Oral glutamine supplementation during preoperative radiochemotherapy in patients with rectal cancer: a randomised double blinded, placebo controlled pilot study

BACKGROUND & AIMS: Enteral glutamine may have protective effects on gut function and reduce metabolic stress in patients receiving radiochemotherapy. The aim of our study was to evaluate its influence in patients with rectal cancer undergoing preoperative radiochemotherapy. METHODS: We performed a randomized double blind, placebo controlled pilot study in 33 patients. 30 g of glutamine, average dose 0.41 g/kg (SD = 0.07) g/kg/day was administered orally in three doses per day for five weeks during preoperative radiochemotherapy of rectal cancer. 30 g of maltodextrin was given as placebo. Body weight was measured and NRS 2002 screening was performed before and after treatment. Bowel function was evaluated by stool consistency and frequency. Plasma levels of inflammatory parameters and hormones were measured. RESULTS: There was no difference between groups in frequency and severity of diarrhoea during radiochemotherapy (p = 0.5 and p = 0.39 respectively), insulin levels significantly increased in both groups, IL-6 only in glutamine group. CONCLUSION: Results of this small pilot study in rectal cancer patients receiving preoperative radiochemotherapy, showed that ingestion of larger quantities of glutamine given more often as previously reported did not diminish the incidence and severity of diarrhoea and did not affect inflammatory and metabolic activity compared to the placebo treatment with maltodextrin.