Polydextrose and gut transit in constipated adults
What it found
In 128 adults with chronic constipation, taking 8 g or 12 g of polydextrose daily for up to 4 weeks did not shorten gut transit time or improve stool frequency or consistency.
Some rectal and stool symptom scores improved with the 8 g dose after 4 weeks.
What they found
Studies in people
Gut transit time
After 2 weeks, neither dose of polydextrose shortened whole gut transit time compared to placebo. The 12 g dose showed a tendency to lengthen transit, mainly in the left colon.
Stool frequency and consistency
There were no improvements in stool frequency or consistency with either dose after 2 or 4 weeks. One sensitivity analysis found a small increase in spontaneous bowel movements with the 8 g dose.
Rectal and stool symptoms
The 8 g dose improved rectal symptom scores at 2 and 4 weeks, and stool symptom scores at 4 weeks, compared to placebo. The 12 g dose did not show these improvements.
Quality of life
Improvements in quality of life satisfaction scores with the 8 g dose after 4 weeks did not reach statistical significance.
Tolerance and adverse events
No changes in product tolerance were seen in any group, and no link was found between treatment group and adverse events.
What the authors conclude
“Consumption of 8 g/day or 12 g/day polydextrose for 2 weeks did not improve measures of intestinal transit, stool frequency or stool consistency.”
Also in their conclusions
- They conclude that 8 g or 12 g of polydextrose daily for 2 weeks did not improve measures of intestinal transit, stool frequency, or stool consistency in chronically constipated adults.
- They suggest that future studies should use longer term intervention (4 weeks or longer) and focus on rectal and stool-related symptoms as well as quality of life satisfaction.
How it was done
Guidelines recommend increasing fiber intake for constipation, but the evidence for specific fibers like polydextrose needs strengthening. Most studies of polydextrose have been in healthy people, not those with constipation.
They randomly assigned 128 adults with chronic constipation to 8 g or 12 g of polydextrose daily, or a placebo, for 4 weeks. Gut transit time was measured after 2 weeks using X-rays and markers, and symptoms were tracked with questionnaires.
What it can’t tell you
- This trial lasted only 4 weeks, so it cannot show what happens with longer term use.
- Most participants were women, so the results may not apply to men.
- The study cannot show whether polydextrose would help people with different types of constipation or other doses.
Who paid
- Conflicts
- Author disclosures: P.I.D., N.E., P.M., T.N., M.B., R.C. and G.B. are/were employees of Nestec SA and participated in the design of the study, the analyses and interpretation of data, the writing of the manuscript and in the decision to publish the results. S.M.S. has previously received funding from Nestec SA. K.W. has, in the last three years, received researching funding from agencies including National Institute of Health Research, Medical Research Council, charities including Crohn’s and Colitis UK, Kenneth Rainin Foundation, ForCrohns and industrial companies including Almond Board of California, California Dried Plum Board, Clasado Biosciences, Nestlé, and has received speaker honoraria and consulting fees from Danone and Nestlé. N.J.deW. has previously received funding from The Netherlands organization for Health Research and Development (ZonMW), KWF Dutch Cancer Society (KWF), Zilveren Kruis Health Insurance Company, Danone research. C.F.E.-W., T.W. and D.E.G. declare no conflicts of interest.
- Authors work at
- Nestlé Research Center, Switzerland; Julius Center for Health Sciences and Primary Care, The Netherlands; King's College London, UK
The paper
- Title
- Short-Term Daily Intake of Polydextrose Fiber Does Not Shorten Intestinal Transit Time in Constipated Adults: A Randomized Controlled Trial
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Duncan PI, Enters-Weijnen CF, Emami N, et al (2018). Short-Term Daily Intake of Polydextrose Fiber Does Not Shorten Intestinal Transit Time in Constipated Adults: A Randomized Controlled Trial. Nutrients. doi:10.3390/nu10070920Free full textPubMed 30029461DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error