Role of Gut Microbiota in Modulating Oxidative Stress Induced by Environmental Factors.

The widespread presence of environmental pollutants, including toxic metals, microplastics, and antibiotics, has significantly altered gut microbiota composition and functionality, leading to dysbiosis and oxidative stress. These changes contribute to various adverse physiological effects, including systemic inflammation, mitochondrial dysfunction, and intestinal barrier dysfunction. This review provides a comprehensive analysis of the molecular mechanisms by which these environmental factors induce oxidative damage, emphasising the importance of redox imbalance, the overproduction of reactive oxygen species, and inflammatory signalling pathways. Key pathways involved include NF-κB, Nrf2/Keap1, PI3K/AKT, p38-MAPK, JAK/STAT and TLR4/MyD88. These pathways collectively contribute to the progression of chronic inflammatory conditions. Furthermore, this article synthesises findings from 354 studies published between 2016 and 2024, integrating human and animal research evidence. Existing literature suggests that gut dysbiosis exacerbates oxidative stress through impaired short-chain fatty acid production, downregulation of peroxisome proliferator-activated receptor gamma, and disruption of antioxidant enzyme activity. This review explores these mechanisms in more detail. Additionally, the review evaluates studies investigating microbiota-targeted therapeutic interventions to mitigate oxidative stress. These interventions include probiotics, prebiotics, polyphenols, and postbiotics, focusing on their reported modulation of Nrf2 and AMPK signalling pathways. The potential of faecal microbiota transplantation as an innovative approach to restoring a healthy gut ecosystem and counteracting pollutant-induced oxidative damage is also discussed. In light of the growing global exposure to environmental pollutants and their associated long-term health implications, it is imperative to gain a deeper understanding of their impact on gut microbiota and oxidative stress. This topic remains at the forefront of biomedical research due to its implications for public health, disease prevention, and developing novel therapeutic strategies.