Editors' ChoiceImmunology

Protecting the Guts

Sci. Signal.  06 Aug 2013:
Vol. 6, Issue 287, pp. ec185
DOI: 10.1126/scisignal.2004584

Regulatory T cells (Tregs) in the gut are important sentinels in maintaining the peace between our gut and its trillions of resident bacteria and are regulated by specific strains of bacteria in mouse models. Smith et al. (see the Perspective by Bollrath and Powrie ) asked whether metabolite(s) generated by resident bacterial species may regulate Tregs in the gut. Indeed, short-chain fatty acids (SCFAs), bacterial fermentation products of dietary fibers produced by a range of bacteria, restored colonic Treg numbers in mice devoid of a gut microbiota and increased Treg numbers in colonized mice. The effects of SCFAs on Tregs were mediated through GPCR43, a receptor for SCFAs, which is expressed on colonic Tregs. Mice fed SCFAs were protected against experimentally induced colitis in a manner that was dependent on GPCR43-expressing Tregs.

P. M. Smith, M. R. Howitt, N. Panikov, M. Michaud, C. A. Gallini, M. Bohlooly-Y, J. N. Glickman, W. S. Garrett, The microbial metabolites, short-chain fatty acids, regulate colonic Treg cell homeostasis. Science 341, 569–573 (2013). [Abstract] [Full Text]

J. Bollrath, F. Powrie, Feed your Tregs more fiber. Science 341, 463–464 (2013). [Abstract] [Full Text]