No abstract

This study aimed to explore the impact of xylo-oligosaccharide (XOS) on the in vitro proliferation of ninety-four lactic acid bacteria (LAB) strains derived from the rabbit gut. LAB strains with a strong capability to utilize XOS were identified. The molecular mechanisms of XOS metabolism by LAB strains and their probiotic characteristics were investigated based on whole genome sequencing and phenotypic analysis. The results revealed that XOS efficiently promoted the proliferation of thirty-four LAB strains (36.2%, 34/94), among which Lactobacillus sp. YT155 exhibited remarkable XOS metabolism. The genomic sequence of strain YT155 revealed two gene clusters, namely xylABCPRT and xylCFGHT, which were predicted to be associated with XOS consumption. Moreover, strain YT155 displayed excellent tolerance to various conditions, including temperatures ranging from 37℃ to 50℃, pH levels from 5.0 to 10.0, salinity levels from 2–6%, and exposure to gastric and intestinal fluids. Lactobacillus sp. YT155 demonstrated strong antagonistic capabilities against Escherichia coli and Staphylococcus aureus, along with a high antioxidant ability, as evidenced by DPPH and hydroxyl radical scavenging rates of 100.39% ± 1.82% and 34.09% ± 1.57%, respectively. Furthermore, strain YT155 exhibited sensitivity to nine commonly used antibiotics and was devoid of transferable resistance genes. Collectively, XOS emerges as a promising prebiotic for rabbit farming, promoting the proliferation of intestinal beneficial microbes. Lactobacillus sp. YT155, with its proficiency in XOS metabolism and excellent probiotic characteristics, holds potential for syngistic applications with XOS as a synbiotic for the prevention of rabbit diarrhea.