How artificial sweeteners may affect metabolism through gut bacteria.
What the evidence says
- Artificial sweeteners (saccharin, sucralose, aspartame) alter gut microbiota composition and function[1]
- In mice, the microbiome changes are causal: faecal transplant from sweetener-consuming mice into germ-free mice transferred the glucose intolerance, and transplanting saccharin-altered microbiota cultured host-free did the same[1]
- The human evidence is thinner than the mouse evidence and of a different kind: an observational analysis of 381 people found sweetener consumption associated with higher BMI, blood pressure, HbA1c and fasting glucose, and the intervention arm was seven volunteers[1]
- In mice, antibiotic treatment (ciprofloxacin and metronidazole) abrogated the sweetener-induced glucose intolerance, which is what shows the effect is microbiome-mediated[1]
- Individual susceptibility varies: 4 of 7 human volunteers were “responders” who developed glucose intolerance on saccharin, while 3 were unaffected — baseline microbiome composition predicted response[1]
- Microbiome changes were reversible: compositions returned to original configurations within weeks of stopping sweetener consumption[1]