced fatty liver diseases and further extend our understanding on the gut-liver axis in MASLD.