Search

International audience; The gut barrier plays an important role in human health. When barrier function is impaired, altered permeability and barrier dysfunction can occur, leading to inflammatory bowel diseases, irritable bowel syndrome or obesity. Several bacteria, including pathogens and commensals, have been found to directly or indirectly modulate intestinal barrier function. The use of probiotic strains could be an important landmark in the management of gut dysfunction with a clear impact on the general population. Previously, we found that Lactobacillus rhamnosus CNCM 1-3690 can protect intestinal barrier functions in mice inflammation model. Here, we investigated its mechanism of action. Our results show that CNCM 1-3690 can (i) physically maintain modulated goblet cells and the mucus layer and (ii) counteract changes in local and systemic lymphocytes. Furthermore, mice colonic transcriptome analysis revealed that CNCM 1-3690 enhances the expression of genes related to healthy gut permeability: motility and absorption, cell proliferation; and protective functions by inhibiting endogenous proteases. Finally, Spa FED pili are clearly important effectors since an L. rhamnosus Delta spaF mutant failed to provide the same benefits as the wild type strain. Taken together, our data suggest that CNCM 1-3690 restores impaired intestinal barrier functions via anti-inflammatory and cytoprotective responses.

AGA Abstracts Mo1949; International audience

Ce numéro est constitué d’articles issus du colloque « Alimentation périnatale, alimentation des séniors: spécificités, impact du microbiote », organisé le 28 mars 2018 à Paris.; Age-related degeneration gives rise to a number of pathologies, many of which are associated withchanges in the composition of the microbiota (dysbiosis) and disruption of the immune systemassociated with the intestine. The typical dysbiosis in the elderly is characterized by the reduction of thenumber of beneficial species and generally by a low microbial biodiversity. Aging is also characterizedby an increase in the concentration of inflammatory markers in the bloodstream, a phenomenon called"inflammaging" and the decrease in immunity, commonly known as immunosenescence. This low-gradechronic inflammation and immunosenescence is likely to be detrimental to the normal functioning ofmany peripheral tissues.Due to its fundamental role in human health, the intestine is considered as a target organ to improve thequality of life of seniors. In this context, even though the link between the intestinal microbiota and theaging process is only partially understood so far, the intestinal ecosystem is a promising target fornutritional strategies that may contribute to improving the health condition of the elderly.; La dégénérescence liée à l'âge donne lieu à un certain nombre de pathologies, dont beaucoup sontassociées à des modifications de la composition du microbiote (dysbiose) et à un dérèglement dusystème immunitaire intestinal. La dysbiose typique chez les personnes âgées se caractérise par laréduction du nombre d'espèces bénéfiques et par une faible diversité microbienne. Le vieillissement estaussi caractérisé par une augmentation de la concentration de marqueurs inflammatoires dans lacirculation sanguine, un phénomène appelé inflammaging, et par la diminution de l´immunité,communément appelé immunosénescence. Cette inflammation chronique de bas grade couplée àl´immunosénescence est susceptible d'être préjudiciable pour le fonctionnement normal de nombreuxtissus périphériques.De par son rôle fondamental dans la santé humaine, l'intestin est considéré comme un organe ciblepour améliorer la qualité de vie des séniors. Dans ce contexte, même si jusqu'à présent le lien entre lemicrobiote intestinal et le processus de vieillissement n'est que partiellement compris, l'écosystèmeintestinal est une cible prometteuse pour des stratégies nutritionnelles susceptibles de contribuer àaméliorer l'état de santé des personnes âgées

Faecalibacterium prausnitzii is a commensal bacterium, ubiquitous in the gastrointestinal tracts of animals and humans. This species is a functionally important member of the microbiota and studies suggest it has an impact on the physiology and health of the host. F. prausnitzii is the only identified species in the genus Faecalibacterium, but a recent study clustered strains of this species in two different phylogroups. Here, we propose the existence of distinct species in this genus through the use of comparative genomics. Briefly, we performed analyses of 16S rRNA gene phylogeny, phylogenomics, whole genome Multi-Locus Sequence Typing (wgMLST), Average Nucleotide Identity (ANI), gene synteny, and pangenome to better elucidate the phylogenetic relationships among strains of Faecalibacterium. For this, we used 12 newly sequenced, assembled, and curated genomes of F. prausnitzii, which were isolated from feces of healthy volunteers from France and Australia, and combined these with published data from 5 strains downloaded from public databases. The phylogenetic analysis of the 16S rRNA sequences, together with the wgMLST profiles and a phylogenomic tree based on comparisons of genome similarity, all supported the clustering of Faecalibacterium strains in different genospecies. Additionally, the global analysis of gene synteny among all strains showed a highly fragmented profile, whereas the intra-cluster analyses revealed larger and more conserved collinear blocks. Finally, ANI analysis substantiated the presence of three distinct clusters-A, B, and C-composed of five, four, and four strains, respectively. The pangenome analysis of each cluster corroborated the classification of these clusters into three distinct species, each containing less variability than that found within the global pangenome of all strains. Here, we propose that comparison of pangenome subsets and their associated a values may be used as an alternative approach, together with ANI, in the in silico classification of new species. Altogether

Bifidobacterium Animalis SUBSP Lactis CNCM-I2494 Restores Tight Junction Proteins Levels in a Chronic Low-grade Colonic Inflammation Mouse Model. 8. Probiotics, Prebiotics & New Foods for Microbiota and Human Health meeting held

Impact of intestinal dysbiosis on mouse models of colonic hypersensitivity. NeuroGASTRO 2015

Tu1778; International audience

absent

La dégénérescence liée à l'âge donne lieu à un certain nombre de pathologies, dont beaucoup sont associées à des modifications de la composition du microbiote (dysbiose) et à un dérèglement du système immunitaire intestinal. La dysbiose typique chez les personnes âgées se caractérise par la réduction du nombre d'espèces bénéfiques et par une faible diversité microbienne. Le vieillissement est aussi caractérisé par une augmentation de la concentration de marqueurs inflammatoires dans la circulation sanguine, un phénomène appelé inflammaging, et par la diminution de l´immunité, communément appelé immunosénescence. Cette inflammation chronique de bas grade couplée à l´immunosénescence est susceptible d'être préjudiciable pour le fonctionnement normal de nombreux tissus périphériques. De par son rôle fondamental dans la santé humaine, l'intestin est considéré comme un organe cible pour améliorer la qualité de vie des séniors. Dans ce contexte, même si jusqu'à présent le lien entre le microbiote intestinal et le processus de vieillissement n'est que partiellement compris, l'écosystème intestinal est une cible prometteuse pour des stratégies nutritionnelles susceptibles de contribuer à améliorer l'état de santé des personnes âgées, Age-related degeneration gives rise to a number of pathologies, many of which are associated with changes in the composition of the microbiota (dysbiosis) and disruption of the immune system associated with the intestine. The typical dysbiosis in the elderly is characterized by the reduction of the number of beneficial species and generally by a low microbial biodiversity. Aging is also characterized by an increase in the concentration of inflammatory markers in the bloodstream, a phenomenon called "inflammaging" and the decrease in immunity, commonly known as immunosenescence. This low-grade chronic inflammation and immunosenescence is likely to be detrimental to the normal functioning of many peripheral tissues. Due to its fundamental role in human health, the intestine is considered as a target organ to improve the quality of life of seniors. In this context, even though the link between the intestinal microbiota and the aging process is only partially understood so far, the intestinal ecosystem is a promising target for nutritional strategies that may contribute to improving the health condition of the elderly.