Bifidobacterium animalis subsp lactis CNCM-I2494 restores gut barrier permeability in chronically low-grade inflamed mice

Objectives: Growing evidence supports the efficacy of many probiotics in the management of deregulated gut barrier. Bifidobacteria have been studied for their efficacy to treat a broad spectrum of gut disorders. The aim of this work was to study the effects of Bifidobacterium animalis subsp lactis CNCM-I2494, a strain used in fermented dairy products for a long time, on intestinal barrier function. Methodology and results: We first induced gut dysfunction in mice by a chronic low-grade inflammation model. Markers of inflammation, gut permeability and immune function were studied pointing out the absence of an active inflammation process. Nevertheless, gut permeability, lymphocyte populations and colonic cytokines were found to be altered in challenged mice. CNCM-I2494 was able to restore the function of the intestinal barrier improving intestinal permeability and restoring colonic goblet cell populations and cytokine levels. Furthermore, tight junction (TJ) proteins levels were also measured by qRT-PCR showing the ability of this strain to specifically normalize the level of some TJ proteins, particularly claudin-4 protein. Finally, CNCM-I2494 counterbalanced CD4+ lymphocyte alterations in both spleen and mesenteric lymphoid nodes. Conclusion: Altogether, these data suggest that CNCM-I2494 may be an efficient prevention and therapeutic tool for disorders associated with increased barrier permeability.