Tannins and Flavonoids May Help Treat Acute Gastroenteritis

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By Agata P. | Updated: Oct 19, 2020

Tannins and Flavonoids May Restore Intestinal Mucosa in Acute Gastroenteritis
General Information
  • 04 Jun 2018
  • Italy
  • University of Naples Federico II
  • Russo, M.
  • Randomized, case-controlled trial
  • 60 children
  • 7 days

Acute gastroenteritis causes diarrhea with or without vomiting. It is especially challenging in vulnerable populations, like children, due to high risk of dehydration and the associated health risks.1 While the first line of treatment with oral or intravenous fluids tackles the risk of dehydration, it does not reduce the duration or severity of symptoms.

Tannins and flavonoids are phenolic compounds found in plants, including fruits and vegetables. They have been scientifically proven to possess various health-promoting properties, including antioxidant and anti-inflammatory actions.2,3 As such, their use in treatment of a wide array of medical conditions is of high interest. 

This study aimed at evaluating the safety and efficacy of tannins and flavonoids in reducing the duration and severity of symptoms of acute gastroenteritis.

The Study

It was a randomized, case-controlled trial conducted by researchers at the University of Naples Federico II in Naples, Italy. The results were published in the Italian Journal of Pediatrics.

The study involved 60 children, aged 3 months to 12 years, with mild to moderate dehydration due to acute gastroenteritis that lasted less than 7 days. Participants were divided into two groups: the first group was treated with a tannin-rich oral solution and standard oral rehydration (SOR), while the second one received only SOR.

While both groups were treated for seven days, 23 out of 30 children in the intervention group stopped SOR after the first 24 hours and only received tannin solution. 

The intervention solution was made from tannins from agrimony and tormentil as well as flavonoids from chamomile. The SOR consisted of 50/60 mmol/L sodium. 

Frequency of bowel movements, stool consistency, and gastrointestinal symptoms were measured and recorded before, during, and after the study.

The Results

Researchers observed a significant decrease in the number of stools between the two groups within the first 24 hours (average of 5 stools on day 1 vs. 3.5 stools on day 2 in the control group).

Moreover, on the 6th day of the treatment, 76.9% participants in the intervention group reported formed stools (as opposed to loose stool, or diarrhea) in contrast to 50% in the control group.

What Does this Mean?

This study demonstrated potential restorative effects of tannins on intestinal mucosa by strengthening and protecting it from irritants' effects. These are promising results for safe and effective use of tannins as antidiarrheal agents for the treatment of acute gastroenteritis, especially in populations at a higher risk of dehydration and related complications. 

More research is needed to corroborate these findings, further investigate tannins and flavonoids' mechanisms of action in the intestinal mucosa, and explore potential uses for gastrointestinal ailments.

Other antidiarrheal herbs include raspberry, goldenseal, and ginger, while those rich in tannins or flavoinoid are grapes, blueberry, and apples.


  • Italian Journal of Pediatrics, Oral administration of tannins and flavonoids in children with acute diarrhea: a pilot, randomized, control-case study, 2018


  1. BMJ. (2007). Acute gastroenteritis in children. Retrieved November 27, 2019 from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1764079/
  2. Journal of Nutritional Science. (2016). Flavonoids: an overview. Retrieved November 27, 2019 from  https://www.ncbi.nlm.nih.gov/pubmed/28620474
  3. Cornell College of Agriculture and Life sciences. (n.d.). Tannins: fascinating but sometimes dangerous molecules. Retrieved November 27, 2019 from http://poisonousplants.ansci.cornell.edu/toxicagents/tannin.html