Clinical Trials / Research Studies
Clinical Trials / Research Studies

Study for Healthy Adults 18 to 45 Years Old

Why are we doing this research?

Cincinnati Children’s is conducting a research study, sometimes known as a clinical trial or clinical study, to better understand changes in the immune system with aging.

Who can participate?

Healthy adults 18 to 45 years old who are not taking antibiotics, prebiotics / probiotics or a blood thinner may be eligible to participate.


  • Healthy Adults

What will happen in the study?

You will be asked to come in for 3 study visits and complete 3 phone/electronic survey visits over about 3 months. Here are some of the things that will happen in this study:

You will:

  • Answer questions about your health, current medications and demographics
  • Have vital signs taken
  • Be asked about the foods and beverages you eat and drink
  • Submit blood samples
  • Receive collection kits and instructions for collecting stool samples at home and returning the samples

You will be given a consent form that thoroughly explains all of the details of the study. A member of the study staff will review the consent form with you and will be sure that all of your questions are answered.

What are the good things that can happen from this research?

If you agree to take part in this study, you will not receive a direct benefit from taking part in this research. However, it is possible that the study will result in benefit to others in the future. You may gain personal satisfaction from being a part of a study that contributes to advancing our understanding of the relationship between changes in the gut microbiome and the immune system during aging.

What are the bad things that can happen from this research?

There may be some risks and discomforts from being in the study which we will discuss with you. The most common risks are discomfort or bruising from the blood draws.

Will you/your child be paid to be in this research study?

Participants will receive up to $150 for time and effort.


Contact Us.
For more information or to see if you qualify:
Go to


Contact the Study Team

Study Doctor

Contact Us.
Thomas Hagan, PhD
Rebecca Brady, MD
Division of Infectious Diseases
Cincinnati Children’s Hospital Medical Center