Systematic review of the changes in the microbiome following spinal cord injury: animal and human evidence

Abstract

Study design Systematic review. Objectives To investigate the changes in the microbiome among human and animal populations with spinal cord injury (SCI). Methods Four databases (EMBASE, Medline (Ovid), Web of Science, Cochrane Central Register of Trials (CENTRAL)) and Google Scholar were searched. No language restrictions were applied. Data extraction was done in parallel and independently by two reviewers. The search was last conducted on 07 April 2021. Results There were 6869 studies retrieved, 43 full-text studies reviewed, and 19 studies included. There were seven animal gut studies, six human gut studies, and six urinary tract studies identified. There were no publications found on other body sites. Among the included studies, we observed a consistent and significant difference in gut microbiome composition between populations with SCI and able-bodied populations. This is characterized by a decrease in beneficial butyrate-producing bacteria (Faecalbacterium, Megamonas, Roseburia) and an increase in inflammation-associated bacteria (Alistipes, Anaerotruncus, and Lachnoclostridium). On the other hand, the urine of individuals with SCI was polymicrobial and members of Enterobacteriaceae (Escherichia coli, Klebsiella pneumoniae) were frequently observed. Probiotics were shown to induce a significant but transient shift in the urinary tract microbiome. The studies had low to moderate risks of bias. Conclusions There are limited studies on the changes in microbiome among SCI populations. The gut microbiome was characterized by bacterial profiles associated with chronic inflammation and metabolic disorder while the studies of the urinary tract microbiome show the dominance of bacterial genera associated with urinary tract infection.

The association between altered intestinal microbiome, impaired systemic and ocular surface immunity, and impaired wound healing response after corneal alkaline-chemical injury in diabetic mice

“…In response to cornea injury, both diabetic and WT mice demonstrated changes in alpha diversity patterns compared to baseline. Such a response has been previously documented in other forms of severe non-abdominal injuries, including traumatic brain injury and spinal cord injury resulting in intestinal dysbiosis, which subsequently was followed by impaired systemic immunity ( 41 , 42 ). Such changes may represent a stress response resulting in a temporary alteration in gut microbiome composition.…”

The Role of Gut Microbiota in Various Neurological and Psychiatric Disorders—An Evidence Mapping Based on Quantified Evidence

“…According to the AMSTAR-2 criteria, 21 SRs [7,[17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] scored "critically low," 16 SR [13,[37][38][39][40][41][42][43][44][45][46][47][48][49][50][51] scored "low," and 5 SR [36,[52][53][54][55] scored "moderate" (Figure 2). The most frequent drawbacks were as follows: no mentioning of the protocol in the systematic overview, no description of the rationale for the study designs included in the review, and no statement of funding for the included studies.…”

Beneficial Alteration in Growth Performance, Immune Status, and Intestinal Microbiota by Supplementation of Activated Charcoal-Herb Extractum Complex in Broilers

“…In the cecum and colon, CHC and MMT showed no significant difference, which indicated that the absorptive functions of CHC and MMT acted in the foregut rather than the hindgut. Second, CHC inhibited the abundance of Alistipes which is harmful bacteria related to causing intestinal inflammation in the ileum (Schirmer et al, 2019;Valido et al, 2022). This result suggested that although CHC had advantages in surface area and pore size, the function of absorption may also rely on other properties such as hydrophobic character, distances between porous sheets, and electrical conductivity (Nadziakiewicza et al, 2019).…”