Ecological Role of Lactobacilli in the Gastrointestinal Tract: Implications for Fundamental and Biomedical Research

Analysis of bacterial community shifts in the gastrointestinal tract of pigs fed diets supplemented with β-glucan from Laminaria digitata, Laminaria hyperborea and Saccharomyces cerevisiae

“…Most lactobacilli present in the GIT of pigs are autochthonous, as they form stable populations throughout the life of the animal host. Unlike the human stomach, which is lined with a glandular mucosa, the stomachs of pigs are lined with non-glandular, squamous stratified epithelium and form a layer of bacterial cells (Walter, 2008). These regions are densely colonised by lactobacilli, which adhere directly to the epithelium and form a layer of bacterial cells (Fuller and Brooker, 1974).…”

Functional Characterization of a Mucus-Specific LPXTG Surface Adhesin from Probiotic Lactobacillus rhamnosus GG

“…In addition, there are those strains, called allochthonous, that persist only briefly in the intestine, many of these being probiotics (1,9,13) and understood to stimulate health-benefiting immune responses in host intestinal cells (for a review, see reference 14) or cause competitive displacement of invading pathogens (for a review, see reference 35). Thus far, the precise molecular mechanisms that differentiate the colonization ability between autochthonous and allochthonous intestinal lactobacilli remain undefined (42), although they are likely to be partly dependent on a diverse range of cell surface adhesion molecule-mediated interactions with the host intestinal mucosa. With that being said, there are a growing number of reports in the literature that indicate that lactobacillar adherence to the intestinal mucosal layer is mediated by surface proteins with a mucus-binding capacity (15,21,22,25,30,32,33,41).…”

“…However, with the discovery that Lactobacillus rhamnosus GG is a piliated strain (21) and that an intestinal mucus-binding capacity is associated with the corresponding pili (called SpaCBA) (21,41), new light has been shed on the putative role of piliation as a novel surface-localized feature in mediating intestinal colonization by probiotic lactobacilli. As a typical probiotic, L. rhamnosus GG adopts the characteristic colonization behavior associated with allochthonous bacteria (42) and so persists only transiently in the GI tract (1). However, compared to the genetically similar but non-SpaCBApiliated L. rhamnosus LC705 strain, piliation might offer a possible explanation for the heightened ability of L. rhamnosus GG to adhere to intestinal mucosal surfaces (39) and to occupy its intestinal niche with greater duration (21).…”

Pseudoscardovia radai sp. nov., a representative of the family Bifidobacteriaceae isolated from the digestive tract of a wild pig (Sus scrofa scrofa)

“…Isolation and characterization of representatives of novel bacterial taxa within these specific ecological niches is inter alia important from the viewpoint of usage of their potentially beneficial properties in humans and economically important animals (Walter, 2008;Trebichavsky et al, 2009;Rossi et al, 2011). The most studied groups of bacteria by the scientific community with the potential for positive effects on host health are the bifidobacteria and lactobacilli (Tejero-Sariñena et al, 2013;Sikorska & Smoragiewicz, 2013;Vlasova et al, 2013).…”