In vitro fermentation of various pectin substrates by human fecal microbiota

Metabolic activity of the gut microbiota is formation of short chain fatty acids (SCFAs). SCFA contribute to human healthy by serving as an energy source for intestinal epithelial cells and inhibiting pathogenic growth by lowering pH in the intestinal lumen. The aims of this study were to assess the short chain fatty acids production of various pectin samples (High Methoxy Pectin (HMP), Sugar Beet Pectin (SBP), and Soy pectin (SOY)) and to determine the composition of gut microbiota. Fructooligosaccharide (FOS, known prebiotic) was used as a control. Fresh feces were collected from 4 healthy men and incubated anaerobically with various substrates at 37°C. Culture aliquots were taken at 0, 6, 12, 24, and 30 h. SCFAs were measured by GC. FOS resulted in higher butyrate production and decreased the production of acetate compared with other pectin treatments (P<0.05). Compared with other treatments, incubation with SOY showed significantly greater propionate production (P<0.05). Denaturing gradient gel electrophoresis (DGGE) fingerprint analysis showed a distinct profile of fecal microbiota with different samples. The findings indicate that consuming different types of pectin substrates might affect fecal microbiota composition and enhance the production of SCFAs. Funding provided by Arkansas Soybean Promotion Board is greatly appreciated.