Lactobacillus‐ and bifidobacterium‐mediated antigenotoxicity in the colon of rats

作者：Beatrice Louise Pool-Zobel, Christian Neudecker, I. Domizlaff, Seung‐Taek Ji, Ulrich Schillinger, Corinne J. Rumney, Massimo Moretti, I. Vilarini, R. Scassellati‐Sforzolini, I.R. Rowland · 发表于：Nutrition and Cancer · 年份：1996 · DOI：10.1080/01635589609514492 · 被引用次数：257 · 研究领域：Probiotics and Fermented Foods、Genomics, phytochemicals, and oxidative stress、Gut microbiota and health

Lactic acid bacteria (LAB) are proposed to have several beneficial effects, including the inactivation of carcinogens. We have studied the potential of Lactobacillus acidophilus (from a commercially available yogurt), Lactobacillus gasseri (P79), Lactobacillus confusus (DSM20196), Streptococcus thermophilus (NCIM 50083), Bifidobacterium breve and Bifidobacterium longum (from human infant stool) to prevent the induction of DNA damage by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG, 7.5 mg/kg body wt) in colon cells of the rat. Using the new technique of single cell microgel electrophoresis, all investigated strains were antigenotoxic toward MNNG after a single dose of 10(10) viable cells/kg body wt p.o. eight hours before the carcinogen. One-half and one-tenth of this initial dose resulted in a loss of protective activity. High doses of heat-treated L. acidophilus strains were also not antigenotoxic. One mechanism of the preventive effect could be that bacterial metabolites or components are responsible. Accordingly, selected examples were investigated in vitro in colon cells of the rat. Metabolically active L. acidophilus cells, as well as an acetone extract of the culture, prevented MNNG-induced DNA damage. Different cell fractions from L. acidophilus (cytoplasm, cell wall skeleton, cell wall) were devoid of antigenotoxic activity, whereas the peptidoglycan fraction and whole freeze-dried cells were antigenotoxic. As a second carcinogen, 1,2-dimethylhydrazine (DMH) was used. A...