Probiotic microorganisms may benefit the host by influencing diverse physiological processes, whose nature and underlying mechanisms are still largely unexplored. Animal models are a unique tool to understand the complexity of the interactions between probiotic microorganisms, the intestinal microbiota, and the host. In this regard, in this pilot study, we compared the effects of 5-day administration of three different probiotic bacterial strains (Bifidobacterium bifidum MIMBb23sg, Lactobacillus helveticus MIMLh5, and Lacticaseibacillus paracasei DG) on three distinct murine intestinal sites (ileum, cecum, and colon). All probiotics preferentially colonized the cecum and colon. In addition, probiotics reduced in the ileum and increased in the cecum and colon the relative abundance of numerous bacterial taxonomic units. MIMBb23sg and DG increased the inducible nitric oxide synthase (iNOS) in the ileum, which is involved in epithelial homeostasis. In addition, MIMBb23sg upregulated cytokine IL-10 in the ileum and downregulated the cyclooxygenase COX-2 in the colon, suggesting an anti-inflammatory/regulatory activity. MIMBb23sg significantly affected the expression of the main gene involved in serotonin synthesis (TPH1) and the gene coding for the serotonin reuptake protein (SERT) in the ileum and colon, suggesting a potential propulsive effect toward the distal part of the gut, whereas the impact of MIMLh5 and DG on serotonergic genes suggested an effect toward motility control. The three probiotics decreased the expression of the permeability marker zonulin in gut distal sites. This preliminary in vivo study demonstrated the safety of the tested probiotic strains and their common ability to modulate the intestinal microbiota. The probiotics affected host gene expression in a strain-specific manner. Notably, the observed effects in the gut were site dependent. This study provides a rationale for investigating the effects of probiotics on the serotonergic system, which is a topic still widely unexplored.

Probiotics Modulate Mouse Gut Microbiota and Influence Intestinal Immune and Serotonergic Gene Expression in a Site-Specific Fashion / V. Taverniti, V.T. Cesari, G. Gargari, U. Rossi, C. Biddau, C. Lecchi, W. Fiore, S. Arioli, I. Toschi, S.D. Guglielmetti. - In: FRONTIERS IN MICROBIOLOGY. - ISSN 1664-302X. - 12(2021 Sep 01), pp. 706135.1-706135.12. [10.3389/fmicb.2021.706135]

Probiotics Modulate Mouse Gut Microbiota and Influence Intestinal Immune and Serotonergic Gene Expression in a Site-Specific Fashion

V. Taverniti
Primo
;
V.T. Cesari
Secondo
;
G. Gargari;C. Lecchi;S. Arioli;I. Toschi
Penultimo
;
S.D. Guglielmetti
Ultimo
2021-09-01

Abstract

Probiotic microorganisms may benefit the host by influencing diverse physiological processes, whose nature and underlying mechanisms are still largely unexplored. Animal models are a unique tool to understand the complexity of the interactions between probiotic microorganisms, the intestinal microbiota, and the host. In this regard, in this pilot study, we compared the effects of 5-day administration of three different probiotic bacterial strains (Bifidobacterium bifidum MIMBb23sg, Lactobacillus helveticus MIMLh5, and Lacticaseibacillus paracasei DG) on three distinct murine intestinal sites (ileum, cecum, and colon). All probiotics preferentially colonized the cecum and colon. In addition, probiotics reduced in the ileum and increased in the cecum and colon the relative abundance of numerous bacterial taxonomic units. MIMBb23sg and DG increased the inducible nitric oxide synthase (iNOS) in the ileum, which is involved in epithelial homeostasis. In addition, MIMBb23sg upregulated cytokine IL-10 in the ileum and downregulated the cyclooxygenase COX-2 in the colon, suggesting an anti-inflammatory/regulatory activity. MIMBb23sg significantly affected the expression of the main gene involved in serotonin synthesis (TPH1) and the gene coding for the serotonin reuptake protein (SERT) in the ileum and colon, suggesting a potential propulsive effect toward the distal part of the gut, whereas the impact of MIMLh5 and DG on serotonergic genes suggested an effect toward motility control. The three probiotics decreased the expression of the permeability marker zonulin in gut distal sites. This preliminary in vivo study demonstrated the safety of the tested probiotic strains and their common ability to modulate the intestinal microbiota. The probiotics affected host gene expression in a strain-specific manner. Notably, the observed effects in the gut were site dependent. This study provides a rationale for investigating the effects of probiotics on the serotonergic system, which is a topic still widely unexplored.
S24-7, in vivo, SERT, tryptophan hydroxylase, IL-10, zonulin, bifidobacteria;
Settore AGR/16 - Microbiologia Agraria
Settore BIO/19 - Microbiologia Generale
PSR2015-1716MPORR_M - PIANO DI SOSTEGNO ALLA RICERCA 2015-2017 - LINEA 2 "DOTAZIONE ANNUALE PER ATTIVITA' ISTITUZIONALE" - PORRINI, MARISA - PSR2015-17 - Piano di sviluppo di ricerca 2015-17 - 2016
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2434/904036
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