University Hospital Zürich, Zürich, Switzerland.
Triemli-Hospital, Zürich, Zürich, Switzerland.
United European Gastroenterol J. 2013 Jun;1(3):151-9. doi: 10.1177/2050640613484463.
Lactose malabsorption is a common condition caused by reduced expression or activity of lactase in the small intestine. In such patients, lactose intolerance is characterized by abdominal symptoms (e.g. nausea, bloating, and pain) after ingestion of dairy products. The genetic basis of lactose malabsorption is established and several tests for this condition are available, including genetic, endoscopic, and H2-breath tests. In contrast, lactose intolerance is less well understood. Recent studies show that the risk of symptoms after lactose ingestion depends on the dose of lactose, lactase expression, intestinal flora, and sensitivity of the gastrointestinal tract. Lactose intolerance has recently been defined as symptoms developing after ingestion of lactose which do not develop after placebo challenge in a person with lactose maldigestion. Such blinded testing might be especially important in those with functional gastrointestinal diseases in whom self-reported lactose intolerance is common. However, placebo-controlled testing is not part of current clinical practice. Updated protocols and high-quality outcome studies are needed. Treatment options of lactose intolerance include lactose-reduced diet and enzyme replacement. Documenting the response to multiple doses can guide rational dietary management; however, the clinical utility of this strategy has not been tested. This review summarizes the genetic basis, diagnosis, and treatment of lactose malabsorption and intolerance.
乳糖吸收不良是一种常见病症，由小肠内乳糖酶表达或活性降低引起。在这些患者中，乳糖不耐受的特征是摄入乳制品后出现腹部症状（如恶心、腹胀和疼痛）。乳糖吸收不良的遗传基础已经确立，并且有几种针对这种情况的测试，包括基因、内窥镜和 H2 呼气测试。相比之下，乳糖不耐受的机制了解较少。最近的研究表明，摄入乳糖后出现症状的风险取决于乳糖剂量、乳糖酶表达、肠道菌群和胃肠道敏感性。最近将乳糖不耐受定义为在乳糖消化不良的患者中，摄入乳糖后出现而在安慰剂对照挑战后不会出现的症状。在功能性胃肠道疾病患者中，这种盲法测试可能尤为重要，因为他们常自我报告乳糖不耐受。然而，安慰剂对照测试并非当前临床实践的一部分。需要更新的方案和高质量的结局研究。乳糖不耐受的治疗选择包括减少乳糖饮食和酶替代治疗。记录对多种剂量的反应可以指导合理的饮食管理；然而，这种策略的临床实用性尚未得到检验。本综述总结了乳糖吸收不良和不耐受的遗传基础、诊断和治疗。
