Effect of perioperative glutamine-enriched nutritional support on patients with colorectal cancer: A systematic review and meta-analysis

Figure 1 Flow chart for literature screening. COPD: Chronic obstructive pulmonary disease.

Figure 2 Methodological quality graph and summary of the included studies. A: Risk of bias summary; B: Risk of bias graph.

Figure 3 Pooled effect estimates for randomized controlled trials assessing the effect of glutamine supplementation on changes in primary outcomes between the intervention and control groups. A: Morbidity of infectious complications; B: Morbidity of non-infectious complications; C: The length of stay (day).

Figure 4 Pooled effect estimates for randomized controlled trials assessing the effect of glutamine supplementation on changes in nutritional status between the intervention and control groups. A: Albumin level (g/L); B: Prealbumin level (mg/L); C: Peripheral blood lymphocyte counts (× 10⁹/L) levels.

Figure 5  Pooled effect estimates for randomized controlled trials assessing the effect of glutamine supplementation on changes in nitrogen balance levels (g/d) between the intervention and control groups.

Figure 6 Pooled effect estimates for randomized controlled trials assessing the effect of glutamine supplementation on changes in cellular immune function between the intervention and control groups. A: CD3⁺ levels (%); B: CD4⁺ levels (%); C: CD8⁺ levels (%); D: CD4⁺/CD8⁺ levels.

Figure 7 Pooled effect estimates for randomized controlled trials assessing the effect of glutamine supplementation on changes in humoral immune function between the intervention and control groups. A: IgA levels (g/L); B: IgG levels (g/L); C: IgM levels (g/L).

Figure 8 Pooled effect estimates for randomized controlled trials assessing the effect of glutamine supplementation on changes in inflammation level between the intervention and control groups. A: Tumor necrosis factor-α levels (pg/mL); B: C-reactive protein levels (mg/L).

Figure 9 Sensitivity analyses (removing one by one) was performed on the pooled analysis results with high heterogeneity (I² > 75%) to verify the robustness of the pooled analysis. A: Length of hospital stay; B: Albumin levels; C: Prealbumin levels; D: CD8⁺ levels; E: CD4⁺/CD8⁺ levels; F: IgG levels; G: IgM levels; H: Tumor necrosis factor-α levels; I: C-reactive protein levels.

Figure 10  Egger's test. A: Morbidity of infectious complications; B: The morbidity of non-infectious complications; C: Length of hospital stay; D: Albumin levels; E: Prealbumin levels; F: CD4⁺ levels; G: CD8⁺ levels.