Evaluating the Effects of an Exercise Intervention on the Gut Microbiota in Stage II-III Colorectal Cancer Survivors

Inclusion Criteria: 18-70 years of age Previous diagnosis of stage II-III CRC cancer No known recurrent or metastatic disease No comorbid or physical limitations that would limit participation at the discretion of the treating provider At least 60 days to 3 years from last cancer-directed treatment (including surgery, chemotherapy, and radiation. Elective surgery, including ileostomy reversal, is not counted in this timing but patients must be able to eat a normal diet, without post-operative dietary limitations) Body mass index (BMI) 18.5-30 kg/m^2 Able to understand and willing to sign written informed consent in English Access to phone for study contacts Be willing and able to attend the 24 sessions at the Fred Hutch Exercise Research Center Shared Resource Access to smartphone Willingness to participate in all study activities Completion of all run-in activities Participants must not be active smokers within the past 30 days. Active smoking is defined as any smoking, even a puff. Participants who smoke are much less likely to engage in healthy lifestyle behaviors, and it is probably more important for participants to stop smoking than it is to change their exercise patterns. If identified as a smoker, the individual will be referred to the local resources, Washington State Quitline (1-800-QUIT-NOW), ICanQuit.org, Quit2Heal.org, the national resource, Centers for Disease Control and Prevention (CDC) "Quit Now" phone line which supports smoking cessation, or the National Institutes of Health (NIH) quit support website "SmokeFree.gov" At time of consent, participants must engage =< 60 minutes per week of moderate to vigorous physical activity, as assessed by brief questionnaires at screening and then objectively assessed using accelerometers at baseline Participants must have an Eastern Cooperative Oncology Group (ECOG) Scale of Performance Status score of 0 or 1 for performance status Physician approval for participation in an 8-week exercise program Women must not be pregnant at time of enrollment Exclusion Criteria: Use of oral or intravenous antibiotics, antifungals, or antiparasitics during the past 6 months Presence of an ileostomy or colostomy because of known changes to the gut microbiome with ileostomies and colostomies Current status of underweight (BMI < 18.5 kg/m^2) or obese (BMI 30.0 kg/m^2) Presence of inflammatory bowel diseases such as Crohn's disease or ulcerative colitis as these are known to baseline have differences in gut microbiome composition Active smokers within the past 30 days Women who are pregnant or breastfeeding, or planning to become pregnant