Reduction of colitis by prebiotics in HLA-B27 transgenic rats is associated with microflora changes and immunomodulation.
HLA-B27 transgenic rats develop spontaneous colitis under specific pathogen-free conditions (SPF) but germ-free rats remain disease-free, emphasizing a role for intestinal bacteria in the pathogenesis of chronic intestinal inflammation. Prebiotics are dietary substances that affect the host by stimulating growth and/or activity of potentially health promoting bacteria. The aims of this study were to investigate whether prebiotics can prevent colitis in SPF HLA-B27 rats, and secondly, to explore mechanisms of protection. SPF HLA-B27 transgenic rats received orally the prebiotic combination long-chain inulin and oligofructose (Synergy 1), or not, prior to the development of clinically detectable colitis. After seven weeks, cecal and colonic tissues were collected for gross cecal scores (GCS), histologic inflammatory scores (scale 0-4), and mucosal cytokine measurement. Cecal and colonic contents were collected for analysis of the gut microbiota by PCR-denaturing gradient gel electrophoresis (PCR-DGGE) and fluorescent in-situ hybridization (FISH), and analysis of short-chain fatty acid composition. Prebiotic treatment significantly decreased GCS and inflammatory histologic scores in the cecum and colon. Prebiotic treatment also decreased cecal IL-1beta, but increased cecal TGF-beta concentrations. Inulin/oligofructose altered the cecal and colonic PCR-DGGE profiles, and FISH analysis showed significant increases in cecal Lactobacillus and Bifidobacterium populations after prebiotic treatment compared with water-treated rats. In conclusion, the prebiotic combination Synergy 1 reduced colitis in HLA-B27 transgenic rats, which effect was associated with alterations to the gut microbiota, decreased tissue proinflammatory cytokines and increased immunomodulatory molecules. These results show promise for prebiotics as primary or adjuvant maintenance therapy for chronic inflammatory bowel diseases.
Hoentjen
Frank
F
Center for Gastrointestinal Biology and Disease, University of North Carolina, Chapel Hill, North Carolina, USA.
Welling
Gjalt W
GW
Harmsen
Hermie J M
HJ
Zhang
Xiaoyin
X
Snart
Jennifer
J
Tannock
Gerald W
GW
Lien
Kelvin
K
Churchill
Thomas A
TA
Lupicki
Maryla
M
Dieleman
Levinus A
LA
D000818:Animals; D030801:Animals, Genetically Modified; D002432:Cecum / Q000382:microbiology; D003092:Colitis / Q000382:microbiology* / Q000517:prevention & control*; D003106:Colon / Q000382:microbiology; D016207:Cytokines; D004269:DNA, Bacterial / Q000032:analysis; D015180:Electrophoresis, Gel, Two-Dimensional; D015796:HLA-B27 Antigen / Q000235:genetics*; D017404:In Situ Hybridization, Fluorescence; D007249:Inflammation; D016133:Polymerase Chain Reaction; D019936:Probiotics / Q000494:pharmacology*; D051381:Rats; D011916:Rats, Inbred F344; D013047:Specific Pathogen-Free Organisms
D016207:Cytokines; D004269:DNA, Bacterial; D015796:HLA-B27 Antigen