著者

代田 稔 麻生 健治 岩淵 明

出版者

日本細菌学会

雑誌

日本細菌学雑誌 (ISSN:00214930)

巻号頁・発行日

vol.21, no.5, pp.274-283, 1966

被引用文献数

1 14

---

50ml of fermented milk, containing 1 to 2&times;10⁸/ml of live Lactobacillus acidophilus strain Shirota (LAS) and 180ml of market milk were orally administration daily to healthy infants (2-6 years) for 35 days, and its effect on the constitution of microflora in feces was investigated, using appropriate selective media.<br>In control group, normal microflora in one gram of feces was found to consitute of 10⁸-10¹⁰ of Bifidobacterium classified to three physiological type, 10⁶-10⁹ of enterobacteria group in which E. coli was predominant, 10³-10⁵ of lactobacillus group consisting of 60% of L. acidophilus and other lactobacilli (L. plantarum, L. casei and heterofermentives), 10⁴-10⁷ of enterococci, and 10-10⁴ yeasts.<br>During the first 7 days of adminstration, lactobacillus in feces increased to 10⁶-10⁸/gram and this level persisted during the whole administration period. This lactobacillus was serologically identified to be LAS. In contrast, enterobacterial group and enterococci decreased by a facter of 1/100 and 1/50, respectively. When administration was stopped, LAS decreased gradually and one to two weeks after became undetectable, while the suppressed groups recovered to original level. Concomitant with this change, the pH of the feces rised from 5.0-7.5 to original value, 6.7-8.7. Other members in feces were not siginificantly affected through the period of experiment.<br>These results led to the conclusion that LAS survives in human intestinal tract though it does not establish permanent residence, and alter the consititution of microflora, being especically antagonistic against E. coli and enterococci. The antagonistic activity of LAS is discussed.