Scientists Develop Low-Calorie Natural Sugar That Doesn't Spike Insulin

Scientists have identified a rare natural sugar that tastes almost like regular sugar, contains fewer calories, and does not cause sharp spikes in insulin levels. The breakthrough could offer a healthier alternative to both table sugar and artificial sweeteners.

The sugar, called tagatose, is about 92 percent as sweet as sucrose but contains only one-third of the calories. Unlike traditional sugar and many artificial substitutes, tagatose has a minimal impact on blood glucose levels, making it a promising option for people with diabetes or insulin sensitivity.

Researchers from Tufts University, working with biotechnology firms Manus Bio (US) and Kcat Enzymatic (India), have demonstrated a new and more efficient method to produce tagatose on a large scale. Their findings were published in Cell Reports Physical Science.

Tagatose occurs naturally in small amounts in fruits and dairy products, but its limited availability has restricted commercial use. Existing production methods are costly and inefficient.

To overcome this, scientists engineered Escherichia coli bacteria to act as miniature production units. They introduced a newly discovered enzyme from slime mold, known as galactose-1-phosphate-selective phosphatase, which enables the conversion of glucose into tagatose. This process achieved production yields of up to 95 percent, far higher than current methods.

"There are established processes to produce tagatose, but they are inefficient and expensive," explains biological engineer Nik Nair from Tufts.

"We developed a way to produce tagatose by engineering the bacteria Escherichia coli to work as tiny factories, loaded with the right enzymes to process abundant amounts of glucose into tagatose."

Tagatose is also considered tooth-friendly and may help limit harmful oral bacteria. It can withstand baking temperatures, unlike many artificial sweeteners.

While further optimisation is needed, researchers believe this method could unlock wider use of tagatose and other rare sugars. The global tagatose market is projected to reach $250 million by 2032.