Partially hydrolyzed guar gum fermentation in lab tests using six people's gut bacteria
What it found
In lab tests, gut bacteria from six people broke down partially hydrolyzed guar gum at very different speeds.
The amounts of short chain fatty acids produced varied by more than double between individuals.
What they found
Animal and lab studies
Gas production varied widely
After 12 hours, gas ranged from 59 to 80 mL per 0.5 g of fiber across the six donors. By 24 hours it reached 85 to 93 mL per 0.5 g of fiber.
Butyrate levels differed
At 12 hours, butyrate ranged from 6.99 to 23.84 μmol mL(-1) in the lab dishes. At 24 hours it was between 8.78 and 22.84 μmol mL(-1).
Total short chain fatty acids
After 24 hours, total short chain fatty acids ranged from 42.85 to 91.17 μmol mL(-1). That is more than a twofold difference among the six people tested.
Average fatty acid ratio
The overall average ratio of acetate to propionate to butyrate was 30:45:25. This matches what other lab tests have found for similar fibers.
One donor fermented faster
For one of the six donors, short chain fatty acid levels dropped by 24 hours. This suggests their gut bacteria finished breaking down the fiber sooner than the others.
What the authors conclude
- They note that short chain fatty acid production varies greatly among people because of differences in their gut bacteria.
- They point out that lab dish results are limited by the wide variation seen between different stool donors.
How it was done
Scientists know this fiber feeds certain gut bacteria and raises short chain fatty acid levels in the lower gut. But few studies have looked at how much these levels differ from person to person when exposed to the same fiber.
Researchers collected stool samples from six healthy people aged 23 to 68. They mixed each sample with partially hydrolyzed guar gum in lab dishes. They measured gas and short chain fatty acids after 12 and 24 hours.
What it can’t tell you
- We summarised it from the abstract only.
- These were lab dish tests using stool samples, not people eating the fiber.
- Lab tests cannot show exactly what happens inside a living body during digestion.
Who paid
- Authors work at
- University of Minnesota - Twin Cities, USA; USDA Grand Forks Human Research Center, USA
The paper
- Title
- In vitro analysis of partially hydrolyzed guar gum fermentation differences between six individuals
- Type
- Study
- Evidence
- Animals and lab studies
- Summarised from
- Abstract only
- Cite
- Carlson J, Esparza J, Swan J, Taussig D, Combs J, Slavin J (2016). In vitro analysis of partially hydrolyzed guar gum fermentation differences between six individuals. Food & function. doi:10.1039/c5fo01232ePubMed 26862979DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error