Activation of gastrointestinal ileal brake response with dietary slowly digestible carbohydrates, with no observed effect on subjective appetite, in an acute randomized, double-blind, crossover trial

PURPOSE

To test the hypothesis that oral ingestion of slowly digestible carbohydrates (SDCs) that reach the ileum triggers the ileal brake as indicated by delayed gastric emptying, reduced glycemic response, and decreased subjective appetite.

METHODS

The study was a five-arm, randomized, double-blind, crossover trial with a 1-week washout period between treatments (n = 20; 9 females, 11 males). Five treatments consisted of three SDC ingredients [raw corn starch, isomaltooligosaccharide (IMO), sucromalt], and an IMO/sucromalt combination, shown in vitro to have slow and extended digestion profiles, and a rapidly digestible carbohydrate control (maltodextrin). Carbohydrates (26 g) were incorporated into yogurt [300 g total; carbohydrate (~ 77 g), fat (~ 0.2 g), and protein (~ 9 g)] with closely matched energy content (346 kcal) and viscosity (~ 30,000 cP). Outcomes were measured in a 4 h postprandial period.

RESULTS

Mean gastric half-emptying times were moderately though significantly increased for the raw corn starch and IMO treatments (P < 0.05), but they could be sub-divided into larger effect responder (n = 11) and non-responder groups (n = 9). Longer time for glycemic response to return to baseline was associated with increased gastric half-emptying time in an exploratory subset of data removing gastric half-emptying times > 3.5 h (P = 0.02). No significant differences in appetite ratings were observed.

CONCLUSION

SDCs caused slower gastric emptying rate through activation of the ileal brake, as closely matched semi-solid yogurts were used and only rate of carbohydrate digestion differed. Extending glycemic response through consumption of SDCs was associated with triggering the ileal brake.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03630445, August 2018, retrospectively registered.