This review synthesizes evidence that heavy metals, endocrine disruptors, persistent organic pollutants, microplastics, and particulate matter may alter gut microbes and metabolites, connecting environmental exposure with inflammation, neural signaling, and behavior through the gut-brain axis.
Key findings
- Multiple evidence streams link pollutants with dysbiosis, altered microbial function, and cognitive or mental-health outcomes. However, heterogeneity in pollutants, doses, microbiome methods, and outcomes prevents a clear effect estimate, making the paper primarily a mechanistic framework rather than a quantitative risk assessment.
Why this matters globally
If the gut-brain axis mediates pollutant effects, environmental risk assessment may eventually need microbial and metabolite markers alongside exposure measurements. The review helps set a research agenda but does not yet justify probiotic or supplement use to prevent toxicity in the public.
Thai researcher contribution
Chiang Mai University pharmacy researchers contributed an interdisciplinary framework spanning environmental toxicology, microbiology, neuroscience, and health interventions, providing a basis for future population studies in polluted Thai settings.
Limitations to consider
As reported, this is a narrative review without a stated systematic search, risk-of-bias appraisal, or meta-analysis, leaving room for evidence-selection bias. Animal findings do not directly translate to humans, and cohort associations may be confounded by diet, socioeconomic conditions, disease, and mixed exposures.