Investigating the protective effects of physical activity on acute stress reactivity in IBS patients

Abstract

Introduction: Irritable bowel syndrome (IBS) is characterized by gastrointestinal (GI) symptoms, and as a consequence of dysregulated communication via the gut-brain axis, is highly comorbid with mental illnesses such as anxiety and depression. With no known cure, IBS patients must manage their symptoms through lifestyle factors. Physical activity is one such lifestyle factor that reduces GI symptoms and improves mental health; however, it remains unclear whether physical activity buffers against the acute worsening of IBS symptoms following a stressor. Method: To investigate this, we evaluated the stress reactivity and recovery of 9 IBS patients and 13 healthy controls following exposure to acute stress. We exposed participants to an electronic Trier Social Stress Test (e-TSST) and measured changes in psychological stress (state anxiety), physiological stress (sympathovagal balance, where higher LF/HF ratio indicates greater stress system activation), and GI symptom severity before, during and every 20 minutes for one hour after. Physical activity was measured using the Stanford Seven-Day Physical Activity Recall questionnaire and quantified as weekly energy expenditure. Results: IBS patients had higher state anxiety (p = .05), LF/HF ratio (p = .01) and GI symptom severity (p = .01) than healthy controls. Although the e-TSST did not exacerbate these group differences, higher state anxiety at baseline (p = .03) and higher LF/HF ratio in response to an acute stressor (p < .001) were associated with more severe GI symptoms within the first 20 minutes following the e-TSST. Importantly, IBS patients who were more physically active experienced less severe GI symptoms during that same timeframe (p = .03). Conclusion: Physical activity may be a promising lifestyle factor for lessening GI symptom severity in response to an acute stressor.