Abstract
Effect of yogurt (LKM512 yogurt) prepared Bifidobacterium lactis LKM 512, Lactobacillus delbrueckii subsp. bulgaricus LKM 1759 and Streptococcus thermophilus LKM 1742 on fecal microflora in 11 volunteers (six males and five females, average age 76.9 years) given this yogurt 100 g/day for 2 weeks were determined. At week 2 of consumption, the number of bifidobacteria in the fecal microflora increased significantly (p<0.05). Meanwhile, the frequencies of occurrence of peptostreptococci, veillonellae and staphylococci decreased. The isolated bifidobacteria strains were also identified to the species level. While the B. adolescentis group was the dominant flora before yogurt consumption, they decreased in number markedly on week 2 of consumption of LKM512 yogurt. On the other hand, B. lactis LKM 512 was isolated from all the subjects on week 2 of consumption and occupied 10% of the total fecal flora, becoming the dominant bifidobacteria species. While B. bifidum tended to decrease, the incidences of B. breve increased. B. lactis LKM 512 was, however undetectable on 2 weeks after cessation of LKM512 yogurt consumption, and the B. adolescentis group regained dominance.