Table 1. Basic characteristics of each study included in this network meta-analysis.

Study ID	Country	Diagnosis	Age of Participants (years)	Number of Participants (T/C)	Nutrition status (Malnutrition/Well nutrition)	Intervention regimes		Reported outcomes
						Treatment group	Control group
Farreras N 2005[24]	Spain	Gastric cancer	66.7 ± 8.3/ 69.2 ± 13.8	30/30	13/53	Early immune-enhanced nutrition EN given product which enriched with Arg, Gln and ω-3-FAs for the next 7 days	Patients received standard EN support for the next 7 days	ICs, LOS
Fujitani K 2012[3]	Japan	Gastric adenocarcinoma	64 (26~78)/ 65 (30~79)	120/111	239/5	Patients received 1000 ml/day of preoperative oral supplementation in the form of an immunonutrients-enriched enteral feed which mainly composed by Arg of 1.28 g/100 mL and RNA of 0.13 mg/mL) added to normal diet for 5 consecutive days before surgery	Patients received regular diet without any nutritional supplementation for 5 consecutive days before surgery	ICs, NICs, LOS
Liu H 2012[25]	China	Advanced gastric cancer	57.3 ± 7.1/ 58.4 ± 6.3	28/24	Not stated	Patients received standard EN of 500 mL per bottle consisting of 20.0 g total protein, 9.5 g fat, 61.5 g carbohydrate, 7.5 g fiber, 3.0 g minerals and 0.15 g vitamins, providing 500 kcal of total energy supplemented with formula enriched with Gln (12.5 g/L) and Arg (9.0 g/L) for the next 7 days	Patients received standard EN of 500 mL per bottle consisting of 20.0 g total protein, 9.5 g fat, 61.5 g carbohydrate, 7.5 g fiber, 3.0 g minerals and 0.15 g vitamins, providing 500 kcal of total energy for the next 7 days	ICs, LOS
Liu H 2011[26]	China	Advanced gastric cancer	71.5 ± 6.1/ 74.1 ± 9.3	28/28	Not stated	Patients were supplemented with immune nutrition enriched with Arg of 9.0 g/ and Gln of 12.5 g/L in addition to the standard EN for the next 7 days	Patients received standard EN for the next 7 days	ICs, LOS
Liu Z 2011[27]	China	Advanced gastric cancer	61.1 ± 7.5/ 61.6 ± 7.2	21/21	Not stated	Patients were supplemented with immunonutrients enriched with Arg, ω-3-FAs and RNA in addition to the standard EN for the first day after surgery lasted for 8 days	Patients were received standard EN for the first day after surgery lasted for 8 days	ICs
Marano L 2013[6]	Italy	Gastric adenocarcinoma	66.6(55–78)/ 65.1(49–83)	54/55	63/115	Patients received immune nutrition enriched with Arg, ω-3-FAs and RNA in the 6 h after the surgery until the 7 postoperative day	Patients received standard EN in the 6h after the surgery until the 7 postoperative day	ICs, NICs, LOS
Okamoto Y 2009[29]	Japan	Gastric cancer	66.9 ± 11.5/ 70.9 ± 13.2	30/30	Not stated	Patients were given 750 ml per day immune-enhanced formulas supplemented with Arg of 9.6 g, RNA of 0.96, and ω-3 FAs of 3.1 g for 7 consecutive days before the operation.	Patients received isoenergetic standard formulas for 7 consecutive days before the operation.	ICs, NICs, LOS,
Xue JB 2011[31]	China	Gastric cancer	56.6 ± 8.9/ 58.2 ± 8.0	26/26	Not stated	Early immune-enhanced nutrition EN given product which enriched with Arg, Gln and ω-3-FAs for the second day after surgery lasted for 7 days	Patients received standard EN support for the second day after surgery lasted for 7 days	ICs, LOS
Xie Q 2010[30]	China	Gastric cancer	62.5 ± 11.9/ 61.3 ± 11.7	29/29	Not Stated	Patients were supplemented with immunonutrients enriched with Arg, ω-3-FAs and RNA in addition to the standard EN for the first day after surgery lasted for 8 days	Patients were received standard EN for the first day after surgery lasted for 8 days	ICs
Lu QC 2009[28]	China	Gastric cancer	68.6 ± 5.6/ 69.1 ± 5.9	25/25	Not Stated	Patients were supplemented with immunonutrients enriched with Arg, ω-3-FAs and RNA in addition to the standard EN for the second day after surgery lasted for 7 days	Patients were received standard EN for the second day after surgery lasted for 7 days	ICs, LOS
Chen BS 2014[23]	China	Gastric cancer	66.3 ± 8.6/ 66.5 ± 8.2	35/35	Not Stated	Patients were supplemented with immunonutrients enriched with Arg, ω-3-FAs and RNA in addition to the standard EN for the seventh day before surgery lasted the seventh days after 7 surgery	Patients were received standard EN for the seventh day before surgery lasted the seventh days after 7 surgery	ICs, NICs, LOS

T = treatment group, C = control group, EN = enteral nutrition, EIN = enteral immunonutrition, Arg = arginine; Gln = glutamine, RNA = ribonucleic acid, ω-3-FA = omega-3-fatty acids, ICs = infectious complications, NICs = noninfectious complications, LOS = length of hospital stay.