Detection of Lactobacillus, Pediococcus, Leuconostoc, and Weissella species in human feces by using group-specific PCR primers and denaturing gradient gel electrophoresis

Denaturing gradient gel electrophoresis (DGGE) of DNA fragments generated b y PCR with 16S ribosomal DNA-targeted group-specific primers was used to de tect lactic acid bacteria (LAB) of the genera Lactobacillus, Pediococcus, L euconostoc, and Weissella in human feces, Analysis of fecal samples of four subjects revealed individual profiles of DNA fragments originating not onl y from species that have been described as intestinal inhabitants but also from characteristically food-associated bacteria such as Lactobacillus sake i, Lactobacillus curvatus, Leuconostoc mesenteroides, and Pediococcus pento saceus, Comparison of PCR-DGGE results with those of bacteriological cultur e showed that the food-associated species could not be cultured from the fe cal samples by plating on Rogosa agar, On the other hand, all of the LAB sp ecies cultured from feces were detected in the DGGE profile. We also detect ed changes in the types of LAB present in human feces during consumption of a milk product containing the probiotic strain Lactobacillus rhamnosus DR2 0, The analysis of fecal samples from two subjects taken before, during, an d after administration of the probiotic revealed that L. rhamnosus was dete ctable by PCR-DGGE during the test period in the feces of both subjects, wh ereas it was detectable by culture in only one of the subjects.