Therapeutic Potential of Foodborne Indole Derived from Chinese Stinky Tofu in Reducing Intestinal Inflammation and Enhancing Barrier Function to Mitigate Alcoholic Liver Injury

Indole, a compound in Chinese stinky tofu (ST), acts as a ligand for the aryl hydrocarbon receptor (AHR). Despite extensive research on prebiotic compounds, indole's specific role in ST remains unexplored. This study used an ethanol gavage method to create an ALD (alcoholic liver disease) mouse model and investigate dietary indole's effects on the intestinal barrier. Our findings indicate that after 6 weeks of being fed ST, the indole present (2 mg/day) robustly activated the intestinal AHR, upregulating its target gene, CYP1A1 (cytochrome P450 1A1 enzyme). This activation significantly reduced intestinal permeability, mitigated alcohol-induced oxidative stress and inflammation, and restored intestinal barrier function. Consequently, the study demonstrates that foodborne indole substantially reduces alcohol absorption and lowers the expression levels of liver inflammation-related factors, thereby slowing the progression of ALD. These results highlight indole's therapeutic potential for treating ALD and its role in developing functional foods.