Impact of anthocyanin-rich fruits on the modulation of inflammation and oxidative stress in the gut-liver axis: a systematic review of in vivo studies

Anthocyanins, a class of polyphenolic compounds widely present in berries and tropical fruits, have been increasingly investigated for their role in gut-liver axis. This systematic review synthesized evidence from preclinical studies evaluating the effects of anthocyanin-rich fruits on inflammation and oxidative stress, as well as secondary outcomes related to liver and intestinal function. Searches for original articles were performed in PubMed, Scopus, Web of Science, and Embase. A total of 18 studies were selected. Overall, supplementation with anthocyanin-rich fruits reduced pro-inflammatory cytokines (TNF-α, IL-6, IL-1β), enhanced antioxidant enzyme activities (SOD, GPx, CAT), and lowered lipid peroxidation (MDA). These primary outcomes were consistently associated with improvements in liver health, including decreased serum ALT and AST, reduced steatosis, and lower histological damage. At the intestinal level, anthocyanins increased the expression of tight junction proteins (ZO-1, occludin), reduced permeability, and promoted favorable microbial shifts, particularly an enrichment of Lactobacillus, Bifidobacterium, and Akkermansia muciniphila. The gut-liver axis emerged as a central mediator, contributing to systemic anti-inflammatory and metabolic benefits. Collectively, the findings highlight the potential of anthocyanin-rich fruits as dietary strategies to prevent or mitigate metabolic and inflammatory disorders through coordinated modulation of intestinal and hepatic pathways.