Effects of Artificial Sweeteners on Gut Microbiota and Glucose Metabolism

The trial will be 12 weeks randomized, cross-over and double blinded with 2 treatment intervention ( sucralose and aspartame) , there will be a run in period (4 weeks), then phase 1 treatment period for two weeks followed by four weeks washout period then phase 2 treatment period(2 weeks). Healthy, normglycemic (<5.6 mmol/L) males and females ( 17 total) of age 18-45 y with a body mass index (BMI) 20-25 kg/m2 will be recruited.

Each participants will be given the dose of sweetener aspartame or sucralose during the treatment phase in a double-blind procedure.

the participant will be asked to consume the sweetener in a mixed flavoured beverage during each visit in the treatment phase.

Blood and stool sample collection will take place before after the run-in period, and after the washout period, as well as after each two-week treatment period.

glucose measurement: Capillary blood will be collected during each visit by registered nurse. Blood will be collected at fasting and at 12,30,45,60,90 and 120 minutes after the participants drink a glucose drink (75g glucose) for Oral glucose tolerance test.

a food frequency questionnaire will be given to each participant in order to estimate how often each sweetener is consumed on a daily basis.

Participants will also be asked to complete weekly food diaries of food and drink consumption.

Inclusion criteria

• BMI between 20-25 kg/m2
• Fasting blood glucose (FBG) < 5.7 mmol/L
• women with regular menstrual cycle.

Exclusion criteria

• probiotic or antibiotic use within 6 months prior to the start of the study
• metabolic or gastrointestinal disorders (diabetes mellitus types 1 and 2, inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), celiac disease, phenylketonuria)
• pregnant or lactating women