Fig. 2. Individual and mean (±SE) percentage differences in fecal butyrate concentrations for fine versus medium particle size and fine versus low-fiber control treatments on the metabolic study (n=21). Fine wheat bran increased mean fecal butyrate concentrations by 34±13% (p=0.013) compared with the low-fiber control and 33±13% (p=0.023) compared with medium particle size wheat bran.