Microbial-Derived Antioxidants in Intestinal Inflammation: A Systematic Review of Their Therapeutic Potential

Abstract

The potential of microbial-derived antioxidants to modulate intestinal inflammation is increasingly recognized, which is especially important in inflammatory bowel diseases (IBD). Oxidative stress, a major contributor to chronic intestinal inflammation, is the result of an imbalance between the production of reactive oxygen species (ROS) and the body's antioxidant defenses. This systematic review explores the role of microbial-derived antioxidants in alleviating IBD. Among the main findings are certain compounds, such as exopolysaccharides (EPS) and short-chain fatty acids (SCFAs), which have demonstrated their ability to neutralize ROS and strengthen the integrity of the intestinal barrier, thereby attenuating inflammatory responses. These antioxidants offer the dual benefit of mitigating oxidative stress and rebalancing the gut microbiota, which is often disrupted in IBD. Evidence from preclinical and clinical studies provides a better understanding of the mechanisms involved in the effects of these microbial antioxidants. Conventional treatments for IBD primarily focus on immune modulation. In this context, the integration of microbial-derived antioxidants could offer a complementary approach by addressing both oxidative damage and gut dysbiosis. Further research and clinical trials are essential to establish standardized treatment guidelines and clarify the long-term efficacy of these promising therapeutic agents.

Keywords: SCFAs; dysbiosis; gut; inflammation; microbial-derived antioxidants; microbiome; postbiotics.

Figure 1

Schematic representation of the systematic review process, detailing the database searches, application of inclusion and exclusion criteria, and final selection of studies. GI, Gastrointestinal; RCT, Randomized Controlled Trial.

Figure 2

Beneficial effects of microbial-derived antioxidants on gut health. Various metabolites released by bacteria, such as SCFAs, EPS, tryptophan derivatives (e.g., melatonin), organic acids (e.g., lactic acid and isocaproic acid), and other secondary metabolites specific to certain bacteria (e.g., colipterins and thioredoxin), modulate the immune response, strengthen the barrier function, restore the gut microbiome, and reduce oxidative stress. These effects contribute to alleviating IBD symptoms and improving gut health in preclinical and clinical models. CAT: catalase; EPS: exopolysaccharides; GPx: glutathione peroxidase; IBD: inflammatory bowel disease; SCFAs: short-chain fatty acids; SOD: superoxide dismutase.