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Diagnosis of lactose intolerance through the quantification of hydrogen in exhaled air.

Considerations are made on diarrhea secondary to intestinal malabsorption of carbohydrates and on the diagnostic means available in our environment, among which are the reactive strip, the clinitest tablet, tolerance curves and research of intestinal enzymes. The quantification of exhaled hydrogen is mentioned as a diagnostic method, used by several other authors, and a review of the literature on the subject is made. Considerations are made on a hydrogen quantification in the breath of patients with a transitory lactose intolerance. 16 patients were studied, 15 of whom showed an increase in the exhaled H2. 32 children with diarrhea, free from lactose intolerance, were studied. The method used did not show a significant increase in the exhaled hydrogen. 27 patients showed no H2 in their breath. In 4 there was elimination of H2 (false positives). 17 diarrhea-free children were studied. A significant difference was found when comparing the children with diarrhea and lactose intolerance to the other two groups who were free from lactose-intolerance. It is considered that this method can be useful in the diagnosis of intolerance to lactose and other sugars.

Chromatography, Gas↗

[Modified test with oral lactose loading for detecting lactose intolerance in young children].

Twenty-four children with persistent diarrhea or intestinal dysfunction were examined; lactose, glucose with galactose and lactic acid levels in their feces were not a convincing evidence of lactose intolerance. Detection in the feces of elevated levels of 2 or more parameters after oral lactose load (2 g/kg, not more than 15 g), as well as an increment of a previously elevated value or its manifestation evidenced lactose intolerance. No increase of carbohydrate levels or lactic acid in the feces were observed in the group of 21 age-matched controls.

Child, Preschool↗

Colonic fermentation may play a role in lactose intolerance in humans.

The results of our previous study suggested that in addition to the small intestinal lactase activity and transit time, colonic processing of lactose may play a role in lactose intolerance. We investigated whether colonic fermentation of lactose is correlated with lactose intolerance. After 28 Chinese subjects had undergone 1 glucose (placebo) and 2 lactose challenges, consistent lactose tolerant (n = 7) and intolerant (n = 5) subjects with no complaints after glucose administration were classified on the basis of the 6-h symptom scores. Before the challenges, fecal samples were collected for in vitro incubation with lactose. The incubation was carried out in a static system under anaerobic conditions for 5 h during which samples were taken for measurement of short-chain fatty acids, lactate, lactose, glucose, and galactose. Fecal bacterial composition was determined by fluorescent in situ hybridization. The tolerant and intolerant groups did not differ in the rate or degree of hydrolysis of lactose or production of glucose and galactose. The intolerant group produced d- and l-lactate, acetate, propionate, and butyrate significantly faster than the tolerant group. In the intolerant group, the amounts of acetate, propionate, butyrate, and l-lactate produced were higher than those in the tolerant group. Fecal bacterial composition did not differ between the 2 groups. The results indicate that the degree and rate of lactose hydrolysis in the colon do not play a role in lactose intolerance. However, after lactose is hydrolyzed, a faster and higher production of microbial intermediate and end metabolites may be related to the occurrence of symptoms.

Adult↗

[Study on the incidence of lactose intolerance of children in China].

1168 healthy children of 3-13 years old were selected as subjects from Beijing, Shanghai, Guangzhou and Haerbin. Total subjects were challenged by 25 gram lactose test. The breath hydrogen was determined, the symptoms of lactose intolerance were recorded. The results showed that the incidences of lactase deficiency of children of 3-5, 7-8 and 11-13 years old were 38.5%, 87.6% and 87.8% respectively. The incidences of lactose intolerance were 12.3%, 33.2% and 30.5% respectively. Lactase activity decreasing of Chinese children occurred at the age of 7-8 years old, and the symptom of lactose intolerance depended on lactose dose. But, there still are 39%-41.7% children with lactose maldigestion and 14%-16% children with intolerance symptom, after taking 50 gram milk powder (12 g lactose). The relationship between lactase activity and milk intake was not found.

Adolescent↗

Double blind study of milk lactose intolerance.

One hundred and fifty subjects were studied in a double blind fashion to determine the relationship between lactose malabsorption and milk lactose intolerance. Each participant received 250 ml of a different type of milk on 3 consecutive days. Milk A contained no lactose, milk B had 12.5 g, and milk C contained 37.5 g of lactose. After the experiment was completed each subject was classified with a lactose tolerance test as having "sufficient" or "insufficient" lactase activity. Milk A produced no gastrointestinal symptoms in either sufficient or in insufficient persons. Milk B produced symptoms in 3.8% of sufficient and 37.1% of insufficient individuals, and Milk C induced symptoms in 7.6% of sufficient and 83.5% of insufficient subjects. These differences are very highly significant (P less than 0.0001). It is concluded that lactose-intolerant subjects are indeed milk-intolerant and that the frequency with which symptoms occur in persons with lactose malabsorption increases in direct relation to the lactose content of the milk.

Adolescent↗

Lactose intolerance in persistent diarrhoea during childhood: the role of a traditional rice-lentil (Khitchri) and yogurt diet in nutritional management.

Lactose intolerance is frequently encountered in children with persistent diarrhoea (PD). Selection of an appropriate milk-based formulation is a major management problem in the developing world. In a consecutive series of studies, we evaluated the role of feeding a traditional rice-lentil (khitchri) diet alone (KY) or in combination with either soy formula (KY-Soy) a dilute buffalo milk (KY-B), in children (age 6 months-3 years) with PD. Serial observations of stool output, caloric intake and weight gain of these children over a 14 day period indicated satisfactory tolerance of the KY diet with adequate weight gain. The weight gain and stool output was however higher in lactose intolerant children, with the worst results seen with K-Y and buffalo milk combination. While lactose intolerant children with PD do have higher. rates of therapeutic failure, our data indicates that a traditional diet and yogurt combination can be used satisfactorily for nutritional rehabilitation in over 80% of such children.

Animals↗

Properties of porcine and yogurt lactobacilli in relation to lactose intolerance.

Lactobacilli that had been isolated from the stomach of piglets were tested for properties relevant to the production of fermented milk products for consumption by lactose-intolerant humans. The strains were characterized for beta-galactosidase activity, the ability to reduce the lactose concentration of milk, viability, and pH of the fermented milk over a 30-d period. Strains that had favorable attributes were studied further, and the optimal pH for beta-galactosidase activity, ability to grow in the presence of bile salts, and ability to deconjugate bile salts were determined. Commercial yogurts were also examined to determine whether products varied in characteristics that might affect tolerance of milk products by lactose-intolerant subjects. The Lactobacillus sp. isolated from pigs had lower beta-galactosidase activity than did Lactobacillus delbrueckii ssp. bulgaricus strains ATCC 11842 and NCDO 1489 and strains of lactobacilli isolated from yogurt. The beta-galactosidase activity of all strains decreased rapidly once the fermented milk was stored at 4 degrees C. Strain JB10, originating in the stomach contents of the piglets, had properties that were useful for the manufacture of fermented milk products for lactose-intolerant humans. Milk fermented by this strain had a lactose concentration of about 4.0% and contained 6.6 x 10(6) cfu/ml after storage at 4 degrees C for 20 d. Strain JB10 produced a beta-galactosidase that was active at pH 5.5 (35% of the activity at pH 7.0) and was not inhibited by the presence of bile acids in the culture medium. Beta-Galactosidase activity and lactose concentration varied among yogurts.

Animals↗

Lactose intolerance associated with adjuvant 5-fluorouracil-based chemotherapy for colorectal cancer.

BACKGROUND & AIMS: Bowel mucosal injury associated with 5-fluorouracil (5-FU) treatment might result in secondary lactose intolerance. The frequency and clinical significance of 5-FU-related hypolactasia are unknown. METHODS: One hundred fifty patients randomly assigned to receive 1 of 2 adjuvant 5-FU-based chemotherapy regimens, the Mayo regimen or the simplified de Gramont regimen, were studied for lactose tolerance by using an oral lactose absorption test, a symptom questionnaire, treatment-related toxicity, and Subjective Global Assessment of Nutritional Status questionnaire before, during, and 2 and 6 months after chemotherapy for colorectal cancer. RESULTS: The frequency of hypolactasia increased from 24% before treatment to 35% during treatment (P < 0.0001). Therapy-related hypolactasia was reversible on discontinuation of chemotherapy. Symptoms compatible with lactose intolerance occurred in 94% of patients with an abnormal lactose absorption test result during chemotherapy. The frequency of hypolactasia increased during chemotherapy in both treatment groups, but was detected more commonly in those for whom therapy included continuous 5-FU infusions (the de Gramont regimen; 45% vs. 25%; P = 0.006). The presence of hypolactasia during chemotherapy was associated with flatulence, diarrhea, and poor nutritional status. CONCLUSIONS: Reversible chemotherapy-related hypolactasia and lactose intolerance are not infrequent in patients treated with 5-FU-based adjuvant chemotherapy for colorectal cancer. Avoidance of lactose during chemotherapy may improve treatment tolerability in these patients.

Adult↗

Lactose intolerance: analysis of underlying factors.

BACKGROUND: We studied the degree of lactose digestion and orocecal transit time (OCTT) as possible causes for the variability of symptoms of lactose intolerance (LI) in a sample of a population with genetically determined low lactase activity. METHODS: Lactose digestion index (LDI) was measured by the recently developed 13C-lactose/2H-glucose test. The OCTT was determined using the breath hydrogen test. Based on a 6-h symptom score (SSC) after a challenge dose of 25 g of lactose the subjects were divided into a tolerant group (T: n= 15; SSC = 0) and an intolerant group (IT: n= 28; SSC 1-40). The intolerant group was subdivided according to the severity of symptoms: group ITa (n = 17; mild symptoms without diarrhoea) and group ITb (n = 11; with diarrhoea). RESULTS: The LDI was lower in the intolerant group (0.34 +/- 0.14) (mean +/- SD) than in the tolerant group (0.47 +/- 0.14) (P = 0.008). The OCTT of group IT (60, 30-90 min) (median, quartiles) was significantly shorter than that of group T (105, 60-120 min) (P = 0.003) and was positively correlated with the LDI (P = 0.050). In groups ITa and ITb the OCTT (60, 30-90 min; 60, 26-83 min) and LDI (0.30 +/- 0.14; 0.39 +/- 0.14) were similar. CONCLUSIONS: Lactose digestion capacity, which is determined by small intestinal lactase activity as well as by OCTT, affects the occurrence of lactose intolerance. However, the major difference in intolerance symptoms is caused by differences in the colonic processing of maldigested lactose.

Adult↗

Treatment of lactose intolerance with exogenous beta-D-galactosidase in pellet form.

The effectiveness of a new beta-D-galactosidase pellet formulation in the treatment of lactose intolerance was studied. The encapsuled beta-D-galactosidase (lactase) pellets were first tested in vitro for their enzymatic activity within an environment simulating gastric conditions and subsequently within an environment simulating duodenal conditions. Effectiveness was measured by the % of glucose formed by hydrolysis of lactose. The pellets were found to retain their enzymatic activity in gastric pH conditions (mean 69 +/- 1 mg/dl glucose) and were found to hydrolyse lactose in human duodenal fluid (106.35 +/- 1 mg/dl). Finally the effectiveness of the new lactase formulation on glucose absorption was studied in 8 lactose intolerant subjects in a randomized, double blind, crossover trial. After fasting, the subjects were given one capsule containing 100 u/ml beta-galactosidase (i.e. 10 pellets of 10 u/ml each) or one capsule containing placebo pellets, followed by 100 g lactose dissolved in water. The washout period between lactose challenges was one week. Plasma glucose concentrations were measured before and at intervals after the challenges and the subjects completed symptom questionnaires every eight hours for 24 hours. Results showed a statistically significant increase in plasma glucose levels 30, 60, 90 and 120 min after lactose ingestion (repeated measures analysis of variance, p<0.01). Subjective ratings of the severity of abdominal cramping, belching, flatulence, vomiting and diarrhoea were significantly decreased following ingestion of the lactase pellets and lactose (no incidence of diarrhoea) compared with after ingestion of placebo and lactose. The results of the study were considered to be very promising as the beta-D-galactosidase formulation (which was produced at very low cost and with great ease) resisted inactivation in the stomach, effectively transformed lactose to glucose in vivo and reduced symptoms of lactose intolerance.

Adult↗

Lactose intolerance and lactase deficiency in children.

The term lactase deficiency is widely used to indicate a low or absent level of lactase enzyme in the small intestine, leading to lactose intolerance. This term is correctly used when the intestinal mucosa is damaged and results in secondary lactase deficiency. In the case of the genetically determined decrease of lactase activity during childhood, however, low lactase levels suggest that the majority of the world's population is "abnormal," whereas individuals from caucasian extraction with high levels of lactase enzyme throughout life are then considered "normal." It would be better to ascribe racial and ethnic lactose malabsorption as the result of genetically determined reduction of lactase activity, rather then implying an "abnormality" by the term, "deficiency." Recent studies reveal that this genetic control is at the transcriptional level. The symptomatology of lactose intolerance varies widely, and the diagnostic method of choice is the lactose breath hydrogen test in combination with clinical findings, although small intestinal biopsies should be performed when mucosal diseases are suspected. Treatment of lactose intolerance depends on the age of the child. In young infants complete restriction of lactose containing foods is rarely necessary.

Adult↗

Clinical aspects of lactose intolerance in children and adults.

The principal carbohydrate of human milk is the disaccharide lactose. In human and all mammalian species, lactose is hydrolyzed in the small intestine by lactase-phlorizin hydrolase, also abbreviated as lactase. The absence of lactase results in the passage of undigested lactose into the large intestine and is associated with a well-known clinical syndrome: lactose intolerance. Low lactase levels result either from intestinal injury or, as in the majority of world's adult population, from alterations in the genetic expression of lactase. In this review terminology, pathophysiology, symptoms, diagnostic procedures, and therapy of lactose intolerance will be discussed.

Adult↗

Cocoa feeding and human lactose intolerance.

On the basis of evidence of the suppressing effect of cocoa on human lactose intolerance, a feeding study was conducted on 35 subjects with a commercial chocolate-milk formula. Variables studied were breath hydrogen level (BHL), symptoms, and onset time. Data from repeated feeding were analyzed by paired t tests. The addition of cocoa significantly reduced BHL (p less than 0.005) as well as the symptom score of both bloating (p less than 0.05) and cramping (p less than 0.025). Individual lactose intolerance levels ranged from 5% (basal milk) to 12.5% with an average of 7.8% upon consumption of 250 mL milk. Having both plain and cocoa formulas contain sucrose and carrageenan led to a conclusion that the suppressive effect of cocoa observed was independent of the presence of sucrose and carrageenan. Ninety-five percent of the subjects responded positively (BHL greater than 17 ppm) to the plain and 51% to the cocoa formula.

Animals↗

Lactose intolerance in adults with chronic unspecific abdominal complaints.

77 hospitalized patients with chronic unspecific abdominal complaints, in whom any other organic disease had been previously excluded, were investigated for lactose malabsorption; they were subdivided into two groups: 46 patients complaining primarily of colicky abdominal pain and/or intermittent diarrhoea (group 1) and 31 patients presenting with dyspepsia as the predominant symptom (group 2). To establish the exact prevalence of isolated lactase deficiency in the healthy adult population served by our hospital, 40 Italian adult healthy subjects were also studied. The prevalence of lactose malabsorption was significantly higher (p less than 0.005) in patients of the 1st group than in patients of the 2nd group, and in the healthy adult population seen at our hospital (74% vs 35.5% and 37.5%, respectively). Furthermore a high prevalence of lactose intolerance, determined by means of a three-week diet trial (lactose free-diet versus normal diet), was documented among lactose malabsorbers of the 1st group. We concluded therefore that lactose intolerance is a factor in some Italian adult patients who suffer from long-standing aspecific abdominal discomfort, and it should be always considered in these patients, especially when colicky abdominal pain and diarrhoea are present, before the diagnosis of irritable bowel syndrome is made.

Abdomen↗

The myth of increased lactose intolerance in African-Americans.

In the United States, approximately three fourths of African-Americans have the potential for symptoms of lactose intolerance because lactose digestion depends on the presence of the enzyme lactase-phlorizin hydrolase which is reduced by up to 90-95% in individuals with lactase nonpersistence. The 'African-American diet' is more likely to be low in a variety of vitamins and minerals, including calcium. African-Americans consume low amounts of dairy foods and do not meet recommended intakes of a variety of vitamins and minerals, including calcium. Low intake of calcium and other nutrients put African-Americans at an increased risk for chronic diseases. The 2005 Dietary Guidelines recommend consuming three servings of dairy foods per day to ensure adequate calcium intake, among other nutrients, and the National Medical Association has recently published a similar recommendation of three to four servings of dairy per day for the African-American population. Research has shown that lactose maldigesters, including African-American maldigesters, can consume at least one cup (8 oz) of milk without experiencing symptoms, and that tolerance can be improved by consuming the milk with a meal, choosing yogurt or hard cheeses, or using products that aid in the digestion of lactose such as lactase supplements or lactose-reduced milks.

Black or African American↗

Modification of sweet acidophilus milk to improve utilization by lactose-intolerant persons.

Enhanced digestion of yogurt by lactose-intolerant individuals is believed to be due to inherent beta-galactosidase (lactase) in the culture organisms that aids in the hydrolysis of ingested lactose. However, sweet acidophilus milk, which contains lactase-rich organisms, does not enhance lactose digestion. Using breath-hydrogen measurements to indicate malabsorption in 14 human subjects, we compared utilization of: milk, yogurt, heated yogurt, yogurt plus lactose, heated yogurt plus lactase, sweet acidophilus milk (SAM), and SAM made with sonicated cells. Results indicate that both the reduction of lactose during fermentation and the presence of indigenous bacterial lactase are responsible for the increased ability to tolerate lactose in yogurt. Improved utilization of SAM by sonication suggests that intracellular lactase is not available during digestion and that sonication releases the lactase activity from the cells.

Animals↗

[Lactose intolerance in hospitalized infants with acute diarrhea due to classic enteropathogenic Escherichia coil (EPEC)].

Three hundred and eleven hospitalized weaned infants with acute diarrhea, all under 12 months of age, were studied in order to evaluate the development of lactose intolerance and its association with age, nutritional status, birth weight, dehydration and enteropathogenic agents identified in fecal samples. After been rehydrated the infants received whole cow' milk assuring the intake of 100 kcal/kg per day. Lactose intolerance was defined according t the following criteria: 1) persistence of diarrhea associated with weight loss during 48 hours, 2) development of vomiting and/or abdominal distention associated with excretion of carbohydrate in feces and/or acids tools, 3) metabolic acidosis associated with abdominal distention at anytime of refeeding period. Lactose intolerance was detected in 52.1% (162/311) of the patients and it was significantly associated with age under 6 months (P < 0.01), birth weight under 3000 grams (P < 0.01), development of dehydration (P < 0.01) and with enteropathogenic Escherichia coli (EPEC) serotypes infection (P < 0.01).

Acute Disease↗

Lactose intolerance. Pinpointing the source of nonspecific gastrointestinal symptoms.

Lactose intolerance is a common condition that can cause nonspecific gastrointestinal symptoms. A reliable diagnosis cannot be made on the basis of the patient's history. The breath hydrogen test is simple, noninvasive, accurate, and inexpensive and is the diagnostic method of choice. In addition to traditional dietary restriction of lactose, treatment may consist of alterations in dietary fat content or caloric density to reduce symptoms and use of dairy products or additives that provide lactase activity.

Abdominal Pain↗