Dietary modulation of gut microbiota affects susceptibility to drug-induced liver injury

The rising incidence of drug-induced liver injury (DILI) parallels contemporary dietary shifts that have transformed the composition of human gut microbiota. The relationship between these phenomena remains unknown. Here, it is unveiled that a high fiber diet (HFiD) provides substantial protection against DILI, whereas a western style diet (WSD) significantly exacerbates DILI. Gut microbiota transplantation further confirms these differing outcomes are mediated by diet-induced variations in gut microbiota. Mechanistically, Lactobacillus acidophilus, enriched by HFiD, alleviates DILI through its metabolite indole-3-lactic acid (ILA), which activates the AhR/Nrf2 signaling pathway, thus enhancing hepatocellular antioxidant defenses and detoxification capacity. In the clinical intervention of subjects with prediabetes (N = 330), dietary fiber intervention enriches intestinal L. acidophilus, elevates serum ILA levels, and improves liver function. Conversely, WSD induces disturbance in bile acid metabolism and dysbiosis in gut microbiota, which impairs the intestinal barrier and facilitates the translocation of lipopolysaccharides (LPS) to the liver, thus triggering inflammatory responses and exacerbating DILI. These results demonstrate that dietary patterns significantly influence the onset of DILI by modulating gut microbiota. This novel insight expands the understanding of DILI risk factors and highlights the potential of dietary modifications as a preventive strategy against DILI.