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.
OBJECTIVE
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-alpha, 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 IkappaB-zeta mRNA 4 h after culture of HT-29 cells compared to that in the absence of CM.


CONCLUSIONS
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.
Imaoka
Akemi
A
Yakult Central Institute for Microbiological Research, 1796 Yaho, Kunitachi, Tokyo 1868650, Japan. akemi-imaoka@yakult.co.jp
Shima
Tatsuichiro
T
Kato
Kimitoshi
K
Mizuno
Shigeaki
S
Uehara
Toshiki
T
Matsumoto
Satoshi
S
Setoyama
Hiromi
H
Hara
Taeko
T
Umesaki
Yoshinori
Y
D001644:Bifidobacterium / Q000502:physiology*; D018929:Cell Culture Techniques; D003093:Colitis, Ulcerative / Q000276:immunology*; D017077:Culture Media, Conditioned; D016207:Cytokines / Q000378:metabolism; D004269:DNA, Bacterial / Q000378:metabolism; D019073:HT29 Cells / Q000502:physiology*; D006801:Humans; D016753:Interleukin-10 / Q000096:biosynthesis*; D016209:Interleukin-8 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000382:microbiology / Q000502:physiology*; D019936:Probiotics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D017077:Culture Media, Conditioned; D016207:Cytokines; D004269:DNA, Bacterial; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10