Prebiotics enhance the immunomodulatory effect of Limosilactobacillus fermentum DALI02 by regulating intestinal homeostasis

The colonization ability of Limosilactobacillus fermentum DALI02 and the promoting effect of fermented prebiotics have been studied. This study aims to evaluate the systemic immunomodulatory effects of DALI02 and DALI02 + Prebiotics on cyclophosphamide-induced immunosuppressed rats. We found that DALI02 and DALI02 + Prebiotics, especially DALI02 + Prebiotics, exhibited significant restorative effects on the immunocompromised state in rats (p < .05). Specifically, both of them promoted the recovery of body weight and immune organ function, enhanced the proliferative capacity of immune cells, and effectively reduced the levels of interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α). Furthermore, both of them significantly reduced the levels of lipopolysaccharide (LPS) and D-lactic acid in the blood (p < .05). Principal coordinate analysis (PCoA), principal component analysis (PCA), and unsupervised cluster analysis revealed that DALI02 and DALI02 + Prebiotics group were more similar to the blank group at the genus level of the gut microbiota. At the level of short-chain fatty acids (SCFAs), DALI02 + Prebiotics and blank group belonged to Cluster 3. These results suggested that the intervention with DALI02 and DALI02 + Prebiotics effectively modulated the structure of the gut microbiota, and DALI02 + Prebiotics restored the dysregulation of SCFAs. In summary, DALI02 and DALI02 + Prebiotics possess immunomodulatory functions, with the latter showing superior effects.