Antibiotic-induced imbalances in gut microbiota aggravates cholesterol accumulation and liver injuries in rats fed a high-cholesterol diet.

Increasing evidence suggests that maintenance of homeostasis between gut microbiota and host plays an important role in human health. Many diseases, such as those affecting the liver, have been linked to imbalances in gut microbial communities. However, it is not clear whether an imbalance in gut microbiota promotes the onset of liver injury or if the imbalance results from the pathological state. In the current study, antibiotics were used to disturb the gut microbiota of both rats fed a high-cholesterol diet and rats fed a normal diet (controls). The prevalence of Bacteroidetes and Firmicutes were reduced, and Proteobacteria was greatly increased in the guts of rats after antibiotic treatment. The antibiotic-induced perturbation of gut microbiota aggravated cholesterol accumulation and liver injury in rats fed a high-cholesterol diet. This may have been due to an increase in intestinal permeability and plasma lipopolysaccharide (LPS), which lead to an increase in LPS absorption and activation of TLR4 signaling, resulting in the synthesis of pro-inflammatory cytokines and chemokines in liver tissues. This study suggests that imbalances in gut microbiota may be a predisposing factor for the onset of metabolic diseases and liver injuries related to cholesterol and high-cholesterol diets. Modulation of gut microbiota could be a novel target for preventing cholesterol-related metabolic disorders.