Researchers at the University of California, Davis found that chronic liver inflammation is associated with a Western diet via the type of bacteria present in the gut.

“We know the transition from steatosis, or fatty liver, to steatohepatitis (inflammation in the fatty liver) plays a crucial role in liver injury and carcinogenesis,” Yu-Jui Yvonne Wan, professor and vice chair of the Department of Pathology and Laboratory Medicine at UC Davis Health, said in a news release. “Our data show that diet, gender, and different antibiotic treatments alter the gut microbiota as well as bile acid profile and have different effects on liver inflammation.”

Researchers used the bile acid receptor farnesoid x receptor deficient, or FXR-deficient, mouse model that is commonly used to better understand the role of diet and inflammation in the development of liver diseases. “Our results suggest that probiotics and FXR agonists hold promise for the prevention and treatment of hepatic inflammation and progression into advanced liver diseases such as cancer,” Wan said.

“These studies show that a Western diet intake and FXR inactivation also increased hepatic inflammatory signaling, with a combined enhanced effect,” Wan said. “Introducing antibiotics to reduce inflammation also had different effects based on the diets the mice received.”

Researchers fed mice different types of diets, including a Western diet high in fat and sugar and gave broad-spectrum antibiotics that eliminate most gut bacteria, which affected hepatic inflammation differently in FXR-deficient mice.

A cocktail of ampicillin, neomycin, metronidazole, and vancomycin was found to completely block hepatic neutrophil and lymphocyte infiltration in control mice but the same cocktail was unable to eliminate hepatic inflammation in Western diet-fed FXR KO mice.

The study was published in the July edition of The American Journal of Pathology.