Strain-specific ameliorating effect of Bifidobacterium longum on atopic dermatitis in mice

Atopic dermatitis (AD) is among the most common allergic diseases worldwide. This study evaluated differences in the abilities of Bifidobacterium longum strains to alleviate 2, 4-dinitrofluorobenzene-induced AD in mice. Of the 12 tested B. longum strains, CCFM1029 significantly relieved AD symptoms. This outcome was accompanied by the inhibition of inflammatory cells infiltration in AD-like skin lesions, decreases in serum IgE, and inflammatory cytokines levels in dorsal skin tissue, increases in IFN-gamma and IL-10 levels, and a reduction in the cecal propionic acid level. B. longum CCFM1029 also reduced the proportions of unclassified Bacteroidales S24-7, Adlercreutzia, and Allobaculum spp., and restored the gut microbiota structure such that it resembled the control group structure. In conclusion, the administration of B. longum CCFM1029 helped to ameliorate AD by suppressing polarized Th2 immune responses and regulating the gut microbiota and short-chain fatty acids metabolism.