Mihad Omer, Omer I Omer, Ibrahim O Mohamed
This review examines the therapeutic potential of probiotics in alleviating colitis through animal model studies, with particular emphasis on elucidating their mechanisms of action. Growing evidence demonstrates that gut dysbiosis plays a significant role in colitis pathophysiology, and restoring gut homeostasis represents a promising treatment strategy. Recent findings reveal that intestinal homeostasis is regulated not only by microbial composition but also by host-mediated oxygen control, which critically influences intestinal epithelial energy metabolism in both healthy and dysbiotic states. Interventional animal studies demonstrate that probiotics and their metabolites maintain gut homeostasis through multiple mechanisms. These include enhancing intestinal barrier integrity, preserving mucosal barrier function, and suppressing NF-κB pathway activation. Probiotics also modulate inflammatory responses by reducing pro-inflammatory cytokines such as TNF-α, IL-1β, IL-18, IL-6, and IL-17, while increasing anti-inflammatory cytokines like IL-10 and IL-13. Furthermore, they regulate macrophage polarization by downregulating M1 (pro-inflammatory) and upregulating M2 (anti-inflammatory) phenotypes. Additionally, probiotics ameliorate oxidative stress by boosting antioxidant enzyme activity (SOD, CAT, GPx, GST), increasing glutathione (GSH) levels, and decreasing MPO and MDA concentrations.