Table 2.
Major preclinical studies of multiple injuries and effects on the fecal microbiome and/or intestinal barrier. Arrows indicate a significant change (increase or decrease) and ↔ indicates no significant change compared to uninjured controls; we only selected microbial composition changes shown. T—trauma, HS—hemorrhagic shock, LC—lung contusion, LCHS—lung contusion and hemorrhagic shock, CS—chronic stress, polytrauma (PT), NS—not studied.
| Title | Author and Year | Species | Trauma Model | Time Point(s) Studied Postinjury | Fecal Microbiome Diversity and Composition Changes | Intestinal Barrier Effects |
|---|---|---|---|---|---|---|
| Multicompartmental traumatic injury and the microbiome: shift to a pathobiome | Munley et al., 2023 [73] | Male Sprague-Dawley Rats | Lung contusion, hemorrhagic shock, laparotomy with cecectomy, and bifemoral pseudofracture (PT), or PT with CS (PT/CS) |
3, 7 days | ↓ Alpha-diversity (PT, 3 d) ↓ Alpha-diversity (PT/CS, 3 d, 7 d) Beta-diversity differences (3 d, 7 d) ↑ Enterococcus, Bacteroides, Parabacteroides (PT, 3 d) ↑ Bacteroides (PT/CS, 7 d) |
↑ Plasma occludin (PT/CS, 7 d) ↑ Colonic injury (inflammatory cell infiltrates, lamina propria edema) (PT and PT/CS, 7 d) |
| Multicompartmental Traumatic Injury Induces Sex-Specific Alterations in the Gut Microbiome | Munley et al., 2023 [74] | Male and Female Sprague-Dawley Rats | Lung contusion, hemorrhagic shock, laparotomy with cecectomy, and bifemoral pseudofracture (PT), or PT with CS |
2 days | ↓ Alpha-diversity (PT, PT/CS both sexes) Beta-diversity differences (PT, PT/CS both sexes) ↑ Blautia, Bacteroides (PT, both sexes) ↑ Parasutterella, Frisingicoccus (PT/CS, both sexes) |
↑ Plasma occludin (PT, PT/CS both sexes) ↑ Plasma lipopolysaccharide-binding protein (PT, PT/CS both sexes) ↑ Ileum injury (PT/CS, males) ↑ Colon injury (PT/CS, females) |
| Polytrauma independent of therapeutic intervention alters the gut microbiome | Nicholson et al., 2018 [70] | Male Sprague-Dawley Rats | Laparotomy with small intestine and liver crush injuries, femur fracture, skeletal muscle crush, HS (PT) | 2 h | ↔ Alpha-diversity Beta-diversity differences ↑ Deferribacteres, Lachnospiraceae, Mogibacteriaceae |
NS |
| Whole blood resuscitation restores intestinal perfusion and influences gut microbiome diversity | Yracheta et al., 2021 [72] | Male Sprague-Dawley Rats | Laparotomy with liver crush injury, skeletal muscle crush injury, femur fracture (PT), HS | 2 h | ↔ Alpha-diversity Beta-diversity differences ↑ Roseburia, Enterobacteriaceae ↓ Rothia, Streptococcus |
NS |
| Stress-related changes in the gut microbiome after trauma | Kelly et al., 2021 [69] | Male Sprague-Dawley Rats | LCHS, LCHS and 7 d CS (LCHS/CS 7/7), or LCHS and 14 d CS (LCHS/CS 14) |
3, 7, 14 days | ↔ Alpha-diversity (LCHS, all time points) ↑ Alpha-diversity (LCHS/CS 7/7, 3 d, 7 d) ↑ Alpha-diversity (LCHS/CS 14, 7 d, 14 d) ↔ Beta-diversity (7 d, 14 d) ↑ Ruminococcaceae (3 d), Bacteroides (7 d), Lactobacillus (14 d) (LCHS/CS 7/7) ↑ Clostridium (3 d), Bacteroides (7 d), Lachnospiraceae (14 d) (LCHS/CS 14) |
NS |
| Relationship between disruption of the unstirred mucus layer and intestinal restitution in loss of gut barrier function after traumatic hemorrhagic shock | Rupani et al., 2007 [75] | Male Sprague-Dawley Rats | Laparotomy and sham shock (T/SS), or laparotomy and HS (T/HS) |
0, 30, 60, 180 min | NS | ↑ Villous injury in ileum (T/HS, 60 min) ↓ Villous height in ileum (T/HS, all time points) ↑ Enterocyte apoptosis in ileum (T/HS, 30, 60 min) ↓ Mucus layer in ileum (T/HS) ↑ Serum fluorescein isothiocyanate-dextran 4 (T/HS, 0, 60 and 180 min) |
| Remote intestinal injury early after experimental polytrauma and hemorrhagic shock | Wrba et al., 2019 [76] | Male C57BL/6 Mice | Hemorrhagic shock (HS), or bilateral chest trauma, closed head injury, femur fracture with soft tissue injury (PT), or PT and HS (PT/HS) |
2 h | NS | ↑ Plasma intestinal fatty-acid-binding protein (HS, PT, PT/HS) ↓ Zonula occludens protein 1 ileum, colon (PT/HS) |