婴儿乳糖不耐受症

婴儿乳糖不耐受症是由于乳糖酶缺乏 ,不能完成消化分解母乳或牛乳中的乳糖所引起的非感染性腹泻病 ,远东人群中发生率高。　　婴儿饮食以母乳或牛乳为主 ,这两种乳品中的糖类主要是乳糖 ,小肠粘膜表面绒毛的顶端是分泌乳糖酶的地方 ,如分泌量减少或活性不高就不能完全消化和分解乳汁中的乳糖。部分乳糖经大便排出体外 ,使粪中还原糖增加 ,部分留在结肠内的乳糖被结肠菌群酵解成乳酸、氢气、甲烷和二氧化碳[1] 。乳酸刺激肠壁 ,增加肠蠕动而出现腹泻。ＣＯ2 在肠道内产生胀气和增强肠蠕动 ,使婴儿表现不安 ,偶尔还可能诱发肠痉挛而出现肠绞痛…     

Abdominal pain associated with lactose ingestion in children with lactose intolerance

The causal relationship between lactose ingestion and gastrointestinal symptoms is questionable. The aim of this study was to assess symptoms associated with milk ingestion in children with lactose maldigestion. Thirty children (11 males) age 3 to 17 years with lactose maldigestion were studied. In a double-blind, crossover design, subjects ingested 240 mL daily of either lactose-hydrolyzed or lactose-containing milk for 14 days. Diaries were kept daily that recorded diet, medication use, and symptoms. There was a significant increase in abdominal pain experienced by study participants during the lactose ingestion period when compared to the lactose-free period. We conclude that ingestion of 12 g of lactose daily is associated with increased abdominal pain in susceptible children with lactose maldigestion. A trial of dietary lactose restriction may be beneficial in reducing abdominal pain in children with lactose maldigestion.     

Two-hour lactose breath hydrogen test

Current requirements for the lactose breath hydrogen test (LBHT) include serial expired air samplings and multiple hydrogen (H2) determinations. One hundred thirty-two consecutive LBHTs were evaluated to determine whether multiple samplings are indeed necessary for detection of lactose malabsorption. Expired air samples were collected at 0, 30, 60, 90, 120, 150, and 180 min following ingestion of lactose. Fifty-five LBHTs were positive for lactose malabsorption. All tests showed abnormally elevated breath H2 concentrations at 120 min. The mean value of the change in parts per million (delta ppm) of H2 at 120 min (51.1 +/- 4.7 SEM) was higher than at any other time point. If only the 120-min samples were examined without subtracting the initial concentrations, four of the 77 negative tests (5.2%) would have been falsely positive. Thus, the values of H2 at 0 and 120 min were sufficient to define lactose malabsorption in all cases. We conclude that just as a single blood sample now suffices for determining xylose malabsorption, so expired air sampling at only 0 and 120 min during the LBHT is a reliable method for detecting lactose malabsorption and diminishes the need for acquiring and analyzing multiple samples.     

Intestinal parasites and lactose malabsorption

Breath-test was performed for diagnosis of lactose malabsorption in 50 Gabonese children of normal nutritional status, aged 5 to 15 years, with parasites in stools, but without diarrhoea or digestive symptoms. Control group was unparasitized and consisted of 17 children and 18 young adults living in the same area. Parasites discovered by stool examination were Ascaris lumbricoides in 76% of parasitized children, Trichuris trichiura in 58%, Giardia in 24%, Entamoeba histolytica in 20%, Schistosoma intercalatum in 16% and Necator Americanus in 14%. Children were given a 10 g lactose load and adults 20 g. Lactose malabsorption was discovered in 64% of parasitized patients and in 63% of unparasitized. Ten of 12 (83.3%) of Giardia infected children had a lactose malabsorption (no significant difference). These data show that decrease of lactase activity in African children is not related to the presence or to the importance of intestinal parasitism, except for Giardia infestation, if nutritional status is normal.     

Beta-galactosidase tablets in the treatment of lactose intolerance in pediatrics

Lactose-intolerant children manifest diminished or nonexistent intestinal lactase activity, resulting in flatulence, abdominal pain, and diarrhea. To assess the hydrolytic capability of lactase-containing tablets taken immediately before oral lactose challenge, we studied 18 children previously identified as being lactose intolerant and having no underlying organic gastrointestinal disease. Subjects had a mean (+/- SEM) age of 11.4 +/- 3.4 years; 72% were male. At time of the study, lactase-containing tablets or placebo tablets were ingested (double-blind) immediately before drinking a solution of lactose. Breath samples were obtained for hydrogen analysis at 30-minute intervals during a 2-hour period, and clinical symptoms were monitored. In lactose-intolerant patients, hydrogen production was significantly greater following placebo (maximum hydrogen excretion, approximately 60 ppm) compared with lactase-containing tablets (maximum hydrogen excretion, 7 ppm). Increased hydrogen production was associated with clinical symptoms including abdominal pain (89% of subjects following placebo ingestion), bloating (83%), diarrhea (61%), and flatulence (44%). These results indicate, therefore, that coingestion of lactose and lactase-containing tablets significantly reduces both breath hydrogen excretion and clinical symptoms associated with lactose intolerance.     

小儿乳糖不耐受临床探讨

为探讨乳糖不耐受（ＬＩ）在兰州地区的发病情况，我们自１９９１．３１￣１９９３．８采用徐州医学院推荐的醋酸铅氢氧化学法，观察腹泻患和２９５８便，不伴有腹泻闰 状的肠道外感染患儿２０３例，并以４０例健康婴儿粪便对照。发现３岁以下腹泻患儿中乳不耐受的发生率占４６．９％，且年龄越小发生率越高，各年龄组之间有显著差异；３岁以上患儿无１例１１这与不再以乳食为主有关；轮状病毒性肠炎的ＬＩ发生率显著高于细菌性肠炎     

婴儿乳糖不耐受的诊治研究

婴儿乳糖不耐受(LI)最常见的症状为腹泻,约占婴儿腹泻的46%～70%。LI的腹泻无特异性,单凭临床难以确诊。确诊LI必须有乳糖吸收不良(LM)的客观指标。呼气氢试验、肠黏膜活检、双糖酶测定等方法在国外已开展较多,但均需要一定的仪器设备。最简单的方法为测定粪便中的还原糖。国际上已公认,用Clinitest试剂测定粪糖可作为婴儿LI的粗筛试验。由于Clinitest试剂必须进口,购买不便,国内又先后推出了醋酸铅法、改良班氏试剂法。笔者近年来试用了普通班氏试剂检测婴儿粪糖并与Clinitest试剂进行对照,结果相似。班氏试剂价格低廉,易买易配,各基层单位均能采用,可作为Clinitest试剂的代用品。LI一旦确诊,不论原发、继发均应采用去乳糖饮食疗法。