Guava extracts and intestinal glucose transport in lab and mice
What it found
Guava leaf and fruit extracts reduced glucose transport in human intestinal cells and lowered blood sugar peaks in mice after a glucose drink.
What they found
Animal and lab studies
Glucose transport in cells
In human intestinal Caco-2 cells, guava leaf and fruit extracts reduced glucose transport by up to 80% in a dose- and time-dependent way. The effect remained after treatment with digestive juices.
Which transporter is blocked
Under sodium-free conditions, the concentrated guava leaf extract inhibited glucose transport more strongly (about 74% after 30 minutes) than under sodium-containing conditions (about 31%). This suggests it mainly blocks GLUT2 rather than SGLT1.
Blood sugar in mice
In mice, both concentrated guava leaf extract and a supercritical guava fruit extract significantly lowered the postprandial blood glucose rise compared to the control group. The leaf extract reduced the peak rise from 39.5 to 21.8 mg/dL, and the fruit extract to 12.6 mg/dL.
Combining with apple extract
Combining guava extracts with apple extract increased glucose transport inhibition by about 20% compared to single extracts in Caco-2 cells.
Other findings
Polyphenol content
The extracts contained different polyphenols. The concentrated leaf extract was rich in flavonols, especially guaijaverin and quercetin. The supercritical fruit extract had no identifiable polyphenols.
What the authors conclude
“The data demonstrated that guava leaf and fruit extracts can potentially contribute to the regulation of blood glucose levels.”
Also in their conclusions
- They conclude that guava leaf and fruit extracts can potentially contribute to the regulation of blood glucose levels.
- They suggest that consumption of guava extracts may help moderate blood sugar by directly inhibiting intestinal glucose transport.
- They state that further experiments are needed to identify the individual bioactive compounds and understand the molecular mechanisms.
How it was done
Guava is used traditionally for blood sugar, but how it might work is unclear and studies have disagreed. The authors wanted to test whether guava extracts affect glucose transport in the intestine.
They tested guava leaf and fruit extracts on human Caco-2 intestinal cells and gave the extracts with glucose to female C57BL/6N mice. The mice were split into groups of six and blood sugar was measured over 120 minutes.
What it can’t tell you
- The cell and mouse results cannot show what happens in people.
- The study did not test long-term health effects or whether guava extracts help manage diabetes in humans.
Who paid
- Authors work at
- University of Applied Sciences Upper Austria, Austria; Austrian Competence Center for Feed and Food Quality, Austria; Johannes Kepler University, Austria
The paper
- Title
- In Vitro and In Vivo Inhibition of Intestinal Glucose Transport by Guava (Psidium Guajava) Extracts
- Type
- Study
- Evidence
- Animals and lab studies
- Summarised from
- Full text
- Licence
- CC BY. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- Müller U, Stübl F, Schwarzinger B, et al (2018). In Vitro and In Vivo Inhibition of Intestinal Glucose Transport by Guava (Psidium Guajava) Extracts. Molecular nutrition & food research. doi:10.1002/mnfr.201701012Free full textPubMed 29688623DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error