Dietary polyphenols, which are primarily found in plants, offer a range of health promoting and disease prevention benefits. Recent research examines their preventive and therapeutic benefits for cardiometabolic, neurodegenerative, oncological, and gastrointestinal conditions. In particular, polyphenols’ roles in digestion may be of relevance for Irritable Bowel Syndrome (IBS) and Non-Celiac Wheat Sensitivity (NCWS), where multiple and sometimes excessively restrictive dietary interventions may be required to fully manage symptoms.
How Polyphenols Support Digestive Health
Polyphenols, despite their low bioavailability, remain in the digestive tract for extended periods due to their complex structure and interaction with the food matrix. This retention facilitates their interaction with gut microbiota, which in turn helps modulate metabolism, inflammation and more.
Polyphenols’ presence in the digestive tract leads to the production of bioactive metabolites, each of which has unique and robust health benefits (Calabriso, 2023). Polyphenols are of particular importance for their anti-inflammatory effects in the digestive tract, since they and their byproducts help regulate the immune response via inflammation and signaling pathways. In addition, polyphenols prevent growth of pathogenic bacteria and support immunity through their influence on intestinal barrier function (Shabbir). Recent evidence also suggests that polyphenols have prebiotic properties, further underlining their importance in microbiome health through modulation of gut microbiota composition (Shabbir).
Beyond Health Promotion: Polyphenols in Symptom Management
Recent studies provide insight into the impact of polyphenols on symptom management in digestive diseases. Notably, there is growing interest in the role of polyphenols in conditions like IBS and NCWS, where celiac disease (CeD) and wheat allergy (WA) have been ruled out. NCWS presents with nonspecific gastro- and extra-intestinal symptoms following the intake of gluten-containing foods.
Patients with NCWS, as well as IBS, often follow a gluten-free diet as an effective means to control symptoms, though eating strictly gluten-free can put patients at risk for excessive dietary restriction, food anxiety and increased financial burden (Calabriso, Pinto-Sanchez). Polyphenols are being investigated for their potential to mitigate the impact gluten has on symptoms to allow for more diet liberalization. A review by Calabriso et al. highlights the potential protective function of polyphenols against negative effects of gluten.
Polyphenols may influence gluten-derived symptoms through a number of pathways. They have the potential to reduce the bioavailability of gluten peptides, alleviate intestinal epithelial barrier disruption, modulate the intestinal immune response and mitigate oxidative stress and inflammation. For patients with NCWS where a gluten-free diet provides adequate relief, inclusion of particularly polyphenol-rich foods or supplements could improve tolerance to gluten and avoid risks associated with a restrictive diet (Calabriso).
Conclusion and Future Directions
The promise of polyphenols and symptom management could be a means to enable a less restrictive diet and the potential reintroduction of gluten for those with IBS or NCWS. A plant-based diet rich in polyphenols may help reduce the bioavailability of gluten and its role in oxidative stress, inflammation, and intestinal permeability. Still, more studies are warranted to fully understand if these theoretical mechanisms result in clinical benefits for patients.
In the meantime and while research remains ongoing, a polyphenol-rich diet should be encouraged due to its known benefits for overall health. Foods rich in polyphenols include apples, berries, buckwheat, certain lettuces, cilantro, cocoa, cranberry, extra virgin olive oil, grapes, green tea, nuts, onion, persimmons, pomegranates and turmeric, among others. The potential protective role of polyphenols in gastrointestinal health, particularly in IBS and NCWS, is promising and the full extent of the connection between polyphenols and digestion continues to be explored.
References
- Calabriso N, Massaro M, Scoditti E, Carluccio MA. Dietary Polyphenols and Their Role in Gut Health. Nutrients. 2023; 15(12):2650. https://doi.org/10.3390/nu15122650
- Shabbir U, Rubab M, Daliri EB-M, Chelliah R, Javed A, Oh D-H. Curcumin, Quercetin, Catechins and Metabolic Diseases: The Role of Gut Microbiota. Nutrients. 2021; 13(1):206. https://doi.org/10.3390/nu13010206
- Calabriso N, Scoditti E, Massaro M, Maffia M, Chieppa M, Laddomada B, Carluccio MA. Non-Celiac Gluten Sensitivity and Protective Role of Dietary Polyphenols. Nutrients. 2022; 14(13):2679. https://doi.org/10.3390/nu14132679
- Pinto-Sanchez MI, Nardelli A, Borojevic R, et al. Gluten-Free Diet Reduces Symptoms, Particularly Diarrhea, in Patients With Irritable Bowel Syndrome and Antigliadin IgG. Clin Gastroenterol Hepatol. 2021;19(11):2343-2352.e8. doi:10.1016/j.cgh.2020.08.040