Tannic acid-dependent modulation of selected Lactobacillus plantarum traits linked to gastrointestinal survival.

Inés Reverón,Héctor Rodríguez,Alfonso V Carrascosa,Félix López De Felipe,Carmen Ascaso,Alicia Prieto,Rosario Muñoz,José Antonio Curiel,Gema Campos,Blanca De Las Rivas,Ivo G Boneca

doi:10.1371/journal.pone.0066473

Abstract

BackgroundOwing to its antimicrobial properties dietary tannins may alter the functional efficacy of probiotic lactobacilli in the gastrointestinal (GI)-tract influencing their growth, viability and molecular adaptation to the intestinal environment.Methods and FindingsThe effects of tannic acid on Lactobacillus plantarum WCFS1 were studied by in vitro growth monitoring and visualizing the morphological alteration on the cell wall using transmission electron microscopy. Growth upon tannic acid was characterized by dose-dependent reductions of initial viable counts and extended lag phases. Lag phase-cells growing upon 0.5 mM tannic acid were abnormally shaped and experienced disturbance on the cell wall such as roughness, occasional leakage and release of cell debris, but resumed growth later at tannic acid concentrations high as 2.5 mM. To gain insight on how the response to tannic acid influenced the molecular adaptation of L. plantarum to the GI-tract conditions, gene expression of selected biomarkers for GI-survival was assessed by RT-qPCR on cDNA templates synthetized from mRNA samples obtained from cells treated with 0.5 or 2 mM tannic acid. Tannic acid-dependent gene induction was confirmed for selected genes highly expressed in the gut or with confirmed roles in GI-survival. No differential expression was observed for the pbp2A gene, a biomarker negatively related with GI-survival. However PBP2A was not labeled by Bocillin FL, a fluorescent dye-labeled penicillin V derivative, in the presence of tannic acid which suggests for enhanced GI-survival reportedly associated with the inactivation of this function.ConclusionsProbiotic L. plantarum WCFS1 is able to overcome the toxic effects of tannic acid. This dietary constituent modulates molecular traits linked to the adaptation to intestinal environment in ways previously shown to enhance GI-survival.

Highlights

Western populations are currently facing the increased incidence of gut dysbiosis and a loss of gut microbial richness [1] outcome, among other life-style variables, of the consumption of typical western diets high in animal fat, sugars and calorie-dense foods [2]
Probiotic L. plantarum WCFS1 is able to overcome the toxic effects of tannic acid
Given that functional efficacy in the GI-tract of a particular microorganism depends in part on its numerical abundance and viability, in this work we investigated how tannic acid influences the growth and morphology of a gastrointestinal isolate of Lactobacillus plantarum

Summary

Introduction

Western populations are currently facing the increased incidence of gut dysbiosis (an imbalance in the intestinal bacteria leading to disease) and a loss of gut microbial richness [1] outcome, among other life-style variables, of the consumption of typical western diets high in animal fat, sugars and calorie-dense foods [2]. Legumes and leafy vegetables are main sources of tannins which are polyphenols believed to be involved in chronic disease prevention [4]. Owing to their antimicrobial properties [5] tannins may induce transformation changes in our gut microbiota. Supporting this view, a previous report have shown evidence that red wine polyphenols increase Lactobacillus and Bifidobacterium populations in the colon content of rats [6], two bacterial groups inherently resistant to tannins [7] and considered beneficial for the intestinal function [8]. Owing to its antimicrobial properties dietary tannins may alter the functional efficacy of probiotic lactobacilli in the gastrointestinal (GI)-tract influencing their growth, viability and molecular adaptation to the intestinal environment

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Conclusion