Effect of bran, ispaghula, and inert plastic particles on gastric emptying and small bowel transit in humans: the role of physical factors.
Level 2 - randomized trial
Individual randomized controlled comparative trial
PubMed 9071936 · doi:10.1136/gut.40.2.223
What was done
Thirteen healthy volunteers underwent gamma-scintigraphy over 10 hours following a 99mTc-labelled rice pudding test meal to assess gastric emptying and colonic arrival. The study evaluated the effects of 15 g coarse bran, 15 g inert plastic particles, and 7 g ispaghula against control values. Small bowel transit was calculated as the difference between 50% gastric emptying time and 50% colonic arrival time.
What was found
Compared to a baseline gastric emptying time of 88 (SEM 6) minutes, coarse bran significantly delayed gastric emptying by 22 (SEM 8) minutes (p < 0.05), whereas ispaghula and plastic particles had no significant effect. For small bowel transit (control: 322 [SEM 29] minutes), transit was accelerated, decreasing by 95 (29) minutes with bran and by 62 (22) minutes with inert plastic particles. Ispaghula had no significant effect on small bowel transit.
Why it matters
This study demonstrates that physical particle presence, independent of chemical fermentation or viscosity, accelerates small bowel transit, offering insight into the mechanical mechanisms behind dietary fiber actions in the gut.
Limits
The study evaluated a very small sample (13 healthy volunteers) under single-meal acute testing conditions, precluding assessment of clinical populations (such as patients with functional bowel disorders) or long-term physiological adaptation.
Cited by
- contradicts Complete digestion and absorption of ingested food calories takes approximately 30 hours from the time food is eaten.