Exploring the gut-exercise link: A systematic review of gastrointestinal disorders in physical activity

Table 3 Summary of studies on physical activity and cancer risk or outcomes

Ref.	Type of article	Age of patients	Summary of study characteristics	Outcome
Xie et al[114]	Meta-analysis		Systematic review/meta-analysis of 47 studies (5797768 participants) examining the relationship between PA and DSC risk using PRISMA guidelines	PA reduced DSC risk (RR = 0.82, 95%CI: 0.79-0.85), with significant effects for colon (RR = 0.81), colorectal (RR = 0.77), and gastric cancer (RR = 0.83)
Boytar et al[115]	Narrative review		Summarized research on exercise-induced gut microbiota changes and implications for CRC, focusing on the microbiota’s tumorigenic or protective effects	Exercise may promote anti-tumorigenic microbiota changes, reducing CRC risk. Mechanisms involve improved gut microbiota and decreased dysbiosis
Gerhardsson et al[116]	Longitudinal cohort study	mean: 47.2 years	14-year follow-up of 16477 Swedish participants examining PA and colon cancer risk. Adjusted for age, gender, domicile, and diet	Low PA increased colon cancer risk (RR = 3.6, 95%CI: 1.3-9.8). Rectal cancer risk not elevated. Mechanism: Prolonged stool transit increases carcinogen exposure
Jurdana[117]	Review		Overview of biological mechanisms linking PA to cancer risk reduction, focusing on inflammatory, hormonal, and immune responses	PA reduces cancer risk by lowering inflammation, insulin resistance, and improving microbiota. Moderate-to-vigorous PA intensity provides greatest protection
Spanoudaki et al[118]	Comprehensive review		Explored molecular mechanisms through which PA reduces cancer risk and improves outcomes, including effects on inflammation, hormones, immune function, and oxidative stress	Exercise reduces systemic inflammation, enhances immune function, and may slow tumor progression. Potential for integration into cancer care practices
Jung et al[121]	Meta-analysis of RCTs	mean: 55.4 years	Systematic review/meta-analysis of 7 RCTs (803 CRC survivors) examining effects of PA interventions on quality of life and fatigue	PA improved quality of life and PA levels. No significant effect on fatigue or BMI among CRC survivors
Koelwyn et al[122]	Review		Reviewed the impact of PA on the inflammation-immune axis and its role in cancer prevention and progression	PA favorably modulates immune components, reducing tumorigenesis. Exercise can serve as an adjunctive cancer treatment
Ciernikova et al[123]	Minireview		Examined the impact of diet and PA on gut microbiota in cancer patients. Discussed personalized interventions for gut health maintenance during treatment	PA may help restore gut homeostasis and enhance cancer therapy efficacy. Integration with diet may optimize treatment outcomes
Campbell et al[124]	Practice guideline		Updated exercise guidelines for cancer survivors. Included recommendations specific to cancer type and outcomes (e.g., anxiety, fatigue, and physical functioning)	Exercise is safe and beneficial for cancer survivors. PA improves fatigue, quality of life, and physical functioning. However, more research is needed for specific protocols

PA: Physical activity; DSC: Digestive-system cancer; RR: Risk ratio; CI: Confidence interval; CRC: Colorectal cancer; RCTs: Randomized controlled trials; BMI: Body mass index.