Guar gum fiber and gut bacteria in lab tests
What it found
In lab tests using stool samples from six people, partially hydrolyzed guar gum increased two groups of gut bacteria after 24 hours.
This was not a study in living people.
What they found
Animal and lab studies
Parabacteroides increased
In lab tests, Parabacteroides rose from 3.48% of sequence reads to 10.62% after 24 hours.
Bacteroidetes increased
In lab tests, Bacteroidetes rose from 45.89% of sequence reads to 50.29% after 24 hours.
Bacteria linked to health
The authors say Parabacteroides has been linked to lower rates of IBS and ulcerative colitis, and that Bacteroidetes may be tied to positive health markers.
Other findings
Readily fermented fiber
The authors describe partially hydrolyzed guar gum as a prebiotic fiber that gut bacteria can ferment easily.
What the authors conclude
“PHGG stimulates growth of Parabacteroides, a genus of bacteria that have been inversely associated with IBS and ulcerative colitis.”
Also in their conclusions
- They conclude that PHGG stimulates growth of Parabacteroides, a genus of bacteria that have been inversely associated with IBS and ulcerative colitis.
- They say PHGG provides stimulation of beneficial Bacteroidetes (Bacteroides and Parabacteroides), which may be correlated with many positive health markers and outcomes.
- They state that PHGG is a prebiotic dietary fiber that is readily fermentable.
How it was done
The authors note that prebiotic fibers resist digestion and feed bacteria in the lower gut, but the response varies a lot between people. They wanted to see how much the response differs between individuals.
They collected stool samples from six healthy people who ate a typical Western diet, had not taken antibiotics in the past year, had no gut diseases and took no probiotic or prebiotic supplements. The samples were exposed to 0.5 g of partially hydrolyzed guar gum, and bacterial changes were measured at 0, 12 and 24 hours using 16S rRNA sequencing.
What it can’t tell you
- We summarised it from the abstract only.
- This was a lab test on stool samples, not a study in living people, so it cannot show what happens inside the human gut.
- The samples came from only six people, so the results may not apply to everyone.
- The study measured bacterial changes, not health outcomes, so it cannot show whether these changes affect IBS, ulcerative colitis or other conditions.
Who paid
- Authors work at
- University of Minnesota, United States
The paper
- Title
- In vitro analysis of partially hydrolyzed guar gum fermentation on identified gut microbiota
- Type
- Study
- Evidence
- Animals and lab studies
- Summarised from
- Abstract only
- Cite
- Carlson J, Gould T, Slavin J (2016). In vitro analysis of partially hydrolyzed guar gum fermentation on identified gut microbiota. Anaerobe. doi:10.1016/j.anaerobe.2016.08.006PubMed 27585552DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error