Seki Nobuo, Hamano Hirokazu, Iiyama Yuriko, Asano Yuzo, Kokubo Sadayuki, Yamauchi Koji, Tamura Yoshitaka, Uenishi Kazuhiro, Kudou Hideki
Food Research & Development Laboratory, Morinaga Milk Industry Co., Ltd., Zama, Kanagawa 228-8583, Japan.
J Nutr Sci Vitaminol (Tokyo). 2007 Feb;53(1):5-12. doi: 10.3177/jnsv.53.5.
To evaluate the effect of lactulose on calcium (Ca) and magnesium (Mg) absorption, we performed a clinical trial with a double-blind, randomized, crossover design in 24 healthy adult male volunteers. The absorptions of Ca and Mg were evaluated by a single-labeling method using stable isotopes. The test foods, containing lactulose at a dose of 0 g (placebo), 2 g (low-dose), or 4 g (high-dose) together with 300 mg of Ca containing 20 mg of 44Ca, and 150 mg of Mg containing 28 mg of 25Mg, were administered orally. Urine samples were collected for 8 h after the ingestion of the test food. The ratios of stable isotopes in urine (44Ca/40Ca and 25Mg/24Mg) were measured by ICP-MS (inductively coupled plasma-mass spectrometry). The urinary stable-isotopes ratios (44Ca/40Ca and 25Mg/24Mg) increased with lactulose dosage. Significant differences were observed in the Ca ratio between placebo and high-dose lactulose (p<0.01), and in the Mg ratio between placebo and low-dose lactulose and between placebo and high-dose lactulose (p<0.01). Lactulose ingestion did not change the levels of bone-resorption markers (type I collagen cross-linked N-telopeptide and deoxypyridinoline) in urine. The test foods did not cause any side effects. This study demonstrates that lactulose enhances the absorptions of Ca and Mg in adult men.
为评估乳果糖对钙（Ca）和镁（Mg）吸收的影响，我们对24名健康成年男性志愿者进行了一项采用双盲、随机、交叉设计的临床试验。采用稳定同位素单标记法评估Ca和Mg的吸收情况。口服受试食物，其含0 g（安慰剂）、2 g（低剂量）或4 g（高剂量）乳果糖，同时含有300 mg钙（其中含20 mg 44Ca）和150 mg镁（其中含28 mg 25Mg）。摄入受试食物后收集8小时的尿液样本。通过电感耦合等离子体质谱法（ICP-MS）测定尿液中稳定同位素的比率（44Ca/40Ca和25Mg/24Mg）。尿液中稳定同位素比率（44Ca/40Ca和25Mg/24Mg）随乳果糖剂量增加而升高。安慰剂组与高剂量乳果糖组之间的Ca比率存在显著差异（p<0.01），安慰剂组与低剂量乳果糖组以及安慰剂组与高剂量乳果糖组之间的Mg比率存在显著差异（p<0.01）。摄入乳果糖未改变尿液中骨吸收标志物（I型胶原交联N-端肽和脱氧吡啶啉）的水平。受试食物未引起任何副作用。本研究表明，乳果糖可增强成年男性对Ca和Mg的吸收。
