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At least 793 records · Page 44Linked to original sources
PubMed1994

Tolerance and absorption of lactose from milk and yogurt during short-bowel syndrome in humans.

This study aimed to compare the absorption and tolerance of 20-g lactose loads as milk and yogurt in 17 patients with short-bowel syndrome with either a terminal jejunostomy (group A, n = 6) or a jejunocolic anastomosis (group B, n = 11). Records and measurements during the 8 h after the meals included fecal weight, symptoms, lactose and hexose flow rates in stomal effluents (group A), and breath-hydrogen excretion (group B). In group A lactose was better absorbed in the form of yogurt than in the form of milk (mean +/- SE: 76 +/- 6% vs 50 +/- 9%, P < 0.05), whereas no significant difference could be detected by using the breath-hydrogen test in group B. The excellent tolerance to 20 g lactose from milk and yogurt suggests that lactose should not be excluded from the diet of these subjects.

Adult↗
PubMed2001

High prevalence of lactose absorbers in Northern Sardinian patients with type 1 and type 2 diabetes mellitus.

BACKGROUND: Increased intestinal lactase activity has been shown to occur in alloxan and streptozotocin diabetic rats. OBJECTIVE: The objective of this study was to determine whether increased intestinal lactase activity is present in humans with diabetes mellitus. DESIGN: We assessed the capacity to digest lactose by measuring breath-hydrogen production after oral administration of lactose in 50 patients with type 1 diabetes, 50 patients with type 2 diabetes, and 50 healthy control subjects from Sassari, Sardinia, Italy, a population characterized by a low prevalence of lactase persistence (lactose absorbers). RESULTS: Fourteen percent of control subjects were lactose absorbers, compared with 48% of patients with type 1 diabetes and 52% of patients with type 2 diabetes (P < 0.005). The odds ratio of lactase persistence in patients with type 1 diabetes was 5.3 (95% CI: 2.0, 14.0) and in patients with type 2 diabetes was 5.5 (95% CI: 2.1, 14.5). CONCLUSIONS: Diabetes is associated with increased intestinal lactase activity in humans. Consequently, there is a greater exposure to glucose and galactose in diabetic patients with high lactose consumption. This may explain the association between diabetes and the risk of cataract.

Adult↗
PubMed1999

Lactose intolerance: problems in diagnosis and treatment.

Lactose malabsorption and lactase deficiency are chronic organic pathologic conditions characterized by abdominal pain and distention, flatulence, and the passage of loose, watery stools. Though malabsorption of the sugar lactose is determinable by breath hydrogen test or jejunal biopsy, intolerance can only be confirmed by challenge with lactose-containing food, the response to which may not be immediate. The difficulty of making a positive diagnosis of these conditions has led to a proportion of lactose-intolerant patients being misdiagnosed with irritable bowel syndrome (IBS), which has a remarkably similar symptom complex and for which there is no current pathophysiologic marker. The incidence of the two disorders is approximately equal, but the actual proportion of patients with IBS incorrectly diagnosed in this way varies as a function of the methodology used. Once correct diagnosis is established, introduction of a lactose-free dietary regime relieves symptoms in most patients. Symptom similarity and the resultant incorrect diagnosis of IBS may explain the refractory nature of some patients labeled as IBS who remain largely unaware of the relationship between food intake and symptoms.

Breath Tests↗
PubMedDate not supplied

Lactose malabsorption and small-intestinal lactase in normal Chinese children.

A total of 852 healthy Chinese children from 1 month to 14 years of age were investigated for lactose malabsorption using the breath hydrogen test. A lactose load of 2 g/kg was administered to 528 children and 1 g/kg to another 324 children. The incidence of lactose malabsorption was significantly different among various age groups and between the two different lactose dosages. While the incidence of malabsorption increased strikingly from the age of 3 to the age of 5 years, the age effect remained constant after the age of 6 years. The lactose load of 2 g/kg induced a higher incidence of malabsorption in study subjects than 1 g/kg did, and the dose effect increased for those aged below 5 years and decreased above 5 years. Small-intestinal lactase was also studied in 34 children aged from 2 months to 15 years. The lactase activity was highest in children 2 years old or younger, gradually decreasing with increasing age. In conclusion, lactase activity in Chinese children decreases gradually after 3 years of age, a finding that correlates well with the results of the breath hydrogen test.

Adolescent↗
PubMed1994

Bone mineral content and dietary calcium intake in children prescribed a low-lactose diet.

Bone density is related to body size and other factors including dietary calcium intake. The purpose of this study was to determine the effect of a low-lactose, low-calcium diet on the bone mineral content (BMC) of prepubertal children with documented lactose intolerance. Radial BMC was determined by single-photon absorptiometry. Dietary intake was assessed by 24-h recall and two 3-day food records, and weight and height were measured. The group of lactose-intolerant children was compared with a group of healthy children of similar age, gender, race, and size and to the prediction equations based on body size from Chan's Utah children. Nineteen children, ages 9.6 +/- 1.9 years, participated in the study. They were relatively short compared with standards (height Z score, -0.30 +/- 0.83). BMC was 0.428 +/- 0.081 g/cm in the study group versus 0.440 +/- 0.116 g/cm in the comparison group (n = 19; p > 0.05). Both the study group and the size-selected comparison group had lower BMC than the Utah children. The diet of the study group was low in calcium: 84% of the Recommended Dietary Allowance in children < 11 years old and 32% in children > 11. Calcium intake was associated (p = 0.03) with BMC in the study group after adjusting for body size. The low-lactose diet resulted in a low calcium intake, and BMC was associated with calcium intake in prepubertal children with lactose intolerance. Evaluation of dietary calcium intake should be considered in this group of patients, with follow-up dietary counseling, calcium supplementation (diet or medication), and bone density assessment when clinically indicated.

Body Height↗
PubMed1992

Lactose feeding during persistent diarrhoea.

Lactose intolerance is a recognized complication of some episodes of diarrhoea. Whereas it is of clinical importance in relatively few children with acute diarrhoea it seems to be a more common problem in children presenting with persistent diarrhoea, especially in malnourished children with severe diarrhoea. We describe a recent study which also demonstrated adverse clinical and nutritional consequences in the majority of children with mild but persistent diarrhoea consuming 6 g lactose/kg body weight/d. It is desirable to identify these children who need to reduce their lactose intake in order to limit unnecessary dietary changes which are expensive to implement and/or nutritionally disadvantageous. Admission clinical characteristics were analyzed for their ability to predict clinical outcome in a group of 33 children with persistent diarrhoea taking a lactose-containing diet. The results of tests of stool reducing substances and a lactose breath hydrogen test (LHBT) were analyzed in the same group whose clinical management had been independent of the test results. Eighty-nine percent of children who deteriorated had one of the following characteristics: age < 12 months, weight-for-height less than -2 SD below NCHS norms or fever > 37 degrees C. Children who unequivocally improved while continuing to take lactose could not be selected without the risk of including children who deteriorated. Neither tests of stool reducing substances nor the LBHT improved the predictive value of simple clinical parameters.(ABSTRACT TRUNCATED AT 250 WORDS)

Breath Tests↗
PubMed1963

INDUCTION OF LACTOSE UTILIZATION IN STAPHYLOCOCCUS AUREUS.

McClatchy, J. K. (The University of Texas, Dallas), and E. D. Rosenblum. Induction of lactose utilization in Staphylococcus aureus. J. Bacteriol. 86:1211-1215. 1963.-Adaptation to the utilization of lactose by Staphylococcus aureus has been compared with that by Escherichia coli. Lactose and galactose were found to be efficient inducers of the beta-galactosidase and the postulated galactoside-permease of S. aureus; the thiogalactosides, active as gratuitous inducers for E. coli, were inactive and inhibited induction of staphylococci by lactose and galactose. Mutants lacking beta-galactosidase or galactoside-permease, as well as a constitutive mutant for lactose utilization, were isolated. Like that in E. coli, the genetic system of staphylococcus seems to consist of two structural genes for the synthesis of the two enzymes and at least one regulatory gene simultaneously controlling the expression of the structural genes. The mutants were grouped by cross-transduction studies in three loci corresponding to the three phenotypes. Mutants of the pleiotropic locus were also isolated.

Escherichia coli↗
PubMed1986

Lactose absorption, milk consumption, and fasting blood glucose concentrations in women with idiopathic osteoporosis.

Lactose tolerance tests were performed in 33 women with osteoporosis and 33 control women matched for age. A questionnaire was used to elicit any history of milk intolerance and the subjects' daily intake of calcium derived from milk and dairy products. Eleven patients and four controls gave a history of milk intolerance (p less than 0.01); 13 patients had lactose malabsorption compared with four controls (p less than 0.01). The daily intake of calcium derived from milk was significantly lower in patients (125 (SEM 20) mg v 252 (43) mg; p less than 0.05). Curves of blood glucose concentrations during the lactose tolerance test in subjects with lactose malabsorption were significantly flatter in patients than controls (p less than 0.05). The fasting blood glucose concentration was higher (5.44 (0.17) mmol/l (98 (3) mg/100 ml) in the patients than the controls (4.88 (0.11) mmol/l (88 (2) mg/100 ml); p less than 0.05), although body weight was significantly lower (61.6 (2.2) kg v 66.3 (1.6) kg; p less than 0.05). Absorption of lactose is significantly impaired in women with "idiopathic" osteoporosis; this combined with low consumption of milk and a subclinical disorder of glucose metabolism may be a major factor in the development of idiopathic osteoporosis in women.

Adult↗
PubMed1984

Nutritional support of malnourished lactose intolerant African patients.

The effectiveness of two commonly available liquid diets was assessed in 40 severely malnourished black African patients. All patients were shown to have normal xylose absorption. The diets were given according to the manufacturer's recommendations. One diet was lactose containing (LC diet) (150 g/d) and high protein (112 g/d), the other normal protein and lactose free (LF diet) (protein 67 g/d), total energy content being similar. Patients were randomly divided into two equal groups and allocated (blind) to one of the diets. Tolerance and nitrogen balance were assessed over two three day periods on half and then full strength formulations. Severe intolerant symptoms were observed in 50% of patients on half strength and 94% of patients on full strength lactose containing diet with evidence of malabsorption of fluid, nitrogen, and fat. Despite high stool nitrogen losses (3.75 +/- 1.04 g/d), however, positive nitrogen balance was achieved in most patients receiving the full strength LC formulation. On the other hand, the full strength LF diet was generally well tolerated and was associated with significantly lower faecal losses and positive nitrogen balance. The results indicate that high density lactose containing liquid formulae are poorly tolerated by severely malnourished black African patients, while lactose free formulae containing approximately 10 g nitrogen/d are well tolerated and result in positive nitrogen balance.

Blood Glucose↗
PubMed2006

Physicochemical characteristics of commercial lactases relevant to their application in the alleviation of lactose intolerance.

Selected microbial lactases are used to treat lactose intolerance. A series of experiments were carried out in vitro in order to determine the likely relative suitability of four major commercial lactase products used in this regard. The lactases displayed between 55 and 61% of maximum activity at 37 degrees C and significant activity between pH 3.0 and 6.5. They retained between 0 and 65% of original activities after exposure to full simulated digestive tract conditions for 6 h. All four enzymes proved to be particularly acid sensitive and only two products were enteric coated. The products demonstrated varying ability to hydrolyze lactose under simulated digestive tract conditions. The most effective product hydrolyzed 2.7 g lactose per capsule, suggesting that consumption of several capsules, as opposed to the usually recommended one or two, would be required to hydrolyze the entire 12 g lactose load characteristic of a dairy-based meal. All enzymes were substantially pure and displayed similar kinetic properties and molecular weights. None appeared ideally suited for use in the alleviation of lactose intolerance. The findings may in part explain the variability and often disappointing results previously reported for lactase-based clinical trials and will provide comparative baseline data against which candidate second-generation lactases may be assessed.

Animals↗
PubMed1980

Lactose synthesis: the possibilities of regulation.

Elucidation of the details of lactose synthesis, in particular its dependence upon alpha-lactalbumin and its location within the lumen of the Golgi apparatus, now allows one to ask useful questions pertaining to its regulation. Attention is directed towards galactosyltransferase itself (EC 2.4.1.22), which appears to be rate-limiting in the uridine nucleotide cycle that supports lactose synthesis, and to those factors that may affect its activity. In laboratory animals alpha-lactalbumin appears to be the major agent of regulation during lactogenesis but is not necessarily limiting at other times, whereas the increase in amount of galactosyltransferase seems largely to account for the rising yield of lactose during lactation. Studies with pinched-off Golgi membrane vesicles, together with measurements of intracellular chemical concentrations, suggest that beta-glucose and uridine diphosphategalactose do not saturate lactose synthesis and are, therefore potentially regulatory features of this process. Further aspects of lactose synthesis that may offer points of regulation include calcium ions, generation of protons within the Golgi lumen, and the generally rate-limiting nature of the Golgi membrane.

Animals↗
PubMed1991

Lactose absorption by postweaning rats from yogurt, quarg, and quarg whey.

Lactose-intolerant postweaning rats were fed experimental diets including yogurt, quargs prepared from yogurt culture and buttermilk culture, and two types of whey obtained from quarg processing. After feeding each diet for a period of 7 d, absence of blood glucose elevation and occurrence of diarrhea were used as indicators of lactose malabsorption. Blood glucose assays and absence of diarrhea indicated that yogurt and quargs prepared from yogurt and buttermilk culture were well tolerated by the rats. Wheys containing the same levels of viable organisms and lactose as the quargs caused severe symptoms of diarrhea and poor lactose absorption as indicated by no changes in blood glucose levels. Plate counts and enzyme assays of gastrointestinal contents confirmed presence of viable culture organisms and beta-galactosidase activity after feeding the two types of quarg. The availability of viable organisms, the exogenous lactase activity, and especially the slow gastric emptying may all have contributed to more efficient hydrolysis and digestion of lactose from quargs and yogurt than from the wheys.

Animals↗
PubMed1977

A trial of lactose hydrolysed milk in Australian Aboriginal children.

Weight gains in 50 young Australian Aboriginal children were studied in a blind controlled hospital trial of reconstituted, lactose hydrolysed milk powder (test) and full-cream milk powder (control). The mean weight gains (+/- SEM) were 4.80 +/- 0.80 g kg-1 day-1 for children receiving the lactose hydrolysed milk, and 2.20 +/- 0.75 g kg-1 day-1 for those receiving the normal milk P less than 0.0125). Weight gain of infants (that is, those under one year of age) in the control group was less than 10% of that in the test group (P less than 0.0025). Weight gain was higher in children fed hydrolysed milk irrespective of percentage of Standard Weight for Age or the presence or absence of recognizable symptoms of lactose intolerance. Lactose malabsorption appears to be a major factor in the growth retardation of Aboriginal children. It is recommended that lactose hydrolysed milk replace normal milk in the supplementary feeding of Aboriginal infants and children.

Animals↗
PubMed1976

Lactose malabsorption in Thai infants and children: effect of prolonged milk feeding.

More than one-third of Thai infants were lactose malabsorbers soon after birth and the percentage of lactose malabsorption increased with age. Beyond 4 years of age, all Thai children studied were lactose malabsorbers. Continued milk supplementation over the study period did not affect the ability to digest lactose in the amount given in the load test. Since the milk-supplemented group of children tended to have better weight gain and few undesirable gastrointestinal symptoms, it seems milk feedings can be used to advantage even among populations with a record of high lactose intolerance.

Animals↗
PubMedDate not supplied

Lactose intolerance.

Although lactose intolerance is very common it is not a serious health condition. The diagnosis is relatively simple and minimally invasive. Treatment is geared towards a life-long plan of management. Persons who have difficulty digesting lactose will learn by trial and error what food items cause distress and learn to avoid offending milk sugars. In addition many products are available over-the-counter to aid in digestion of lactose. Often these additives enable the person to consume lactose. Adequate amounts of calcium may be consumed by eating a carefully chosen diet containing lactose free sources of calcium in order to maintain healthy bone, nerve, and muscle development.

Adolescent↗
PubMed1988

Improved lactose digestion during pregnancy: a case of physiologic adaptation?

Loss of intestinal lactase activity among adults could theoretically limit milk consumption and hence dietary availability of calcium during pregnancy. The present study sought to define, using breath hydrogen (H2) production as an index of incomplete carbohydrate absorption, the prevalence during pregnancy of lactose maldigestion of 360 mL of milk (18 g of lactose), and to determine whether lactose digestion improved as pregnancy advanced. The prevalence of lactose maldigestion among 114 pregnant women tested before the 15th week of gestation was 54%. By term, 44% of those originally classified as maldigesters had become digesters. There was a significant reduction in the four-hour sum of the changes in breath H2 concentration from the period before 15 weeks (116.6 +/- 9.6 ppm) to the time after 36 weeks (54.4 +/- 7.3 ppm; P less than .01). This apparent adaptive improvement in intestinal handling of milk lactose during gestation has implications for calcium intake and absorption.

Acidosis, Respiratory↗
PubMed1987

Lactose and calcium absorption in postmenopausal osteoporosis.

The prevalence of lactase deficiency and the relationship between lactose and calcium malabsorption in postmenopausal osteoporosis has been assessed in 46 subjects. Malabsorption of lactose occurred in 25 (54%) of the subjects and was associated with a significantly lower milk intake. Malabsorption of calcium occurred in 11 (44%) of the lactase-deficient subjects and in 11 (52%) of normal lactose absorbers. There was no relationship between lactose and calcium malabsorption. Vertebral and forearm mineral densities were not significantly different between normal lactose absorbers and lactase-deficient subjects.

Aged↗
PubMedDate not supplied

Lactose intolerance in protein-energy malnutrition: a clinical case study and family study using a hydrogen (H2) breath-analysis test for carbohydrate malabsorption.

A non-invasive, interval sampling hydrogen (H2) breath-analysis test for carbohydrate malabsorption was used in a 3 year-old Guatemalan child with severe protein-energy malnutrition (kwashiorkor) and in this relatives: mother half-sister and step-father to examine genetic and nutritional factors in lactose intolerance in young children. Clinical lactose intolerance was present in the patient on admission, and lactose malabsorption, even of 0.88 g per kg of weight, persisted after complete nutritional recobly due to gastric retention of the substrate. Malabsorption of a physiological dose of lactose, 12.5 g, was detected in the mother and step-father while their daughter exhibited normal growth and development and normal lactose absorption at 8 months of age. The H2 breath test proved to be a sensitive, well-tolerated procedure for both adults and young children. Pitfalls, such as delayed gastric emptying, absence of normal bacterial flora, prior use of antibiotics, must be considered in interpreting H2 breath test results in children.

Adult↗