Effect of Carbonated Prebiotic Beverages Versus Caloric and Non-caloric Beverages on Satiety, Glucose, Insulin, and GLP-1 Response in Healthy Male Participants

Summary

The study aims to study healthy men aged 18-40 to explore how different beverages affect hunger, blood sugar, insulin, and a hormone called GLP-1, which helps regulate appetite and blood sugar. The tested beverages include two prebiotic sodas (Olipop and Poppi), Diet Coke, and Coca-Cola Classic. What's the study about? It aims to understand how these drinks influence how full participants feel and how the body handles sugar and hormones compared to each other. This could help us learn more about how prebiotic drinks, which may support gut health, compare to regular sugary or diet sodas. What will participants do? Participants will visit our lab at TCU (Rickel Building, rooms 256/259) four times over four weeks, with each visit lasting about 2-2.5 hours. Participants will need to fast for 8-12 hours before each visit. Here's what happens: * First visit involves participants' consent, measurement of height and weight, and performing a finger-stick test to check blood sugar and HbA1C. Participants will also fill out questionnaires about health, diet, and beverage preferences. * Visits 2-4: In visit 2, a DEXA scan will be performed to assess body composition. In visits 2-4, participants will drink one of the four beverages (in a random order, served in an unlabeled black container to prevent drink identification). Other variables measured at these time points include blood pressure, fasting glucose, insulin, and GLP-1. Participants will also complete questionnaires about hunger and how the drink tastes. Each visit is spaced out by a week, and the total time commitment is about 10.5 hours. The study is expected to complete participant recruitment by December 10, 2025. Who can join? Ten healthy men aged 18-40 who don't have diabetes, heart disease, kidney or liver issues, or other specific health conditions. Participants shouldn't smoke, vape, or have certain dietary habits like intermittent fasting. Participants will be screened to confirm eligibility. What are the risks? The risks are low but include discomfort from blood draws or the IV catheter, a small chance of infection, and minimal radiation exposure from the DEXA scan (similar to everyday background radiation). There's also a small risk of a data breach, but participant information will be secured with password-protected systems and use ID numbers instead of names. What do participants get? Participants will receive a DEXA scan, baseline blood sugar, and HbA1C tests. If participants have abnormal results (like high blood sugar), doctor visits would be recommended. There are no direct benefits to participants, but participation could help develop better dietary recommendations in the future. How is privacy protected? Data will be stored securely on password-protected computers and in locked lab facilities, following HIPAA rules. Blood samples will be frozen for up to 10 years for possible future research (with participants' consent) and labeled with an ID number, not participants' names. How to join? Participants will be recruited through flyers, emails, social media, and TCU classes. If interested, participants will complete an online screening form or scan a QR code on our flyer. If eligible, participants will be contacted to confirm details and explain the study further. If participants have questions or want to join, contact Dr. Elisa Marroquin at e.marroquin@tcu.edu or Matthew Loritz at m.loritz@tcu.edu. Participation is voluntary, and participants can withdraw at any time, though data will be kept for analysis.

Description

Eligibility

Age range

18–40 years

Sex

Male

Healthy volunteers

Yes

Interventions

• Other
  Prebiotic Soda 1

  A single dose of 12 ounces of Olipop will be provided to the 10 participants while fasted. Blood samples will be collected at baseline (before the drink) and at 15, 30, 60, 90, and 120 minutes after the drink.

• Other
  Prebiotic Soda 2

  A single dose of 12 ounces of Poppi will be provided to the 10 participants while fasted. Blood samples will be collected at baseline (before the drink) and at 15, 30, 60, 90, and 120 minutes after the drink.

• Other
  Diet Soda

  A single dose of 12 ounces of Diet Coke will be provided to the 10 participants while fasted. Blood samples will be collected at baseline (before the drink) and at 15, 30, 60, 90, and 120 minutes after the drink.

• Other
  Regular Coke

  A single dose of 12 ounces of Regular Coke will be provided to the 10 participants while fasted. Blood samples will be collected at baseline (before the drink) and at 15, 30, 60, 90, and 120 minutes after the drink.

Location