The prevalence of lactase deficiency and lactose intolerance in Chinese children of different ages

To determine lactose metabolism and lactase activity in Chinese children of different ages, prevalence of lactase deficiency (LD), and lactose intolerance (LI) Methods All 1168 healthy subjects between 3 and 13 years were recruited from schools in four large cities in China They were screened by a 25?g lactose tolerance test Some subjects were challenged with 50?g milk powder on different days Both indicators, the expiratory H 2 concentration and intolerance symptoms, were analyzed Results LD occurred in 38 5% of children in the 3-5 year age group, and 87% of the 7-8 year and 11-13 year old groups The age of occurrence for LD may be at 7-8 years among Chinese children The prevalence of LI among Chinese children was 12 2% at age 3-5 years, 33 1% at age 7-8 years, and 30 5% at age 11-13 years, respectively Conclusion The results demonstrate that LD is very common in Chinese children from these four cities LD and LI have a dose dependent response: lactose absorption and symptoms are based on lactase activity The relationship between breast feeding history (or the history of cow milk intake) and lactase activity among Chinese children has not been

Efficacy of incremental loads of cow's milk as a treatment for lactose malabsorption in Japan

BACKGROUND Lactose intolerance(LI)is commonly seen in East Asian countries.Several studies showed that lactose or milk loading has been used as a treatment for lactose malabsorption(LM)in Western countries,but there have been no reports regarding this type of treatment in Japan.As lactose or milk loading requires ingestion of large amounts of lactose within a short period,this is considered to be too harsh for Japanese people because of their less habitual milk consumption(175 mL per day in average)than Western people.In this study,we demonstrated lactose tolerance acquisition in a suitable way for Japanese.AIM To examine the efficacy of lactose(cow’s milk)loading treatment in patients with LM.METHODS Individuals with abdominal symptoms induced by milk or dairy products(LI symptoms)were identified with a questionnaire.A 20 g lactose hydrogen breath test(LHBT)was carried out to confirm LM diagnosis and to evaluate co-existence of small intestinal bacterial overgrowth(SIBO).Respondents diagnosed with LM were selected as study subjects and were treated with incremental loads of cow’s milk,starting from 30 mL and increasing up to 200 mL at 4-7 d intervals.After the treatment,changes in symptoms and LM diagnostic value of 20 g LHBT were investigated.Stool samples pre-and post-treatment were examined for changes in intestinal microbiota using 16S rRNA sequencing.Informed consent was obtained prior to each stage of the study.RESULTS In 46 subjects with LI symptoms(10-68 years old,mean age 34 years old)identified with the questionnaire,35(76.1%)were diagnosed with LM by 20 g LHBT,and 6 had co-existing SIBO.The treatment with incremental cow’s milk was carried out in 32 subjects diagnosed with LM(14-68 years old,median age 38.5 years old).The mean period of the treatment was 41±8.6 d.Improvement of symptoms was observed in 29(90.6%;95%confidence interval:75.0%-98.0%)subjects.Although 20 g LHBT indicated that 10(34.5%)subjects had improved diagnostic value of LM,no change was observed in 16(55.2%)subjects.Analysis of the fecal intestinal microbiota showed a significant increase in Blautia in 7 subjects who became symptom-free after the treatment(P=0.0313).CONCLUSION LM was diagnosed in approximately 75%of the subjects who had LI.Incremental loads of cow’s milk is regarded as a useful treatment for LM without affecting everyday life.

Effect of Temperature, pH and Amount of Enzyme Used in the Lactose Hydrolysis of Milk

Lactose intolerance is becoming a health state that requires the restriction of dairy products in the diet of people suffering from this condition. But milk and dairy products, due to a well-balanced composition in the main macro and micronutrients, cannot be missing from the diet of the consumer of any age. For these reasons, in recent years, in the milk processing industry, the production of low-lactose or lactose-free dairy products is explored. To reduce the lactose content of dairy raw materials, various industrial and biotechnological methods were used: enzymatic hydrolysis of lactose, baromembranous methods, bioconversion of lactose by lactic bacteria and others. The most widely used lactase enzymes in the industry are mesophilic enzymes from filamentous fungi (Aspergillus spp.) and yeasts (Kluyveromyces spp.). Therefore, the aim of this study was to evaluate the effect of the commercial enzyme β-galactosidase on the hydrolysis of cow’s milk at different enzyme concentrations, temperatures and pH. Two commercial enzymes β-galactosidase obtained from Bacillus licheniformis and β-galactosidase obtained from Kluyveromyces lactis, were used in this study, according to information provided by the manufacturer. The thermal stability of lactose, the effect of milk pH, the effect of temperature, duration of hydrolysis and the amount of enzymes on the lactose hydrolysis degree and the sweetness degree of milk were determined. Research has identified the optimal parameters for obtaining a high degree of lactose hydrolysis in the use of these enzymes. Therefore, to ensure a high lactose hydrolysis degree (over 80%), the following lactose hydrolysis regimens were identified: temperature 4°C - 6°C, 0.3% Bacillus licheniformis enzymes, duration 4 hours;temperature 4°C - 6°C, 0.3% enzymes from Klavyromyces lactis, duration 12 hours and temperature 38°C - 40°C, 0.15% enzymes from (Bacillus licheniformis or Klavyromyces lactis), duration 2 - 3 hours. The results obtained allow the efficient use of Bacillus licheniformis and Klavyromyces lactis enzymes in industrial processes for the manufacture of “lactose-free” or “low-lactose” drinking milk and fermented dairy products for people with lactose intolerance.

Cow’s milk-induced gastrointestinal disorders:From infancy to adulthood

Milk is related to many gastrointestinal disorders from the cradle to the grave due to the many milk ingredients that can trigger gastrointestinal discomfort and disorders.Cow’s milk protein allergy(CMPA)is the most common food allergy,especially in infancy and childhood,which may persist into adulthood.There are three main types of CMPA;immunoglobulin E(IgE)-mediated CMPA,non-IgEmediated CMPA,and mixed type.CMPA appears before the first birthday in almost all cases.Symptoms may start even during the neonatal period and can be severe enough to simulate neonatal sepsis.CMPA(often non-IgE mediated)can present with symptoms of gastroesophageal reflux,eosinophilic esophagitis,hemorrhagic gastritis,food protein-induced protein-losing enteropathy,and food protein-induced enterocolitis syndrome.Most CMPAs are benign and outgrown during childhood.CMPA is not as common in adults as in children,but when present,it is usually severe with a protracted course.Lactose intolerance is a prevalent condition characterized by the development of many symptoms related to the consumption of foods containing lactose.Lactose intolerance has four typical types:Developmental,congenital,primary,and secondary.Lactose intolerance and CMPA may be the underlying pathophysiologic mechanisms for many functional gastrointestinal disorders in children and adults.They are also common in inflammatory bowel diseases.Milk consumption may have preventive or promoter effects on cancer development.Milk may also become a source of microbial infection in humans,causing a wide array of diseases,and may help increase the prevalence of antimicrobial resistance.This editorial summarizes the common milk-related disorders and their symptoms from childhood to adulthood.

Hypolactasia is associated with insulin resistance in nonalcoholic steatohepatitis

AIM To assess lactase gene(LCT)-13910C>T polymorphisms in Brazilian non-alcoholic fatty liver disease(NAFLD) and nonalcoholic steatohepatitis(NASH) patients in comparison with healthy controls.METHODS This was a transverse observational clinical study with NAFLD patients who were followed at the Hepatology Outpatient Unit of the Hospital das Clínicas, S?o Paulo, Brazil. The polymorphism of lactase non-persistence/lactase persistence(LCT-13910C>T) was examined by PCR-restriction fragment length polymorphism technique in 102 liver biopsy-proven NAFLD patients(steatosis in 9 and NASH in 93) and compared to those of 501 unrelated healthy volunteers. Anthropometric, clinical, biochemical and liver histology data were analyzed. Continuous variables were compared using the t or Mann-Whitney tests, and categorical data were compared with the Fisher's exact test. Univariate logistic regression and multivariate logistic regression adjusted for gender and age were performed.RESULTS No differences in the LCT-13910 genotype frequencies were noted between the NAFLD patients(66.67% of the patients with steatosis were CC, 33.33% were CT, and none were TT; 55.91% of the patients with NASH were CC, 39.78% were CT, and 4.3% were TT; P = 0.941) and the healthy controls(59.12% were CC, 35.67% were CT, and 5.21% were TT) or between the steatosis and NASH patients. That is, the distribution of the lactase non-persistence/lactase persistence polymorphism(LCT-13910C>T) in the patients with NAFLD was equal to that in the general population. In the NASH patients, the univariate analysis revealed that the lactase nonpersistence(low lactase activity or hypolactasia) phenotype was associated with higher insulin levels(23.47 ± 15.94 μU/m L vs 15.8 ± 8.33 μU/m L, P = 0.027) and a higher frequency of insulin resistance(91.84% vs 72.22%, P = 0.02) compared with the lactase persistence phenotype. There were no associations between the LCT genotypes and diabetes(P = 0.651), dyslipidaemia(P = 0.328), hypertension(P = 0.507) or liver histology in these patients. Moreover, in the NASH patients, hypolactasia was an independent risk factor for insulin resistance even after adjusting for gender and age [OR = 5.0(95%CI: 1.35-20; P = 0.017)].CONCLUSION The LCT-13910 genotype distribution in Brazilian NAFLD patients was the same as that of the general population, but hypolactasia increased the risk of insulin resistance in the NASH patients.