Bifidobacterium breve with \u03b1-linolenic acid alters the composition, distribution and transcription factor activity associated with metabolism and absorption of fat

Elaine Patterson,R Paul Ross,Sara Lisai,Sebastiano Banni,Gerald F Fitzgerald,Timothy G Dinan,Eamonn M Quigley,John F Cryan,Rebecca Wall,Fergus Shanahan,Catherine Stanton

doi:10.1038/srep43300

Abstract

This study focused on the mechanisms that fatty acid conjugating strains - Bifidobacterium breve NCIMB 702258 and Bifidobacterium breve DPC 6330 - influence lipid metabolism when ingested with α-linolenic acid (ALA) enriched diet. Four groups of BALB/c mice received ALA enriched diet (3% (w/w)) either alone or in combination with B. breve NCIMB 702258 or B. breve DPC 6330 (109 CFU/day) or unsupplemented control diet for six weeks. The overall n-3 PUFA score was increased in all groups receiving the ALA enriched diet. Hepatic peroxisomal beta oxidation increased following supplementation of the ALA enriched diet with B. breve (P < 0.05) and so the ability of the strains to produce c9t11 conjugated linoleic acid (CLA) was identified in adipose tissue. Furthermore, a strain specific effect of B. breve NCIMB 702258 was found on the endocannabinoid system (ECS). Liver triglycerides (TAG) were reduced following ALA supplementation, compared with unsupplemented controls (P < 0.01) while intervention with B. breve further reduced liver TAG (P < 0.01), compared with the ALA enriched control. These data indicate that the interactions of the gut microbiota with fatty acid metabolism directly affect host health by modulating n-3 PUFA score and the ECS.

Highlights

This study investigated the impact of dietary ALA enrichment with or without fatty acid conjugating B. breve supplementation on fat composition/distribution and the mechanisms through which commensal gut microbes alter lipid metabolism
We reported that dietary supplementation with linoleic acid and B. breve NCIMB 702258 significantly increased bioactive c9t11CLA concentrations in the liver of mice[16], while dietary supplementation with B. breve NCIMB 702258 together with ALA increased tissue n-3 LC-PUFA in mice, compared with those that did not receive the strain[17]
ALA is a poor precursor for n-3 LC-PUFA, DHA, first due to the efficiency for ALA to undergo beta-oxidation in the mitochondria[40], rendering this fatty acid less available for desaturation and elongation and second because biosynthesis of DHA requires a crucial step in the peroxisome for partial beta-oxidation[40]

Summary

Introduction

Dietary supplementation with B. breve NCIMB 702258 and B. breve DPC 6330 positively influenced tissue fatty acid profiles in different animal species and models, while influencing host intestinal microbiota composition[16,17,18,19]. These data suggest that dietary supplementation with a commensal bacterium can significantly influence health through the production of bioactive conjugated fatty acids and by increasing tissue concentrations of bioactive long-chain (LC) members of the n-3 PUFA family (eicosapentaenoic acid (EPA; C20:5), docosapentaenoic acid (C22:5) and docosahexaenoic acid (DHA; C22:6). Flaxseed has emerged as an important functional food ingredient, as it is one of the richest sources of ALA (1 tablespoon of flaxseed oil contains ~8 g ALA)[43]

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