Study finds sugar-free diet disrupted gut microbiome and metabolic health in mice

KUWAIT CITY, Kuwait — Research conducted at Kuwait's Dasman Diabetes Institute found that a diet completely free of table sugar produced unexpected negative effects on the gut microbiome and metabolic health in mice. The study, presented at the ENDO 2026 congress, divided 12 mice into two groups and fed one a low-fat diet with sugar and the other a low-fat sugar-free diet for 16 weeks. Although both groups consumed the same number of calories and showed similar body and liver weights, mice on the sugar-free diet developed impaired glucose tolerance, reduced insulin sensitivity and lower fasting insulin levels. The same group also showed a decline in beneficial gut bacteria such as Lactobacillus murinus and an increase in inflammation-linked bacteria, along with signs of fat accumulation and inflammation in the colon and liver. Researchers noted that the findings have not yet gone through peer review and that further studies are needed to determine whether the results apply to humans. Bariatric surgeon Dr. Mir Ali said sugar and carbohydrate restriction remains a core element of weight-loss strategies and that the results should be interpreted cautiously.