B vitamin acquisition by gut commensal bacteria

About the Authors: Emily E. Putnam Affiliation: Department of Microbial Pathogenesis and Microbial Sciences Institute, Yale University School of Medicine, New Haven, Connecticut, United States of America ORCID logo http://orcid.org/0000-0002-3428-094X Andrew L. Goodman * E-mail: andrew.goodman@yale.edu Affiliation: Department of Microbial Pathogenesis and Microbial Sciences Institute, Yale University School of Medicine, New Haven, Connecticut, United States of America ORCID logo http://orcid.org/0000-0001-7599-3471 Citation: Putnam EE, Goodman AL (2020) B vitamin acquisition by gut commensal bacteria. Given the wide range of strategies that bacteria encode for synthesis and transport of thiamine and the recent discovery of OMthi as a novel outer-membrane transporter of thiamine in a gut commensal, it is clear there is still much to learn about acquisition of this essential nutrient by microbes in the gut environment. Since vitamin B12 is a minority of the total cobamides present in the gut, variations of the transport machinery might be involved in acquisition of different types of cobamides or precursors [13, 14]. Because humans absorb vitamin B12 predominantly in the small intestine and B. thetaiotaomicron and other gut commensals are found predominantly in the large intestine, vitamin B12 piracy from intrinsic factor by microbes is unlikely to impact vitamin B12 availability for the host in most cases.