Prediction of lactose malabsorption in referral patients

Fecal Calprotectin in Self-Reported Milk Intolerance: Not Only Lactose Intolerance

The hypothesis is that inflammatory/allergic conditions should be considered in self-reported milk intolerance (SRMI) patients who test negative and/or are asymptomatic at Lactose Hydrogen Breath Test (LHBT). We analyzed fecal calprotectin (FCP) values in SRMI patients to investigate the frequency of a "positive" intestinal inflammation marker and its correlation with lactose tolerance/intolerance. Data from 329 SRMI patients were retrospectively analyzed; according to the positive/negative results (maldigester/digester) and the presence/absence of symptoms reported during LHBT (intolerant/tolerant), patients were divided into: 'lactose tolerants' (n. 104), 'maldigesters/intolerants' (n. 187), 'digesters/intolerants' (n. 38). FCP values were analyzed in all three subgroups. A percentage of SRMI patients complained of constipation (>15%), extraintestinal symptoms (>30% including anemia), multiple food hypersensitivity (7.6%) and had intraepithelial lymphocytic infiltration at duodenal biopsy (>50%). Over 50.0% showed FCP values above the normal limit. Lactose tolerants and maldigesters/intolerants had higher positivity frequencies (p < 0.0001, for both) and absolute values (p = 0.04, for maldigesters/intolerants) of FCP compared to digesters/intolerants. FCP was not useful to differentiate tolerant from intolerant subjects (AUC 0.58). Our data suggest the existence of an allergic/inflammatory pathogenetic mechanism in a subset of SRMI subjects. FCP results are in keeping with this hypothesis, even if they cannot differentiate lactose tolerant from intolerant patients.

Whole Cow's Milk but Not Lactose Can Induce Symptoms in Patients with Self-Reported Milk Intolerance: Evidence of Cow's Milk Sensitivity in Adults

BACKGROUND

Lactose intolerance is the most frequent food intolerance, but many subjects with self-reported milk intolerance (SRMI) are asymptomatic at lactose hydrogen breath test (LHBT). The aim of this study was to evaluate the frequency of lactose intolerance in SRMI patients and their clinical characteristics.

METHODS

In a retrospective study, the clinical records of 314 SRMI patients (259 females, mean age: 39.1 ± 13.5 years) were reviewed; 102 patients with irritable bowel syndrome (IBS) served as controls. In a prospective study, 42 SRMI patients, negatives at the LHBT, underwent a double-blind, placebo-controlled (DBPC) whole cow's milk challenge.

RESULTS

In the retrospective study, only 178 patients (56%) were lactose maldigesters and intolerant at LHBT; 68% of the subjects with SRMI were suffering from IBS; 74% reported dyspepsia (p = 0.0001 vs. IBS controls); and weight loss was recorded in 62 SRMI patients (20%) (p = 0.01 vs. IBS controls). Duodenal histology showed intra-epithelial lymphocytosis in about 60% of cases. In the prospective study, 36 patients (86%) experienced symptoms during the DBPC cow's milk challenge, and only 4 patients (9%) reacted to placebo (p = 0.0001).

CONCLUSIONS

A percentage of SRMI patients were not suffering from lactose intolerance. DBPC revealed that SRMI patients had clinical reactions when exposed to whole cow's milk.

Carbohydrate Intolerance and Disaccharidase Measurement - a Mini-Review

Carbohydrate intolerance is one of several syndromes and diseases which together are known as malabsorption syndromes. These include small intestinal bacterial overgrowth (SIBO), coeliac disease, intestinal lymphangiectasia, short bowel syndrome, tropical sprue and some inherited metabolic disorders such as galactosaemia and pyruvate kinase deficiency. Specifically, the malabsorption of sugars affects morbidity for millions of sufferers across the world. Disaccharidase measurement is used in the investigation of disorders of the gastrointestinal tract. Diagnosis is by endoscopic small bowel biopsy of the duodenum or jejunum with subsequent biochemical and histopathological analysis. The diagnosis of bowel disorders presents several challenges with numerous overlapping presentations and symptoms such as bloating, diarrhoea, constipation, flatulence, borborygmus, weight loss and severe discomfort.

Dietary practices and inflammatory bowel disease

The etiology of inflammatory bowel disease (IBD) remains elusive but it is believed to result from incompletely understood interactions between environmental triggers in a potentially genetically susceptible host and a subsequent aberrant immune response. Its incidence is increasing worldwide at an unprecedented rate, outpacing what genetic influences alone could instigate. The increasingly integral role played by eating in social life has led patients to gravitate to diet and food in their consultations with physicians and other health care professionals, in an attempt to improve, control, or even "cure" IBD through diet. Diet is a modifiable factor, and both patients and healthcare professionals have fuelled resurgent interest in the role of diet in maintaining IBD remission. Despite significant and increasing interest, there is a lack of credible evidence to support dietary modification or restrictions to prevent relapse of IBD. However, recent studies have shown that more than half of the patients believe that diet plays an important role in triggering relapse, leading to self-imposed dietary restrictions, some of which can have adverse consequences. This underpins the need for physicians and health care professionals to have a better understanding of dietary practices, in triggering, perpetuating, and improving IBD. This review examines and discusses the evidence behind this.

Combinatorial effects of diet and genetics on inflammatory bowel disease pathogenesis

Inflammatory bowel disease (IBD) encompasses a group of disorders affecting the gastrointestinal tract characterized by acute and chronic inflammation. These are complex and multifactorial disorders that arise in part from a genetic predisposition. However, the increasing incidence of IBD in developing countries suggests that environmental factors, such as diet, are also critical components of disease susceptibility. Evidence suggests that consumption of a Western diet, enriched with saturated fat, refined carbohydrates, and food additives, is associated with increased IBD risk. Dietary components, such as omega-6 fatty acids, long-chain fatty acids, protein, and digestible carbohydrates, may contribute to IBD pathogenesis through altering intestinal microbiota, increasing intestinal permeability, and promoting inflammation; whereas omega-3 fatty acids, medium chain triglycerides, and nondigestible carbohydrates improve these parameters and intestinal health. However, the limited amount of prospective studies, small sample sizes, and the heterogeneity of disease subtype result in inconsistencies between studies and difficulty in conclusively determining the specific effects of diet on intestinal homeostasis. There are no standard clinical dietary recommendations for patients with IBD. However, exclusionary diet interventions have shown some efficacy in relieving symptoms or inducing remission, suggesting more research is needed to fully understand how diet influences disease behavior or combines with other IBD risk factors to promote disease. This review focuses on the associations of various dietary components and IBD risk in clinical studies and genetically susceptible IBD models.

Popular exclusionary diets for inflammatory bowel disease: the search for a dietary culprit

The evolving understanding of the role of the microbiome and environmental factors in the pathogenesis of inflammatory bowel disease makes diet an interesting and potentially powerful tool in the treatment of disease. However, at this time, evidence is limited but anecdotal reports of success abound. There is a bewildering array of new diets being tried by patients in an attempt to control diseases. This review attempts to summarize the most common diets for the treating physician.

Extending our knowledge of fermentable, short-chain carbohydrates for managing gastrointestinal symptoms

The Monash University low FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) diet is now accepted as an effective strategy for managing symptoms of irritable bowel syndrome (IBS) in Australia, with interest expanding across the world. These poorly absorbed, short-chain carbohydrates have been shown to induce IBS symptoms of diarrhea, bloating, abdominal pain, and flatus due to their poor absorption, osmotic activity, and rapid fermentation. Four clinical trials have been published to date, all with significant symptomatic response to the low FODMAP diet. Up to 86% of patients with IBS have achieved relief of overall gastrointestinal symptoms and, more specifically, bloating, flatus, abdominal pain, and altered bowel habit from the approach. This review provides an overview of the low FODMAP diet and summarizes the research to date, emerging concepts, and limitations. FODMAPs are known to be beneficial to bowel health; the importance of this and how this should be considered in the clinical management of IBS is also discussed. A clinical management flowchart is provided to assist nutrition professionals in the use of this approach.

Carbohydrate challenge tests: do you need to measure methane?

OBJECTIVE

Breath tests that measure hydrogen (H2) have been judged reliable for the detection of lactose maldigestion (LM) and fructose malabsorption (FM). Recently, methane (CH4) testing has been advocated and measurement of CH4 in addition to H2 has been shown to increase the diagnostic accuracy for LM.

PURPOSE

This study was designed to consider the additional yield from CH4 measurement in patients tested for LM and FM.

METHODS

Patients reported for testing after an overnight fast, not smoking and with their prior evening meal carbohydrate restricted. After challenge with 50 g lactose or 25 g fructose in water, end-alveolar breath samples collected over a 4-hour duration were analyzed for H2 and CH4. Diagnostic positivity was compared using a cutoff level of 20 ppm increase above fasting baseline for H2 alone, which is consistent with consensus guidelines, versus H2 plus twice CH4, which recognizes that CH4 consumes twice the hydrogen.

RESULTS

There were 406 LM performed in 93 men and 313 women. Of those tested, 124 (30%) had a positive test for H2 and 139 (34%) had a positive test for H2 + CH4 ×2. There were 178 FM tests performed in 31 men and 147 women. Of those tested, 17 (9%) had a positive test for H2 and 42 (23%) had a positive test for H2 + CH4 ×2.

CONCLUSION

If H2 alone was measured without additional CH4 analysis, 4% of patients with LM and 14% patients with FM would not have been identified.

Lactose malabsorption, calcium intake, and bone mass in children and adolescents

OBJECTIVES

The objective of the present study was to evaluate the calcium intake and bone mass in children and early adolescents in accordance with their absorption capacity to lactose.

PATIENTS AND METHODS

A transversal study was conducted on a sample composed of 76 individuals. Lactose malabsorption status was determined with hydrogen breath test. The hydrogen breath test was applied using 2  g of lactose per kilogram of weight up to a maximum of 50  g. A hydrogen increment ≥20  pm in relation to fasting was used to characterize lactose malabsorption. Two 24-hour recalls were applied for the evaluation of food consumption. Bone mineral content and bone mineral density were evaluated in the lumbar spine by dual-energy x-ray absorptiometry.

RESULTS

The prevalence of lactose malabsorption was 61.8%. The participants were divided into 2 groups: lactose malabsorbers (n = 47) and lactose absorbers (n = 29). There was no statistically significant difference (P > 0.05) between the groups with respect to the intake of total calcium, milk calcium, milk, cheese, yogurt, ice cream, and calcium density of the diet. Additionally, there was no difference with respect to the bone mineral content and the bone mineral density of the lumbar spine. Independent from lactose absorption capacity, it was observed that the majority of the children and early adolescents showed calcium intake lower than the recommended value.

CONCLUSIONS

There was no relation among lactose malabsorption and bone densities, bone mineral content, or calcium intake within the present study.

Lactose malabsorption and intolerance: a systematic review on the diagnostic value of gastrointestinal symptoms and self-reported milk intolerance

BACKGROUND

When lactose malabsorption gives rise to symptoms, the result is called 'lactose intolerance'. Although lactose intolerance is often bothersome for patients, once recognized it may be managed by simple dietary adjustments. However, diagnosing lactose intolerance is not straightforward, especially in primary care.

AIM

To summarize available evidence on the diagnostic performance of gastrointestinal symptoms and self-reported milk (lactose) intolerance in primary care, and the relationship between lactose malabsorption and intolerance.

DATA SOURCES

PubMed, EMBASE and reference screening.

STUDY SELECTION

Studies were selected if the design was a primary diagnostic study; the patients were adults consulting because of non-acute abdominal symptoms; the diagnostic test included gastrointestinal symptoms and/or self-reported milk intolerance. A total of 26 primary diagnostic studies were included in the review.

DATA EXTRACTION

Quality assessment and data extraction were performed by two reviewers independently. They adhered to the most recent guidelines for conducting a diagnostic review as described in the Cochrane Diagnostic Reviewers' Handbook.

RESULTS

The diagnostic performance of diarrhea, abdominal pain, bloating, flatulence and self-reported milk intolerance was highly variable. A non-Caucasian ethnic origin was associated with the presence of lactose malabsorption. Both lactose malabsorbers and lactose absorbers reported symptoms during the lactose hydrogen breath test.

CONCLUSION

Our review shows that high-quality studies on the diagnosis of lactose malabsorption and intolerance in primary care are urgently needed. An important prerequisite would be to clearly define the concept of lactose intolerance, as well as how it should be assessed.

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 intolerance in infants, children, and adolescents

The American Academy of Pediatrics Committee on Nutrition presents an updated review of lactose intolerance in infants, children, and adolescents. Differences between primary, secondary, congenital, and developmental lactase deficiency that may result in lactose intolerance are discussed. Children with suspected lactose intolerance can be assessed clinically by dietary lactose elimination or by tests including noninvasive hydrogen breath testing or invasive intestinal biopsy determination of lactase (and other disaccharidase) concentrations. Treatment consists of use of lactase-treated dairy products or oral lactase supplementation, limitation of lactose-containing foods, or dairy elimination. The American Academy of Pediatrics supports use of dairy foods as an important source of calcium for bone mineral health and of other nutrients that facilitate growth in children and adolescents. If dairy products are eliminated, other dietary sources of calcium or calcium supplements need to be provided.

Women's colonic digestive health

Digestive problems in women are common and sometimes debilitating. Twenty percent of women suffer from irritable bowel syndrome, 20% have constipation, and all American women will need screening for colon cancer, the number two cause of cancer death in women. This article reviews management of these disorders as well as lower gastrointestinal symptoms associated with menses, hysterectomy, fecal incontinence, and rectal bleeding.

Lactose intolerance in active Crohn's disease: clinical value of duodenal lactase analysis

BACKGROUND

Patients with active Crohn's disease (CD) often report having abdominal symptoms after ingestion of milk products, but the pathomechanism for lactose malabsorption seems to be complex.

GOALS

To investigate the prevalence of clinical milk intolerance and to objectify symptoms with hydrogen (H 2 ) breath testing, analysis of lactase protein, and enzyme activity in the duodenal mucosa in patients with CD and in healthy controls.

STUDY

In 49 patients with CD and 24 controls, H 2 breath testing was performed. All individuals underwent endoscopy of the upper gastrointestinal tract, in which multiple pinch samples were taken from the distal duodenum. Lactase activity was measured using the method of Dahlquist. The lactase protein expression was analyzed by gel electrophoresis using the monoclonal antibody mlac 10 and by immunochemistry using the monoclonal antibody mlac 4.

RESULTS

Prevalence of milk intolerance in healthy controls was 16.6% versus 46.9% in patients with CD, with a high frequency (83.3%) in patients with active disease (CD activity index >150). Milk intolerance was correlated to the duration of inflammatory bowel disease ( p = 0.023) but not to the location or previous bowel resection. Hydrogen breath testing had a moderate sensitivity in detecting lactose maldigestion (70.4%) and a high specificity (95.6%). Duodenal lactase levels were also correlated to disease activity, whereas correlations to clinical symptoms remained poor. Patients with milk intolerance had a significantly reduced bone density at the lumbar spine (z-score, -1.33 +/- 0.92 vs. -0.19 +/- 0.95 [mean +/- SD]; p = 0.002)

CONCLUSIONS

Milk intolerance is a frequent problem in active CD, which can be objectified accurately by H 2 lactose breath testing. Decreased lactase levels in the duodenal mucosa may be found during an acute flare but are not the predominant cause of milk intolerance in CD.

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.

Recurrent abdominal pain and lactose maldigestion in school-aged children

Recurrent abdominal pain of childhood affects 10 to 15% of school-aged children and leads to disability and learning difficulties. Lactose maldigestion may be a causative or contributory factor that when identified may lead to improvement. Thus, formal diagnostic testing using breath hydrogen lactose challenge methods is encouraged. This review focuses on this important condition and management options.

Belching, bloating, and flatulence. How to help patients who have troublesome abdominal gas

Gaseous belching, bloating, and flatulence are common complaints. These symptoms may herald the onset of important and treatable gastrointestinal diseases or may represent functional bowel disorders. The clinical challenge is to identify a cause so as to exclude serious gastrointestinal diseases and provide symptomatic relief. Detailed history taking and examination provide the basis for appropriate testing that may provide vital clues. Among otherwise healthy patients, intolerance to lactose or other food items is a common source of symptoms. This cause can be evaluated noninvasively using the breath hydrogen test. A clear understanding of the underlying pathophysiology paves the way for a rational approach to treatment, such as withdrawal of an offending food item, enzyme supplementation, simple reassurance, or psychotherapy.

Does lactose maldigestion really play a role in the irritable bowel?

Patients who met International Congress of Gastroenterology criteria for irritable bowel syndrome (IBS) and had breath hydrogen lactose testing were interviewed to determine whether detection of lactose maldigestion (LM) had an impact on their symptoms. Of 199 patients initially evaluated, 161 (81%) were contacted and asked to rate their symptoms. At baseline, 47 (29%) of the IBS group had LM. Before testing, 23 (49%) were aware that ingestion of lactose-containing food was associated with their gastrointestinal symptoms. Lactose-maldigesting IBS subjects (IBSLM, n = 47) and those who had IBS and no LM (n = 114) were similar in terms of age, sex, and ethnic background. Interviews performed 41 +/- 1.1 (SEM) months after baseline evaluation revealed no significant differences in abdominal pain, altered bowel habits, bloating/distension, mucus, and relief with defecation among those with IBS or LMIBS. Overall symptoms resolved, improved, did not change, or worsened in a manner not statistically different between IBS and IBSLM groups. IBSLM subjects (a) felt that identifying LM helped them gain awareness of food-symptom relationships (78.7%), (b) experienced some improvement in symptoms (83%), (c) were avoiding lactose foods (87.2%), or (d) used lactase enzyme supplements (38.3%). Identifying LM did not significantly affect rated variables.

Lactose maldigestion and recurrent abdominal pain in children

Our objectives were to evaluate children with recurrent abdominal pain for lactose maldigestion and to assess factors which might predict lactose absorption status. One hundred thirty-seven children were referred for specialty evaluation of recurrent abdominal pain of at least three months' duration. Study subjects were evaluated by history and physical examination, dietary interviews, hematologic and biochemical laboratory testing, stool parasite examination, and radiologic or endoscopic structural examinations, as indicated. Lactose hydrogen breath testing was performed after challenge with 1 g/kg lactose 10% aqueous solution). There were 53 males and 84 females, whose ages ranged from 6 to 18 years (9.64 +/- 2.9; mean +/- SD) Lactose maldigestion was detected in 33/137 patients (24%). The prevalence of abdominal pain, bloating, gas, flatulence, diarrhea, and constipation was similar in children with or without lactose maldigestion. The perception of symptoms related to the ingestion of dairy products was similar in both groups. No other clinical parameter predicted lactose maldigestion. However, children with lactose maldigestion had overall clinical improvement with a lactose-restricted diet. Clinical evaluation alone cannot adequately predict the presence of lactose maldigestion in children. Formal evaluation for lactose maldigestion using breath hydrogen testing methods should be considered in children with recurrent abdominal pain.

Lactose intolerance and bone mass in postmenopausal Italian women

Previous studies on the role of lactose malabsorption in the pathogenesis of postmenopausal osteoporosis have yielded conflicting results and further information is needed. To date, all studies have been carried out on populations with a low prevalence of lactose malabsorption and the lactose intestinal absorptive capacity was tested using a non-physiological dose of lactose. In fifty-eight Italian postmenopausal women (mean age 57 (SD 7) years), bone mineral density (BMD) at lumbar spine, H2 breath response after ingestion of 20 g lactose, intensity of symptoms of intolerance after a lactose load and daily Ca intake were evaluated. No differences were found between women with or without a positive H2 breath test with regard to BMD (-1.2 (SD 0.9) v. -0.9 (SD 0.8)) and Ca intake (509 (SD 266) v. 511 (SD 313) mg/d). On the contrary, both BMD and Ca intake were significantly lower in women with lactose malabsorption and symptoms of intolerance (-1.5 (SD 0.7) and 378 (SD 220) mg/d) than in those with malabsorption without symptoms (-0.9 (SD 0.9) and 624 (SD 254) mg/d). Moreover, in lactose malabsorbers Ca intake was correlated inversely with symptom score (rs -0.31, P < 0.05) and positively with BMD (rs 0.42, P < 0.005). Our results show that in Italian postmenopausal women Ca intake and BMD are not influenced directly by lactose malabsorption; the appearance of symptoms of intolerance seems to influence BMD unfavourably through a reduced Ca intake.

Diagnosis of hypolactasia and lactose malabsorption

The article briefly describes the various methods that are available for diagnosing hypolactasia. Special attention is drawn to the fact that different methods are useful at different levels of the health care organization. When the test result indicates lactose malabsorption, general malabsorption should be excluded by a glucose-galactose tolerance test, for example. If the glucose-galactose tolerance test produces a normal result, it can be assumed that the patient has primary adult-type selective lactose malabsorption. The possibility of secondary lactose malabsorption must be excluded according to the principles described by Villako & Maaroos (104).

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.