Non-caloric sweeteners are common food supplements consumed by millions worldwide as means of combating weight gain and diabetes, by retaining sweet taste without increasing caloric intake. While they are considered safe, there is increasing debate regarding their potential role in contributing to metabolic derangements in some humans. The investigators recently demonstrated that non-caloric sweeteners consumption could induce glucose intolerance in mice and, in preliminary experiments, in distinct human subsets, by functionally altering the gut microbiome, and that the gut microbiome plays an important role in mediating differential glucose responses to identical foods. The proportion of the human population that is susceptible to glucose intolerance induced by non-caloric sweeteners, the common factors that are shared between these individuals and whether and how the microbiome promotes the metabolic derangements remain to be addressed.

Inclusion Criteria:

1. BMI<28
2. Age - 18-70
3. Capable of working with smartphone application
4. Capable to work with a glucometer

Exclusion Criteria:

1. Consumption of antibitioics 3 months prior to the first day of the experiment.
2. Consumption of Non caloric sweetners 6 months prior to the first day of the experiment.
3. Diagnosis with type 1 or type 2 diabetes.
4. Pregnancy, fertility treatments
5. Breastfeeding (Including baby to breast and bottle feeding expressed breast milk)
6. Chronic disease (e.g. AIDS, Cushing syndrome, CKD, acromegaly, hyperthyroidism etc.)
7. Cancer and recent anticancer treatment
8. Psychiatric disorders
9. Coagulation disorders
10. IBD (inflammatory bowel diseases)
11. Bariatric surgery
12. Alcohol or substance abuse
13. BMI>28
14. Aspartame group only: phenylketonuria.