Integrative review links chronic heavy metal exposure to intestinal infection susceptibility in Yunnan

Chronic exposure to low levels of multiple heavy metals has emerged as a major public health concern in regions with complex geochemical backgrounds such as Yunnan Province, China. This study aimed to systematically elucidate the relationship between chronic composite heavy metal exposure and increased susceptibility to intestinal infection. To achieve this, we conducted a multidisciplinary synthesis integrating environmental monitoring data with evidence from cellular, immunological, and microbiological studies. Our analysis demonstrates that long-term exposure to lead, cadmium, and arsenic is associated with intestinal barrier dysfunction, gut microbiota dysbiosis, and altered immune responses, which together contribute to enhanced susceptibility to opportunistic pathogens, particularly Pseudomonas aeruginosa. Based on this integrated evidence, we propose a coherent causal framework linking multi-metal exposure to host vulnerability. Furthermore, this study provides strategic recommendations, including biological monitoring, environmental and nutritional interventions, and clinical management approaches, and highlights future research directions such as multi-omics investigations and model development. Importantly, this study has proposed a comprehensive interdisciplinary causal framework that links environmental exposure to the host-pathogen interactions within the specific regional geochemical background.