Galacto-oligosaccharides stimulate the growth of bifidobacteria but fail to attenuate inflammation in experimental colitis in rats.
BACKGROUND
Galacto-oligosaccharides potentially attenuate colonic inflammation by two mechanisms: through beneficial effects on intestinal microflora and by increasing the colonic short-chain fatty acid concentration. The purpose of this study was to investigate the effects of galacto-oligosaccharides on the development of inflammation and on the growth of bifidobacteria in trinitrobenzene sulphonic acid (TNBS)-induced colitis, a model that has been shown to benefit from short-chain fatty acid administration and to be associated with alterations in the colonic microflora.


METHODS
Rats were given daily either whey-derived or lactose-derived galacto-oligosaccharides (4 g kg(-1) day(-1), p.o.); starting 10 days before colitis induction, or dexamethasone (2 mg kg(-1) day(-1), s.c., a positive control), starting at colitis induction. Colon wet weight, macroscopic damage and myeloperoxidase activity were assessed 72 h after the induction of colitis. Faecal bifidobacteria were counted at the beginning of the study, and immediately before and 72 h after colitis induction.


RESULTS
Galacto-oligosaccharides increased the colonic levels of bifidobacteria but also the levels of other bacterial species. Neither whey-derived nor lactose-derived galacto-oligosaccharides reduced the severity of inflammation.


CONCLUSIONS
Galacto-oligosaccharides are able to modify gut microflora in severe TNBS-induced colitis, but unable to attenuate the inflammation.
Holma
R
R
Institute of Biomedicine, Pharmacology, Biomedicum Helsinki, University of Helsinki, Finland.
Juvonen
P
P
Asmawi
M Z
MZ
Vapaatalo
H
H
Korpela
R
R
D000818:Animals; D001644:Bifidobacterium / Q000502:physiology*; D001835:Body Weight; D003092:Colitis / Q000139:chemically induced / Q000382:microbiology* / Q000517:prevention & control; D003106:Colon / Q000187:drug effects / Q000382:microbiology*; D015169:Colony Count, Microbial; D003907:Dexamethasone / Q000008:administration & dosage; D005685:Galactans / Q000008:administration & dosage*; D005938:Glucocorticoids / Q000008:administration & dosage; D007413:Intestinal Mucosa / Q000187:drug effects / Q000382:microbiology*; D008297:Male; D023421:Models, Animal; D009844:Oligosaccharides / Q000008:administration & dosage*; D051381:Rats; D014302:Trinitrobenzenesulfonic Acid / Q000633:toxicity
D005685:Galactans; D005938:Glucocorticoids; D009844:Oligosaccharides; D003907:Dexamethasone; D014302:Trinitrobenzenesulfonic Acid