How Chewing Chickpeas Differently Could Change Your Gut Hormones and Microbes

Chickpeas are chickpeas, or so it seems on a nutrition label. But new research suggests that how the cells inside a chickpea are structured when you eat it — intact versus broken apart — can shape what happens inside your digestive tract in ways that go well beyond calorie counting.

A team of researchers from Imperial College London, the Quadram Institute, and collaborating institutions ran a small but intricately designed study to look at what actually happens along the human gut, from mouth to small intestine, after eating chickpea-based meals with different physical structures. The findings, published in Nature Communications, offer a rare direct look inside the human gastrointestinal tract during digestion, something that's difficult to study and rarely done with this level of detail.

Getting a Look Inside the Digestive Tract

Ten participants took part in a randomized crossover trial, meaning each person ate both versions of the meal on separate occasions, serving as their own comparison. One meal contained chickpeas with intact plant cell walls; the other contained chickpeas where those cellular structures had been broken down during preparation. Researchers then collected fluid samples from the mouth, stomach, duodenum, and ileum at various points after eating, alongside blood samples to track hormone levels.

This kind of direct intestinal sampling is unusual in nutrition research, which more often relies on stool samples or blood work alone. Being able to trace metabolites and microbes through each segment of the gut in real time gave the researchers a much finer-grained picture of digestion as it unfolds.

Structure Shaped the Timing and Type of Hormone Release

The main thing the researchers were tracking was the release of gut hormones involved in appetite and blood sugar regulation: GIP, GLP-1, and PYY. These hormones are produced by cells lining the gut in response to nutrients passing through, and they play a role in signaling fullness and managing glucose metabolism.

When participants ate the meal with broken cell structures, glucose and maltose showed up quickly in the upper gut, and this was linked to a fast rise in GIP, a hormone associated with insulin release. The intact-cell meal told a different story: amino acids built up in the duodenum, while the ileum — further along the intestine — saw higher levels of sugars, amino acids, and a compound called formate. This pattern lined up with a stronger, more sustained release of GLP-1 and PYY, hormones tied to satiety and slower digestion.

In other words, keeping a food's cellular architecture intact appeared to slow down and redirect nutrient release further into the gut, triggering a different hormonal signature than when those same nutrients were more immediately accessible. Nutrition scientists have long suspected that how food is structured, not just its nutrient content, affects how the body processes it; this study offers a more detailed physiological picture of that process in humans.

Bacteria Along for the Ride

One of the more unexpected findings involved the gut microbiome. The researchers used shotgun metagenomic sequencing to track bacterial populations across the different gut regions and found that microbial communities shifted rapidly depending on what had been eaten and where digestion stood.

More strikingly, there was evidence that bacterial strains normally found in the mouth were showing up in the ileum, seemingly having hitched a ride via the food itself as it moved through the gut. Where these oral bacteria appeared in greater abundance, local metabolite levels and PYY hormone responses also shifted, hinting at a possible relationship between these traveling microbes and gut signaling. The authors describe this as a potentially underappreciated pathway by which bacteria from the mouth could influence metabolism further down the digestive tract, though the study wasn't designed to prove a direct causal chain between oral bacteria and hormone changes.

What Chickpea Structure Tells Us About Food Processing

The trial involved just ten participants under controlled experimental conditions rather than everyday eating patterns, so it's best read as an early, detailed look at a phenomenon worth exploring further, not a settled conclusion about how all legumes or plant foods behave in the body. Even so, the results add to growing evidence that the physical form of food — not just its ingredient list — can meaningfully influence digestion, hormone signaling, and even microbial activity in the gut.

For a starchy, fiber-rich food like chickpeas, that raises interesting questions about how cooking, processing, or food preparation methods might affect metabolic responses, appetite regulation, or even blood sugar control over time. None of this translates into specific dietary recommendations, and anyone managing digestive issues, diabetes, or weight concerns should still talk with their own doctor or a registered dietitian about what makes sense for their situation. What this study does offer is a more detailed map of a process that, until now, has largely been a black box.

Source: Nature Communications, DOI: 10.1038/s41467-026-77714-7, based on a randomised crossover trial by Fernandes, Cai, Warren, and colleagues.