Open AccessEffect of short-chain carbohydrates on human intestinal bifidobacteria and Escherichia coli in vitro
Author(s) -
Richard Sharp,
Susan Fishbain,
G.T. Macfarlane
Publication year - 2001
Publication title -
journal of medical microbiology/journal of medical microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.91
H-Index - 117
eISSN - 1473-5644
pISSN - 0022-2615
DOI - 10.1099/0022-1317-50-2-152
Subject(s) - biology , fructose , bifidobacterium , fermentation , microbiology and biotechnology , actinomycetaceae , bifidobacterium longum , escherichia coli , ribosomal rna , bacteria , 16s ribosomal rna , food science , lactobacillus , biochemistry , genetics , gene
Plate counts and small subunit (SSU) rRNA abundance were used to study the effects of fructo-oligosaccharides (FOS), fructose, or galacto-oligosaccharides (GOS) on bifidobacterial populations in human faecal microbiotas. The bacteria were grown in pH-controlled anaerobic fermentation vessels. Untreated cultures and fructose-amended fermenters were used as controls. Bifidobacterium longum, B. adolescentis and B. angulatum comprised the dominant bifidobacterial populations throughout the experiment. No major differences were found in the four treatments, in terms of viable counts of the organisms or of total populations of bifidobacteria at any time point. However, large differences were observed with respect to the abundance of bifidobacterial SSU rRNA between the treatments. Greatest bifidobacterial SSU rRNA abundance was seen in FOS cultures, with the lowest in the untreated control fermentation. GOS and fructose also increased bifidobacterial SSU rRNA. Cultures supplemented with FOS and GOS were also associated with lower colony counts and SSU rRNA abundance for Escherichia coli, compared with fructose-supplemented and control fermenters. At the 24-h time point, the untreated control contained 19.8 microg of enterobacterial SSU rRNA/ml of culture fluid, compared with 11.4 microg/ml for the fructose fermentation, and 2.6 and 0.5 microg/ml for the FOS and GOS culture vessels, respectively.