Increasing the diversity of dietary fibers in a daily-consumed bread modifies gut microbiota and metabolic profile in subjects at cardiometabolic risk

Gut Microbes. 2022 Jan-Dec;14(1):2044722. doi: 10.1080/19490976.2022.2044722.


Some cardiometabolic risk factors such as dyslipidemia and insulin resistance are known to be associated with low gut microbiota richness. A link between gut microbiota richness and the diversity of consumed dietary fibers (DF) has also been reported. We introduced a larger diversity of consumed DF by using a daily consumed bread in subjects at cardiometabolic risk and assessed the impacts on the composition and functions of gut microbiota as well as on cardiometabolic profile. Thirty-nine subjects at cardiometabolic risk were included in a double-blind, randomized, cross-over, twice 8-week study, and consumed daily 150 g of standard bread or enriched with a 7-dietary fiber mixture (5.55 g and 16.05 g of fibers, respectively). Before and after intervention, stool samples were collected for gut microbiota analysis from species determination down to gene-level abundance using shotgun metagenomics, and cardiometabolic profile was assessed. Multi-fiber bread consumption significantly decreased Bacteroides vulgatus, whereas it increased Parabacteroides distasonis, Fusicatenibacter saccharivorans, an unclassified Acutalibacteraceae and an unclassified Eisenbergiella (q < 0.1). The fraction of gut microbiota carrying the gene coding for five families/subfamilies of glycoside hydrolases (CAZymes) were also increased and negatively correlated with peaks and total/incremental area under curve (tAUC/iAUC) of postprandial glycemia and insulinemia. Compared to control bread, multi-fiber bread decreased total cholesterol (-0.42 mM; q < 0.01), LDL cholesterol (-0.36 mM; q < 0.01), insulin (-2.77 mIU/l; q < 0.05), and HOMA (-0.78; q < 0.05). In conclusion, increasing the diversity of DF in a daily consumed product modifies gut microbiota composition and function and could be a relevant nutritional tool to improve cardiometabolic profile.

Keywords: Dietary fiber diversity; Eisenbergiella sp.; Parabacteroides distasonis; cardiometabolic profile; glycoside hydrolases; gut microbiota.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bread / analysis
  • Cardiovascular Diseases*
  • Dietary Fiber / analysis
  • Gastrointestinal Microbiome*
  • Humans
  • Metabolome


  • Dietary Fiber

Grants and funding

This study was funded by Bridor and in part by Metagenopolis grant Agence Nationale de la Recherche ANR-11-DPBS-0001. JD acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant agreement ERC-2017-AdG No. 788191 - Homo.symbiosus). We thank all the subjects who participated in this study. We thank Bernard Henrissat who annotated the IGC2 with CAZy.