Swagerty Daniel L, Walling Anne D, Klein Robert M
Department of Family Medicine, University of Kansas School of Medicine, Kansas City 66160-7370, USA.
Am Fam Physician. 2002 May 1;65(9):1845-50.
Persons with lactose intolerance are unable to digest significant amounts of lactose because of a genetically inadequate amount of the enzyme lactase. Common symptoms include abdominal pain and bloating, excessive flatus, and watery stool following the ingestion of foods containing lactose. Lactase deficiency is present in up to 15 percent of persons of northern European descent, up to 80 percent of blacks and Latinos, and up to 100 percent of American Indians and Asians. A sizable number of adults believe they are lactose intolerant but do not actually have impaired lactose digestion, and some persons with lactase deficiency can tolerate moderate amounts of ingested lactose. A diagnosis of lactose intolerance can usually be made with a careful history supported by dietary manipulation. If necessary, diagnosis can be confirmed by using a breath hydrogen or lactose tolerance test. Treatment consists primarily of avoiding lactose-containing foods. Lactase enzyme supplements may be helpful. The degree of lactose malabsorption varies greatly among patients with lactose intolerance, but most of them can ingest up to 12 oz of milk daily without symptoms. Lactose-intolerant patients must ensure adequate calcium intake.
乳糖不耐受者由于乳糖酶的基因数量不足，无法消化大量乳糖。常见症状包括腹痛、腹胀、屁多，以及摄入含乳糖食物后出现水样便。北欧血统的人群中，高达15%的人存在乳糖酶缺乏；黑人及拉丁裔中，这一比例高达80%；美国印第安人和亚洲人中，则高达100%。相当一部分成年人认为自己乳糖不耐受，但实际上其乳糖消化功能并未受损，而且一些乳糖酶缺乏者能够耐受适量摄入的乳糖。乳糖不耐受的诊断通常可通过详细病史并辅以饮食调整来做出。如有必要，可通过呼气氢试验或乳糖耐量试验来确诊。治疗主要包括避免食用含乳糖的食物。补充乳糖酶可能会有所帮助。乳糖不耐受患者的乳糖吸收不良程度差异很大，但大多数人每天摄入多达12盎司的牛奶也不会出现症状。乳糖不耐受患者必须确保摄入足够的钙。
