In an ant colony, the queen isn't in charge. So who is?
Ant colonies function as self-organized systems without centralized leadership; the queen's primary role is reproduction, not governance. Complex colony behaviors, such as efficient transportation networks and intricate nest construction, emerge from simple individual rules, pheromone-based communication, and stigmergy. Collective problem-solving and coordination improve with group size in ants, contrasting with human group dynamics.

original article.

New study challenges the idea that testosterone drives risk-taking behavior
A meta-analysis of 52 studies with over 17,000 participants found no reliable association between testosterone levels and risk-taking behavior. The relationship between testosterone and risk-taking did not differ between men and women, and only weak links appeared in specific tasks such as lottery games. Risk-taking appears to result from a combination of biological, psychological, and social factors rather than testosterone alone.
A separate meta-analysis looking at sex differences found that testosterone's link to risk-taking behaviour is no stronger in men than in women.

Irene Sánchez Rodríguez et al, No relationship between testosterone and risk aversion: A meta-analytic review, Neuroscience & Biobehavioral Reviews (2026). DOI: 10.1016/j.neubiorev.2026.106575

Bitter herbal extracts spur stomach acid in human gastric cells, study finds

Bitter herbal extracts, particularly those rich in polyphenols, stimulate proton secretion in human gastric cells via activation of bitter taste receptors TAS2R4, TAS2R5, and TAS2R39, promoting gastric acid production. Combinations of multiple extracts produced stronger effects than individual extracts, suggesting synergistic interactions among various plant compounds.
Bitter-tasting herbal extracts have traditionally been used to support digestion, yet the molecular basis of their effects has remained largely unclear.
Researchers 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 a 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.
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.
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.
Apart from polyphenols, other plant constituents are also likely to contribute to this synergistic effect.
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.

Phil Richter et al, A Digestive Herbal Mixture Preparation Stimulates Proton Secretion in Human Parietal Cells through Phenolic Compounds Targeting Bitter Taste Receptors, Molecular Nutrition & Food Research (2026). DOI: 10.1002/mnfr.70443

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