Polydextrose, inulin and grain fiber compared for gut and metabolic effects
What it found
In the large intestine, polydextrose acts much like natural grain fiber by feeding gut bacteria and helping bowel movements.
Its effects on blood sugar after meals and fasting cholesterol were modest.
What they found
Studies in people and animals
Gut bacteria and bowels
In the large intestine, polydextrose and inulin act like grain fiber. All three are broken down by gut bacteria, feed helpful bacteria, and help keep bowels moving.
Blood sugar and cholesterol
Effects on blood sugar after eating and fasting cholesterol levels were modest for polydextrose and inulin. Grain fibers also showed mixed results for these measures.
Other findings
What these fibers are
Grain fiber comes naturally from plants. Inulin is a chain of fructose sugars taken from chicory. Polydextrose is a man-made chain of glucose sugars that the body cannot digest.
What the authors conclude
- They note that polydextrose and inulin share many of the same gut functions as natural grain fiber.
- They say the effects on blood sugar and cholesterol have been modest across all three fiber types.
- They call for new ways to measure how specific fibers link to long-term health benefits.
How it was done
Newer definitions of dietary fiber require isolated or synthetic types to show real health benefits before they can be called fiber. The authors wanted to compare how different fibers actually work in the body.
The authors compared three types of fiber: natural grain fiber, inulin from chicory, and synthetic polydextrose. They looked at how each type behaves in the gut and affects blood markers.
What it can’t tell you
- We summarised it from the abstract only.
- This work compares general properties rather than running a single controlled trial. It cannot prove that one fiber causes better health outcomes than another.
- Scientists do not yet know how these short-term gut effects translate into long-term health benefits.
Who paid
- Authors work at
- University of Eastern Finland, Finland
The paper
- Title
- Dietary fiber type reflects physiological functionality: comparison of grain fiber, inulin, and polydextrose
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Abstract only
- Cite
- Raninen K, Lappi J, Mykkänen H, Poutanen K (2011). Dietary fiber type reflects physiological functionality: comparison of grain fiber, inulin, and polydextrose. Nutrition reviews. doi:10.1111/j.1753-4887.2010.00358.xPubMed 21198631DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error