Edible microbeads trap fat to support weight loss

Weight-loss interventions, including gastric bypass surgery and drugs that prevent dietary fat absorption, can be invasive or have negative side effects. Now, researchers have developed edible microbeads made from green tea polyphenols, vitamin E and seaweed that, when consumed, bind to fats in the gastrointestinal tract. Preliminary results from tests with rats fed high-fat diets show that this approach to weight loss may be safer and more accessible than surgery or pharmaceuticals.

Yue Wu, a graduate student at Sichuan University, will present her team's results at the ACS Fall 2025 Digital Meeting, a meeting of the American Chemical Society.

Losing weight can help some people prevent long-term health issues like diabetes and heart disease. Our microbeads work directly in the gut to block fat absorption in a noninvasive and gentle way."

Yue Wu, graduate student at Sichuan University

Weight gain is caused by genetic and lifestyle factors, including eating a high-fat diet. A high-fat diet is defined by the U.S. Department of Agriculture as one where 35% or more of a person's daily calories come from fat, as opposed to protein or carbohydrates. Some pharmaceuticals, such as orlistat, inhibit certain gastric enzymes from breaking down dietary fats, leading to less fat being absorbed by the body. Orlistat is a U.S. Food and Drug Administration (FDA)-approved medication and is effective for weight loss. However, for some people it causes serious side effects, including liver and kidney damage.

So, Wu and her colleagues wanted to target the fat absorption process with their weight-loss intervention but do so without negative side effects. "We want to develop something that works with how people normally eat and live," says Wu.

To get started, the team created tiny plant-based beads that spontaneously form through a series of chemical bonds between the green tea polyphenols and vitamin E. These structures can form chemical tethers to fat droplets and serve as the fat-binding core of the microbeads. The researchers then coated the spheres in a natural polymer derived from seaweed to protect them from the acidic environment of the stomach. Once ingested, the protective polymer coating expands in response to the acidic pH, and the green tea polyphenols and vitamin E compounds bind to and trap partially digested fats in the intestine.

The microbeads are nearly flavorless, and the researchers foresee them being easily integrated into people's diets. For example, the microbeads could be made into small tapioca- or boba-sized balls and added to desserts and bubble teas.

The researchers assessed the microbeads as a weight-loss treatment in rats. They put the animals into three groups (eight rats per group), those which were fed a high-fat diet (60% fats) either with or without microbeads and those which were fed a normal diet (10% fats) for 30 days. Rats fed the high-fat diet and microbeads:

• Lost 17% of their total body weight, while rats in the other groups didn't lose weight.
• Had reduced adipose tissue and less liver damage compared to rats fed the high-fat and normal diets without microbeads.
• Excreted more fat in their feces compared to rats not given microbeads. The extra fat in the rats' feces had no apparent ill effects on the animals' health.

Additionally, the eight rats on high-fat diets that consumed microbeads showed similar intestinal fat excretion, but without the gastrointestinal side effects the researchers observed with a fourth group of rats they treated with orlistat.

Wu and her team have started working with a biotechnology company to manufacture the plant-based beads. "All the ingredients are food grade and FDA-approved, and their production can be easily scaled up," says Yunxiang He, Sichuan University associate professor and co-author on Wu's presentation.

They've also initiated a human clinical trial in collaboration with the West China Hospital of Sichuan University. "This represents a major step toward clinical translation of our polyphenol-based microbeads, following our foundational results," says Wu. "We have officially enrolled 26 participants in our investigator-initiated trial, and we anticipate that preliminary data may become available within the next year."