Substituting whole grains for refined grains in a 6-wk randomized trial has a modest effect on gut microbiota and immune and inflammatory markers of healthy adults.

Observational studies suggest an inverse association between whole-grain (WG) consumption and inflammation. However, evidence from interventional studies is limited, and few studies have included measurements of cell-mediated immunity. We assessed the effects of diets rich in WGs compared with refined grains (RGs) on immune and inflammatory responses, gut microbiota, and microbial products in healthy adults while maintaining subject body weights.

Estimation and interpretation of fermentation in the gut: coupling results from a 24 h batch in vitro system with fecal measurements from a human intervention feeding study using fructo-oligosaccharides, inulin, gum acacia, and pea fiber.

Gut bacteria ferment fiber at different rates to primarily short chain fatty acids (SCFA) and gas while proteins are metabolized to SCFA, branched chain fatty acids (BCFA), gas, and undesirable metabolites. Large volumes of gas produced in vivo may contribute to bloating and flatulence in an individual. The objectives of this trial were to (1) compare the in vitro fermentation profiles of fructo-oligosaccharides (FOS), inulin, gum acacia, and pea fiber alone or blended using a 24 h batch model and (2) relate these findings to a human study that fed enteral formula fortified with fiber blend (FB) or no fiber (FF).

Healthy subjects experience bowel changes on enteral diets: addition of a fiber blend attenuates stool weight and gut bacteria decreases without changes in gas.

Background: Tube-fed patients frequently suffer from abnormal bowel function that affects intestinal bacteria and quality of life. Dietary fiber affects laxation and can be fermented by gut bacteria to metabolites that influence gut health and fecal moisture. The aim of this study was to compare the effects of a fiber-blend fortified enteral formula (FB, 15 g/L), a fiber-free formula (FF), and habitual diet on bowel function, fecal bacteria, and quality of life.