Artificial sweeteners, such as aspartame, sucralose and saccharin, are a popular option for those looking to add sweetness without the calories. They are used to flavor a wide variety of common products, from Diet Coke to toothpaste, but there are concerns about their long-term health effects. According to Scientific American, the case against artificial sweeteners was strengthened last year, when a team of Israeli researchers found that artificial sweeteners could, ironically, lead to obesity and related conditions such as diabetes by changing the gut bacteria in mice. While other studies have found a link between obesity and artificial sweeteners, this was the first to propose a causal mechanism.
Researchers found that the sweeteners can alter the population of intestinal bacteria involved in direct metabolism. This process converts food to energy or stored fuel. Even though the study was conducted in mice, Scientific America reports that the findings may also be reflective of what occurs in humans.
The human gut microbiome consists of trillions of bacteria living within our digestive tract. These microbes, in combination with our genes, impact our ability to digest and extract energy from food. According to Scientific American, the Israeli scientists found that artificial sweeteners enhance growth of bacteria that are better at converting food into fat.
The researchers fed a daily dose of aspartame, sucralose of saccharin to a group of 10-week-old mice while another group was fed water laced with one of two natural sugars, glucose or sucrose. The mice fed sweeteners had abnormally high blood sugar at 11 weeks, whereas those who received sugar did not. These findings suggest that the artificial sweetener group had more trouble absorbing glucose from the blood, or “glucose intolerance”. In left uncorrected, this can lead to a number of health issues, such as diabetes and an elevated risk of liver and heart disease. However, the researchers found this effect to be reversible. Researchers killed all gut bacteria in the mice via broad-spectrum antibiotics; after this was conducted, the microbiome returned to normal and so did blood sugar.