The Influence of Physical Activity on the Gut Microbiome of Pre-Diabetic Adults

The present study is a 100-participant randomized controlled 2-arm parallel trial that employs a metagenomic approach to examine how 8 weeks of supervised moderate-intensity treadmill walking exercise (MWE) for 30-45 min 3 times/week alters the gut microbiome, serum short chain fatty acids, and the cardiometabolic profile, body weight, and body composition of individuals 30-64 years old who have overweight or obesity and have prediabetes.

All eligible and consented participants will complete a 3-week run-in phase during which baseline outcome assessments will be performed. During run-in weeks 1 and 2, participants will wear a Fitbit Inspire 2 smartwatch and complete three unannounced dietary recalls. During the run-in week 3 (see table below), participants will consume their 3-day standardized meal plan on days three through five, obtain a fecal sample, complete a study questionnaire, and complete a study assessment visit. To quantify compliance with the 3-day meal plan, participants will be provided with a paper checklist of all foods to be consumed, and will be asked to indicate which foods were consumed and to document any deviation. The study assessment visit will include a fasting blood draw (at baseline and week eight only), blood pressure in triplicate, weight measure and body fat assessment in duplicate, and a saliva sample.

Eligibility Criteria:
Inclusion Criteria:

* Classified as overweight or obese with BMI 25.0-39.9 kg/m2.
* Documentation\* of a prediabetes diagnosis within one year of enrollment by physician or primary care provider based on lab tests showing a fasted blood glucose of 100-125 mg/dL, a 2-hour oral glucose tolerance test of 140-199 mg/dL, or an HbA1c level of 5.7%-6.4%76; OR a study screening lab value of HbA1C within the afore mentioned range.
* Currently engaged in \<100 min/week of physical activity - confirmed by questionnaire.
* No exercise contraindications as assessed by the Physical Activity Readiness Questionnaire (PAR-Q)78-this Questionnaire involves seven "yes" or "no" questions regarding an individual's health status, with answering "yes" to any one of these questions requiring a prospective participant to acquire a written doctor's note stating they can safely participate in the trial's exercise intervention.
* No self-reported physical/mental disabilities or gastrointestinal conditions.
* No antibiotic usage within the last 45 days.
* Stable weight over the last 6 months (\<10% change).
* Not currently pregnant, planning to become pregnant, or currently breastfeeding.
* Willing to maintain current dietary and exercise habits, aside from any changes to be made per the study exercise protocol.

  * Note: Documentation can include either a print out or screen shot of the lab value illustrating eligibility, along with the date of the test and the participant's name. If a hard copy is provided, the date and name will be redacted.

Exclusion Criteria:

* Self-reported use of metformin and/or other medications that could interfere with the primary outcome.
* History of bariatric surgery or a history of other medical interventions that would interfere with the primary outcome.