This study will assess global small molecule profiles identified in the human gastrointestinal tract of healthy human volunteers.

The gut is home to an extensive interaction between the host and its microbiota, in different regions exposed to endogenous and exogenous signals, such as nutrition, medications, immune alterations, and geographical location-related factors. this study aims to characterize the small molecule profiles of a cohort of healthy individuals, including their polar, semi-polar, non-polar, and protein landscape. The investigators will develop a pipeline enabling to integrate these small molecule profiles with a variety of inter-individual readouts, as assessed in stools of healthy volunteers. Data will be used to characterize molecular patterns potentially associated with a variety of dietary, immune, and health-related human features, with an aim to characterize small molecules for future causative investigation.

Inclusion Criteria:

• Normal BMI
• Age 18-70

Exclusion Criteria:

• Known food allergies to the tested food items
• Chronic constipation (less than one bowel movement every two days)
• Chronic treatment with any drug upon enrolment.
• The use of systemic antibiotics, probiotics, or proton pump inhibitors 3 months prior to enrollment.
• Diagnosis of type 1 or type 2 diabetes.
• Any chronic disease at the discretion of the study team- such as active or recent cancer, inflammatory bowel disease, systemic autoimmunity
• Any psychiatric disorders
• Alcohol or substance abuse
• Gut-related surgery, including bariatric surgery, but not including previous appendectomy.
• Pregnancy, breastfeeding, or fertility treatments 6 months prior to enrollment for female participants