Physical Activity and Stool Metabolite Relationships Among Adults at High Risk for Colorectal Cancer.

BACKGROUND: Adenomatous polyps are associated with an increased risk of developing colorectal cancer. Physical activity (PA) and spending less time sedentary may reduce risk of polyp recurrence and cancer incidence. This study examined associations between PA, sedentary time, and stool metabolites in adults at high risk for developing colorectal cancer. METHODS: Participants were ≥18 years old with ≥1 adenomatous polyps removed in the previous 3 years. PA and sedentary time were assessed using an activPAL™ accelerometer. Stool samples were analyzed for short-chain fatty acids, and primary/secondary bile acid metabolites by mass spectrometry. Linear regression models examined associations between PA, sedentary time, and stool parameters, with dietary fiber as a covariate. RESULTS: Participants (N = 21) were 59 (9) years old and had a body mass index of 28.1 (3.35 kg/m2). Light-intensity PA was associated with butyrate (ß = 1.88; 95% confidence interval [CI], 0.477 to 3.291) and propionate (ß = 1.79; 95% CI, 0.862 to 2.724). Moderate to vigorous PA was associated with deoxycholic acid (ß = -6.13; 95% CI, -12.14 to -0.11) and ursodeoxycholic acid (ß = -0.45; 95% CI, -0.80 to -0.12) abundance. CONCLUSIONS: Both light and moderate to vigorous PA were associated with gut microbial metabolite production. These findings suggest the importance of examining PA intensity alongside stool metabolites for colorectal cancer prevention.

Feasibility of Beans/Bran Enriching Nutritional Eating For Intestinal Health & Cancer Including Activity for Longevity: A Pilot Trial to Improve Healthy Lifestyles among Individuals at High Risk for Colorectal Cancer.

PURPOSE: Examine the feasibility and preliminary effects of a lifestyle intervention of rice bran plus navy bean supplementation, and physical activity (PA) education on intake of fiber and whole grains, and PA levels. DESIGN: Randomized-controlled, single-blinded. SETTING: Academic institution and free-living. SUBJECTS: Adults >18 years, with ≥1 adenomatous polyp removed within 3 years. INTERVENTION: Participants received powder and pre-prepared meals and snacks that contained either rice bran (30 g/day) plus navy bean (30 g/day), or Fibersol-2® (10 g/day), for 12-weeks. All participants received a 1-hour (PA) education session. MEASURES: Feasibility was assessed by recruitment and retention rates, and compliance to the study foods and procedures. Three-day food logs were analyzed using Nutritionist Pro™ to estimate fiber intake, and the Automated Self-Administered 24-hour (ASA24®) Dietary Assessment Tool calculated Healthy Eating Index (HEI) whole grain and total scores. PA was measured using an ActivPAL™ accelerometer. ANALYSIS: Continuous data were summarized as median, range, and percent change from baseline to post-intervention. RESULTS: N = 20 (86.9%) completed the intervention. Compliance was 92% in the rice bran plus navy bean versus 89% in Fibersol-2®. Navy bean consumption increased from 2 g/day to 30 g/day, and rice bran from 0 g/day to 30 g/day. Fiber intake (g/day) increased by 73% versus 82%, HEI whole grain improved by 270% versus 37%, and HEI total improved by 10% versus 9.1% in rice bran plus navy bean and Fibersol-2®, respectively. Total PA (MET-hours/day) showed minimal change for intervention (+0.04%) and control (+4%). CONCLUSION: Findings merit a larger trial of rice bran plus navy bean and PA to evaluate efficacy for dietary and cancer prevention-related outcomes.