posted on 2023-08-30, 14:34authored byJustin D. Roberts, Craig Suckling, Georgia Peedle, Dan Gordon, Hannah Marshall, Lee Taylor, Michael G. Roberts
Beneficial use of probiotic (PRO) interventions on gastrointestinal endotoxemia (GE) prior to an ultra-endurance triathlon has been previously demonstrated. The prevalence of GE (and whether PRO strategies minimise gastrointestinal (GI) symptoms) relating to multi-day ultra-events is less known. Understanding if nutritional periodization strategies confer similar GI benefits also warrants investigation.
PURPOSE: To assess the impact of probiotic supplementation and caloric periodization prior to an extreme ultra-marathon on GI symptoms and race performance.
METHODS: Thirty-eight healthy participants were recruited from entrants of the 2015 Marathon Des Sables (age: 42±9yrs; weight: 77.71±10.31kg; VO2max: 52.58±8.66 mL·kg·min-1), and randomly assigned to either: PRO (100mg.d-1 capsulated Lactobacillus acidophilus); CP (caloric periodization of 500kcal above habitual intake on alternate days) or control (CON) for 12 weeks pre-race. Plasma lipopolysaccharides (LPS) via Limulus Amebocyte Lysate chromogenic endotoxin quantification were determined at baseline, pre and post-race. Participants graded duration and severity of GI symptoms through daily questionnaires. Performance times were obtained from accumulated race tracking. Data presented as mean ±SE.
RESULTS: Race times (hrs:mins) were 41:28±2:31, 45:12±2:05 and 50:43 ±4:38 for PRO, CP and CON respectively (p>0.05). Overall LPS significantly increased from baseline (10.08±0.53pg.ml-1) to pre-race (13.12±0.74pg.ml-1; p=0.001). Delta LPS pre-race was not different between groups (PRO: 2.94±1.11pg.ml-1; CP: 3.71±1.28pg.ml-1; CON: 2.32±1.26pg.ml-1; p>0.05). Similarly, delta LPS post-race was not different, despite greater reductions in both intervention groups (PRO: -4.57±1.93pg.ml-1; CP: -6.95±1.84pg.ml-1; CON: -2.16±2.21pg.ml-1; p>0.05). GI symptom count favoured PRO (21.8%) compared with CP (41.6%) and CON (36.6%) respectively (p=0.001), although no differences for GI symptom index were reported between groups (p>0.05).
CONCLUSIONS: Moderate GE was evident in a UK cohort undertaking a multi-day ultra-marathon. PRO use did not significantly impact on GE prevalence, despite evidence of reduced GI symptoms. Caloric periodization appeared to favour GE recovery post-race, but was not deemed significant.