AUTHOR=Shang Jiacui , Wan Feng , Zhao Le , Meng Xiangchen , Li Bailiang 

TITLE=Potential Immunomodulatory Activity of a Selected Strain Bifidobacterium bifidum H3-R2 as Evidenced in vitro and in Immunosuppressed Mice

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.02089

DOI=10.3389/fmicb.2020.02089

ISSN=1664-302X

ABSTRACT=<p>The microbiota is directly involved in the development and modulation of the intestinal immune system. In particular, members of the genus <italic>Bifidobacterium</italic> play a primary role in immune regulation. In the present study, <italic>Bifidobacterium bifidum</italic> H3-R2 was screened from 15 bifidobacterium strains by <italic>in vitro</italic> experiment, showing a positive tolerance to digestive tract conditions, adhesion ability to intestinal epithelial cells and a regulatory effect on immune cell activity. Immunostimulatory activity of <italic>B. bifidum</italic> H3-R2 was also elucidated <italic>in vivo</italic> in cytoxan (CTX)-treated mice. The results showed that the administration of <italic>B. bifidum</italic> H3-R2 ameliorated the CTX-induced bodyweight loss and imbalanced expression of inflammatory cytokines, enhanced the production of secretory immunoglobulin A (SIgA), and promoted splenic lymphocyte proliferation, natural killer (NK) cell activity and phagocytosis of macrophages in immunosuppressed mice. In addition, <italic>B. bifidum</italic> H3-R2 restored injured intestinal mucosal, and increased the villus length and crypt depth in CTX-treated mice. The results could be helpful for understanding the functions of <italic>B. bifidum</italic> H3-R2, supporting its potential as a novel probiotic for immunoregulation.</p>