Insight into the prebiotic concept: lessons from an exploratory, double blind intervention study with inulin-type fructans in obese women

Abstract

ObjectiveTo highlight the contribution of the gut microbiota to the modulation of host metabolism by dietary inulin-type fructans (ITF prebiotics) in obese women.MethodsA double blind, placebo controlled, intervention study was performed with 30 obese women treated with ITF prebiotics (inulin/oligofructose 50/50 mix; n=15) or placebo (maltodextrin; n=15) for 3 months (16 g/day). Blood, faeces and urine sampling, oral glucose tolerance test, homeostasis model assessment and impedancemetry were performed before and after treatment. The gut microbial composition in faeces was analysed by phylogenetic microarray and qPCR analysis of 16S rDNA. Plasma and urine metabolic profiles were analysed by 1H-NMR spectroscopy.ResultsTreatment with ITF prebiotics, but not the placebo, led to an increase in Bifidobacterium and Faecalibacterium prausnitzii; both bacteria negatively correlated with serum lipopolysaccharide levels. ITF prebiotics also decreased Bacteroides intestinalis, Bacteroides vulgatus and Propionibacterium, an effect associated with a slight decrease in fat mass and with plasma lactate and phosphatidylcholine levels. No clear treatment clustering could be detected for gut microbial analysis or plasma and urine metabolomic profile analyses. However, ITF prebiotics led to subtle changes in the gut microbiota that may importantly impact on several key metabolites implicated in obesity and/or diabetes.ConclusionsITF prebiotics selectively changed the gut microbiota composition in obese women, leading to modest changes in host metabolism, as suggested by the correlation between some bacterial species and metabolic endotoxaemia or metabolomic signatures.

Expert consensus document: The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of prebiotics

“…In 2015, Bindels et al 21 proposed that specificity requirements should be removed on the basis of reports showing that multiple taxa, rather than particular species, were enriched by prebiotics 22 . This proposal led to another definition of a prebiotic as "a non digestible compound that, through its metabolization by microorganisms in the gut, modulates the composition and/or activity of the gut microbiota, thus, conferring a beneficial physiological effect on the host" (REF.…”

“…Hence, it is recognized today that prebiotic effects probably extend beyond bifidobacteria and lactobacilli, but to meet the selectivity criterion of a prebiotic, the range of microorganisms affected must be limited. To this end, in two human studies that used high throughput sequencing, bifidobacteria responded to prebiotic use 22,27 . However, other groups such as Faecalibacterium prausnitzii also increased in abundance in one trial 22 and in another study Anaerostipes spp.…”

“…To this end, in two human studies that used high throughput sequencing, bifidobacteria responded to prebiotic use 22,27 . However, other groups such as Faecalibacterium prausnitzii also increased in abundance in one trial 22 and in another study Anaerostipes spp. were additionally elevated, whereas Bilophila spp.…”

L’altération de la perméabilité intestinale : chaînon manquant entre dysbiose et inflammation au cours de l’obésité ?

“…Chez l'homme, les travaux ayant évalué le rôle des probiotiques sur la perméabilité intestinale sont peu nombreux et restent discordants [41]. Récemment, il a été montré que l'adjonction, pendant 3 mois, de prébiotiques, sous forme de fibres alimentaires de type fructans (un polymère de fructose), dans l'alimentation des sujets obèses était associée à des modifications discrètes du microbiote et à une diminution très limitée de la masse grasse [42]. La perméabilité intestinale n'a pas été mesurée dans cette étude mais une diminution significative des LPS sériques a été rapportée.…”

Microbiome: A complicated relationship status

“…Last year, Cani and his colleagues reported that obese women who took a supplement of oligofructose and a similar substance called inulin every day for three months showed a slight decrease in fat mass and a reduction in blood levels of an inflammation-promoting molecule 12 . But the results "were not really equivalent to the ones we observed in mice", Cani says.…”