Galacto-oligosaccharides and fructo-oligosaccharides in the human small intestine
What it found
In seven healthy Dutch adults, most galacto-oligosaccharides with three or more sugar units and fructo-oligosaccharides with two or more units reached the end of the small intestine intact, while most galacto-oligosaccharide dimers were broken down.
The breakdown of these dimers depended on how the sugar units were linked together.
What they found
Studies in people
FOS recovery
About 96% of the fructo-oligosaccharides were recovered in the lower small intestine or start of the large intestine. Their breakdown was negligible.
GOS recovery
About 76% of the galacto-oligosaccharides were recovered, meaning some breakdown happened in the small intestine.
GOS dimers broken down
Most galacto-oligosaccharide dimers were broken down in the small intestine. How much depended on the link between the sugar units.
Linkage matters
Dimers with beta(1 to 1) and beta(1 to 2) plus beta(1 to 3) links had low recovery, at about 23% and 19%. Dimers with beta(1 to 6) and beta(1 to 4) links had higher recovery, at about 44% and 68%.
Larger GOS intact
Galacto-oligosaccharides with three or more sugar units were not broken down in the small intestine of these healthy adults.
Lactose still present
Lactose was still found in the lower small intestine or start of the large intestine of all participants. The authors say this lactose came from the drink.
What the authors conclude
“To conclude, FOS DP ≥ 2 and GOS DP ≥ 3 were not degraded in the small intestine of healthy adults, while most prebiotic GOS DP2 was hydrolyzed in a structure-dependent manner.”
Also in their conclusions
- They conclude that fructo-oligosaccharides with two or more sugar units and galacto-oligosaccharides with three or more sugar units were not broken down in the small intestine of healthy adults.
- They say most prebiotic galacto-oligosaccharide dimers were broken down in a way that depended on their structure.
- They say their evidence supports the development of galacto-oligosaccharide prebiotics that resist digestion in the small intestine.
How it was done
The authors say that galacto-oligosaccharides and fructo-oligosaccharides are food ingredients that improve human health, but how they break down in the human small intestine is not clear. They wanted to study this in detail.
Seven healthy Dutch men, aged 19 to 59, had a tube placed in the lower small intestine or the start of the large intestine. They drank 5 g of chicory fructo-oligosaccharides and 5 g of galacto-oligosaccharides, and samples of gut contents were collected for up to 350 minutes.
What it can’t tell you
- The study was small, with only seven men, all Dutch, and mostly young. The results may not apply to women, older people, or other ethnic groups.
- The authors could not tell whether the galacto-oligosaccharide dimers were broken down by human enzymes or by gut bacteria.
- The authors did not check whether any galacto-oligosaccharides passed into the blood or urine.
Who paid
- Conflicts
- The authors declare no competing financial interest.
- Authors work at
- Wageningen University, The Netherlands; University of Groningen, The Netherlands; Hospital Gelderse Vallei, The Netherlands
The paper
- Title
- Detailed Analysis of Prebiotic Fructo- and Galacto-Oligosaccharides in the Human Small Intestine
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Full text
- Licence
- CC BY. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- van Trijp MPH, Rios-Morales M, Logtenberg MJ, et al (2024). Detailed Analysis of Prebiotic Fructo- and Galacto-Oligosaccharides in the Human Small Intestine. Journal of agricultural and food chemistry. doi:10.1021/acs.jafc.4c03881Free full textPubMed 39282870DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error