Behavior of Lactobacilli Isolated from Fermented Slurry (ben-saalga) in Gnotobiotic Rats

Abstract

Most bacterial strains, which have been studied so far for their probiotic functions, are extensively used by manufacturers in developed countries. In our work, we sought to study a mix (called BSL) comprising three strains belonging to Lactobacillus fermentum, L. paraplantarum and L. salivarius, that were isolated from a traditional African pearl millet based fermented slurry. Our objective was to study this BSL cocktail in gnotobiotic rats, to evaluate their survival and their behavior in the digestive tract conditions. After a single oral inoculation of germfree rats with BSL, the species established stably in the digestive tract with the following hierarchy of abundance: L. salivarius> L. plantarum> L. fermentum. BSL cocktail was metabolically active since it produced 50 mM lactate and it expressed genes involved in binding mechanism in the caecum. Furthermore, the global morphology of the colon epithelium was not disturbed by the BSL cocktail. BSL cocktail did not modify mucus content and host mucus-related genes (MUC1, MUC2, MUC3 or resistin-like molecule β). The cocktail of lactobacilli enhanced the proliferating cell nuclear antigen (PCNA) at a level comparable to what was observed in conventional rats. PCNA was involved in proliferation and DNA repair, but the presence of the cocktail did not provoke proliferative events (with Ki67 as indicator), so we suppose BSL may help gut preservation. This work is the first step towards the selection of strains that are derived from traditional fermented food to formulate new probiotic mixture.

Characterization of Mucus-Related Properties of Streptococcus thermophilus: From Adhesion to Induction

“…This is consistent with the stimulation of cell-cycle arrest proteins and the anti-proliferative effect described for lactate in vivo and in vitro ( Rul et al, 2011 ; Matsuki et al, 2013 ). However, we have previously reported that lactate accumulation produced by a mixture of three lactobacilli has no effect on mucus production in gnotobiotic rodents ( Turpin et al, 2013 ). Thus, it is likely that the induction of the mucus pathway requires lactate and additional factors brought by S. thermophilus during its transit through the gut.…”

“…But, it has been recently shown that a key factor involved in in vitro adhesion of the Lactococcus lactis IBB477 strain did not confer a selective advantage in the intestinal tract of conventional mice ( Radziwill-Bienkowska et al, 2017 ). The ability of lactic-acid bacteria to colonize the gut in animal models harboring a simplified microbiota is not determined by their ability to bind mucus ( Turpin et al, 2013 ). The assumption that high adhesion confers a selective advantage in the gut and provides health benefits is thus not implicit.…”

Bacteroides thetaiotaomicron and Faecalibacterium prausnitziiinfluence the production of mucus glycans and the development of goblet cells in the colonic epithelium of a gnotobiotic model rodent

“…When B. thetaiotaomicron is associated with Eubacterium rectale , a representative of the C. coccoides group, both bacteria adapt their own metabolism to the presence of the other [6]. Thus, bacteria in the GIT presumably adapt to the host, and also to other bacteria [40]. In this study, we observed that in mono-associated rats, B. thetaiotaomicron induces goblet cell differentiation leading to an increase in mucin gene expression and goblet cell number, and a parallel decrease in chromogranine produced by enteroendocrine cell.…”

AggLb Is the Largest Cell-Aggregation Factor from Lactobacillus paracasei Subsp. paracasei BGNJ1-64, Functions in Collagen Adhesion, and Pathogen Exclusion In Vitro

“…It was found that aggregation ability is a rare phenotype among lactobacilli (1–2%). Bearing in mind the complexity of the mechanisms and components involved in cell aggregation and adherence, the species specificity, environmental dependence, and contribution to multiple probiotic functional roles [ 11 , 15 , 16 , 17 , 21 , 41 ], we decided to analyze the aggregation-promoting factor specific for Lb . paracasei and its role in collagen binding and pathogen exclusion.…”