Research Advances on the Impact of Environmental Pollutants on Gut Microbiota

Environmental pollutants such as microplastics, pesticides, and heavy metals are emerging as critical determinants of gut microbiota composition and function. This review synthesizes current evidence from animal models, human studies, and mechanistic investigations to delineate how these contaminants disrupt gut microecology and compromise host health. Across pollutant classes, common pathogenic features include induction of dysbiosis, characterized by depletion of beneficial commensals and enrichment of pro-inflammatory taxa; impairment of intestinal barrier integrity, facilitating translocation of microbial metabolites into systemic circulation; and activation of innate immune signaling pathways. Notably, all three pollutant categories converge on the LPS/TLR4/NF-B pathway, driving the release of pro-inflammatory cytokines such as TNF- and IL-6, thereby promoting chronic inflammation and metabolic dysfunction. While animal studies provide robust mechanistic insights, human evidence remains limited, with few large-scale longitudinal cohorts. Future research should prioritize multi-omics, physiologically relevant models, and microbiota-targeted interventions to clarify causal pathways and mitigate pollutant toxicity.