Effects of glutamine on markers of intestinal inflammatory response and mucosal permeability in abdominal surgery patients: A meta-analysis

Abstract

The present meta-analysis was carried out to determine whether supplementation with glutamine (Gln) would reduce the intestinal inflammatory response and mucosal permeability in patients undergoing abdominal surgery. The PubMed, EMBASE, Web of Science, and The Cochrane Library databases were searched for randomized controlled trials on the effects of supplementation with Gln, and published from August, 1966 to June 2014. Inclusion criteria for the meta-analysis were: i) Study design was a randomized controlled trial, ii) study included patients undergoing abdominal surgery, iii) study patients received a supplementation with Gln peptide (Ala-Gln or Gly-Gln) whereas control patients did not use any supplements, and iv) study outcomes included inflammatory markers [C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), and interleukin (IL)-6, and IL-2 receptor] and markers of intestinal permeability [lactulose/mannitol, diamine oxidase, D(−)lactic acid, and endotoxin]. Qualities of controlled trials were assessed using the Jadad score. Meta-analyses were performed with fixed- or random-effect models depending on the heterogeneity of studies. There were 21 trials meeting the inclusion criteria. The meta-analysis revealed that the levels of CRP, TNF-α, and IL-6 in patients supplemented with Gln were significantly lower than those in control patients, whereas the levels of IL-2 receptor were increased by Gln supplementation. Gln also significantly decreased the lactulose/mannitol ratio, the levels of diamine oxidase and endotoxin, and tended to decrease the levels of cyclic D-lactic acid. In conclusion, Gln appears to effectively reduce the inflammatory response and intestinal mucosal permeability in patients after abdominal surgery.

Dietary supplementation with Clostridium butyricum helps to improve the intestinal barrier function of weaned piglets challenged with enterotoxigenic Escherichia coli K88

“…d ‐lactic acid is a metabolite of bacterial fermentation and, as intestinal mucous membrane permeability increases, higher levels of d ‐lactic acid are observed in the bloodstream (Shu et al . ). When the intestinal barrier function is impaired, damaged intestinal mucosal epithelial cells can also release diamine oxidase into blood plasma (Shu et al .…”

“…When the intestinal barrier function is impaired, damaged intestinal mucosal epithelial cells can also release diamine oxidase into blood plasma (Shu et al . ). Therefore, d ‐lactic acid and diamine oxidase are reliable markers for the indirect assessment of intestinal mucosal damage and impaired permeability (Liu et al .…”

“…; Shu et al . ). In the current experiment, consistent with improved intestinal barrier function, C. butyricum regulated intestinal mucosal permeability, indicated by decreased d ‐lactic acid levels in serum when compared to control pigs fed the basal diet.…”

“…The effects of C. butyricum on the markers for intestinal mucosal permeability were examined by measuring the D-lactic acid concentration and diamine oxidase activity. D-lactic acid is a metabolite of bacterial fermentation and, as intestinal mucous membrane permeability increases, higher levels of D-lactic acid are observed in the bloodstream (Shu et al 2016). When the intestinal barrier function is impaired, damaged intestinal mucosal epithelial cells can also release diamine oxidase into blood plasma (Shu et al 2016).…”

Therapeutic benefits of glutamine: An umbrella review of meta-analyses

“…Therefore, glutamine serves a critical role in the protection of the intestinal immune barrier and leads to increased resistance to bacterial translocation and, hence, reduces infectious complication rates. This fact is supported by a meta-analysis that presented beneficial changes in the markers of intestinal inflammation and mucosal permeability with abdominal surgery patients (35). Finally, glutamine supplementation enhances cellular heat shock protein production (HSP70 and HSP72) and glutathione expression, which both protect cells and enhance cell survival.…”