Table 2.
Human studies assessing the effect of combat-training on intestinal permeability.
| Stress duration | Study population | Study design | Intestinal permeability test | Intestinal permeability measure | Results | Reference |
|---|---|---|---|---|---|---|
| 18 days | 71 male U.S. marines | Within-subjects design | LBP | Increased transepithelial uptake of LPS | LBP concentrations decreased from pre to post combat training (p < 0.001) | Varanoske et al. (2022) |
| 6 weeks | 38 male Asian Medical Response Force soldiers | Within-subjects design | Sucralose (24h) | Total gastrointestinal permeability | Total gastrointestinal permeability was increased in the combat-training group compared to the rest group (p < 0.001) | Phua et al. (2015) |
| 6 weeks | 39 male Asian Medical Response Force soldiers | Within-subjects design | Sucrose (5h) | Gastroduodenal permeability | Significantly higher in solders during combat-training compared with rest (p < 0.01) | Li et al. (2013) |
| L/M ratio (5h and 24h) | Small intestinal permeability | Significantly increased in a subgroup of soldiers with IBS-SSS≥75 during combat training compared with soldiers IBS<75 (p < 0.05) | ||||
| Sucralose (5h and 24h) | Total gastrointestinal permeability | Significantly higher in soldiers during combat-training compared with rest (p < 0.01 and p < 0.001, respectively) |
Abbreviations: LBP, lipopolysaccharide binding protein; LPS, lipopolysaccharide; L/M, lactulose/mannitol ratio; IBS-SSS, irritable bowel syndrome symptom severity score; IBS, irritable bowel syndrome.