The effect of glutamine supplementation on serum levels of some inflammatory factors, oxidative stress, and appetite in COVID-19 patients: a case-control study

Inflammopharmacology. 2021 Dec;29(6):1769-1776. doi: 10.1007/s10787-021-00881-0. Epub 2021 Oct 28.


Background: Malnutrition is seen in COVID-19 patients, and reducing malnutrition with appropriate therapies may improve these patients' health. This case-control study aimed to assess and compare serum levels of some inflammatory factors, oxidative stress, and appetite in COVID-19 patients with respiratory infections that receive glutamine treatment with a control group.

Methods: In this study, patients who consented to use glutamine were considered as the case group and other patients who did not use glutamine were considered as a control group. Two hundred twenty-two COVID-19 patients (51.2 ± 6.7) using L-Glutamine and 230 COVID-19 patients (51.3 ± 8.2) with similar age, gender, and clinical status, as the control group, were included in the study. For 5 days, the case group consumed 10 g of glutamine supplement three times per day. At the end of the 5 days, blood samples were taken again to test for serum levels of IL1β, tumor necrosis factor-α, malondialdehyde, and total antioxidant capacity, then all data were analyzed.

Results: Serum levels of β-1 interleukin, tumor necrosis factor-α and hs-CRP were significantly reduced with five days of glutamine supplementation (p < 0.05), and patients' appetite during 5 days of glutamine supplementation compared with the control group had a significant increase (p < 0.05).

Conclusion: Glutamine supplementation in COVID-19 patients with respiratory infection significantly reduces serum levels of interleukin-1 β, hs-CRP, and tumor necrosis factor-α and significantly increases appetite, so glutamine supplementation may be useful for COVID-19 patients in the hospital.

Keywords: Appetite; COVID-19; Glutamine; Oxidative stress.

Publication types

  • Clinical Trial

MeSH terms

  • Appetite / drug effects*
  • COVID-19 / pathology
  • COVID-19 Drug Treatment*
  • Case-Control Studies
  • Dietary Supplements
  • Female
  • Glutamine / therapeutic use*
  • Humans
  • Inflammation / prevention & control*
  • Interleukin-1beta / blood*
  • Male
  • Malondialdehyde / blood*
  • Middle Aged
  • Nutritional Status
  • Oxidative Stress / drug effects*
  • Tumor Necrosis Factor-alpha / blood*


  • IL1B protein, human
  • Interleukin-1beta
  • Tumor Necrosis Factor-alpha
  • Glutamine
  • Malondialdehyde