Background: Human intestines are home to a complex gut flora, also called microbiome; this is a natural occurring community of bacteria, fungi, yeast, and viruses. Changes in the balances of the gut flora can lead to illnesses, such as diabetes, colorectal cancer, and inflammatory bowel diseases. Synbiotics are dietary supplements people take to maintain proper balances of their gut flora aiming to improve health.

Objective: To find out if a synbiotic supplement can increase the type and amount of beneficial gut bacteria in healthy people as well as improve cardio-vascular protection markers. The supplement contains a natural sugar from human milk.

Eligibility: Healthy people aged 18 years or older who eat a typical western diet. They must take no medications (with a few exceptions).

Design: Participants will have 2 clinic visits. The first visit will start with screening. They will have a blood test and wait around 2 hours for the results of the blood test. The test will determine if they are eligible for the study. Eligible participants will have additional blood drawn during the screening visit. They will be given a kit to collect a stool sample at home with instructions. They may complete a 3-day food diary. They will meet with a nutritionist and a physician by phone, telehealth, or in person. The supplement is a powder that is mixed with water or another noncarbonated drink. Participants will drink 2 doses per day. Each dose will be 1 hour before or after a meal. The second visit will be about 8 weeks after the first. Participants may repeat the 3-day food diary and nutrition visit. The physical exam, blood tests, and stool sample will be repeated.