The metabolic profile of Bifidobacterium dentium reflects its status as a human gut commensal

• Published in: BMC microbiology 2021-05, Vol.21 (1), p.154-154, Article 154
• Main Authors: Engevik, Melinda A, Danhof, Heather A, Hall, Anne, Engevik, Kristen A, Horvath, Thomas D, Haidacher, Sigmund J, Hoch, Kathleen M, Endres, Bradley T, Bajaj, Meghna, Garey, Kevin W, Britton, Robert A, Spinler, Jennifer K, Haag, Anthony M, Versalovic, James
• Format: Article
• Language: English
• Subjects: Acid resistance; Acid stress; Acids; Acids - metabolism; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Bifidobacteria; Bifidobacterium; Bifidobacterium - genetics; Bifidobacterium - growth & development; Bifidobacterium - metabolism; Carbohydrates; Colonization; Commensalism; Diet; Gastrointestinal Microbiome; Gastrointestinal mucosa; Gastrointestinal system; Gastrointestinal tract; Gastrointestinal Tract - microbiology; Gastrointestinal Tract - physiology; Gene expression; Genome, Bacterial; Genomes; Glucose - metabolism; Glycans; Glycosidases; Glycosyl hydrolase; Health aspects; Host-bacteria relationships; Humans; Hydrolase; Intestine; Metabolic pathways; Metabolism; Microbiota; Microbiota (Symbiotic organisms); Microorganisms; Mucin; Mucus; Nutrient sources; Phenotyping; Physiological aspects; Proteins; Scanning electron microscopy; Symbiosis
• ISSN: 1471-2180; 1471-2180
• DOI: 10.1186/s12866-021-02166-6

Bifidobacteria are commensal microbes of the mammalian gastrointestinal tract. In this study, we aimed to identify the intestinal colonization mechanisms and key metabolic pathways implemented by Bifidobacterium dentium. B. dentium displayed acid resistance, with high viability over a pH range from 4 to 7; findings that correlated to the expression of Na+/H+ antiporters within the B. dentium genome. B. dentium was found to adhere to human MUC2+ mucus and harbor mucin-binding proteins. Using microbial phenotyping microarrays and fully-defined media, we demonstrated that in the absence of glucose, B. dentium could metabolize a variety of nutrient sources. Many of these nutrient sources were plant-based, suggesting that B. dentium can consume dietary substances. In contrast to other bifidobacteria, B. dentium was largely unable to grow on compounds found in human mucus; a finding that was supported by its glycosyl hydrolase (GH) profile. Of the proteins identified in B. dentium by proteomic analysis, a large cohort of proteins were associated with diverse metabolic pathways, indicating metabolic plasticity which supports colonization of the dynamic gastrointestinal environment. Taken together, we conclude that B. dentium is well adapted for commensalism in the gastrointestinal tract.