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Quebracho Tannins & IBS

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Quebracho Tannins and IBS Symptoms

A large clinical trial exploring how tannin-rich polyphenols may support digestive function, symptom relief, and quality of life in people with irritable bowel syndrome.

Study:
Improving Irritable Bowel Syndrome (IBS) Symptoms and Quality of Life with Quebracho and Chestnut Tannin-Based Supplementation: A Single-Centre, Randomised, Double-Blind, Placebo-Controlled Clinical Trial

Authors:
Silvia Molino, Lorenza Francesca De Lellis, Maria Vittoria Morone, Marcello Cordara, Danaè S. Larsen, Roberto Piccinocchi, Gaetano Piccinocchi, Alessandra Baldi, Alessandro Di Minno, Hesham R. El-Seedi, Roberto Sacchi, Maria Daglia, et al.

Reviewed by:
Paula Owen & Andrea Helleman

Journal:
Nutrients (2025)

Scientific Oversight:
Kenneth Brown, MD

Study Type:
Independent Clinical Trial

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SYNOPSIS

Tannin-Rich Polyphenols Improve Symptoms and Quality of Life in IBS

Researchers conducted a randomized, double-blind, placebo-controlled clinical trial involving 156 adults with irritable bowel syndrome (IBS). Participants received either a placebo or a supplement containing quebracho and chestnut tannins for 56 days. Compared with placebo, the tannin group experienced significant improvements in overall IBS symptom severity, quality of life, bloating, abdominal distension, flatulence, abdominal pain, and feelings of heaviness. Improvements were observed across multiple IBS subtypes, including constipation-predominant, diarrhea-predominant, and mixed IBS.

Key Takeaways

  • This was a randomized, double-blind, placebo-controlled trial involving 156 IBS patients.
  • Participants receiving quebracho and chestnut tannins experienced significant improvements in overall IBS symptom severity compared with placebo.
  • The treatment group improved from moderate IBS symptom severity to mild symptom severity over the course of the study.
  • Significant improvements were observed in bloating, abdominal distension, flatulence, abdominal pain, and feelings of heaviness.
  • Quality-of-life measures improved significantly in the tannin-treated group.
  • Researchers reported improvements across constipation-predominant, diarrhea-predominant, and mixed IBS subtypes.
  • No adverse events were reported during the study.

WHY THIS CAUGHT OUR ATTENTION

Looking Beyond Symptoms

What caught our attention about this study is that it focuses on a class of plant compounds that has become increasingly interesting in digestive research: tannin-rich polyphenols.

The authors discuss several mechanisms that may contribute to IBS symptoms, including microbial imbalance, altered intestinal motility, fermentation, gut-brain interactions, and intestinal dysfunction. Rather than targeting a single symptom, the intervention was designed around supporting the broader gut environment.

Of particular interest is the use of quebracho tannins. Quebracho is rich in condensed tannins, a class of polyphenols that has been studied for its interactions with microbial communities, fermentation processes, and digestive function. The authors also note emerging evidence suggesting that tannins may influence microbial composition, support beneficial metabolite production, and help regulate intestinal activity.

At KBS, we are especially interested in research that explores the relationship between microbial balance, fermentation, motility, and symptom development. This study contributes to that conversation by showing that a tannin-rich intervention was associated with improvements across multiple symptom categories and quality-of-life measures in a large IBS population.

WHAT IT MEANS FOR POLYPHENOL SCIENCE

The Growing Evidence for Tannin-Based Polyphenols

Polyphenol science has evolved far beyond the idea that plant compounds simply act as antioxidants. Increasingly, researchers are studying how specific polyphenols interact with the gut ecosystem itself.

This study is particularly important because it examines tannin-rich extracts derived from quebracho and chestnut in a rigorous clinical setting. The findings suggest that these compounds may influence several interconnected aspects of digestive health, including symptom severity, bowel function, quality of life, and the overall intestinal environment.

The authors highlight previous evidence suggesting that tannins may affect microbial balance, support beneficial metabolite production, influence intestinal motility, and contribute to healthier digestive function. While more research is needed to fully understand these mechanisms, studies like this help establish a stronger scientific foundation for the role of polyphenols in digestive health.

For KBS, the study reinforces an important principle: digestive symptoms often emerge from interactions between microbes, fermentation, motility, and the gut-brain axis. Understanding how polyphenols influence those systems remains one of the most promising areas of modern digestive research.

REFERENCE

Molino S, De Lellis LF, Morone MV, Cordara M, Larsen DS, Piccinocchi R, Piccinocchi G, Baldi A, Di Minno A, El-Seedi HR, et al. Improving Irritable Bowel Syndrome (IBS) Symptoms and Quality of Life with Quebracho and Chestnut Tannin-Based Supplementation: A Single-Centre, Randomised, Double-Blind, Placebo-Controlled Clinical Trial. Nutrients. 2025;17(3):552. doi:10.3390/nu17030552.
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This article is for educational purposes and summarizes published research. It is not medical advice and does not diagnose, treat, cure, or prevent any disease. Talk with your healthcare provider before making significant dietary, medication, or supplement changes.