Polydextrose and gut bacteria in a human feeding trial
What it found
In 31 healthy adults, 8 g a day of polydextrose changed the mix of gut bacteria and reduced DNA-damaging activity in stool water.
It also led to less abdominal discomfort and a trend toward softer, more formed stools.
What they found
Studies in people
Gut bacteria changes
Polydextrose increased Ruminococcus intestinalis and bacteria in Clostridium clusters I, II and IV, but decreased the Lactobacillus-Enterococcus group. Bifidobacterium and Bacteroides numbers stayed unchanged.
DNA damage in stool water
Stool water after polydextrose caused significantly less DNA damage to colon cells in lab tests than stool water after the placebo.
Bowel habits
Volunteers recorded less abdominal discomfort while taking polydextrose, and there was a trend toward less hard and more formed stools.
Short-chain fatty acids
No significant changes in faecal short-chain fatty acids, including butyrate, were seen after either treatment.
Immune markers
Total faecal IgA was lower after polydextrose than after placebo, while PGE2 levels did not differ between treatments.
Snacking and appetite
There was a trend for reduced snacking during the polydextrose period, but no other measured aspects of quality of life changed.
What the authors conclude
“This study demonstrated the impact of PDX on the colonic microbiota and showed some potential for reducing the risk factors that may be associated with colon cancer initiation.”
Also in their conclusions
- They conclude that polydextrose impacts the colonic microbiota and shows some potential for reducing risk factors that may be associated with colon cancer initiation.
- They advise that further investigation is required to determine the activities of genes involved in butyrate formation.
How it was done
The authors wanted to identify which groups of gut bacteria are affected when polydextrose is fermented in the colon, since human trials of candidate prebiotics are scarce.
Thirty-one healthy adults aged 18 to 50 took 8 g a day of polydextrose or a placebo (maltodextrin) for 3 weeks each, in a double-blind, randomised, crossover design with a 3-week washout between treatments. Stool samples were collected at five time points and analysed for bacteria, short-chain fatty acids, immune markers and DNA damage.
What it can’t tell you
- This was a 3-week study in healthy adults, so it cannot show what happens over longer periods or in people with health conditions.
- The study measured markers of colon cancer risk, not whether colon cancer actually develops.
Who paid
- Authors work at
- University of Reading, UK
The paper
- Title
- Impact of polydextrose on the faecal microbiota: a double-blind, crossover, placebo-controlled feeding study in healthy human subjects
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Costabile A, Fava F, Röytiö H, et al (2012). Impact of polydextrose on the faecal microbiota: a double-blind, crossover, placebo-controlled feeding study in healthy human subjects. The British journal of nutrition. doi:10.1017/S0007114511005782Free full textPubMed 22099384DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error