An Exploratory Investigation of Endotoxin Levels in Novice Long Distance Triathletes, and the Effects of a Multi-Strain Probiotic/Prebiotic, Antioxidant Intervention

Justin D. Roberts, Craig A. Suckling, Georgia Y. Peedle, Joseph A. Murphy, Tony G. Dawkins, Michael G. Roberts

Gastrointestinal (GI) ischemia during exercise is associated with luminal permeability and increased systemic lipopolysaccharides (LPS). This study aimed to assess the impact of a multistrain pro/prebiotic/antioxidant intervention on endotoxin unit levels and GI permeability in recreational athletes. Thirty healthy participants (25 males, 5 females) were randomly assigned either a multistrain pro/prebiotic/antioxidant (LAB⁴ANTI; 30 billion CFU·day(-1) containing 10 billion CFU·day(-1)Lactobacillus acidophilus CUL-60 (NCIMB 30157), 10 billion CFU·day(-1)Lactobacillus acidophillus CUL-21 (NCIMB 30156), 9.5 billion CFU·day(-1)Bifidobacterium bifidum CUL-20 (NCIMB 30172) and 0.5 billion CFU·day(-1)Bifidobacterium animalis subspecies lactis CUL-34 (NCIMB 30153)/55.8 mg·day(-1) fructooligosaccharides/ 400 mg·day(-1) α-lipoic acid, 600 mg·day(-1)N-acetyl-carnitine); matched pro/prebiotic (LAB⁴) or placebo (PL) for 12 weeks preceding a long-distance triathlon. Plasma endotoxin units (via Limulus amebocyte lysate chromogenic quantification) and GI permeability (via 5 h urinary lactulose (L): mannitol (M) recovery) were assessed at baseline, pre-race and six days post-race. Endotoxin unit levels were not significantly different between groups at baseline (LAB⁴ANTI: 8.20 ± 1.60 pg·mL(-1); LAB⁴: 8.92 ± 1.20 pg·mL(-1); PL: 9.72 ± 2.42 pg·mL(-1)). The use of a 12-week LAB⁴ANTI intervention significantly reduced endotoxin units both pre-race (4.37 ± 0.51 pg·mL(-1)) and six days post-race (5.18 ± 0.57 pg·mL(-1); p = 0.03, ηp² = 0.35), but only six days post-race with LAB⁴ (5.01 ± 0.28 pg·mL(-1); p = 0.01, ηp² = 0.43). In contrast, endotoxin units remained unchanged with PL. L:M significantly increased from 0.01 ± 0.01 at baseline to 0.06 ± 0.01 with PL only (p = 0.004, ηp² = 0.51). Mean race times (h:min:s) were not statistically different between groups despite faster times with both pro/prebiotoic groups (LAB⁴ANTI: 13:17:07 ± 0:34:48; LAB⁴: 12:47:13 ± 0:25:06; PL: 14:12:51 ± 0:29:54; p > 0.05). Combined multistrain pro/prebiotic use may reduce endotoxin unit levels, with LAB⁴ANTI potentially conferring an additive effect via combined GI modulation and antioxidant protection.