Investigating therapeutic efficacy of Lactobacillus salivarius GZLC1 on colitis by examining its effects on intestinal fungi, antioxidant capacity, and inflammatory response in mice.

We investigated the therapeutic potential of Lactobacillus salivarius in colitis mice, and the mice were randomly allocated into three groups with each consisting of 10 mice (n = 10): a control group (CSG), a DSS-induced colitis model group (DSG), and a L. salivarius intervention group (LSG). The intervention group received daily oral administration of L. salivarius for seven consecutive days. Compared to the DSS model group, mice receiving L. salivarius exhibited significantly reduced weight loss, lower DAI scores, lessened colon shortening, and improved histopathological profiles, indicating a substantial reduction in inflammatory damage. Additionally, ITS sequencing revealed that L. salivarius significantly influenced the composition of the intestinal fungal community, decreasing the abundance of pathogenic fungi, such as Candida species, by approximately 40%, and restoring fungal homeostasis by reducing the Basidiomycota/Ascomycota ratio. Moreover, L. salivarius effectively alleviated DSS-induced oxidative stress by lowering serum MDA levels while enhancing the activity of SOD and GSH-Px. Furthermore, the probiotic intervention resulted in 30-40% reduction in pro-inflammatory factors (TNF-α, IL-6, and IL-1β) and an increase in the anti-inflammatory factor IL-10 levels, suggesting a pronounced anti-inflammatory effect. In conclusion, L. salivarius exerts significant protective effects against DSS-induced colitis by modulating the gut fungal community, mitigating oxidative stress, and suppressing inflammatory responses. This study is novel in that few probiotic studies have investigated the impact of L. salivarius on gut fungi in DSS-induced colitis. These findings highlight its potential as a therapeutic candidate for managing inflammatory bowel disease.