Effect of a 4-week Moderate Intensity Exercise Programme on Gut Microbiota, Cardiovascular Disease Risk Factors and Appetite Regulation in Overweight Women

Study Design: This is a randomized controlled study with a parallel design. Healthy, sedentary females aged between 18-45 years old will be recruited by means of an advertisement leaflet and word of mouth. Eligible participants will be enrolled in the study and will be randomly allocated to either exercise intervention (EX) or control (C) groups. The EX group will participate in a 4-week exercise intervention and the C group will be asked to continue with habitual life style for 4 weeks. Before and after 4 weeks of the intervention, participants from both groups will be asked to conduct a submaximal exercise test and a 7-hour experimental trial during which blood samples will be collected and metabolic rate will measured before and after consumption of standardized breakfast and lunch. Prior to the first 7-hour trial, participants will be asked to record diet for 3 days and replicate this diet prior to the second 7-hour trial. During these 3 days participants will provide fresh stool samples. Participants allocated to control group will have the option to participate in exercise intervention. A subset of the participants will repeat a 7-hour experimental trial and provide fresh stool and urine sample after 7 days of detraining.

Methods:

Preliminary Health Check: Participants will undertake a health screening questionnaire on the day of recruitment. Participants will also need to fill in Physical Activity Readiness Questionnaire (PARQ). Only participants who answered "no" to all questions in PARQ will conduct the submaximal exercise test.

Anthropometry: All participants will have height, weight and waist circumference measured at baseline and 4 weeks after the intervention.

7-hour Experimental Trial: Participants will attend the metabolic suite (New Lister Building, Glasgow Royal infirmary) in a fasted state at approximately 9.00 am. Participants will be instructed to lie supine on the couch, with the head resting on the pillow provided. Resting metabolic rate will be measured for 20 minutes and fasting blood sample will be obtained. A breakfast meal will be consumed immediately after the fasting sample and a lunch meal after 4 hours. Blood samples will be taken throughout a cannula hourly after breakfast and lunch consumption. Following each blood sample, metabolic rate will be measured for the duration of 20 minutes. Prior each blood sample, participants will fill in appetite questionnaires. Blood samples will be analysed for plasma lipids, glucose, insulin, inflammatory markers and gut appetite hormones using standard existing procedures.