Scientists at Tufts University have developed a method using genetically modified bacteria to efficiently produce tagatose, a rare sugar that mimics table sugar's taste with fewer health risks. This breakthrough could provide a low-calorie alternative that supports oral and gut health without spiking blood sugar. The innovation achieves yields up to 95 percent, far surpassing traditional production techniques.
For over a century, researchers have sought sugar substitutes that deliver sweetness without the calories, tooth decay, and risks of obesity and diabetes linked to sucrose. A new study from Tufts University brings a promising solution: biosynthetic production of tagatose, a naturally rare sugar found in tiny amounts in dairy and fruits like apples and pineapples.
Tagatose offers 92 percent of sucrose's sweetness but with about 60 percent fewer calories. Classified by the FDA as "generally recognized as safe," it is absorbed minimally in the small intestine and fermented by gut bacteria, resulting in little impact on blood glucose or insulin levels. Studies show it limits cavity-causing oral bacteria and may promote beneficial microbes in the mouth and gut.
The Tufts team, led by Nik Nair, associate professor of chemical and biological engineering, engineered Escherichia coli bacteria as "tiny factories." They incorporated a slime mold enzyme, galactose-1-phosphate-selective phosphatase (Gal1P), to convert abundant glucose into galactose, followed by arabinose isomerase to yield tagatose. "There are established processes to produce tagatose, but they are inefficient and expensive," Nair said. This method boosts yields to 95 percent, compared to 40-77 percent in prior techniques, making it more economical.
Unlike high-intensity sweeteners, tagatose acts as a bulk sweetener, browning like sugar when heated and matching its mouthfeel. "The key innovation... was in finding the slime mold Gal1P enzyme and splicing it into our production bacteria," Nair explained. Published in Cell Reports Physical Science in 2025, the research could enable efficient synthesis of other rare sugars, potentially transforming food production for healthier options.
