Calcium absorption from milk in lactase-deficient and lactase-sufficient adults

To determine whether lactose influences the absorption of calcium, the uptake of calcium from lactose-hydrolyzed milk and from unhydrolyzed milk was measured in 20 adults: 10 were lactase-deficient and 10 were lactase-sufficient as defined by breath hydrogen test, plasma glucose determination after oral lactose dose, and presence or absence of symptoms after lactose ingestion. On different days, each subject received either lactose-hydrolyzed or unhydrolyzed milk. Calcium absorption was measured by a double-isotope technique. In the lactase-deficient group, the mean absorptions were 33.5% from hydrolyzed milk and 36.2% from the same volume of unhydrolyzed milk (P greater than 0.30). In the lactase-sufficient group, mean absorptions were 24.2% from hydrolyzed milk and 25.7% from unhydrolyzed milk. The mean calcium absorption from both lactose-hydrolyzed milk and unhydrolyzed milk was significantly greater (P less than 0.01) in the lactase-deficient group compared to the lactase-sufficient group, presumably reflecting lower dietary calcium intake in the former. These data indicate that, in lactase-deficient subjects, malabsorption of lactose does not affect calcium absorption.     

Absorption of nutrients in lactase deficiency

The influence of malabsorption of lactose, as a result of primary lactase deficiency, on the absorption of the nutrients in milk was tested in four healthy controls and four subjects with lactase deficiency. An ileal perfusion technique was used to quantify arrival in the ileum of nutrients and a nonabsorbable marker (polyethylene glycol, PEG 4000) ingested as a test meal of milk. The meal was 250 ml of whole milk or milk in which the lactose had been hydrolyzed to glucose and galactose. In the fasting state, ileal flow of volume, protein, carbohydrate, and electrolytes was small and not different in controls and lactase-deficient subjects. Ileal flow increased in all subjects after the test meal of milk; more fluid and nutrient was recovered from the ileum in lactase-deficient subjects after whole milk than in control subjects or in lactase deficiency after hydrolyzed milk. Two deficient subjects showed marked malabsorption of lactose (35 and 50%); two did not. Protein, calcium, magnesium, and phosphorus were also recovered from the ileum in greater quantities in lactase deficients after whole milk. However, apart from decreased absorption of lactose, the nutritional consequences of malabsorption in association with primary lactase deficiency in adults are probably minimal.Supported in part by a Grant-in-Aid from the National Dairy Council, and by Research Grants AM-6908 and RR-585 from the National Institutes of Health, Bethesda, Maryland.     

Lactose malabsorption and rate of bone loss in older women.

OBJECTIVES: to study the prevalence of lactose malabsorption with increasing age and to determine whether lactose malabsorbers consume less dietary calcium, have lower bone mineral density or display faster bone loss than lactose absorbers. DESIGN: 80 healthy Caucasian women aged 40-79 years (20 per decade) were studied for 1 year. METHODS: breath hydrogen exhalation was measured for 3 after a 50 g oral lactose challenge. Bone density was assessed in the radius, femoral neck, lumbar spine and total body by dual energy x-ray absorptiometry and dietary calcium intake was estimated by 4-day diet records and food-frequency questionnaires. RESULTS: lactose malabsorption rose with age (15% in those aged 40-59 years versus 50% in those aged 60-79; P < 0.01). Malabsorbers aged 70-79 years consumed significantly less calcium than lactose absorbers of this age (P < 0.05). Baseline total body calcium values were lower in lactose malabsorbers (n=26) than in lactose absorbers (n=54) but age-adjustment eliminated this difference. Bone change (% per year) was correlated with dietary calcium intake at the femoral neck and trochanter (P < 0.05) but was not statistically greater in malabsorbers than in absorbers. CONCLUSIONS: the ability to absorb lactose declines in the 7th decade. This may contribute to decreased dietary intakes of milk products and calcium in elderly women. However, lactose malabsorption without reduction in calcium intake has little effect on bone mineral density or the rate of bone loss.     

Lactase deficiency: a common genetic trait of the American Indian

Intestinal lactase activity was assessed indirectly in 156 American Indians by measuring breath hydrogen after an oral lactose load. Lactase deficiency was present in 66% of subjects and correlated highly with the percentage of Indian blood. Lactase deficiency was present by the age of 5 years and was unrelated to sex. Most lactase-deficient subjects (81%), but only a minority (23%) of lactase-sufficient subjects, developed symptoms after the oral lactose load, and among lactase-deficient subjects, symptoms occurred more frequently in adults than in children (P = 0.05). Indeed, by history, 53% of lactase-deficient adults, but only 10% of lactase-deficient children under 18 years of age, were aware of milk intolerance. Despite these differences, milk consumption was only slightly less (19 g) in the lactase-deficient subjects than in those with normal lactase activity (25 g) (P less than 0.05). The results indicate that lactase deficiency is a common autosomal genetic trait in the American Indian that becomes manifest in early childhood. Tolerance to dietary lactose appears to decline in the American Indian as he reaches adulthood, but in this population the decline in tolerance had only minor influence on lactose intake.     

Quantitative measurement of lactose absorption.

The quantity of lactose not absorbed by 4 normal and 6 lactase-deficient subjects was determined by three indirect methods which involved: (1) measurement of pulmonary hydrogen (H2) excretion, (2) pulmonary (14)CO2 excretion, and (3) stool (14)C excretion, after ingestion of 12.5 g of 1-(14)C-lactose and 4 g of polyethylene glycol (PEG). Results were compared with absorption determined directly from the (14)C:PEG ratio of multiple terminal ileal aspirates. The fraction of lactose not absorbed determined by ileal aspiration ranged from 0 to 8% in normals and 42 to 75% in mild-intolerant subjects. Whereas all three indirect methods were useful in qualitatively separating normal from deficient subjects, the quantity of lactose absorbed as determined by H2 excretion correlated most closely with ileal measurements (r = 0.94). Pulmonary (14)CO2 excretion for 24 hr after (14)C-lactose ingestion did not distinguish normal (17 +/- 4% (SEM) of ingested (14)C per 24 hr) from lactase-deficient subjects (21.1 +/- 3%). Likewise, stool (14)C:PEG ratios grossly underestimated malabsorption with less than one-quarter of the nonabsorbed (14)C appearing in the stool. This study suggests that individual differences in susceptibility to diarrhea after milk ingestion by lactase-deficient subjects may be due to differences in the quantity of lactose not absorbed and/or differences in the rate of bacterial metabolism of lactose in the colon. Analysis of ileal fluid collected during passage of the lactose meal indicated that about two-thirds of the osmotic load delivered to the colon consists of endogenous electrolytes. Thus the water load delivered to the colon is about 3 times that calculated to be osmotically held by the nonabsorbed sugar.     

Respiratory methane excretion in children with lactose intolerance

Two evaluate the relationship between colonic methane production and carbohydrate malabsorption, we measured end-expiratory methane levels in 70 normal and 40 lactose-intolerant children. Time-dependent excretion of hydrogen and methane was determined every 30 min for 120 min following a fasting oral lactose challenge (2 g/kg). Mean breath hydrogen levels in normals (lactose-tolerant) equaled 3.7 parts per million (ppm) throughout the study, but increased to >10 ppm by 60 min and remained elevated in lactose-intolerant subjects. Breath methane in normal children averaged 1.6 ppm from 0 to 120 min. In contrast, CH₄ excretion by lactose-intolerant children averaged 5.1 ppm at 90 min; and, by 120 min levels increased significantly compared with control. Breath methane levels in lactose-intolerant subjects following a lactose load continued to increase, however, despite the coingestion of exogenous lactase in amounts calculated to result in complete hydrolysis of the disaccharide. These data demonstrate that lactase-deficient children manifest significant increases in breath methane excretion following lactose ingestion and that enhanced methane production may be a consequence of several factors, including altered fecal pH and increased methanogenic substrates provided by colonic lactose fermentation. Further studies are required to determine the clinical significance of elevated methane production in lactose intolerance.     

Agreement between indirect calorimetry and traditional tests of lactose malabsorption

BackgroundLactose malabsorption occurs frequently and the variable consequent intolerance may seriously impair quality of life. No reliable and convenient test method is in routine clinical practice. A recent animal study showed that the respiratory quotient changed significantly after ingestion of sucrose and lactose in naturally lactase-deficient rats.AimsThis exploratory study evaluated the relevance of monitoring the respiratory quotient after lactose ingestion to detect malabsorption.MethodsHealthy volunteers were identified and classified lactose absorbers and malabsorbers by a lactose tolerance test (25 g). After an overnight fast, a second lactose challenge was performed to monitor hydrogen excretion and respiratory quotient kinetics over 4 h. Participants also completed questionnaires to score and localise their gastrointestinal symptoms.Results20 subjects were enrolled (10 per group, 60% males, mean age 34 ± 4 years). Respiratory quotient kinetics were different between absorbers and malabsorbers during the first 100 min after lactose ingestion (p < 0.01) and during the initial 30–50 min period. Respiratory quotient was significantly, positively correlated to peak glycaemia (R = 0.74) and negatively correlated to hydrogen excretion (R = ?0.51) and symptoms score (R = ?0.46).ConclusionsIndirect calorimetry could improve the reliability of lactose malabsorption diagnosis. Studies on larger populations are needed to confirm the validity of this test and propose a simplified measurement.     

Effects of age on lactose malabsorption in Oklahoma Native Americans as determined by breath H2 analysis

Breath H₂ excretion was used to determine lactose malabsorption in 30 healthy females and 30 healthy males between the ages of 3 and 64 yr who were at least 7/8 Native American. The test meal consisted of 5 ml reconstituted nonfat dry milk (0.25 g lactose) per kg of body weight. On the basis of breath H₂ tests in 15 control subjects with normal oral lactose tolerance tests, a response factor of 20 ppm was selected as the upper limit for lactose absorbers. Of the 60 subjects in the study group, 36 (60%) were classified as lactose malabsorbers since they had a response factor of 20 ppm or greater of breath H₂. Only 3 of 20 children (15%) who were under the age of 12 yr were nondigesters of the small lactose dose used in this study. Approximately 82 percent (82.5%) of subjects who were 13 yr and older were lactose malabsorbers. Adolescence appears to be the period in which malabsorption of lactose becomes evident in Native North Americans.Supported by the Nutrition Foundation, Inc., New York, New York; Biomedical Sciences Support Grant (USPH) 5-S05-RR7077 to The Research Foundation, Oklahoma State University.     

Effect of absorbable and nonabsorbable sugars on intestinal calcium absorption in humans

The effects of glucose, galactose, and lactitol on intestinal calcium absorption and gastric emptying were studied in 9, 8, and 20 healthy subjects, respectively. Calcium absorption was measured by using a double-isotope technique and the kinetic parameters were obtained by a deconvolution method. The gastric emptying rate was determined with 99mTc-diethylenetriaminepentaacetic acid and was expressed as the half-time of the emptying curve. Each subject was studied under two conditions: (a) with calcium alone and (b) with calcium plus sugar. Glucose and galactose increased the calcium mean transit time and improved the total fractional calcium absorption by 30% (p less than 0.02). Lactitol decreased the mean rate of absorption (p less than 0.001) and reduced the total fractional calcium absorption by 15% (p less than 0.001). The gastric emptying rate did not appear to influence directly the kinetic parameters of calcium absorption. These results show that both glucose and galactose exert the same stimulatory effect as lactose on calcium absorption in subjects with normal lactase whereas lactitol mimics the effects of lactose in lactase-deficient patients. Thus the absorbability of sugars determines their effect on calcium absorption.     

Lactose malabsorption and intolerance and peak bone mass

BACKGROUND & AIMS: Lactose malabsorption per se is not associated with alterations of bone mineral density (BMD) or calcium intake, but when intolerance symptoms are present a lower calcium intake and reduction of BMD values are evident. The purpose of this study was to evaluate whether lactose intolerance interferes with the achievement of an adequate peak bone mass in young adults. METHODS: Of 103 enrolled healthy subjects, 55 proved to be lactose malabsorbers with H(2) breath test after lactose administration, and 29 of them experienced intolerance symptoms (diarrhea, abdominal pain, bloating, flatulence). Lumbar and femoral BMD by dual-energy X-ray absorptiometry was measured, and calcium intake and biochemical indices of bone and mineral metabolism were evaluated. RESULTS: Lumbar and femoral BMD, calcium intake, and mineral metabolism did not differ between malabsorbers and absorbers, although among malabsorbers, intolerant subjects showed significant alterations of all these parameters in comparison with tolerant subjects. A strict correlation was evident between BMD values and both severity of symptoms and calcium intake and between calcium intake and severity of symptoms. CONCLUSIONS: Lactose intolerance prevents the achievement of an adequate peak bone mass and may, therefore, predispose to severe osteoporosis.     

Lactose Malabsorption Is Associated with Early Signs of Mental Depression in Females (A Preliminary Report)

Lactose malabsorption is characterized by adeficiency of mucosal lactase. As a consequence, lactosereaches the colon where it is broken down by bacteria toshort-chain fatty acids, CO₂, andH₂. Bloating, cramps, osmotic diarrhea, and other symptoms ofirritable bowel syndrome are the consequence and can beseen in about 50% of lactose malabsorbers. Having madethe observation that females with lactose malabsorption not only showed signs of irritable bowelsyndrome but also signs of premenstrual syndrome andmental depression, it was of interest to establishwhether a statistical correlation existed betweenlactose malabsorption and mental depression. Thirtyfemale volunteers were analyzed by measuring breathH₂ concentrations after an oral dose of 50 glactose and were classified as normals or lactosemalabsorbers according to their breath H₂concentrations. All patients filled out a Beck'sdepression inventory questionnaire. Of the 30 femalevolunteers, six were lactose intolerant (20%) and 24were normal lactose absorbers (80%). Subjects with lactosemalabsorption showed a significantly higher score in theBeck's depression inventory than normal lactoseabsorbers did. The data thus suggest that lactosemalabsorption may play a role in the development of mentaldepression. In lactose malabsorption high intestinallactose concentrations may interfere with L-tryptophanmetabolism and 5-hydroxytryptamine (serotonin)availability. Lactose malabsorption should be considered inpatients with signs of mental depression.     

Hydrogen breath test quantification and clinical correlation of lactose malabsorption in adult irritable bowel syndrome and ulcerative colitis

Lactose malabsorption was studied, by hydrogen breath test, in 72 adults suffering from irritable bowel syndrome, in 20 ulcerative colitis patients, and in 69 healthy subjects. The minimum dose of lactose required to cause a positive breath test was determined, and the symptoms caused and the resulting hydrogen eliminated quantified. A high incidence of lactose malabsorption was shown at standard doses (up to 50 g) in both the healthy subjects (70%) and the patients (86% and 85%, respectively). In the irritable bowel syndrome and the ulcerative colitis groups, symptoms occurred with a smaller quantity of breath hydrogen, presumably in association with a greater individual sensitivity of the colon to distension. The threshold lactose dose was notably lower in the diseased subjects who registered as evidence a prevalence of malabsorption at a 20-g lactose load. The pathogenetic role of lactose malabsorption in the irritable bowel syndrome is emphasized, as is the importance of the personal lactose tolerance.     

Coincidental Malabsorption of Lactose, Fructose, and Sorbitol Ingested at Low Doses Is Not Common in Normal Adults

Normal subjects may incompletely absorb either lactose, fructose, or sorbitol and may therefore have abdominal symptoms. The frequency of coincidental malabsorption of these sugars is not known. This is clinically important, since we often ingest them during the same day and malabsorption may cause abdominal symptoms. To shed light on this issue we studied 32 normal subjects. Volunteers drank in random order the following solutions: 20 g lactulose, 50 g sucrose, 50 and 25 g lactose, 50 and 25 g fructose, 20 and 10 g sorbitol. Semiquantitative carbohydrate malabsorption was estimated with lactulose standards. Frequency of 50-g lactose (69%), 50-g fructose (81%), and 20-g sorbitol (84%) malabsorption was not significantly different (P = 0.3). The estimated median fraction of the ingested high dose malabsorbed was 42, 19, and 68% for lactose, fructose, and sorbitol, respectively. At low challenging doses, 63% of the volunteers absorbed two of three or all three sugars, and 88% were asymptomatic to two or all three sugars. In conclusion, the frequency of coincidental malabsorption of lactose, fructose, and sorbitol and intolerance to these sugars is not common, when normal adults ingest them at low doses.     

Assessment of lactose absorption by measurement of urinary galactose

Individuals with sufficient intestinal lactase hydrolyze ingested lactose to galactose and glucose and these monosaccharides are absorbed. Lactose is not digested completely when intestinal lactase activity is low and the disaccharide is malabsorbed. Breath hydrogen excretion after lactose ingestion is used commonly to diagnose lactose malabsorption. However, no direct tests are currently used to assess lactose absorption. We tested a new method of assessing lactose absorption in 26 healthy individuals. Each subject ingested 50 g of lactose. Participants were evaluated for lactose malabsorption using a standard 3-h breath hydrogen test. In addition, the urinary excretions of galactose, lactose, and creatinine were quantitated for 3-5 h after lactose ingestion. On the basis of breath hydrogen analysis after lactose ingestion, 12 individuals were lactose malabsorbers (defined as a rise in the breath hydrogen concentration of greater than 20 parts per million above the baseline value). The 14 subjects who did not malabsorb lactose by breath hydrogen testing (defined as a rise in the breath hydrogen concentration of less than or equal to 20 parts per million above the baseline value), had significantly more galactose in their urine 1, 2, and 3 h after lactose ingestion than lactose malabsorbers. The ratio of excreted lactose to excreted galactose was significantly decreased in lactose absorbers compared with lactose malabsorbers (p less than 0.001). Determination of the ratio of urinary galactose to urinary creatinine separated lactose absorbers from lactose malabsorbers completely (p less than 0.001). We conclude from this study that the determination of urinary galactose, urinary lactose/galactose ratio, and urinary galactose/creatinine ratio may be used to assess lactose digestion and absorption in healthy adults.     

Breath testing to evaluate lactose intolerance in irritable bowel syndrome correlates with lactulose testing and may not reflect true lactose malabsorption

OBJECTIVES: An increased prevalence of lactose intolerance is seen in irritable bowel syndrome (IBS). Recently, we demonstrated a high prevalence of abnormal lactulose breath test results in IBS suggesting bacterial overgrowth. Because symptoms of lactose intolerance result from bacterial fermentation, the purpose of this study was to determine whether an abnormal lactose breath test is reflective of malabsorption or early presentation to bacteria. METHODS: Subjects with diarrhea-predominant IBS were enrolled. On day 1, subjects underwent a lactulose breath test after an overnight fast. Within 1 wk, subjects returned after fasting for a lactose breath test with simultaneous blood glucose measurements every 15 min to complete a lactose tolerance test (LTT). Symptoms were evaluated 3 h after lactose administration. RESULTS: Twenty subjects completed the study. One subject inadvertently received dextrose through the intravenous and was excluded. Of the remaining 19 subjects, three (16%) had an abnormal LTT suggesting malabsorption. In all, 10 subjects (53%) had an abnormal lactose breath test, 14 (74%) had an abnormal lactulose breath test, and 11 (58%) had symptoms after lactose administration. The agreement with symptoms was moderate (kappa = 0.47) and fair (kappa = 0.24) when compared to the lactose breath test and LTT, respectively. There was a fair correlation between lactose breath test and LTT (kappa = 0.29). However, lactose breath test hydrogen levels >166 ppm were universally predictive of abnormal LTT. Finally, a significant correlation was seen between the hydrogen production on lactose and lactulose breath test (r = 0.56, p = 0.01). CONCLUSIONS: Lactose breath testing in IBS subjects does not seem to reflect malabsorption; it may be an indicator of abnormal lactulose breath test, suggesting bacterial overgrowth.     

Development, Validation, and Applicability of a Symptoms Questionnaire for Lactose Malabsorption Screening

Lactase deficiency has a high prevalence worldwide. Thus, a valid symptom scale would be a useful tool for identifying patients with lactose malabsorption. Objective To develop, validate, and apply a symptoms questionnaire on lactose malabsorption to identify lactose malabsorbers diagnosed with the gold-standard hydrogen breath test. Methods In the first part of the study, 292 patients completed a questionnaire at the end of a 50-g lactose breath test. The questionnaire included five items (diarrhea, abdominal cramping, vomiting, audible bowel sounds, and flatulence or gas) scored on a 10-cm visual analogue scale. In the second part of the study, 171 patients completed the questionnaire twice: first, according to their opinion when consuming dairy products at home and second, after a 50-g lactose breath test. Patients were grouped as absorbers or malabsorbers according to the result of the breath test. Results Diarrhea, abdominal cramping, and flatulence were scored significantly higher in malabsorbers than in absorbers. Total score of the symptomatic questionnaire was significantly higher in malabsorbers (17.5 versus 3.0, P < 0.01). According to receiver operator characteristics (ROC) analysis, the most discriminant cut-off of the total score to identify lactose malabsorption was 6.5 (sensitivity 0.75, specificity 0.67). In 58 malabsorbers the effect size of the questionnaire to determine sensitivity to change was 1.32. In the second part of the study, scoring of the home questionnaire was higher than after the lactose-breath test. The lactose malabsorbers rate was higher according to the home questionnaire than after the lactose breath test (72% versus 52%). The home questionnaire had excellent sensitivity (0.82) but low specificity (0.35). Conclusion We developed and validated a five-item symptoms questionnaire for lactose malabsorption. This is a valid test that permits patients with a total score lower than 7 to be excluded from future studies.     

Lactose malabsorption and intolerance in the elderly.

BACKGROUND: Lactase activity declines with age in rats, but it is not clear whether this model is also shared by humans. Few studies have evaluated lactose intolerance and malabsorption in the elderly and no definite conclusions can be drawn. The aim of our study was therefore to verify the impact of age on lactose intolerance and malabsorption. METHODS: Eighty-four healthy subjects took part in the study. Thirty-three were <65 years, 17 were between 65 and 74 years and 34 were >74 years. All the subjects underwent a preliminary evaluation of intestinal gas production capacity and oro-cecal transit time by H2/CH4 breath test after lactulose. After a 3-day period, an H2/CH4 breath test after lactose was performed. The occurrence of intolerance symptoms during the test and in the 24 h after the test was recorded. RESULTS: Breath H2 and CH4 excretion parameters at fasting and after lactulose did not differ between the three groups. Cumulative breath H2 excretion after lactose was higher in subjects >74 years than in subjects <65 years and in subjects aged 65-74 years, while no difference was found between the latter two groups. In subjects >74 years, the prevalence of lactose malabsorption was higher than in the other two groups, while no significant difference was observed between subjects <65 years and subjects aged 65-74 years. Within the malabsorber subjects, the prevalence of lactose intolerance was higher in subjects <65 years than in those aged 65-74 years and in those aged >74 years. No significant difference was found between the latter two groups. No difference was found between the three groups in terms of daily calcium intake and a significant negative correlation between symptom score and daily calcium intake was only found in the group of subjects aged <65 years. CONCLUSIONS: As age increases, the prevalence of lactose malabsorption shows an increase while the prevalence of intolerance symptoms among malabsorbers shows a decrease. Accordingly, daily calcium intake was similar among the adults and elderly studied.     

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.     

Comparative tolerance of elderly from differing ethnic backgrounds to lactose-containing and lactose-free dairy drinks: a double-blind study.

Milk intolerance was investigated in 87 healthy elderly individuals with a mean age of 77 years who were given 240 ml of a chocolate dairy drink twice in one week with a light lunch. No significant differences in symptomatic responses distinguished the subjects consuming a lactose-free (LF) drink from those consuming a drink containing 4.5% lactose (LC) under double-blind study conditions. Breath hydrogen analysis during lactose tolerance testing identified 23 malabsorbers, none of whom responded exclusively to the LC drink, although five were symptomatic on both days, and two had symptoms only on the day the LF drink was served. A similar percentage of absorbers (72%) and malabsorbers (70%) were asymptomatic on both days. Factors other than lactose malabsorption appeared to be responsible for the symptoms of intolerance reported, and most may have been psychosomatic in origin.     

Does Oral Enzyme Replacement Therapy Reverse Intestinal Lactose Malabsorption?

The effects of oral enzyme replacement therapy on breath hydrogen excretion and symptoms after milk ingestion were studied in lactase-deficient patients. Sixteen symptomatic patients underwent interval hydrogen breath tests using whole milk as substrate. Each study was repeated with the addition of 250 mg of β-D-galactosidase derived from Aspergillus oryzae (Lactrase) given orally with the milk. Subsequently seven of those 11 patients who did not normalize their hydrogen excretion with 250 mg of Lactrase were available to be restudied with a 500-mg dose. Mean cumulative and peak hydrogen excretions were calculated for the baseline (milk alone), 250 mg, and 500 mg Lactrase groups. Significant (p ≤ 0.05) decreases in cumulative and peak hydrogen excretion were noted between the 500 mg Lactrase versus the baseline group, but not between the 250 mg versus baseline group. Five of the 16 (31%) symptomatic lactase-deficient patients normalized their hydrogen excretion after 250 mg of Lactrase; four of seven (57%) who bad not normalized on 250 mg, normalized their hydrogen excretion with 500 mg of Lactrase. A different pattern was observed in the incidence of symptoms. Five of the nine patients (56%) whose hydrogen excretion normalized with the addition of Lactrase at either dosage became asymptomatic after milk ingestion; in addition, three patients who did not normalize their hydrogen also became asymptomatic. We conclude that oral Lactrase in sufficient dosage temporarily reverses lactose malabsorption in some patients.