Invitro characterization of the impact of selected dietary fibers on fecal microbiota composition and short chain fatty acid production

The effects of six dietary fibers [pectin, guar gum, inulin, arabinoxylan, β-glucan, and resistant starch] on the human fecal microbiota during invitro fermentation were determined. Bifidobacterium increased almost 25% on pectin compared with the control; a significant increase in Bifidobacterium adolescentis type-2 was observed on resistant starch. Bacteroides exhibited a positive correlation with propionate/short chain fatty acid (SCFA) production (r=0.59, p<0.01), while Ruminococcaceae and Faecalibacterium displayed positive correlations with butyrate/SCFA production (r=0.39, 0.54, p<0.01). A negative correlation was detected between inulin utilization and Subdoligranulum (r=-0.73, p≤0.01), while strong positive relationships were found between β-glucan utilization and Firmicutes (r=0.73, p≤0.01) and resistant starch utilization and Blautia wexlerae (r=0.82, p<0.01). Dietary fibers have specific and unique impacts on intestinal microbiota composition and metabolism. These findings provide a rationale for the development of functional ingredients targeted towards a targeted modulation of the gut microbiota.