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PubMed1985

Absorption and tolerance of lactose in infants recovering from severe diarrhea.

Nineteen infants were challenged during their convalescence from severe diarrhea with a lactose-containing meal. Twenty-four hour intake, pre- and post-challenge breath H2 levels, clinical responses, and growth were measured at approximately biweekly intervals for 3 months beginning 1 month after hospital discharge. Ten lactose-tolerant infants were assigned randomly to receive one of two formulas similar in composition except for carbohydrates: lactose (Group L) (n = 6) and sucrose (Group S) (n = 4). Infants in Group L had greater intakes and growth rates during the initial 15 days of the study. No difference in weight for age z-scores was detected between groups at the end of the observation period. Infants in Group L had higher baseline and peak breath H2 levels indicating greater colonic carbohydrate fermentation than infants in Group S: however, breath H2 levels were not predictive of tolerance to lactose-containing meals. Carbohydrate absorption by infants in Group S appeared to exceed that of infants in Group L. Thus, colonic fermentation of malabsorbed carbohydrate may have prevented diarrhea and allowed acceptable rates of catch-up growth.

Diarrhea, Infantile↗
PubMedDate not supplied

Test-retest reproducibility of hydrogen breath test for lactose maldigestion in preschool children.

The test-retest reproducibility of the H2 breath test within the same individual has not been rigorously evaluated in preschool children. In the present study, 10 children--5 of whom were diagnosed as lactose-digesters on their first testing, and 5 of whom were diagnosed as lactose-maldigesters at first screening--were retested under identical conditions of a second opportunity. In each case, the same diagnostic classification was provided, for a reproducibility of 100%. Regression of the area under the curve of the change in breath H2 concentration during the 3 h of the test had a Pearson's correlation coefficient of 0.59 (p = 0.05). The time-course of 3-h H2 breath tests in 43 children with lactose maldigestion revealed a peaking of the concentration of H2 most commonly 120 min following the oral dose of 240 ml whole milk. Seventy-seven percent of the children who eventually proved to be lactose maldigesters were so diagnosed by the end of the second hour of the breath test. Thus, even the abbreviated breath sampling schedule used in children is sensitive, and few maldigesters would go undetected because of a late rise in breath H2 concentration.

Animals↗
PubMed1978

Fermentation of raffinose by lactose-fermenting strains of Yersinia enterocolitica and by sucrose-fermenting strains of Escherichia coli.

Introduction of plasmids carrying the lacY gene (lactose permease gene) into Yersinia enterocolitica results in cells being able to ferment both lactose and raffinose. Transfer of such plasmids into Escherichia coli C600 (lacY) confers ability to ferment lactose but not raffinose. Derivatives of C600 that ferment both lactose and sucrose (Lac+ Scr+ strains) are able to ferment raffinose, but do not grow well on raffinose minimal medium. Fermentation of raffinose by Lac+ strains of Y. enterocolitica, and by Lac+ Scr+ strains of E. coli, is explained in terms of transport of raffinose via the lac permease and subsequent breakdown catalyzed by invertase.

Conjugation, Genetic↗
PubMed1982

Distribution of human adult lactose phenotypes in Egypt.

Lactose absorption was studied in 570 health adolescent and adult males in Egypt. Employing a field version of the noninvasive hydrogen breath test, 156 (27.4%) lactose absorbers and 414 (72.6%) lactose malabsorbers were identified. The age-specific prevalence of the lactose phenotypes indicated that lactase repression is complete at the age of 14 years in Egyptians. The regional distribution showed significant differences between the Nile Delta and the northern and southern part of Upper Egypt. The existence of a north-south gradient of decreasing frequencies of the hypolactasia gene from the Nile Delta to the Sudan is suggested.

Adolescent↗
PubMed1994

Management of lactose intolerance.

The management of lactose intolerance comprises two parts: (1) the basic principles of treatment in persons intolerant to a dietary dose of lactose, and (2) main manoeuvres to reduce the lactose content in food, and/or consumption of special products of milk or exogenous lactase enzyme. The tactics of management depend on the type of hypolactasia, the severity of intolerance, and on the age of the patient. Special attention is paid to the development of lactose intolerance in some patients via iatrogenic mechanisms such as certain drugs, gastric surgery and ionizing radiation.

Age of Onset↗
PubMed1984

Effect of viable starter culture bacteria in yogurt on lactose utilization in humans.

Breath hydrogen production was used as a measure of lactose malabsorption in human test subjects following the consumption of both heated and unheated cultured yogurt. Less hydrogen was produced when the subjects consumed the unheated cultured yogurt than when they consumed the heated product, indicating that lactose hydrolysis was improved in the small intestine of the individuals consuming the unheated cultured yogurt. Lactase activity in yogurt samples was increased in the presence of bile. Yogurt starter bacteria growing in milk normally do not hydrolyze more lactose than needed for their growth. However, the increased lactase activity in the presence of bile indicates that these bacteria could function as a source of lactase to hydrolyze lactose in the small intestine even though the organisms themselves are not expected to grow in that environment.

Bile Acids and Salts↗
PubMed1991

Influence of nonfermented dairy products containing bacterial starter cultures on lactose maldigestion in humans.

The effect of nonfermented dairy products containing yogurt or acidophilus cultures on lactose utilization by lactose-maldigesting humans was investigated. Yogurt and acidophilus milk containing 10(7) or 10(8) of Streptococcus thermophilus and Lactobacillus bulgaricus, or Lactobacillus acidophilus, respectively, were prepared using commercially processed 2% low fat milk. Immediately following inoculation, products were refrigerated. Lactose maldigestion was monitored by measuring breath hydrogen excretion at hourly intervals for 8 h following consumption of 400 ml of each test meal containing approximately 20 g of lactose. The yogurt milk containing 10(8) cfu/ml was shown to contain significant concentrations of microbial beta-galactosidase (EC 3.2.1.23; approximately 3 U/ml), which remained stable for at least 14 d at refrigerator temperatures. Breath hydrogen peaks were delayed and significantly lower (approximately 20 ppm at 5 to 7 h) than control values (approximately 70 ppm at 4 h), and intolerance symptoms were eliminated in all subjects. Yogurt milk containing 10(7) cfu/ml demonstrated intermediate breath hydrogen values and was marginally significantly different from control values. Lactobacillus acidophilus strains with varying resistance to bile and total beta-galactosidase-producing potential were also tested. Only one strain, LA-1, which demonstrated low bile resistance and intermediate beta-galactosidase activity, was capable of significantly decreasing breath hydrogen values when 10(8) cfu/ml of milk was consumed.

Adult↗
PubMed1976

Lactose tolerance in adult Jordanian Arabs.

Lactose tolerance tests were performed in 56 male and female Jordanian Arabs who were permanently resident in the Hashemite Kingdom of Jordan. Forty three had a low rise in blood glucose and 36 had one or more symptoms after oral lactose. Lactose tolerance was not related to sex, age, milk or milk products consumption. The data presented confirm the few existing reports that the majority of Arabs, originating from the Mediterranean basin are hypolactasic and intolerant to lactose.

Adolescent↗
PubMed2003

[Lactose tolerance in children with chronic gastroduodenal zone diseases].

We determined the dependence of the frequency of lactose intolerance, particular features of the clinical presentation and laboratory showings on lactase deficiency on the basis of a complex clinical, anamnestic and laboratory study of 149 children with chronic gastroduodenal pathologies. It was established that the prevalence of lactose intolerance in children with superficial gastroduodenitis amounts to 58.8%, in children with erosive gastroduodenitis--66.7% and in children with stomach ulcers--83.3%. During the oral lactose load and a subsequent laboratory study we revealed an impairment of the hydrolytic function of small intestines accompanied by an increase of fecal excretion of carbohydrates (lactose and monosaccharides) as well as a considerable enhancement of bacterial fermentation. The detection of fecal excretion of the total glycoprotein hexoses characterizes a disorder of the morphofunctional state of the gastrointestinal tract in children with intestinal enzymopathies.

Adaptation, Physiological↗
PubMed1991

Gastric emptying of maltose, sucrose, lactose and lactulose in rats with ontogenic lactase deficiency.

The gastric emptying of maltose, sucrose, lactose and lactulose was compared in young adult rats with ontogenic lactase deficiency. Eight animals were employed for each sugar meal at each time of study (total number of animals = 192). Each animal received a test meal consisting of a solution of the sugar (100 mg/ml) and phenol red as marker and gastric retention was measured at 5, 10, 20, 30, 45 and 60 min after orogastric infusion of the test meal. Gastric retention was determined by measuring the concentration of the marker in the residual test meal recovered from the stomach after killing the animal. There was no difference between the gastric emptying of lactose and lactulose. The gastric emptying of maltose was significantly slower during the initial 30 min and the emptying of sucrose was identical to that of maltose only at 5 min and could not be distinguished from that of lactose and lactulose at later times. These data support the observation, made in human subjects, that, under conditions of ontogenic lactase deficiency, the modulation of gastric emptying of lactose is ineffective. It is possible that the rapid emptying of sucrose is due to the saturation of sucrase because of substrate overload which impairs the intestinal inhibitory control of gastric emptying.

Animals↗
PubMedDate not supplied

[Trial of milk with low-lactose contents in acute diarrhea].

Fifty infants with acute diarrhea (less than or equal to 5 days of duration) were refed with either a low-lactose formula (experimental group, N = 25) or whole powdered cow's milk (control group, N = 25). During a two-month follow up etiology, clinical course, changes of anthropometric parameters and tolerance to the milk products were evaluated. The etiology of diarrhoea, the mean duration of the episodes (3.6 +/- 1.9 and 3.9 +/- 1.9 days in the experimental and control group, respectively) and the clinical course were comparable in both groups. Nutritional parameters remained unchanged during and after the episode. In two children (8.3%) of the control group stools continued to be liquid, fecal pH was 5 and reducing substances were positive. They had to be refed with the low-lactose product to induce remission of the symptoms. Both products were well tolerated. These findings suggest that availability of low-lactose formulae may be advantageous in the clinical management of infants with acute diarrhea and evidence of lactose intolerance.

Acute Disease↗
PubMedDate not supplied

Recent advances in the management of lactose intolerance.

Lactose intolerance is a concern for the majority of the world's population. Persons who experience symptoms following the consumption of milk should consult with their physician. Symptoms may be eliminated or reduced with good dietary management that includes: Limiting milk consumption to one glass at a time. Drinking milk with other foods rather than alone. Eating yogurts instead of fluid milk. Using enzyme tablets to predigest the lactose in milk or to supplement the body's own lactase. Possibly eating small amounts of dairy foods each day to adapt the colonic bacteria. For an additional review of the research findings on lactose intolerance and milk drinking, the reader is directed to reference 4, a very recent and complete review by Scrimshaw and Murray. For information on dietary management of lactose intolerance suitable for the consumer, contact your local affiliate of the National Dairy Council.

Animals↗
PubMed1988

13CO2 breath test using naturally 13C-enriched lactose for detection of lactase deficiency in patients with gastrointestinal symptoms.

A 13CO2 breath test using naturally enriched 13C-lactose as a substrate was performed in 47 patients with chronic abdominal pain or chronic diarrhea, taken from a population with a low prevalence of primary acquired lactase deficiency. The cumulative 13CO2 excretion 4 hours after 13C-lactose intake was compared with the H2 breath excretion and with jejunal lactase activity. A physiologically significant relation was found between the cumulative 13CO2 excretion (at 4 hours) and lactase activity, 14.5% 13CO2 excretion being the best cutoff point for discrimination between patients with low and normal lactase activity. The 13CO2 breath test was found to be more sensitive (0.84 versus 0.68) and more specific (0.96 versus 0.89) than the H2 breath test in detecting low jejunal lactase activity. Concordant results of both breath tests performed simultaneously give a reliable picture of the lactose absorption status of the patient. Discordance in results of 13CO2 and H2 lactose breath tests, if not explained by history, indicates in which patients a jejunal biopsy should be performed. If lactase activity and morphology of the biopsy are normal, other causes of discordance must be investigated.

Abdomen↗
PubMed1988

Lactose malabsorption in adult patients with Crohn's disease.

In order to evaluate, in adult patients with Crohn's disease (CD), the prevalence of lactose malabsorption and intolerance, and the percentage who can tolerate a physiologic amount of milk in their diet, we tested 37 patients with CD (19 with intestinal resection, and 18 without) and 67 healthy controls (C) with the H2-breath test after they had ingested increasing loads of lactose as 10% solution (12.5 g, 25 g, and 50 g). Patients with malabsorption after the 12.5-g dose were tested further with 250 ml of milk. In the total group of patients and in the subgroup of those with resection, the prevalence of malabsorption was higher than in controls at all lactose loads; in patients who had not undergone resection, no significant difference was observed with the 12.5-g dose. Eleven of 18 patients who were malabsorbers with the 12.5-g dose had malabsorption also with 250 ml milk; however, only three of them (8% of the total group) experienced symptoms of intolerance. We conclude that, in adult patients with CD, 1) the prevalence of lactose malabsorption is increased, 2) in patients who have undergone intestinal resection, malabsorption occurs at a lower dose of the sugar than in patients who did not, and 3) since only 8% of patients experienced symptoms of intolerance after the ingestion of milk 250 ml, this amount can be empirically inserted in the daily diet of an adult with CD.

Adolescent↗
PubMed1985

Oral lactose tolerance test in foals: technique and normal values.

Oral lactose tolerance tests were evaluated in 25 healthy foals (principals) assigned to 4 groups of approximately 1 week, 4 weeks, 8 weeks, and 12 weeks of age. Lactose monohydrate (1 g/kg of body weight [in a 20% water solution]) was administered via nasogastric tube after a 4-hour fast. Plasma glucose concentrations were monitored before dosing (0 minutes) and sequentially for 300 minutes. Six control foals were given a volume of water equivalent to the volume of lactose monohydrate administered to principal foals. After oral lactose loading, mean plasma glucose concentrations of all principal foals increased from 99.76 mg/dl at 0 minutes to 176.80 mg/dl by 90 minutes. Peak increases in plasma glucose concentrations were attained by 8% of the foals (2 foals) at 30 minutes, 76% (19 foals) at 60 minutes, and 16% (4 foals) at 90 minutes. The mean plasma glucose concentration increase of principal foals, regardless of age or time of peaking, was 77.04 mg/dl. There was no significant (P greater than 0.05) difference in fasting plasma glucose concentrations (0 minutes) among the 4 groups of principal foals or between principal and control foals; however, there was a significant (P less than 0.05) difference in peak glucose concentrations between 1-week-old and 12-week-old principal foals, with the older foals having the higher concentrations. Mean plasma glucose concentrations of control foals decreased from 79.67 mg/dl at 0 minutes to 55.17 mg/dl by 180 minutes. The mean peak decrease in plasma glucose concentrations of control foals, regardless of time of peaking, was 24.50 mg/dl.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1977

Lactose malabsorption among the Pima indians of Arizona.

Lactose loading tests and other means were used to determine the pattern of primary "adult" lactose malabsorption (LM) and milk use among 171 subjects, including 122 children and 49 adults, almost all of them Pima Indians of Arizona. LM develops at quite young ages in full-blooded Pima children: already in the 3- to 4-year age group, 40% had LM. Of 62 full-blooded Indians (greater than or equal to 4 years of age), 59 (95%) had LM. Of 41 Indians (greater than or equal to 4 years) who were of mixed Indian-northern European ancestry, however, only 25 (61%) had LM, and, among them, prevalence of LM correlated with degree of northern European admixture. Whereas only 21% of Pima lactose absorbers reported symptoms after the loading test, 72% of malabsorbers did so, with older malabsorbers more likely to experience symptoms. In their everyday lives, only 23% of malabsorbers recognized symptoms brought on by milk consumption, but the percentage of malabsorbers making such an association increased with age. Nevertheless the Pima, adults as well as children, continue to drink reasonable quantities of milk. Family pedigrees are consistent with the hypothesis that adult lactose absorption is inherited as an autosomal dominant trait. Over-all results of this study, moreover, support the geographic hypothesis advanced to explain ethnic or racial differences in prevalence of LM, rather than the induction hypothesis.

Adolescent↗
PubMed1983

Sensitivity and specificity of the hydrogen breath-analysis test for detecting malabsorption of physiological doses of lactose.

We examined the changes in sensitivity and specificity that would occur with alterations in the sample-collection schedule and (or) cutoff criterion for the increase in hydrogen concentration in breath after administration of doses of lactose in the dietary range. In a breath-analysis test to classify individuals as lactose-absorbers or lactose-malabsorbers, 41 subjects drank 360 mL of intact cow's milk, containing 18 g of lactose, and breath samples were collected and analyzed at 30-min intervals for 5 h. An increase in H2 concentration of greater than or equal to 20 microL/L above basal values at any of the 10 intervals was diagnostic of malabsorption. Increases of greater than or equal to 18 or greater than or equal to 15 microL/L were only 85% as specific in classifying the same individuals. Reduction in the number of samples tested per subject uniformly reduced the sensitivity. However, a simplified procedure suitable for field studies (in which four samples--at 0, 2, 3, and 4 h--are collected and analyzed with greater than or equal to 20 microL/L as the cutoff value) gives 80% sensitivity and 100% specificity, as compared with the 11-sample procedure.

Adult↗
PubMed1978

[Lactose intolerance in adults (author's transl)].

A study on the lactose intolerance of adults was carried out through dietary survey, clinical data and tolerance tests. It was performed in 24 healthy persons, aged 19 to 39 years. Only one of the participants referred milk intolerance since childhood. Eleven of the 24 adults had signs of lactose intolerance through clinical symptoms and/or low increase of blood sugar after the load test. It was noteworthy that the majority of the intolerants were white people. It is discussed the practical importance of these lactose tolerance tests as an index of milk tolerance, considering the high recommended amount of lactose used in the tests.

Adult↗