目的 探讨乳糖酶添加剂对早产儿乳糖不耐受改善的有效性以及安全性。方法 2018年1月至2019年12月对上海交通大学医学院附属新华医院、上海市第一妇婴保健院、浙江大学医学院附属儿童医院和苏州大学附属儿童医院收治的有乳糖不耐受症状并符合入组标准的早产儿进行研究，将研究对象随机分为乳糖酶治疗组及对照组，各80例。乳糖酶治疗组患儿每顿母乳或早产儿配方奶中加入4滴（180 mg）乳糖酶，同时予双歧杆菌三联活菌散口服及腹部按摩作为辅助治疗。对照组患儿则在每顿奶中加入同等剂量的安慰剂，并予与治疗组相同的益生菌和腹部按摩进行辅助治疗。在干预后第1周末和第2周末比较两组患儿临床症状、体重、粪便pH值、粪便还原糖等指标。结果 乳糖酶治疗组和对照组分别有78例、77例完成研究。干预后第1周末，乳糖酶治疗组还原糖阳性率较对照组低（P<0.05）；干预后第2周末，乳糖酶治疗组患儿腹胀发生率较对照组低（P<0.05），还原糖阳性率低于对照组（P<0.05），同时乳糖酶治疗组患儿喂养增加量高于对照组（P<0.05）。研究过程中两组均未发现患儿对乳糖酶添加剂或益生菌产生不良反应。结论 外源性乳糖酶添加剂可有效并且安全地缓解早产儿乳糖不耐受相关的临床症状。

Objective To explore the efficacy and safety of lactase additive in improving lactose intolerance in premature infants. Methods Preterm infants with lactose intolerance admitted to Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai First Maternal and Infant Health Hospital, Children's Hospital Affiliated to Zhejiang University School of Medicine and Children's Hospital Affiliated to Soochow University from January 2018 to December 2019, who met the inclusion criteria were included in the study. They were divided into lactase treatment group and control group randomly, with 80 cases in each group. For the patients in the lactase treatment group, 4 drops (180 mg) of lactase were added to each feeding of breast milk or formula milk for premature infants, and Bifidobacterium triple viable powder was orally administered and abdominal massage was used as adjuvant therapy. For patients in the control group, 4 drops (180 mg) of placebo were added to each feeding, and the same probiotics and abdominal massage as the treatment group were given, After 1 and 2 weeks treatment, symptoms of lactose intolerance, weight, fecal pH, fecal reducing sugar and other indicators were compared between the two groups. Results seventy-eight patients in the lactase treatment group and 77 patients in the control group, respectively, completed the whole study. After the first week intervention, the positive rate of reducing sugar in the lactase treatment group was lower than that in the control group (P<0.05). At the end of the second week treatment, the proportion of abdominal distension in the lactase treatment group were lower than those in the control group (P<0.05), and the positive rate of reducing sugar was lower than that in the control group (P<0.05). The increase of feeding amount was also higher than that of the control group (P<0.05). During the course of the study, no adverse reactions to lactase additives or probiotics were found in both groups. Conclusions Lactase supplementation can effectively and safely improve the clinical symptoms caused by lactose intolerance in premature infants.