<i>Leuconostoc citreum</i> enhances the colonization ability of <i>Lactiplantibacillus plantarum</i> in the gut by synergistically modifying the intestinal niche

<i>Lactiplantibacillus plantarum</i> HNU082 (Lp082) exhibits a wide range of health-modulating effects. However, its limited ability to colonize the intestines has hindered long-term effects. To enhance the colonization capability of Lp082, we conducted an intermittent intervention trial in mice and humans. After two interventions, Lp082 strain rapidly mutated after the second intervention, with a greater number of mutations observed in the human gut. By analyzing the abundance of Lp082 and fluctuations of gut microbiota, the key microbial factors that promote Lp082 colonization were identified. Through examination of the abundance changes and correlation analysis, we identified <i>Leuconostoc citreum</i> as the most positively correlated species with Lp082, and its synergistic effect on Lp082 colonization was verified <i>in vivo</i>. Coadministration of <i>L. citreum</i> more than doubled Lp082 abundance through the regulation of other bacterial species in the gut, reducing the number of species competing with Lp082 and increasing the beneficial fecal metabolite levels in the host intestine. This study provides a viable strategy for enhancing the colonization capability of <i>L. plantarum</i>, ensuring the long-term effectiveness of probiotics in the gut.