Probiotics in a Snack Bar?

Great Lakes Clinical Trials is looking for male and female volunteers between the ages of 18 and 65 for a investigational research study involving the consumption of a daily snack bar. Participants will be randomly assigned to consume either a standard snack bar or a snack bar containing a probiotic for a 4 week period.

The purpose of the study is to measure levels of the probiotic that pass through your gut and appear in your stool. The study will require you to collect your stool on 4 separate occasions throughout the 6-week study period. You will be provided with a stool collection kit and transport systems.

You may be able to participate if you:

  • are of slender build, having a body mass index between 18.5-29.9 kg/m2. Our study staff can help determine this over the phone.
  • have not taken any probiotics in last 4 weeks or antibiotics in the past 6 weeks.
  • have not made any substantial dietary changes or significant weight changes in the past 4 weeks.
  • do not have a history or presence of any GI condition, such as inflammatory bowel disease, IBS, chronic constipation, bowel movement irregularity or eating disorder.

Note other entry criteria will apply and can be discussed with our study staff

You will be asked to visit our clinic on 6 occasions over approximately 6 weeks. One visit is simply to drop off a stool sample. The other 5 visits last between 30-90 minutes.

There is no cost for participation in this study. All medications, tests and doctor visits are free of charge and we do not bill insurance. For your participation, you will receive $25 for visits 1, 2 & 3 and $75 for visits 4, 5, and 6, for a total of up to $300 for completing the trial.

Want to learn more? Visit us at or call (773) 275-3500.