The Effects of Glutamine Supplementation on Inflammatory and Oxidative Stress Indices in Chronic Diseases: a Systematic Review.

Chronic diseases are often associated with increased inflammation and oxidative stress, which contribute to disease progression. Glutamine, a conditionally essential amino acid, has been studied for its potential anti-inflammatory and antioxidant properties in various chronic conditions. The present systematic review evaluates the effects of glutamine supplementation on inflammatory markers and oxidative stress indices in patients with chronic diseases. Systematic searches were performed in web databases; Web of Science, Scopus, and PubMed/Medline until May 2025, to identify related randomized controlled trials (RCTs) according to the Cochrane Library and PICOS criteria (population: individuals > 18 years, intervention: glutamine, Comparison: placebo or control, Outcomes: inflammatory and oxidative stress markers in chronic diseases). The Cochrane collaboration tool was used to assess the risk of bias in clinical trials. Six RCTs that assessed the effect of glutamine supplementation on inflammation and oxidative stress markers were included in the study. In these studies, glutamine was administered to the participants through oral or parenteral routes. In three studies improve inflammation via significant reductions in CRP were observed. However, in three studies that examined TNF-α as an inflammatory marker, only one study found its levels to be significantly reduced. Also, of the two studies that examined oxidative stress levels, only one study significantly decreased the MDA and increased SOD levels, and in the other study, glutamine supplementation had no significant effect on glutathione levels. Our findings showed that glutamine supplementation might have a positive effect on inflammation and oxidative stress indices such as TNF-α, CRP, MDA, and SOD in some chronic diseases, however, these effects have not been shown in all studies, so more carefully designed clinical trial studies with different doses of glutamine on inflammation and oxidative stress in chronic diseases are needed. PROSPERO Code: This study was registered in the PROSPERO international prospective register of systematic reviews registration number: CRD420251049112.