How maltitol is broken down and used by the body in men
What it found
In healthy men, most maltitol passed through the gut to be fermented by gut bacteria rather than digested like regular sugar.
The usable energy from maltitol was much lower than from sugars like sucrose.
What they found
Studies in people
Gut bacteria do the work
Most of the maltitol reached the large intestine where gut bacteria fermented it. Only a small part was broken down by digestive enzymes in the small intestine.
Carbon dioxide in breath
About 56% of the tagged maltitol left the body as carbon dioxide in the breath over 48 hours. The biggest release happened around 3 hours after taking it.
Hydrogen gas rises fast
Breath hydrogen rose clearly 1 hour after the men took 30 g of maltitol and peaked at 3.5 hours. Taking 30 g of regular sugar did not raise breath hydrogen at all.
Very little leaves in waste
Only about 14.3% of the tagged maltitol came out in stool and 2.6% in urine over 48 hours. A tiny 0.2% left the body as methane gas in the breath.
Blood sugar stayed steady
Blood sugar levels did not change significantly in the 3 hours after the men took maltitol. Radioactive material in the blood peaked around 90 minutes.
Lower energy than sugar
The authors say that because gut bacteria ferment most of the maltitol, the usable energy it gives the body is much lower than from sugars like sucrose.
What the authors conclude
- They conclude that most maltitol escapes digestion in the small intestine and is instead fermented by gut bacteria in the large intestine.
- They advise that the usable energy from maltitol is much lower than the energy from regular sugars like sucrose.
How it was done
Maltitol tastes almost as sweet as sugar but is thought to be harder for the body to digest. Scientists wanted to track exactly how the body handles it and how much energy it provides.
Six healthy men took a single dose of maltitol tagged with a tiny amount of radioactive carbon so scientists could follow it. Their breath, urine, stool and blood were collected for 48 hours. Another 15 healthy men took 30 g of maltitol or regular sugar while their breath hydrogen was measured for 10 hours.
What it can’t tell you
- This study only included healthy men, so the results might differ for women, children or people with health conditions.
- It tracked a single dose over 48 hours, so it cannot show what happens when someone eats maltitol every day.
Who paid
- Authors work at
- University of Tokyo, Japan
The paper
- Title
- Metabolic fate of ingested [14C]-maltitol in man
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Oku T, Akiba M, Lee MH, Moon SJ, Hosoya N (1991). Metabolic fate of ingested [14C]-maltitol in man. Journal of nutritional science and vitaminology. doi:10.3177/jnsv.37.529Free full textPubMed 1802977DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error