Two-month consumption of bread enriched with a fiber mix: impact on gut microbiota and cardiometabolic profile in at cardiometabolic-risk subjects

• Published in: Proceedings of the Nutrition Society Vol. 79; no. OCE2
• Main Authors: Ranaivo, Harimalala, Guilly, Susie, Sothier, Monique, Van Den Berghe, Laurie, Lambert-Porcheron, Stéphanie, Dussous, Isabelle, Roger, Loïc, Béra-Maillet, Christel, Roume, Hugo, Galleron, Nathalie, Pons, Nicolas, Le Chatelier, Emmanuelle, Ehrlich, Dusko, Laville, Martine, Doré, Joël, Nazare, Julie-Anne
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 2020
• Subjects: Adipose tissue; adiposity; Anthropometry; Bacteroides vulgatus; Bread; breads; Cholesterol; Clostridiales; Composition; Consumption; cross-over studies; Diet; Dietary fiber; Dietary intake; digestive system; Dyslipidemia; Enrichment; Fibers; Food intake; Gene mapping; Genes; glycemic index; High protein diet; hyperlipidemia; Insulin; insulin resistance; Intestinal microflora; intestinal microorganisms; Low density lipoprotein; low density lipoprotein cholesterol; Low protein diet; Mapping; Metagenomics; Microbiota; Microorganisms; Nutrient deficiency; nutritional intervention; Parameter sensitivity; Phenotypes; Relative abundance; Risk analysis; Risk assessment; Risk factors; risk profile; waist circumference
• ISSN: 0029-6651; 1475-2719; 1475-2719
• DOI: 10.1017/S002966512000083X

IntroductionIncreased adiposity, dyslipidemia and insulin resistance are associated with increased risk of developing cardiometabolic diseases (CM). Such deleterious phenotypes have been shown to be associated with a low gene-richness microbiota that can partly be restored by a short-term dietary intervention (energy-restricted high-protein diet, low glycemic index, enrichment with fibers) in parallel to an improvement of CM profile. In this study, we aimed at increasing fiber intake in quantity and diversity through a two-month consumption of bread enriched with a mix of selected fibers and evaluated the impact of this dietary intervention on gut microbiota gene richness and CM risk profile in subjects at risk of developing CM.Materials and methodsIn a randomized double blind cross-over design, thirty-nine subjects with CM risk profile (18–70 years old, BMI: 25–35 kg/m2, waist circumference > 80 cm for women and > 96 cm for men, fiber intake < 20g/day, low fiber diversity) consumed daily for 8 weeks 150 g of standard bread vs. 150 g of bread enriched with a 7-selected fibers mix (5.55 g vs. 16.35 g of fiber respectively; 4-week washout). Gut microbiota and CM risk factors’ analyzes were conducted before and after intervention. Stool samples were analyzed by shotgun metagenomics; microbial genes and metagenomics species (MSP) profiles were generated by mapping reads on a reference genes catalog (1529 MSP).ResultsThe included dyslipidemic subjects with CM risk profile presented a lower microbiota gene richness compared to reference healthy cohorts. The two-month consumption of fiber-rich bread did not alter microbiota gene richness but modified microbiota composition with a significant decrease of Bacteroides vulgatus (q = 1.7e-4) and a significant increase of Parabacteroides distasonis (q = 2.8e-6), Fusicatenibacter saccharivorans (q = 5e-5) and Clostridiales (q = 3.8e-2). We observed in parallel a significant decrease in total cholesterol (- 0.26 mmol/L; - 5%; p = 0.021), LDL-cholesterol (- 0.2 mmol/L; - 6%, p = 0.0061) and an improvement of insulin sensibility estimated by HOMA index (3.23–2.54 mUI/L; - 21%; p = 0.0079).These effects were even significantly more pronounced for subjects presenting the higher waist circumference. Anthropometric parameters were not altered.DiscussionThe enrichment of the diet with a mix of selected fibers for 2 months altered microbiota composition by modifying the relative abundance of specific gut bacterial species, in parallel to a significant improvement of cholesterol and insulin sensitivity parameters. Increasing the quantity and diversity of dietary fiber intake could be used as an efficient tool to favorably impact CM profile.