High molecular weight genomic DNA was isolated from TMC0356 and 14 reference strains of L. gasseri, including the type strain. The DNA samples were digested with the selected rare-cutting restriction endonucleases SmaI, SacII and ApaI and the resulting fragments separated by pulsed-field gel electrophoresis (PFGE) in a size range between 20 to 290 kb. TMC0356 check details could be distinguished from the other L. gasseri strains on the basis of the SmaI and SacII macrorestriction patterns. Furthermore, L. gasseri strains isolated from the feces of subjects
who had ingested TMC0356 were identical to TMC0356 in the SmaI, SacII and ApaI macrorestriction fragments of digested DNA. These results suggest that PFGE of genomic DNA digested with SmaI, SacII, could be a practical means of identification of TMC0356. Furthermore, these
results indicate that ingested TMC0356 can survive in, and colonize, the human intestine. Lactobacillus gasseri is one of the primary members of the genus Lactobacillus, the most important group of lactic acid bacteria (1, 2). Among the 50 well-known species of lactobacilli, L. gasseri appears to be one of the principal Lactobacillus species that inhabit the human gastrointestinal tract and have developed a deep symbiotic relationship with humans. L. gasseri is widely used as a probiotic and is believed to be IBET762 beneficial for humans by ameliorating intestinal disorders (3), Ureohydrolase producing bacteriocins (4), enhancing and regulating immune responses (5), and lowering serum cholesterol (6). However, the health-promoting effects of L. gasseri have been found to be strain dependent. Because emerging scientific evidence has indicated that each probiotic, even within
the same taxonomic species, displays individual characteristic effects in host animals, strain-specific evaluation of the potent health-promoting effects of probiotics is very important in both academic and industrial contexts (5, 7). Lactobacillus gasseri TMC0356, a new probiotic strain, was originally isolated from the intestine of a healthy adult. Identification of this bacterium was based on phenotypic and genotypic characteristics, such as carbohydrate fermentation profiles, 16S-rDNA sequences, and DNA hybridization patterns. Cell line studies have also shown that TMC0356 induces production of pro-inflammatory (IL-12) and anti-inflammatory (IL-10) cytokines by macrophages (7). TMC0356 also suppresses the increase in serum IgE concentration that occurs in mice and humans with perennial allergic rhinitis (8, 9). In our previous studies, oral administration of L. rhamonsus GG and TMC0356 significantly inhibited an increase in ovalbumin-stimulated nasal vascular permeability in rats and antigen-induced nasal blockage in guinea pigs with allergic rhinitis (10, 11).