Healthier New Sweetener Created—It Could Also Be Good for Oral, Gut Health

A healthier alternative to table sugar that looks, tastes and cooks like the real thing has been cooked up by scientists—with the help of slime mold.

Using engineered bacteria, engineers at Tufts University produced tagatose, which is about 92 percent as sweet as sucrose but contains roughly 60 percent fewer calories. 

It occurs naturally only in trace amounts—less than 0.2 percent of the sugars found in foods like dairy products and certain fruits such as apples, oranges and pineapples. 

Because extraction is impractical, tagatose has traditionally been manufactured through chemical processes that are costly and inefficient, limiting its widespread use. 

“There are established processes to produce tagatose, but they are inefficient and expensive,” said paper author and chemical and biological engineer professor Nik Nair in a statement.

By genetically engineering Escherichia coli bacteria to act as microscopic production plants, the researchers created a biosynthetic pathway that converts abundant glucose into tagatose in a much more economically-friendly manner.

The breakthrough hinges on a newly identified enzyme sourced from slime mold, known as galactose-1-phosphate–selective phosphatase (Gal1P). When combined with another enzyme the system effectively reverses a natural metabolic pathway—first generating galactose from glucose, then converting it into tagatose. 

The result is a yield that can reach up to 95 percent, far surpassing conventional manufacturing methods, which typically achieve yields between 40–77 percent. 

Because tagatose is only partially absorbed in the small intestine and largely fermented by gut bacteria in the colon, it has a minimal effect on blood glucose and insulin levels—an important consideration for people with diabetes or insulin resistance.  

Tagatose may also offer benefits beyond calorie reduction. Unlike sucrose, which feeds cavity-causing bacteria in the mouth, tagatose appears to inhibit their growth.  

Emerging evidence suggests it may even support beneficial oral and gut bacteria, giving it potential probiotic properties. 

Crucially for food manufacturers and home cooks alike, tagatose behaves like sugar in ways many substitutes do not. Classified as a “bulk sweetener,” it provides not just sweetness but also the volume and texture sugar adds to baked goods. It browns during cooking and in taste tests has shown greater similarity to table sugar than many popular alternatives. 

Tagatose is already designated by the U.S. Food and Drug Administration as “generally recognized as safe,” placing it in the same regulatory category as everyday staples like salt, vinegar, and baking soda.  

“The key innovation in the biosynthesis of tagatose was in finding the slime mold Gal1P enzyme and splicing it into our production bacteria,” Nair said.

“That allowed us to reverse a natural biological pathway that metabolizes galactose to glucose and instead generate galactose from glucose supplied as a feedstock. Tagatose and potentially other rare sugars can be synthesized from that point.” 

If the process can be scaled for industrial use, researchers said it could open the door not only to broader adoption of tagatose, but to the production of other rare sugars as well—potentially reshaping how sweetness is added to foods, without the health trade-offs that have long come with it.