an improvement in the proportions of these bacteria when aligned with previous studies. During transit throughout the distal gastrointestinal tract , carbohydrate availability progressively diminishes and fermentation may become increasingly proteolytic (Bach Knudsen et al., 1993). The current study suggests that supplementation of a wheat-based diet with β-glucans delivered a suitable substrate to prolong proliferation of more typically saccharolytic microbial populations in the colon.