Impact of mindfulness tendency and physical activity on brain-gut interactions

Background: Irritable bowel syndrome (IBS) is a disorder of brain-gut interactions characterized by abdominal pain and bowel dysfunction. Exercise and mindfulness have been reported to be effective on IBS, but there has been no study of their interaction. In this study, we hypothesized that exercise and mindfulness interactively affect the severity of IBS symptoms. Methods: Subjects were 703 adolescents with 590 women and 113 men. Their IBS status was evaluated with Rome III Diagnostic Questionnaire and IBS Severity Index (IBS-SI). They also fulfilled past exercise experience, athletic performance and exercise enthusiasm, International Physical Activity Questionnaire (IPAQ), Mindful Attention Awareness Scale (MAAS), Kessler 6 Scale (K6), and Perceived Stress Scale (PSS). Statistical analysis was performed using SPSS v25. Results: In this population, 184 (158 women and 26 men, 14.1%) subjects had Rome III IBS symptoms. IBS subjects scored significantly less in exercise enthusiasm at high school (p = 0.017) and MAAS (p < 0.001) and significantly more K6 (p < 0.001) and PSS (p < 0.001) than non-IBS. The two-way ANOVA on IBS-SI showed a significant main effect of MAAS (p < 0.001) and interaction between MAAS and IPAQ (p = 0.008). Conclusion: It is suggested that mindfulness per se decreases IBS severity, but that mindfulness and physical activity interactively affect the severity. Further studies on how to design interventional trials for IBS patients with mindfulness and physical exercise are warranted.