Lactobacillus murinus ZNL-13 Modulates Intestinal Barrier Damage and Gut Microbiota in Cyclophosphamide-Induced Immunosuppressed Mice

Cyclophosphamide (CTX) is a widely used anticancer drug in clinical practice; however, its administration can lead to gastrointestinal damage and immune suppression. <i>Lactobacillus murinus</i> (<i>L. murinus</i>) has been shown to regulate immune cell activity and protect the gastrointestinal system, showing potential application as a functional food. The objective of this study was to investigate the effects of <i>L. murinus</i> ZNL-13 on CTX-induced intestinal mucosal injury and gut microbiota in mice. The results demonstrated that <i>L. murinus</i> ZNL-13 significantly alleviated weight loss and intestinal pathological damage. Moreover, in CTX-induced intestinal injury mice, <i>L. murinus</i> ZNL-13 enhanced the release of immune factors, suppressed cell apoptosis, and protected the intestinal mucosal barrier. Additionally, it activated the TLR4/NF-κB pathway, thereby promoting immune cell activity. Furthermore, <i>L. murinus</i> ZNL-13 contributed to the restoration of gut microbial homeostasis by increasing the relative abundance of short-chain fatty acid-producing bacteria. Taken together, this investigation highlights the potential of <i>L. murinus</i> ZNL-13 in protecting the intestinal barrier and enhancing immune function while laying the groundwork for its development as a novel probiotic and functional food.