Barley extrudates and gut bacteria in lab tests
What it found
In lab tests, barley extrudates changed gut bacteria and boosted butyric acid, with differences by barley type.
The purple barley produced phenolic breakdown products earlier.
What they found
Animal and lab studies
Butyric acid boost
Barley extrudates increased butyric acid production during fermentation, especially the high beta-glucan types Hilose and Annapurna. Butyric acid became the main short-chain fatty acid by 48 hours.
Phenolic breakdown
The purple barley DHL-151340 produced phenolic breakdown products earlier and in larger amounts than other types. These products included hydroxyphenylpropanoic acid, which exceeded 100 micromoles per 100 grams in some samples.
Gut bacteria shifts
All barley extrudates changed the gut bacteria mix over time, but the communities became more similar by 24 to 48 hours. High beta-glucan types boosted Bacillota bacteria, which are linked to butyrate production.
Beta-glucan breakdown
Beta-glucans from all barley types were almost completely used up by gut bacteria within 24 to 48 hours. Most of this breakdown happened in the first 10 hours.
Digestion release
After lab digestion, 40 to 55 percent of beta-glucans and 15 to 20 percent of phenolic compounds were released in a form available for absorption. Most phenolics stayed in the leftover fraction that reaches the colon.
What the authors conclude
“Overall, genotype- and processing-driven differences translated into distinct fermentation and phenolic biotransformation footprints, highlighting the relevance of barley matrix composition in shaping the colonic fate of cereal bioactive compounds.”
Also in their conclusions
- They say that barley genotype and processing lead to distinct fermentation and phenolic breakdown patterns.
- They highlight that the barley matrix composition shapes what happens to barley compounds in the colon.
- They suggest that extruded barley products could be classified based on prebiotic and antioxidant-related components.
How it was done
The authors wanted to see how barley genotype and extrusion processing affect the release and fermentation of barley compounds in the gut.
They made extruded snacks from four barley types, digested them in lab tests, then fermented the leftovers with human fecal bacteria for up to 48 hours.
What it can’t tell you
- These are lab tests using human fecal bacteria, not studies in people. They cannot show what happens in the human gut.
- The lab fermentation system does not fully mimic the human colon, so the bacterial changes may not reflect real life.
- The digestion model does not include all human enzymes, so some starch may have been counted as undigested when it would be digested in people.
Who paid
- Authors work at
- University of Lleida-Agrotecnio CERCA Center, Spain; Institute of Food Science Research (CIAL), Spain
The paper
- Title
- Barley extrudates modulate the gut microbiome-metabolome axis in vitro through β-glucan fermentation and polyphenol biotransformation
- Type
- Study
- Evidence
- Animals and lab studies
- Summarised from
- Full text
- Cite
- Martínez-Subirá M, Cortijo Alfonso ME, Friero I, et al (2026). Barley extrudates modulate the gut microbiome-metabolome axis in vitro through β-glucan fermentation and polyphenol biotransformation. Food & function. doi:10.1039/d6fo00601aFree full textPubMed 42132693DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error