Bitter tasting herbal extracts stimulate gastric cells
The Leibniz Institute for Food Systems Biology at the Technical University of Munich has now gained new insights
Leibniz-Institut für Lebensmittel-Systembiologie an der TU München
image:
Dr. Phil Richter in a lab of the Leibniz Institute for Food Systems Biology at the Technical University of Munich.
view moreCredit: Dr. Gisela Olias / Leibniz-LSB@TUM
Bitter-tasting herbal extracts have traditionally been used to support digestion, yet the molecular basis of their effects has remained largely unclear. The Leibniz Institute for Food Systems Biology at the Technical University of Munich has now gained new insights into this mechanism. Using a cellular model, its researchers demonstrated that herbal extracts can stimulate proton secretion in human gastric cells as key mechanism of gastric acid production, with combinations of extracts showing particularly strong effects. Extracts rich in polyphenols proved especially potent. The study further identified three human bitter taste receptor subtypes as key mediators of this response.
The researchers investigated a commercially available herbal preparation commonly used to alleviate digestive complaints. The formulation consists of extracts from nine plants and is characterized by a pronounced bitter taste. Based on this, the scientists hypothesized that the bitter compounds it contains, including polyphenols, not only activate bitter taste receptors in the mouth, but also stimulate gastric acid secretion through extraoral bitter taste receptors located in the stomach. Roughly 25 different human bitter taste receptor subtypes are known.
Four herbal extracts found to be especially effective
To test this hypothesis, the research team led by first author Phil Richter and principal investigator Veronika Somoza analyzed both the effects of individual plant extracts and three different extract mixtures using a cell-based testing system. Their experiments revealed that several extracts, especially those from masterwort, juniper, sage, and yarrow, enhanced proton secretion in human gastric cells. In contrast, extracts from plants such as dandelion and gentian did not produce significant effects within the tested concentration range of up to 300 micrograms per milliliter.
The study also found that extracts with particularly high polyphenol levels exerted the strongest stimulatory effects. The researchers therefore propose that these phytochemicals may play an important role in promoting gastric acid secretion. Additional molecular biology analyses further indicated that the bitter taste receptors TAS2R4, TAS2R5, and TAS2R39 are involved in mediating the observed increase in proton secretion.
Variety is key
“Comparing the different extract mixtures yielded particularly interesting results,” explains Phil Richter. “The combination containing all nine plant extracts produced the strongest stimulation of cellular proton secretion. In contrast, the mixture composed of the four most active individual extracts showed a considerably weaker effect, while the blend of the five least active extracts triggered only a slight increase in proton secretion.”
According to the researcher, the findings indicate that cellular response emerges through the interaction of multiple compounds that enhance one another’s effects. “Our data suggest that several bitter taste receptor types are activated simultaneously,” says Phil Richter. “Apart from polyphenols, other plant constituents are also likely to contribute to this synergistic effect”, adds Veronika Somoza.
The study therefore offers a potential molecular explanation for why bitter-tasting herbal preparations have long been regarded as digestive aids. By activating bitter taste receptors in the stomach, these compounds may directly stimulate gastric acid secretion and thereby support digestive processes. The results also indicate that complex herbal mixtures can, in some cases, be more effective than isolated extracts.
At the same time, Veronika Somoza, head of the Metabolic Function & Biosignals research group at the Leibniz Institute, cautions that the findings are currently based on cell culture experiments. Future clinical studies will be necessary to determine whether comparable effects occur in humans. Nevertheless, the researcher believes that the new insights could help guide the development of more targeted herbal formulations in the future.
Publication: Richter, P., Piqué-Borràs, M.-R., Künstle, G., Somoza, V. (2026). A Digestive Herbal Mixture Preparation Stimulates Proton Secretion in Human Parietal Cells through Phenolic Compounds Targeting Bitter Taste Receptors. Mol. Nutr. Food Res. 70, 6. doi.org/10.1002/mnfr.70443
Funding: The authors declare that this study was financially supported by Weleda AG. The funder was not involved in the study design, data collection, analysis, or evaluation, the writing of this article, or the decision to submit it for publication.
Two of the co-authors declare the following financial conflicts of interest: M.-R. Piqué-Borràs and G. Künstle are employed by Weleda AG in Arlesheim, Switzerland.
More Information:
The study was based on extracts from nine plants: common wormwood, common sage, common yarrow, common centaury, common chicory, great yellow gentian, common juniper, masterwort, and common dandelion.
Phenolic compounds, also known as polyphenols, are among the most important phytochemicals. They are credited with a wide range of health-promoting effects, including immunomodulatory and anti-inflammatory properties. Recent research findings also show that polyphenols can specifically target so-called bitter taste receptors (TAS2Rs).
Bitter taste receptors are widespread throughout the human body. A total of about 25 different types are known. Originally, they were primarily associated with the perception of bitter tasting substances in the oral cavity. It is now known that these receptors are also found outside the mouth, for example on blood cells as well as on cells of organs such as the brain, the heart, and the gastrointestinal tract. It is not yet fully understood what functions they perform in these locations or which substances activate the so-called extraoral bitter taste receptors. These open questions are the focus of current research, including at the Leibniz Institute for Food Systems Biology at the Technical University of Munich.
Contacts:
Expert Contacts:
Prof. Dr. Veronika Somoza
Head of Section II and the Metabolic Function & Biosignals research group at the
Leibniz Institute for Food Systems Biology
at the Technical University of Munich (Leibniz-LSB@TUM)
Lise-Meitner-Str. 34
85354 Freising
Email: v.somoza.leibniz-lsb(at)tum.de
Dr. Phil Richter
Metabolic Function & Biosignals research group
Phone: +49 8161 71-2932
Email: p.richter.leibniz-lsb(at)tum.de
Press Contact at Leibniz-LSB@TUM:
Dr. Gisela Olias
Knowledge Transfer, Press and Public Relations
Phone: +49 8161 71-2980
Email: g.olias.leibniz-lsb(at)tum.de
Information About the Institute:
The Leibniz Institute for Food Systems Biology at the Technical University of Munich (Leibniz-LSB@TUM) comprises a unique research profile at the interface of Food Chemistry & Biology, Chemosensors & Technology, and Bioinformatics & Machine Learning. As this profile has grown far beyond the previous core discipline of classical food chemistry, the Institute spearheads the development of a food systems biology. Its aim is to develop new approaches for the sustainable production of sufficient quantities of food whose biologically active effector molecule profiles are geared to health and nutritional needs, but also to the sensory preferences of consumers. To do so, the Institute explores the complex networks of sensorically relevant effector molecules along the entire food production chain with a focus on making their effects systemically understandable and predictable in the long term.
A Member of the Leibniz Associatation
The Leibniz-LSB@TUM is a member of the Leibniz Association, which connects 96 independent research institutions. Their orientation ranges from the natural sciences, engineering and environmental sciences through economics, spatial and social sciences to the humanities. Leibniz Institutes address issues of social, economic and ecological relevance.They conduct basic and applied research, including in the interdisciplinary Leibniz Research Alliances, maintain scientific infrastructure, and provide research-based services. The Leibniz Association identifies focus areas for knowledge transfer, particularly with the Leibniz research museums. It advises and informs policymakers, science, industry and the general public.
Leibniz institutions collaborate intensively with universities – including in the form of Leibniz ScienceCampi – as well as with industry and other partners at home and abroad. They are subject to a transparent, independent evaluation procedure. Because of their importance for the country as a whole, the Leibniz Association Institutes are funded jointly by Germany’s central and regional governments. The Leibniz Institutes employ around 21,400 people, including 12,200 researchers. The financial volume amounts to 2,3 billion euros.
Note on the use of AI
The press release was first translated from German into American English using DeepL Pro. Prof. Veronika Somoza then reviewed the text for factual and linguistic accuracy, making corrections where necessary.
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Journal
Molecular Nutrition & Food Research
Method of Research
Experimental study
Subject of Research
Cells
Article Title
A Digestive Herbal Mixture Preparation Stimulates Proton Secretion in Human Parietal Cells through Phenolic Compounds Targeting Bitter Taste Receptors
