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Background: Wholegrain rye has been associated with decreased hunger sensations. This may be partly mediated by colonic fermentation. Sustained consumption of fermentable components is known to change the gut microflora and may increase numbers of saccharolytic bacteria. Objective: To investigate the effect of wholegrain rye consumption on appetite and colonic fermentation after a subsequent meal. Methods: In a randomized, controlled, three-arm cross-over study, twelve healthy male subjects consumed three iso-caloric evening test meals. The test meals were based on white wheat bread (WBB), wholegrain rye kernel bread (RKB), or boiled rye kernels (RK). Breath hydrogen excretion and subjective appetite sensation were measured before and at 30 min intervals for 3 h after a standardized breakfast in the subsequent morning. After the 3 h, an ad libitum lunch meal was served to assess energy intake. In an in vitro study, RKB and RK were subjected to digestion and 24 h-fermentation in order to study SCFA production and growth of selected saccharolytic bacteria. Results: The test meals did not differ in their effect on parameters of subjective appetite sensation the following day. Ad libitum energy intake at lunch was, however, reduced by 11% (P < 0.01) after RKB and 7% (P < 0.05) after RK compared with after WWB evening meal. Breath hydrogen excretion was significantly increased following RKB and RK evening meals compared with WWB (P < 0.01 and P < 0.05, respectively). Overall, RKB and RK were readily fermented in vitro and exhibited similar fermentation profiles, although total SCFA production was higher for RK compared with RKB (P < 0.001). In vitro fermentation of RKB and RK both increased the relative quantities of Bifidobacterium and decreased Bacteroides compared with inoculum (P < 0.001). The C. coccoides group was reduced after RKB (P < 0.001). Conclusion: Consumption of wholegrain rye products reduced subsequent ad libitum energy intake in young healthy men, possibly mediated by mechanisms related to colonic fermentation. [ABSTRACT FROM AUTHOR]

Abstract: We conducted two single-blinded randomized crossover acute studies with 24 and 20 subjects, respectively, to compare (I) Control vs. Flax drink; and (II) Flax drink vs. Flax tablets. The subjects were exposed to one of the treatments after an overnight fast, and rated appetite sensation for 120min using visual analog scales (VAS). Hereafter they consumed an ad libitum early lunch to assess energy intake. The treatments were iso-caloric and iso-volumeric: Control: 300mL drink; Flax drink: Control drink with addition flax fiber extract (2.5g of soluble fibers); and Flax tablet: Control drink with flax fiber tablets (2.5g of soluble fibers). Flax drink increased sensation of satiety and fullness compared to Control and a significant decrease in subsequent energy intake was observed after the Flax drink compared to Control (2937 vs. 3214kJ). Appetite ratings were similar for Flax tablets and Flax drink as they did not differ by more than 1–4%. Subsequent energy intake was similar after the two treatments (3370 vs. 3379kJ). A small dose of flaxseed fiber significantly suppresses appetite and energy intake. Furthermore, flaxseed fibers administered as drinks or tablets produce similar responses. [Copyright &y& Elsevier]