SummaryThe effects of galactooligosaccharides intake on fecal mic

The effects of lactose intake on the human faecal microflora and on the faecal organic acids were investigated in 24 Japanese male volunteers who took 15 g of the test sugar daily for 6 d. Twenty-two of the 24 subjects (92 per cent) were classified as lactose maldigestors by the hydrogen breath test. The numbers of total faecal bacteria, and specifically of bacteroides and Clostridium perfringens decreased while the numbers of lactobacilli, enterococci, Candida spp. and staphylococci increased after lactose consumption. The ingestion of lactose did not markedly alter faecal short chain fatty acids but increased the concentration of formic acid and valeric acid. These results suggest that in subjects with verified lactose maldigestion, part of the lactose passes into the colon, inducing changes in the colonic microflora composition.

SummaryThe effects of transgalactosylated disaccharide (TD) intake on human fecal microflora and their metabolism were investigated in 12 Japanese males. TD is a mixture of sugars, galactosyl galactose, and galactosyl glucose, synthesized from lactose through the transgalactosyla tion reaction of Streptococcus thermophilus /3-galactosidase. Volunteers took 15 g of the test sugar daily for 6 days. The TD ingestion increased the number of bifidobacteria and lactobacilli, but decreased the number of Bacteroidaceae and Candida spp. in the feces. The ratio of bifidobacteria to total bacteria increased from 0.28 to 0.51. TD decreased the fecal concentrations of propionic acid, isobutyric acid, isovaleric acid, and valeric acid. This sugar also lowered the fecal pH, and the concentrations of fecal ammonia, p-cresol, and indole. Moreover, a positive correlation was found between the concentration of ammonia, and that of branched chain fatty acids (isobutyric acid and isovaleric acid), p-cresol, and indole. All of these compounds are produced from amino acids through deamination by the intestinal bacteria. The depression of amino acid fermentation by intestinal bacteria may be involved in the reduction of fecal ammonia. These results suggest that a part of the trans galactosylated disaccharides passes into the colon, inducing changes in the colonic microflora composition, hastening carbohydrate fermentation, and depressing amino acid fementation in the human gut.

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SUMMARY Clostridium perfringens was isolated from bile in 13 cases of 150 patients examined. The serotypes of Cperfringens strains isolated from bile and faeces were investigated using antisera to Hobbs' type 1-17. Two or more serological types were often found in a single specimen, but in the same patient the serotypes of Cperfringens strains isolated from the bile were identical with those from the faeces.Beta-glucuronidase production in these C perfringens serotypes was tested with the API-Strep system. Strains agglutinated with Hobbs' antisera produced ,&glucuronidase, but non-agglutinated strains did not.