Four weeks of probiotic supplementation reduces GI symptoms during a marathon race.

Jamie N Pugh,Simon C Fleming,Andy S Sparks,Dominic A Doran,Robert Fearn,Ben Kirk,James P Morton,Graeme L Close,Carl Langan-Evans

doi:10.1007/s00421-019-04136-3

Abstract

PurposeTo evaluate the effects of probiotic supplementation on gastrointestinal (GI) symptoms, circulatory markers of GI permeability, damage, and markers of immune response during a marathon race.MethodsTwenty-four recreational runners were randomly assigned to either supplement with a probiotic (PRO) capsule [25 billion CFU Lactobacillus acidophilus (CUL60 and CUL21), Bifidobacterium bifidum (CUL20), and Bifidobacterium animalis subs p. Lactis (CUL34)] or placebo (PLC) for 28 days prior to a marathon race. GI symptoms were recorded during the supplement period and during the race. Serum lactulose:rhamnose ratio, and plasma intestinal-fatty acid binding protein, sCD14, and cytokines were measured pre- and post-races.ResultsPrevalence of moderate GI symptoms reported were lower during the third and fourth weeks of the supplement period compared to the first and second weeks in PRO (p < 0.05) but not PLC (p > 0.05). During the marathon, GI symptom severity during the final third was significantly lower in PRO compared to PLC (p = 0.010). The lower symptom severity was associated with a significant difference in reduction of average speed from the first to the last third of the race between PLC (− 14.2 ± 5.8%) and PRO (− 7.9 ± 7.5%) (p = 0.04), although there was no difference in finish times between groups (p > 0.05). Circulatory measures increased to a similar extent between PRO and PLC (p > 0.05).ConclusionProbiotics supplementation was associated with a lower incidence and severity of GI symptoms in marathon runners, although the exact mechanisms are yet to be elucidated. Reducing GI symptoms during marathon running may help maintain running pace during the latter stages of racing.

Highlights

Gastrointestinal (GI) symptoms are widely reported in athletes participating in prolonged endurance events (Costa et al 2017a)
The aim of the present study was to evaluate the effects of probiotic supplementation on gastrointestinal (GI) symptoms, circulatory markers of GI permeability and damage, cytokines and cortisol during a marathon race
Utilising an officially sanctioned track marathon race in a wide range of experienced marathon runners, we report that all runners experienced GI symptoms, with two athletes abandoning the race due to severe GI discomfort

Summary

Introduction

Gastrointestinal (GI) symptoms are widely reported in athletes participating in prolonged endurance events (Costa et al 2017a). 27% of recreational runners report moderate or more severe GI symptoms during a race (Pugh et al 2018). The pathogenesis of such symptomology is still poorly understood, it is likely multifactorial in nature. The exercise-induced reduction in splanchnic blood flow is well characterised (Otte et al 2001) and results in dysregulation of the intestinal barrier. This likely leads to endotoxemia and an immunological response, which has been associated with GI symptoms during ultraendurance events (Jeukendrup et al 2000). Carbohydrate (CHO) intake during exercise is suggested to be a potential causative and or aggravating factor, due to malabsorption when consumed in excess (de Oliveira and Burini 2014),

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