Objective To investigate relations between milk consumption and lactose intolerance (LI) in adults and to explore the effect of milk consumption on lactase activity.Methods Total of 182 subjects aged 20‐70 years were recruited and interviewed by questionnaires,and their accumulative cow's milk intake (AMI) was calculated.LI was evaluated by hydrogen breath test (HBT).Results A negative correlation was found between AMI and severity of observed LI symptom (r=-0.2884;P<0.05).Binary logistic regression analysis showed a negative correlation between LI and duration and frequency of milk consumption (OR,0.317 and 0.465,respectively;both P<0.05) and a positive correlation between LI and amount of milk consumed per sitting (OR,6.337;P<0.05).Conclusion LI is related to various milk consumption behaviors.Most Chinese adults with LI may tolerate moderate milk consumption <160 mL.
Objective To study the mechanism of lactose intolerance (LI) by cloning the mouse lactase cDNA and recombining a vector. Methods Total murine RNA was isolated from the small intestine of a 4-week-old BALB/c mouse (♂). Gene-specific primers were designed and synthesized according to the cDNA sequences of lactase-phlorizin hydrolase (LPH) in human, rat, and rabbit. A coding sequence (CDS) fragment was obtained using RT-PCR, and inserted into a clone vector pNEB-193, then the cDNA was sequenced and analyzed using bioinformatics. Results The cDNA from the BALB/c mouse with 912 bp encoding 303 amino acid residues. Analysis of the deduced amino acid sequence using bioinformatics revealed that this cDNA shared extensive sequence homology with human LPH containing a conserved glycosy1 hydrolase family 1 motif important for regulating lactase intolerance. Conclusion BALB/c mouse LPH cDNA (GenBank accession No: AY751548) provides a necessary foundation for study of the biological function and regulatory mechanism of the lactose intolerance in mice.
目的寻找膳食改善牛奶不耐受的措施。方法采用氢呼气试验从38名受试者中筛选出8名有水样状腹泻的乳糖不耐受者,参加用正交实验设计的不同食物与25 g 奶粉搭配的饮奶试验;采用随机整群抽样方法选取健康大学生100名参加以不同方式摄入25 g 奶粉的饮奶试验,观察饮奶试验后出现的不耐受症状。结果受试者饮牛奶,同时摄入鸡蛋、馒头、锅魁、面包后氢呼气浓度比单独饮用牛奶均有降低(均小于1.786 mg/m^3);正交直观分析、方差分析均表明:鸡货与牛奶混食者粪便乳糖和症状评分比馒头与牛奶混食者低,差异有统计学意义。全麦面包与牛奶混食者症状评分最高;不同饮奶方式引起不耐受症状的发生率不同,早餐空腹饮牛奶者不耐受发生率27.6%(27/98),午餐或晚餐饮牛奶者13.7%(13/98),两者的差异有统计学意义。结论食物种类和不同饮奶方式对牛奶不耐受症状有明显影响,建议不要空腹饮奶,而在正餐饮牛奶,并注意与高蛋白膳食、固体食物搭配,不要与含膳食纤维高的食品(如全麦面包)一起食用。
