- Researchers have engineered bacteria to convert glucose into a sugar substitute much more efficiently than existing methods.
- This biosynthetic production method may make the sweetener more readily available as a sugar substitute in food products.
- The sweetener, known as tagatose, tastes similar to table sugar but contains fewer calories, may have a much smaller effect on blood glucose and insulin levels, and have potential benefits for oral and gut health.
- However, while tagatose seems promising, large-scale human studies and regulatory evaluations are still necessary.
Artificial sweeteners, or sugar substitutes, are becoming increasingly common as the demand for low-calorie options to help manage weight and blood sugar control increases.
However, growing evidence indicates that the impact of sweeteners on human health may be more complex than previously understood, and further research on their long-term safety is necessary. As investigations continue, a substitute that shows promise may soon be more readily available.
Researchers at Tufts University have developed a new method to produce tagatose, which may offer the sweetness and taste of table sugar without the potential harms.
The new study, published in
Tagatose is a rare, low-calorie sugar that occurs naturally in some fruits and dairy products. It is able to provide a similar taste to sucrose, offering roughly 92% of table sugar’s sweetness, but with less than half of the calories.
Tagatose meets the
In 2001, the Food and Drug Administration (FDA) recognized tagatose as Generally Recognized As Safe (GRAS). This designation means that scientific evidence supports the intended use of tagatose as a sugar substitute. However, it is not the same as getting formal FDA approval.
Although tagatose occurs naturally, it is present in very small quantities compared with other sugars, such as glucose, sucrose, and fructose. Due to this scarcity, manufacturers typically produce it synthetically rather than extracting it directly from foods, which is often inefficient and expensive.
To address the costly and ineffective production, researchers at Tufts developed a method utilizing Escherichia coli (E.coli) bacteria to serve as microscopic sugar factories.
“There are established processes to produce tagatose, but they are inefficient and expensive,” said Nik Nair, associate professor of chemical and biological engineering at Tufts, in a press release.
“We developed a way to produce tagatose by engineering the bacteria E. coli to work as tiny factories, loaded with the right enzymes to process abundant amounts of glucose into tagatose. This is much more economically feasible than our previous approach, which used less abundant and expensive galactose to make tagatose.”
— Nik Nair, associate professor
The research team were able to do so by reversing the Leloir pathway, which is how bacteria such as E.coli usually break down and consume galactose.
Reversal was possible by engineering the bacteria to include a newly discovered enzyme called galactose-1-phosphate-selective phosphatase (Gal1P), which produces galactose from glucose. A second enzyme, known as arabinose isomerase, then completes the conversion of galactose to tagatose.
Previous methods of manufacturing tagatose may be able to produce a yield of up to 77% at a high cost. Using this method, the research team suggest they could convert glucose directly into tagatose with yields of up to 95%. This cheaper and more efficient production method could support broad use in food products.
In addition to offering similar sweetness as sugar with significantly fewer calories, it may also behave the same in recipes.
Other sugar substitutes can provide sweetness, but cannot provide the bulk or texture that sugar does in baking. However, tagatose browns like sucrose and performs similarly in culinary applications, suggesting it could replace sugar in many foods without sacrificing taste or texture.
Kristin Kirkpatrick, MS, RDN, a nutrition expert who was not involved in the study, spoke to Medical News Today, commenting on the potential advantages of tagatose over other sugar alternatives.
“Some nonnutritive sweeteners have drawn scrutiny over the last few years as potentially contributing to vascular events, as seen in some studies with certain sugar alcohols and obesity, especially artificial sweeteners,” she said.
“Tagatose has minimal impact on blood sugar management and acts as a prebiotic with the formation of short-chain fatty acids (SCFAs). It is not considered an artificial sweetener or sugar alcohol which is part of its appeal to consumers.”
— Kristin Kirkpatrick, MS, RDN
“There are also reported benefits to overall gut health and oral health and is found to be safe alternative to sugar in individuals with diabetes. Finally, tagatose tastes profile is closer to actual that other nonnutritive sweeteners,” Kirkpatrick noted.
The researchers also note that unlike sucrose, tagatose does not fuel cavity-causing bacteria in the mouth. Instead, some research suggests tagatose may even help prevent dental caries.
Still, while tagatose appears promising, it may produce gastrointestinal effects when people consume it in large quantities. Similar to other poorly absorbed carbohydrates, excessive intake might lead to diarrhea, nausea, and flatulence in some people.
Kirkpatrick added that tagatose metabolism involves absorption in the small intestine followed by fermentation in the large intestine and formation of SCFAs. This fermentation in the colon can lead to general gastric distress and symptoms may be mild to moderate.
“Though tagatose is GRAS, individuals with gastrointestinal disorders may be sensitive to these potential symptoms although the dose will often determine the severity of side effects where high doses of tagatose may lead to more severe symptoms.”
— Kristin Kirkpatrick, MS, RDN
“If someone is interested in consuming products utilizing tagatose but is unsure about the impact of side effects, they should start slow, consuming lower doses to assess tolerance,” Kirkpatrick said.
Guidance from the World Health Organization (WHO) advises that people limit their tagatose intake in a single serving to 30 grams to avoid gastrointestinal discomfort.
Furthermore, because tagatose shares similarities with fructose, the sugar alternative may not be suitable for individuals with hereditary fructose intolerance. This describes a condition where people cannot digest fructose as normal and may experience gastrointestinal effects.
As such, despite showing promise, health experts caution that people should wait for large-scale human studies and regulatory evaluations before adding tagatose to their dietary plan.
This research adds to a growing body of evidence suggesting that tagatose may offer a sweetener with a more favorable health profile than many current sugar substitutes.
Additionally, it signals a broader shift towards biotechnologically produced natural ingredients, which may provide an option to help commercialize tagatose and other rare sugars.
However, it is important to emphasize that while sweeteners can help to reduce overall added sugar consumption, more research is still necessary. Although tagatose appears promising, further research into potential long-term effects is required, as well as FDA approval.
