Cranberry, gut bacteria and colitis in mice
What it found
In mice with chemically induced colitis, a diet containing whole cranberry powder reduced signs of colon inflammation and partly restored the gut bacteria.
The same diet given to healthy mice caused no noticeable adverse effects.
What they found
Animal and lab studies
Colitis severity
Mice with colitis that ate cranberry had lower disease activity scores, longer colons, and less spleen enlargement than mice with colitis that did not eat cranberry. Their colons also showed less tissue damage.
Inflammation markers
In the colon, cranberry reduced levels of three pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) that were raised by DSS. In the blood, cranberry lowered IL-6 and increased the anti-inflammatory cytokine IL-10.
Gut bacteria diversity
DSS lowered the variety of gut bacteria, but cranberry treatment improved it. The overall bacterial community in cranberry-fed colitis mice was partly shifted back toward that of healthy mice.
Specific bacteria
Cranberry increased the abundance of potentially beneficial Lactobacillus and Bifidobacterium, which DSS had suppressed. It also reduced potentially harmful Sutterella and Bilophila, and lowered the overgrowth of Akkermansia seen in colitis.
Predicted bacterial functions
The predicted functions of gut bacteria changed with DSS, including higher cancer and neurodegenerative disease pathways. Cranberry partly reversed these changes, but the authors note that more work is needed to see if these functional shifts cause or result from inflammation.
What the authors conclude
“Clinical studies are needed to demonstrate the suppressive effects of cranberry on IBD and its beneficial impact on gut microbiota in humans.”
Also in their conclusions
- They conclude that dietary whole cranberry has a preventive effect against colonic inflammation in DSS-treated mice.
- They say the anti-inflammatory effect is closely related to cranberry's ability to ease DSS-induced changes in the composition and function of gut bacteria.
- They call for clinical studies to show whether cranberry suppresses IBD and benefits gut bacteria in humans.
How it was done
The authors wanted to understand how whole cranberry might protect against inflammatory bowel disease and whether gut bacteria play a role, since many cranberry components reach the colon intact.
Forty male mice were split into four groups: healthy controls, healthy mice fed cranberry, mice given DSS to cause colitis, and mice given both DSS and cranberry. The cranberry diet contained 1.5% freeze-dried whole cranberry powder, and the DSS groups received DSS in drinking water for four cycles over 32 days.
What it can’t tell you
- These are animal studies. They can't show what happens in people.
- The study used a chemical to cause colitis in mice, so it does not show whether cranberry prevents IBD in humans.
- The authors say clinical studies are needed to demonstrate the effects in humans.
Who paid
- Funding
- Funded by NCCIH NIH HHS (from the PubMed record).
- Authors work at
- University of Massachusetts Amherst, USA
The paper
- Title
- Dietary cranberry suppressed colonic inflammation and alleviated gut microbiota dysbiosis in dextran sodium sulfate-treated mice
- Type
- Study
- Evidence
- Animals and lab studies
- Summarised from
- Full text
- Cite
- Cai X, Han Y, Gu M, et al (2019). Dietary cranberry suppressed colonic inflammation and alleviated gut microbiota dysbiosis in dextran sodium sulfate-treated mice. Food & function. doi:10.1039/c9fo01537jFree full textPubMed 31524900DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error