The association between gastrointestinal injury, complaints, and food intake in 60-km ultramarathon runners

We aimed to assess the association between gastrointestinal (GI) injury, complaints, and food intake in 60-km ultramarathon runners. Thirty-three ultramarathon runners provided pre-and post-race blood samples for assessment of GI injury by intestinal fatty-acid binding protein (I-FABP), and inflammatory response by interleukin (IL)-6, IL-8, tumour necrosis factor alpha (TNF-a), and C-reactive protein (CRP). GI complaints and nutritional intake were reported by a post-race questionnaire. GI complaints were reported by 73% of the runners, of which 20% reported 1 or 2 severe complaints. IL-6, IL8, TNF-a, and CRP increased significantly from pre-to post-race (P < 0.001 for all biomarkers), while I-FABP did not (1375 [IQR: 1264–2073] to 1726 [IQR: 985– 3287] pg/mL; P = 0.330). The ‘GI complaints score’, as the integral of the number and severity of GI complaints, did not correlate with DI-FABP (rs: –0.050, P = 0.790) or energy intake (rs: 0.211, P = 0.260). However, there was a significant negative correlation between energy intake and DI-FABP (rs: –0.388, P = 0.031). In conclusion, GI complaints were neither associated with food intake nor GI injury as assessed by plasma I-FABP response. Energy intake, however, was inversely related to the I-FABP response to exercise. This finding suggests that substantial energy intakes during exercise may prevent exercise-induced GI injury as assessed by the I-FABP response. Novelty: • No association between gastrointestinal complaints and gastrointestinal injury (I-FABP response) or food intake was present. • There was an inverse correlation between energy intake and plasma I-FABP response, suggesting that higher energy intakes may prevent gastrointestinal injury as assessed by the I-FABP response.