ハッコウニュウ ガ マウス フンベンチュウ ノ ハツガン カンレン コウソ カッセイ ニ オヨボス エイキョウ

腸管内の有害微生物によって生成される糞便中のアゾレダクターゼ及びニトロレダクターゼは,発癌前駆物質を発癌物質に変換する作用がある.発酵乳の投与がマウス糞便中のこれらの酵素活性に及ぼす影響について調査した.発酵乳は,Lactobacillus gasseri JCM 1130とLactobacillus amylovorus JCM 5811をスターター菌株として1%低脂肪乳に加えて製造した.これら2つの酵素活性はマウスに高蛋白・高脂肪食を与えることにより高くなったが,発酵乳を投与することで非投与群と比較し,有意に低下した.さらに,マウス糞便中の乳酸菌数は,発酵乳の経口投与により増加し,経口投与終了後でも数日間維持された.これら糞便中に供試乳酸菌株が含まれることをRandom amplified polymorphic DNA fingerprinting(RAPD)法によって確認した.The fecal enzymes originating from the injurious bacteria in the intestinal tract, azoreductase and nitroreductase, convert pro-carcinogens to proximal carcinogens. The effect of fermented milk on the activity of fecal enzymes in mice was studied. The fermented milk was prepared using 1% low-fat milk with the starter of Lactobacillus gasseri JCM 1130 and Lactobacillus amylovorus JCM 5811. Mice were fed with diets containing high contents of protein and fat. When administered fermented milk as Lactobacillus strains supplement, the mice exhibited significantly lower levels of azoreductase and nitroreductase activities in the feces as compared with the levels of their activities in the feces of nontreated mice. The number of viable lactic acid bacteria increased in the mice feces for 5 days after the administration of fermented milk, and the same species of lactic acid bacteria from fermented milk was detected in their feces by using random amplified polymorphic DNA (RAPD) method