Developed by scientists at Imperial College London and the University of Glasgow, inulin propionate ester (IPE) is a mixture of inulin—an indigestible soluble fiber and prebiotic found in chicory and onions—and propionate, a naturally occurring short chain fatty acid (SCFA).
The mixture is designed to promote satiety, delivering propionate directly to receptors in the colon that trigger appetite‑regulating hormones. Meanwhile inulin absorbs water to form a gel-like substance, slowing digestion and increasing feelings of fullness.
On its own, propionate is rapidly absorbed in the upper small intestine. By combining it with inulin, the propionate is protected from digestion and absorption, allowing it to reach the large intestine intact.
Dr. Douglas Morrison of SUERC at the University of Glasgow, who developed IPE, said the new ingredient could help prevent slow, steady weight gain, potentially reducing obesity incidence.
“Obesity occurs through a gradual persistent gain in fat mass over a period of 10 years or more that can be explained by eating around 50–100 calories daily in excess of what a person needs,” he told NutraIngredients. “So, preventing that 1–2kg of weight gain each year is where IPE can play an important role.”
IPE positioned as an alternative or adjunctive to GLP-1s
With the rise of GLP-1 drugs, consumer interest in fiber and digestive supplements has increased considerably. This is primarily because GLP-1 users often experience gastrointestinal side effects, including constipation, diarrhea and nausea, with fiber emerging as a promising strategy to relieve some of these effects.
Certain fiber supplements can also promote satiety, helping people feel fuller for longer. Morrison said IPE could therefore be positioned as a weight management tool either during the tapering phase of GLP-1 drugs, or as an alternative strategy.
“There are two important areas,” he said. “The first is prevention of weight gain which can negate the need for GLP-1 drugs in the first place. The second market space is weight loss maintenance.
“In the era of GLP-1 drugs, significant weight loss is now achievable for some—at a cost—but the challenge is to keep that weight off. All of the research so far shows that without continued GLP-1 drug use, weight regain is rapid and occurs in most people within a year or two of stopping treatment. Slowing down or preventing that weight regain trajectory will be necessary to get any long-term benefits after using GLP-1 drugs.”
Clinical evidence shows that a dose of 10 g of IPE per day can regulate appetite and help prevent weight gain, with longer-term studies suggesting that the fiber blend can preserve lean body mass, improve liver fat levels and have potential effects on immune and metabolic health.
However, the strongest evidence is in older overweight people. When researchers tested the effects of IPE in overweight 20-40-year-olds, IPE did not differentially affect weight gain compared with the inulin control. The researchers said further studies are therefore required to understand whether there are age-related differences in appetite regulation and energy balance in response to SCFAs.
“We did see improvements in body composition in those participants on IPE which is an important observation given the importance of lean body mass for metabolic regulation,” Morrison said. “We also think the younger cohort were more sporadic in their eating behaviors compared with the earlier work in older people and therefore timing of consumption of IPE relative to mealtimes may be important. This is something we will continue to investigate.”
The road to commercialization
Fifteen years since IPE was first developed, the fiber blend is now on the road to commercialization.
Morrison, along with a wider team including Professor Gary Frost, chair in nutrition and dietetics at Imperial College London, have now launched a spinout company: Satisfed.
Currently, the research team is only able to produce IPE at a pilot scale of a few hundred kilograms at a time, and now, Satisfed is now seeking industrial partners capable of scaling production to thousands of tonnes.
The aim is to bring the dietary intervention into the mainstream, both as a supplement and an additive for everyday foods such as smoothies, shots, cereals and bread.
“The current plans for Satisfed are to scale towards commercial production of IPE and to extend the regulatory approvals to other jurisdictions, such as the UK and USA,” Morrison said. “On production, we have already taken IPE through food-grade, pilot plant production processes so scaling to commercial production is simply a matter of production capacity and scale.
“We are actively discussing with commercial partners about taking the next steps to bring commercial production of IPE to the market. The timing of commercial launch is not certain yet, but with the right partners, we could see IPE commercially available in 2027.”
