By Peace Erewunmi

A new study by researchers at the University of Cambridge has found that many commonly used low-calorie and artificial sweeteners may alter the growth of gut bacteria, raising fresh questions about their long-term effects on human health. The findings suggest that these sweeteners may not be as biologically inactive as previously believed.

The researchers examined 39 natural and artificial sweeteners against 25 species of gut bacteria in laboratory tests. They found that about 75 per cent of the sweeteners affected the growth of at least one bacterial species, with some slowing or completely inhibiting the growth of beneficial microbes that support digestion and metabolism.

The study also identified more than 100 interactions between sweeteners and commonly consumed substances, including medications, caffeine and flavourings. One notable finding showed that isosteviol, a compound derived from stevia, combined with the antidepressant duloxetine, had a stronger suppressive effect on beneficial gut bacteria than either substance alone.

Despite the findings, the researchers cautioned that the study was conducted in laboratory conditions and does not establish that the same effects occur in humans. They stressed that further clinical studies are needed to determine whether these bacterial changes translate into meaningful health outcomes.

The study adds to a growing body of research examining how artificial sweeteners may influence the gut microbiome, an ecosystem of microorganisms that plays an important role in digestion, immunity and overall health. Scientists say understanding these interactions could help guide future dietary recommendations and the development of safer food additives.