Table 3.
Summary of human research studies investigating the potential role of nutritional supplement interventions for the prevention or attenuation of exercise-induced gastrointestinal syndrome (EIGS) markers, and exercise-associated gastrointestinal symptoms (GIS), in response to exertional-heat stress and (or) field competitive events, in comparison to placebo or control.
| Supplement | Supplementation intervention | Exertional-heat stress and (or) field competitive events | Gastrointestinal integrity, function, symptom, and systemic outcomes (pre- to post-exercise magnitude vs. placebo or control) |
|---|---|---|---|
| Antioxidants [77] |
2 weeks Vitamin E, 1000 IU/day. |
Marathon competition, Tamb not reported. | ↔ Intestinal permeability. ↔ Overall incidence and severity of gastrointestinal symptoms. |
| L-Arginine [150] |
14 days 30 g/day. | Marathon competition in Tamb -2°C | ↔ Intestinal permeability. ↔ Incidence and severity of gastrointestinal symptoms. |
| Glutamine [73][151][152] |
7 days 0.9g/kgFFM/day. Pre-exercise 0.9g/kgFFM. Pre-exercise 0.25, 0.5, and 0.9 g/kgFFM. |
1 h running at 70% V̇O2max in Tamb 30°C. 1 h running at 70% V̇O2max in Tamb 30°C. 1 h running at 70% V̇O2max in Tamb 30°C. |
↓ Intestinal permeability. ↑ IκBα expression. ↑ HSF-1, HSP70 and occludin expression in response to heat stress. ↔ Intestinal permeability. ↔ Endotoxemia. ↔ TNF-α. ↔ HSP70 and IκBα expression. ↓ Intestinal permeability, ↔ Epithelial injury, ↔ Gastrointestinal symptoms. |
| Bovine colostrum [65][153] |
7 days 1.7 g/kg/day. 14 days 20 g/day. |
90 min of altered intensity cycling and running exercise in Tamb 30ºC 46 min running at 95% ventilatory threshold in Tamb 40ºC. |
↔ Intestinal permeability ↔ endotoxemia and cytokinemia (IL-1β, TNF-α, IL-6, IL-10 and IL-8). ↔ I-FABP. |
| Probiotics [154][81][155][156][157] |
4 weeks multistrain probiotic capsule. 7 days 1.0 ×1010 L. casei CFU/day beverage24. 12-weeks multi-strain probiotic + prebiotic + antioxidant capsule vs. multi-strain probiotic + prebiotic capsule. 3 months 4.0 × 1010 L. rhamnosus CFU/day beverage. 12-weeks multi-strain probiotic capsule vs. multi-strain probiotic + glutamine powder. |
Running exercise to fatigue at 80% of ventilatory threshold (~35 min) in Tamb 35ºC. 2 h running exercise at 60% V̇O2max in Tamb 34.0ºC. Long distance triathlon competition, Tamb not reported. Marathon competition, Tamb not reported. Multi-stage ultra-marathon (7 days 249 km, Sahara Desert, Tmax 39ºC). |
↔ Intestinal permeability. ↔ Neutrophil function. ↔ LPS and anti-LPS IgM. ↔ Cytokinemia (TNF-α, IL-6, IL-10 and IL-1ra). ↔ Incidence and severity of gastrointestinal symptoms. ↑ Endotoxemia. ↔ Cytokinemia (IL-1β, TNF-α, IFN-γ, IL-6, IL-10 and IL-8). ↔ Incidence of gastrointestinal symptoms. ↔ Intestine permeability.a ↔ Endotoxemia and anti-endotoxin.a Unclear description of gastrointestinal symptoms during and after exercise. ↔ Incidence of Gastrointestinal symptoms. ↓ Duration of Gastrointestinal symptoms incidence. ↔ Incidence of oral and upper respiratory tract symptoms. ↔ eHSP72. |
| Curcumin [158] |
3-days 500 mg/day curcumin. | 1 h running at 65% V̇O2max in Tamb 37ºC. | ↓ I-FABP. ↓ IL-1ra. ↔ IL-6, MCP-1, and TNF-α. |
Significant reduction ↓↓ (p < 0.01) and ↓ (p < 0.05) vs. placebo or control, significant increase ↑ (p < 0.05) vs. placebo or control, ↔ no significant change or unclear statistical consistency and representation vs. placebo or control. BM: Body mass, FFM: fat free mass, Tamb: ambient temperature, Tmax: maximal ambient temperature, CFU: colony forming units. a Measured day prior to event and then at 6-days postevent.