Specificity of Polysaccharide Use in Intestinal Bacteroides Species Determines Diet-Induced Microbiota Alterations

Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA.
Cell (Impact Factor: 32.24). 06/2010; 141(7):1241-52. DOI: 10.1016/j.cell.2010.05.005
Source: PubMed


The intestinal microbiota impacts many facets of human health and is associated with human diseases. Diet impacts microbiota composition, yet mechanisms that link dietary changes to microbiota alterations remain ill-defined. Here we elucidate the basis of Bacteroides proliferation in response to fructans, a class of fructose-based dietary polysaccharides. Structural and genetic analysis disclosed a fructose-binding, hybrid two-component signaling sensor that controls the fructan utilization locus in Bacteroides thetaiotaomicron. Gene content of this locus differs among Bacteroides species and dictates the specificity and breadth of utilizable fructans. BT1760, an extracellular beta2-6 endo-fructanase, distinguishes B. thetaiotaomicron genetically and functionally, and enables the use of the beta2-6-linked fructan levan. The genetic and functional differences between Bacteroides species are predictive of in vivo competitiveness in the presence of dietary fructans. Gene sequences that distinguish species' metabolic capacity serve as potential biomarkers in microbiomic datasets to enable rational manipulation of the microbiota via diet.

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    • "Therefore, we next tested the potential of levan- 540 coated Co 3 O 4 NPs to dissolve in the growth medium and serve as a Co source for gut bacteria 541 using B. thetaiotaomicron. According to recent data, this bacterium which is abundant in the 542 human gut, can utilize levan as a sole carbon source using an extracellular endolevanase for 543 levan depolymerization (Adamberg et al., 2014; Sonnenburg et al., 2010). It was previously 544 shown that B. thetaiotaomicron, though possessing Co-containing vitamin B 12 -dependent 545 enzymes, is auxotrophic for this vitamin and encodes multiple B 12 transporters to internalize it 546 from environment (Degnan, Barry, Mok, Taga, & Goodman, 2014). "
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