Dear Editor,
In a recent article, the authors reported a randomized, double-blinded controlled trial focusing on the effect of enteral immunonutrition (EIN) on the immune, inflammatory marker and nutritional status in postoperative gastric cancer (GC) patients compared to that of standard enteral nutrition (SEN) [Citation1]. This study is very interesting, as it systematically investigated various immune and inflammation markers in postoperative GC patients in different nutrition groups, and the study could show a more comprehensive effect of EIN.
Increasing evidence has indicated that proper nutritional support could reduce the risk of adverse events after major gastrointestinal surgery, and enteral nutrition is recognized as the first-line nutritional support recommended by ESPEN guidelines [Citation2, Citation3]. Various nutritional formulas have been tested to identify optimal nutritional support. With the introduction of novel immune-enhancing nutrients, including arginine (Arg), ω-3 fatty acids, glutamine (Gln), and nucleotides, EIN was first proposed almost twenty years ago. EIN aims not only to supply necessary energy but also to modify immune function [Citation4, Citation5]. Since the introduction of EIN, its clinical impact has been evaluated by several studies. Although controversy remains between different studies because of heterogeneity of study design, several high-quality meta-analyses have validated the benefit of EIN in decreasing postoperative complication rates and reducing the patient’s length of stay [Citation6–8]. However, randomized controlled trials are still limited, and more specific effects of EIN need to be investigated. In this study, the authors performed a well-designed randomized controlled trial with comparable demographic characteristics among different groups, and thorough laboratory variables including peripheral blood immune cells counts, serum immunoglobulin levels, and nutritional indexes were examined. The number of CD4+ T cells, the number of CD3+ T cells, and the serum level of IgA, IgM, and IgG significantly decreased in the SEN group after surgery, whereas these indexes showed no significant changes in the EIN group. The results showed that early postoperative EIN could improve immune function and inflammatory response in gastric cancer patients compared to patients receiving SEN. As T lymphocyte-mediated immunity plays a vital role in antitumor immunity, decreasing the adverse effect of surgery on T cells might benefit the outcome in cancer patients [Citation9]. In addition, there was no difference in the nutritional markers between the two groups, indicating that the nutritional formulas applied in this study were comparable to SEN nutrients. Limited by the sample size, the data on postoperative complications were not enough to analyze and compare in this study. Furthermore, as the focus of this study was to explore the immune and inflammatory markers one week after surgery, the data on long-term outcomes between the SEN group and SIN group were lacking, and long-term outcomes are worth exploring in the future.
This study is significant for its design and broad investigation into immune and inflammation markers in GC patients, as these markers specifically elucidate the benefits of EIN. We believe that early postoperative EIN has the potential to become one crucial component of the Enhanced Recovery After Surgery (ERAS) for GC patients, and its effect on postoperative patients with other diseases is promising and should be explored in further studies.
DECLARATION OF INTEREST
The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the article.
References
- Li K, Xu Y, Hu, Y, Liu Y, Chen X, Zhou Y. Effect of enteral immunonutrition on immune, inflammatory markers and nutritional status in gastric cancer patients undergoing gastrectomy: a randomized double-blinded controlled trial. J Invest Surg In press.
- Bozzetti F, Gianotti L, Braga M, et al. Postoperative complications in gastrointestinal cancer patients: the joint role of the nutritional status and the nutritional support. Clin Nutr. 2007;26(6):698–709. doi:10.1016/j.clnu.2007.06.009.
- Weimann A, Braga M, Harsanyi L, et al. ESPEN guidelines on enteral nutrition: surgery including organ transplantation. Clin Nutr. 2006;25(2):224–244. doi:10.1016/j.clnu.2006.01.015.
- Senkal M, Zumtobel V, Bauer KH, et al. Outcome and cost-effectiveness of perioperative enteral immunonutrition in patients undergoing elective upper gastrointestinal tract surgery: a prospective randomized study. Arch Surg. 1999;134(12):1309–1316.
- Braga M, Gianotti L, Radaelli G, et al. Perioperative immunonutrition in patients undergoing cancer surgery: results of a randomized double-blind phase 3 trial. Arch Surg. 1999;134(4):428–433.
- Wong CS, Aly EH. The effects of enteral immunonutrition in upper gastrointestinal surgery: A systematic review and meta-analysis. Int J Surg. 2016;29:137–150. doi:10.1016/j.ijsu.2016.03.043.
- Cerantola Y, Hubner M, Grass F, et al. Immunonutrition in gastrointestinal surgery. Br J Surg. 2011;98(1):37–48. doi:10.1002/bjs.7273.
- Guan H, Chen S, Huang Q. Effects of enteral immunonutrition in patients undergoing pancreaticoduodenectomy: a meta-analysis of randomized controlled trials. Ann Nutr Metab. 2019;74(1):53–61. doi:10.1159/000495468.
- Bethune MT, Joglekar AV. Personalized T cell-mediated cancer immunotherapy: progress and challenges. Curr Opin Biotechnol. 2017;48:142–152. doi:10.1016/j.copbio.2017.03.024.