Clinical Research
Copyright ©2008 The WJG Press and Baishideng. All rights reserved.
World J Gastroenterol. Apr 28, 2008; 14(16): 2511-2516
Published online Apr 28, 2008. doi: 10.3748/wjg.14.2511
Anti-inflammatory activity of probiotic Bifidobacterium: Enhancement of IL-10 production in peripheral blood mononuclear cells from ulcerative colitis patients and inhibition of IL-8 secretion in HT-29 cells
Akemi Imaoka, Tatsuichiro Shima, Kimitoshi Kato, Shigeaki Mizuno, Toshiki Uehara, Satoshi Matsumoto, Hiromi Setoyama, Taeko Hara, Yoshinori Umesaki
Akemi Imaoka, Tatsuichiro Shima, Satoshi Matsumoto, Hiromi Setoyama, Taeko Hara, Yoshinori Umesaki, Yakult Central Institute for Microbiological Research, Yaho, Kunitachi, Tokyo 1868650, Japan
Kimitoshi Kato, Shigeaki Mizuno, Toshiki Uehara, Department of Gastroenterology and Hepatology, Nihon University School of Medicine, Tokyo 1738610, Japan
Author contributions: Imaoka A, Kato K and Umesaki Y designed the research; Imaoka A, Shima T, Kato K, Mizuno S, Uehara T, Matsumoto S, Setoyama H and Hara T performed the research; Imaoka A, Kato K and Umesaki Y wrote the paper.
Correspondence to: Akemi Imaoka, Yakult Central Institute for Microbiological Research, 1796 Yaho, Kunitachi, Tokyo 1868650, Japan. akemi-imaoka@yakult.co.jp
Telephone: +81-42-5778960
Fax: +81-42-577-3020
Received: September 20, 2007
Revised: March 11, 2008
Published online: April 28, 2008
Abstract

AIM: To determine the anti-inflammatory activity of probiotic Bifidobacteria in Bifidobacteria-fermented milk (BFM) which is effective against active ulcerative colitis (UC) and exacerbations of UC, and to explore the immunoregulatory mechanisms.

METHODS: Peripheral blood mononuclear cells (PBMNC) from UC patients or HT-29 cells were co-cultured with heat-killed probiotic bacteria or culture supernatant of Bifidobacterium breve strain Yakult (BbrY) or Bifidobacterium bifidum strain Yakult (BbiY) to estimate the amount of IL-10 or IL-8 secreted.

RESULTS: Both strains of probiotic Bifidobacteria contained in the BFM induced IL-10 production in PBMNC from UC patients, though BbrY was more effective than BbiY. Conditioned medium (CM) and DNA of both strains inhibited IL-8 secretion in HT-29 cells stimulated with TNF-α, whereas no such effect was observed with heat-killed bacteria. The inhibitory effect of CM derived from BbiY was greater than that of CM derived from BbrY. DNAs of the two strains had a comparable inhibitory activity against the secretion of IL-8. CM of BbiY induced a repression of IL-8 gene expression with a higher expression of IκB-ζ mRNA 4 h after culture of HT-29 cells compared to that in the absence of CM.

CONCLUSION: Probiotic Bifidobacterium strains in BFM enhance IL-10 production in PBMNC and inhibit IL-8 secretion in intestinal epithelial cells, suggesting that BFM has anti-inflammatory effects against ulcerative colitis.

Keywords: Bifidobacterium; Ulcerative colitis; Anti-inflammatory; Interleukin-10; Interleukin-8