Lomer M C E, Parkes G C, Sanderson J D
Department of Gastroenterology, Guy's and St Thomas' NHS Foundation Trust, London, UK.
Aliment Pharmacol Ther. 2008 Jan 15;27(2):93-103. doi: 10.1111/j.1365-2036.2007.03557.x. Epub 2007 Oct 23.
Approximately 70% of the world population has hypolactasia, which often remains undiagnosed and has the potential to cause some morbidity. However, not everyone has lactose intolerance, as several nutritional and genetic factors influence tolerance.
To review current clinical practice and identify published literature on the management of lactose intolerance.
PubMed was searched using the terms lactose, lactase and diet to find original research and reviews. Relevant articles and clinical experience provided the basis for this review.
Lactose is found only in mammalian milk and is hydrolysed by lactase in the small intestine. The lactase gene has recently been identified. 'Wild-type' is characterized by lactase nonpersistence, often leading to lactose intolerance. Two genetic polymorphisms responsible for persistence have been identified, with their distribution concentrated in north Europeans. Symptoms of lactose intolerance include abdominal pain, bloating, flatulence and diarrhoea. Diagnosis is most commonly by the lactose hydrogen breath test. However, most people with hypolactasia, if given appropriate advice, can tolerate some lactose-containing foods without symptoms.
In clinical practice, some people with lactose intolerance can consume milk and dairy foods without developing symptoms, whereas others will need lactose restriction.
世界上约70%的人口患有乳糖酶缺乏症，该病常常未被诊断出来，且有可能引发一些发病率。然而，并非所有人都有乳糖不耐受症，因为多种营养和遗传因素会影响耐受性。
回顾当前临床实践，并找出已发表的关于乳糖不耐受症管理的文献。
使用“乳糖”“乳糖酶”和“饮食”等术语在PubMed上进行检索，以查找原始研究和综述。相关文章和临床经验为本综述提供了依据。
乳糖仅存在于哺乳动物的乳汁中，并在小肠中被乳糖酶水解。乳糖酶基因最近已被确定。“野生型”的特征是乳糖酶不持续存在，常导致乳糖不耐受。已确定了两种导致乳糖酶持续存在的基因多态性，其分布集中在北欧人身上。乳糖不耐受的症状包括腹痛、腹胀、肠胃胀气和腹泻。诊断最常用的方法是乳糖氢呼气试验。然而，大多数乳糖酶缺乏症患者，如果得到适当的建议，可以耐受一些含乳糖的食物而不出现症状。
在临床实践中，一些乳糖不耐受患者可以食用牛奶和奶制品而不出现症状，而另一些患者则需要限制乳糖摄入。
