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Thanks for you interest in the study!

Enrollment is Complete  

 for this study. 




The Gut Feelings Study for Couples 40 and over

What is the purpose of the study?

On average, people who are married or in a marriage-like relationship have better health than people who do not have a partner, and people’s interactions with their partner have also been related to health.  This study is designed to help understand how people’s feelings about their partner may be related to their immune, cardiovascular, and digestive systems in ways that might influence health. The researchers will measure aspects of your immune system, your heart rate and blood pressure, and your gut microbiome to see if these are linked to your relationship with your partner in ways that could impact long-term health.

What does the study involve?
The study involves a screening appointment (1 hour) and two 7-hour study days that will take place at the Clinical Research Center (CRC), a hospital research unit located at the OSU Medical Center. These full-day visits will be scheduled about 2 years apart.
Because this research is designed in part to understand how your life with your partner is related to the functioning of your immune, cardiovascular, and digestive systems, both partners must be willing to participate; you cannot take part in the study if your partner does not participate at the same time.

What do the screening visits involve?
The purpose of the screening visit is to determine whether or not the couple is eligible to participate in the full study.  Couples do not need to attend the initial 1-hour screening visit together or even on the same day.  This visit will take place on a weekday and can start anytime between 7:30am and 3:00pm.  No fasting is required for this visit.  After both individuals have completed the screening appointment, the couple will be notified if they are eligible to continue with the remainder of the study. The screening visits will include a small blood draw to test for anemia and hemoglobin A1C (a test related to your risk for diabetes) and the completion of study questionnaires.

What do the 7-hour study days involve?
The couple will attend the 7 hour study days together.  These two visits will be scheduled on a weekday and will start at 7:30 am and will last until approximately 2:30 pm. 
At the beginning of each of the 7-hour visits, a nurse will measure your weight, height, blood pressure, and the amount of fat present in your abdominal area. Ideally, the measurements are taken on bare skin or over underwear. If you are uncomfortable with removing your lower body clothing, the measurements will be taken over your clothes. This information is of interest because it is related to risk for heart disease.

A nurse will place sensors on your chest to assess your heart rate and on your wrists to assess perspiration throughout the visit. Your blood pressure will also be measured at regular intervals throughout each 7-hour visit.

A catheter (a small, hollow plastic tube, about the size of a small plastic sewing needle) will be inserted into a vein in your arm so that small amounts of blood can be drawn at different times across the visit. The catheter will be removed at the end of each visit. You will have a total of 235 ml (1 cup) of blood drawn during each of the 7 hour visits; this is 1/2 of the amount that you would give if you were donating blood. A total of 2 cups will be drawn in the 2 sessions that are 2 years apart. These samples will be used to examine the blood levels of hormones and immune function indicators.

You cannot eat anything after 7:30 PM on the nights before the two 7-hour visits. On the day of each visit, you will be given a breakfast as soon as your first blood sample has been drawn, and a lunch at midday.

In order to assess your typical food intake, you will be asked to list all the foods you ate in the last 24 hours before the visit.  In addition, because people eat different foods on different days, you and your partner will each have two telephone interviews after each of the two 7-hour visits and will be asked to list all the foods you ate in the last 24 hours.  These interviews will last 15-25 minutes each. We collect this information because your diet affects your immune system and your gut microbiome.

Following breakfast, you and your partner will be asked to have several conversations.  In the first conversation, each of you will be asked to discuss 2-3 positive events that have happened in your own personal life. Next, each of you will have 10 minutes to talk about something you would like to change about yourself. Then, each of you will be asked to recount a past memory while the other partner listens for 10 minutes. In the last discussion, you and your partner will be asked to discuss and try to resolve an area of disagreement. This discussion will last 20 minutes and the topics will be chosen based on your ratings of common areas of disagreement. The research team will remain out of sight during these discussions. These conversations will be videotaped, and you will be asked about your reactions afterward.

After you are given lunch, you will be asked to complete physical performance tasks that assess your grip strength, walking speed, balance, and ability to stand from a chair. Near the end of the visit, you will be asked about depression and anxiety symptoms that you have experienced over your lifetime, and this interview will be audiotaped; all audiotapes (and the videotapes made during your discussions with your partner) will be kept in locked file cabinets and erased once they have been coded and/or transcribed (typed).

During the visit you will complete survey questions of a personal nature regarding your medications, health conditions, mood, feelings, health behaviors, personality, your relationship with your partner, as well as aspects of your current living environment (for example, pets) that may be related to your immune system and your gut microbiome. You will also be asked to perform several tasks on the computer, including tasks that measure aspects of attention.

Everyone has bacteria in their gut (intestines), and these bacteria typically help the body to digest food and synthesize vitamins. Studies have also linked differences in the gut microbiome (the bacteria in your gut) to moods and to a person’s typical daily diet, as well as gut health and metabolic disorders. In order to help understand how your gut bacteria may be related to aspects of your immune system and to any stress you may be experiencing, you and your partner will each provide a stool sample for your gut microbiome analysis, and you will be asked about bowel-related problems like constipation and diarrhea. You will receive a kit at the visit that contains a cotton swab and a tube with a liquid preservative. You will collect the sample at your home after the visit by swabbing a soiled place on your toilet paper after you have had a bowel movement, then swishing the swab (a sterile Q-tip) in the tube with the preservative liquid for two minutes before capping the tube and throwing away the swab. The amount of sample needed is quite small, and the cotton swab goes immediately into the liquid preservative, so there is no smell from the sample. You will return the sample in a special envelope that will be provided.

Who is eligible to be in the study?
You may be eligible for this study if both you and your partner:

  • Are 40 years of age or older
  • Are not diabetic
  • Are non-smokers
  • Have been living together at least 3 years
  • Are in a heterosexual relationship (Due to current budget constraints, the study is recruiting only heterosexual couples and will open recruitment to same-sex couples with additional funding. We welcome all couples to apply for participation in this study, and will contact same-sex couples who meet all eligibility criteria to enroll, pending the additional funds. In the meantime, click HERE for information regarding our other study that looks at the gut microbiome in both heterosexual and same-sex couples.)

Participants who are pregnant or nursing are not eligible.

How would I benefit from being in the study?
~Free breakfast and lunch at each 7-hour study visit
~Free parking for each CRC visit
~Detailed report regarding your eating patterns, your average daily intake of different nutrients, and recommendations for improving your diet.
~ Detailed report of your gut microbiome results

Will I be paid for participating?
Each partner may be reimbursed up to $535 for your joint participation (for a total of $1070 per couple) over the course of the two year study.

Who are the investigators and where does the funding come from?
Our investigators are scientists and physicians in the Ohio State University Colleges of Medicine and Public Health.  Our project is a joint venture of the Institute for Behavioral Medicine Research, the Department of Medicine, Department of Human Nutrition, and the School of Public Health. The study is funded by the National Institutes of Health (NIH).

Please consider participating! If you would like to participate in this study, please contact us. We would be very happy to discuss our research with you and give you more specific information. If you have any questions, feel free to call us at 614-366-5029 or email us at

Need more info?
Click here to read the consent form (pdf)
Click here to read the HIPAA privacy policy (pdf)

Ready to apply!
Enrollment has been completed for ths study, and we continue to conduct study visits.