Establishment of orally-administered Lactobacillus gasseri SBT2055SR in the gastrointestinal tract of humans and its influence on intestinal microflora and metabolism

Aims: To investigate the fate of a streptomycin-rifampicin-resistant variant of Lactobacillus gasseri SBT2055 (LG2055SR) and the influence of its oral administration on the composition and metabolism of the intestinal microflora. Methods and Results: Intestinal passage of LG2055SR was monitored by a combination of selection with antibiotics and identification by a randomly amplified polymorphic DNA (RAPD)-PCR method. Composition of intestinal microflora was analysed by the method developed by Mitsuoka et al. (1965, 1974). Establishment of orally-administered LG2055SR in the human intestine was confirmed in this study. LG2055SR ingestion specifically lowered faecal populations of Staphylococcus and faecal contents of p-cresol. Conclusions: LG2055SR and its parent strain, LG2055, are considered to be appropriate candidates for probiotics. Significance and Impact of the Study: It is clarified that LG2055SR has the ability to establish in the human gastrointestinal tract and alters the composition and metabolism of the intestinal microflora and physical characteristics of faeces.