AUTHOR=D’hoe Kevin , Conterno Lorenza , Fava Francesca , Falony Gwen , Vieira-Silva Sara , Vermeiren Joan , Tuohy Kieran , Raes Jeroen TITLE=Prebiotic Wheat Bran Fractions Induce Specific Microbiota Changes JOURNAL=Frontiers in Microbiology VOLUME=9 YEAR=2018 URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2018.00031 DOI=10.3389/fmicb.2018.00031 ISSN=1664-302X ABSTRACT=

Wheat bran fibers are considered beneficial to human health through their impact on gut microbiota composition and activity. Here, we assessed the prebiotic potential of selected bran fractions by performing a series of fecal slurry anaerobic fermentation experiments using aleurone as well as total, ultrafine, and soluble wheat bran (swb) as carbon sources. By combining amplicon-based community profiling with a fluorescent in situ hybridization (FISH) approach, we found that incubation conditions favor the growth of Proteobacteria such as Escherichia and Bilophila. These effects were countered in all but one [total wheat bran (twb)] fermentation experiments. Growth of Bifidobacterium species was stimulated after fermentation using ultrafine, soluble, and twb, in the latter two as part of a general increase in bacterial load. Both ultrafine and swb fermentation resulted in a trade-off between Bifidobacterium and Bilophila, as previously observed in human dietary supplementation studies looking at the effect of inulin-type fructans on the human gut microbiota. Aleurone selectively stimulated growth of Dorea and butyrate-producing Roseburia. All fermentation experiments induced enhanced gas production; increased butyrate concentrations were only observed following soluble bran incubation. Our results open perspectives for the development of aleurone as a complementary prebiotic selectively targeting colon butyrate producers.