Gastrointestinal microbial community shifts observed following oral administration of a Lactobacillus fermentum strain to mice

Abstract

The indigenous gastrointestinal microbiota acts as an integral defense against the colonisation of orally introduced microbes. Whilst this can be important in host protection, some introduced species, including lactobacilli, can have a positive impact on existing microbial communities. The interaction of a candidate probiotic strain of Lactobacillus fermentum within the gastrointestinal tract was monitored in a mouse model and its effect on the indigenous microbiota observed. L. fermentum KLD was administered via oro-gastric doses to mice with both a specific pathogen-free (SPF) and an ampicillin-depleted gut microbiota, containing no detectable lactobacilli. Its persistence was monitored by detection in faecal homogenates using culturing methods and polymerase chain reaction with L. fermentum specific primers. Microbial population shifts were observed using denaturing gradient gel electrophoresis (DGGE). L. fermentum KLD was detected within the gastrointestinal tract of SPF mice for up to 36 h, and for greater than 11 days in the ampicillin-treated mice. The administration resulted in substantial changes within the host Lactobacillus levels, determined by DGGE of 16S rDNA from faecal samples. Denaturing gradient profiles, from faecal samples collected at a range of pre-and post-dose intervals of groups of 10 SPF mice, indicated that several other constituents of the gastrointestinal community also fluctuated following dosing. These included Bifidobacterium and Eubacterium, which increased following KLD administration. The indigenous microbiota affected the persistence of L. fermentum KLD and in SPF mice the administration of this strain induced significant shifts in the indigenous microbial community. ß 2002 Published by Elsevier Science B.V. on behalf of the Federation of European Microbiological Societies.

Safety and intestinal microbiota modulation by the exopolysaccharide-producing strains Bifidobacterium animalis IPLA R1 and Bifidobacterium longum IPLA E44 orally administered to Wistar rats

“…Some previous studies have also demonstrated that feeding rats with probiotics, prebiotics or synbiotics promoted increases of bifidobacteria population at different locations in the rat GIT (Lesniewska et al, 2006;Montesi et al, 2005;Vasquez et al, 2009). Similar results have been also found in other rodent models (Kumar et al, 2008;Plant et al, 2003). Total bifidobacteria counts obtained in our study by using qPCR were in the same order of that reported for rat faecal samples by other authors (Delroisse et al, 2008).…”

Diversity and dynamics of bacterial species in a biofilm at the end of the Seoul water distribution system

“…Owing to its sequence variability, the V3 region of the 16S rRNA gene might give sufficient information and might permit the discrimination of bands with a single run of a wide denaturant gradient. Hence, until recently, this short sequence has been used to assess the biodiversity of environmental samples by DGGE (Kurisu et al 2002;Plant et al 2003). For this reason, it was also used in this study.…”

Temporal stability analysis of the microbiota in human feces by denaturing gradient gel electrophoresis using universal and group-specific 16S rRNA gene primers

“…These organisms may belong to at least 400 different bacterial species, although it is thought that 99% of the total community consists of only 30–40 species [1]. The microbial activity of this community has an important metabolic and protective function in the GI‐tract and thus plays a major role in the nutrition and health of the host [2,3]. The genera that are considered to be predominant in the large bowel include Bacteroides , Eubacterium , Clostridium , Ruminococcus , Bifidobacterium and Fusobacterium [4].…”