Beyond Nutritional Treatment: Effects of Fitwalking on Physical Capacity and Intestinal Barrier Integrity in BMI-Stratified IBS Patients

Abstract

Background: Irritable bowel syndrome (IBS) and obesity are associated with intestinal barrier alterations that result in low-grade inflammation. Zonulin and intestinal fatty acid-binding protein (I-FABP) assess gut barrier health, while urinary indican concentrations reflect dysbiosis in the small intestine. Physical activity, such as Fitwalking, aids weight management and improves intestinal permeability. This study assesses the impact of a 12-week Fitwalking program on intestinal barrier health in IBS patients categorized by body mass index (BMI). Methods: Fifty-seven mild IBS patients were categorized as obese (OB = 18), overweight (OW = 24), or normal weight (NW = 15) and assigned to a walking group. Participants walked thrice weekly at moderate intensity for 60 min per session, using the specific Fitwalking technique, supervised by staff. Results: No significant changes in biochemical or anthropometric variables were observed. However, Fitwalking improved the Global Physical Capacity Score (GPCS) by 46%, 48%, and 24% in the NW, OW, and OB groups. Post-intervention, serum zonulin levels notably decreased in OB individuals, suggesting reduced inflammation. OW patients unexpectedly showed increased fecal zonulin levels. OB participants experienced decreased urinary indican levels. Zonulin levels positively correlated with BMI and inversely with GPCS. Conclusions: Regular exercise benefits the intestinal barrier, especially in obese IBS patients. Monitoring zonulin and I-FABP may offer insights into gut barrier integrity and GI injury severity. Future studies should explore longer intervention durations, larger populations, and advanced diagnostic tools to validate findings and investigate the mechanisms behind exercise-induced changes in intestinal permeability and gut health markers.