Maltodextrin as a Supplement for Constipation
Maltodextrin has no therapeutic benefit for constipation and serves only as an inert placebo in clinical trials. 1
Evidence from Clinical Trials
The highest quality evidence comes from the 2023 American Gastroenterological Association-American College of Gastroenterology clinical practice guideline, which explicitly used maltodextrin as the placebo control when studying inulin for constipation treatment. 1 This designation as placebo material definitively establishes that maltodextrin lacks active therapeutic properties for bowel function.
Key Study Details
- In a Brazilian RCT of 60 women with chronic constipation, participants received either 15 g/day of inulin (active treatment) or 15 g/day of maltodextrin as placebo, divided into three 5g sachets daily. 1
- The study design explicitly positioned maltodextrin as the inactive comparator, confirming it has no expected benefit for constipation. 1
Contrast with Digestion-Resistant Maltodextrin
Important distinction: Standard maltodextrin differs fundamentally from digestion-resistant maltodextrin (RMD), which does have documented benefits. 2, 3
Digestion-Resistant Maltodextrin Benefits
- RMD significantly reduced colonic transit time by 13.3 hours compared to baseline (p < 0.01) in a 2016 randomized controlled trial. 3
- Stool volume increased 56% from baseline with RMD supplementation (p < 0.01), while placebo showed no change. 3
- Stool consistency improved significantly only in the RMD group (p < 0.01). 3
- A 2008 study using 20g daily of soluble fiber (inulin plus digestion-resistant maltodextrin) showed significant improvements in straining (p < 0.001), incomplete evacuation sensation (p < 0.001), and obstruction sensation (p < 0.001). 2
Why the Difference Matters
- Standard maltodextrin is fully digestible and absorbed in the small intestine, providing no bulk or osmotic effect in the colon. 1
- Digestion-resistant maltodextrin (RMD/Fibersol-2) is a modified soluble fiber that resists digestion and reaches the colon intact, where it exerts beneficial effects on transit time and stool characteristics. 2, 3
Clinical Recommendation
Do not recommend standard maltodextrin for constipation management. 1 If considering a maltodextrin product, verify it is specifically digestion-resistant maltodextrin (RMD) at doses of 20-24 g/day. 2, 3
Preferred First-Line Alternatives
- Psyllium is the only fiber supplement with consistent effectiveness and should be the first-line fiber choice, taken with 8-10 ounces of fluid. 1, 4, 5
- Polyethylene glycol (PEG) 17g daily receives the strongest recommendation with moderate-quality evidence, increasing complete spontaneous bowel movements by 2.9 per week. 1, 4, 6
- Magnesium oxide improved stool frequency by 3.72 bowel movements per week (p = 0.002) and consistency by 1.14 Bristol points (p = 0.0007), though it must be avoided in renal insufficiency. 7, 6
Common Pitfall
Patients and clinicians may confuse standard maltodextrin with digestion-resistant maltodextrin due to similar naming. Always verify the product label specifies "digestion-resistant" or "resistant maltodextrin" (Fibersol-2) before recommending for constipation. 2, 3