Food intolerances in children and adolescents in Switzerland.

Adverse food reactions have become an important health concern in pediatrics. There are discrepancies between diagnosed and self-reported food allergies and intolerances, leading to food avoidance with possible psychological and nutritional implications in the latter. There is no data available so far on the number of children and adolescents, who reduce or completely avoid certain foods in their diet. The aim of this study was to determine the prevalence of children and adolescents in the Northwest of Switzerland, who omit foods from their diet because of a self-reported intolerance, as well as the prevalence of children and adolescents who eliminate well-tolerated foods for presumed health reasons. This is a cross-sectional study conducted in the Children's hospitals of Aarau and Basel (Switzerland) and in 4 pediatric private practices. A total of 2036 children and adolescents (54% male and 46% female) between 1 month and 18 years (mean age: 7.4 years) were included, of which 316 (16%) participants reported to avoid foods due to intolerance. Lactose intolerance is the most frequent one. In 55% of all cases, no medical tests had been performed to confirm such an intolerance. Avoiding tolerated foods for presumed health reasons was stated by 251 (12%) participants.  Conclusions: Clinicians should be aware of the high frequency of food avoidance in the pediatric population due to true intolerance, functional diseases, or due to lifestyle reasons. Milk is the most avoided food and half of the affected patients avoid foods without guidance by professional dieticians, therefore risking possible negative impacts on their physical and mental health. Pediatricians should perform further investigations or advise nutritional guidance if an avoidance of foods or specific diets occurs. What is Known: • The prevalence of food intolerances in children and adolescents is unknown. • Eating behavior in children is influenced by the consumption of social media. What is New: • Based on this large cross-sectional study, it was shown that 16% of children and adolescents avoid foods, half of them without any medical advice. • Food avoidance is common among this Swiss cohort of children because of different reasons: lifestyle habits, functional diseases, true intolerances with possible consequences such as micronutrient deficiencies if not properly monitored.

Prospective Study of Lactose Intolerance as a Potential Cause of Gas Bloat Syndrome in Patients Treated Surgically for Gastroesophageal Reflux.

Introduction. The high incidence of lactose intolerance leads us to consider that many of our patients could suffer from this alteration. Therefore, as its main sign (even when asymptomatic) is increased intestinal gas, patients recovering from a Nissen fundoplication have a significant probability of suffering from gas bloat syndrome. Materials and Methods. This prospective study was conducted from November 2012 to January 2017, we included all the patients who had been treated by the Nissen technique for gastroesophageal reflux disease with gas bloat syndrome detected during follow-up and tested positive for lactose intolerance. The study participants were then prescribed a lactose-poor diet to be followed for 3 months. The patients were asked to complete quality of life and symptomatology questionnaires before and after diet. The pre- and post-diet results were then compared. Results. The pre- and post-diet results showed statistically significant improvements in both questionnaires. Conclusion. Lactose intolerance may account for the symptoms presented by a significant number of patients with gas bloat syndrome following antireflux surgery; these patients could benefit from consuming a lactose-free diet, which we expect to alleviate or, in some cases, eliminate the above symptoms.

Does primary lactase deficiency reduce bone mineral density in postmenopausal women? A systematic review and meta-analysis.

Postmenopausal osteoporosis is a significant cause of morbidity and mortality. The role of primary lactase deficiency (PLD) in its development is not clear. This meta-analysis showed that PLD is a risk factor for osteoporosis in postmenopausal women. These women need special attention in terms of screening for osteoporosis and its prevention. INTRODUCTION: Postmenopausal osteoporosis is an important predictor of bone fractures. The purpose of the study was to conduct a systematic review and meta-analysis of association of PLD and bone mineral density (BMD) in postmenopausal women. METHODS: The electronic databases PubMed, Scopus, and Web of Science were searched over the course of July 2017 for any date of publication without language limitation. Studies were included in the meta-analysis if the diagnosis of PLD was made by genetic testing or H-2 breath tests and the diagnosis of osteoporosis was made by a modern reliable method for BMD measurement. Two investigators conducted a comprehensive, independent review of all the papers. Five of the studies initially identified met the inclusion criteria. We used MOOSE guidelines for abstracting data and assessing data quality and validity. Meta-analysis was performed using the random effects model. RESULTS: Five case-control studies with 2223 participants and 763 lactase-deficient cases fulfilled the inclusion criteria. Meta-analysis showed a significantly higher bone density Z-score in absorbers (mean difference 0.20, CI (0.14-0.27), P = 0.000), with no significant heterogeneity among the studies. Moreover, the Z-score in the vast majority of the measured sites (femoral head, femoral neck, lumbar spine, radius, and Ward's triangle) was significantly higher in absorbers. There was no significant overall difference in BMD in g/cm2 between absorbers and non-absorbers, but a significantly higher BMD using g/cm2 was observed in absorbers in the total hip site. CONCLUSIONS: Postmenopausal women with PLD had lower Z-scores at most anatomic sites compared to healthy controls.

Lactose Breath Test in Children: Relationship Between Symptoms During the Test and Test Results.

BACKGROUND: Lactose malabsorption affects 70% of the world population. The hydrogen breath test (HBT) is used clinically to test for this condition. The aim of our study was to describe the relationship between symptoms experienced before and during the HBT and test results. METHODS: We included children who underwent the HBT in the pediatric gastroenterology unit at Dana-Dwek Children's Hospital during a 6-month period. Previous symptoms and those experienced before and after the HBT were assessed using a questionnaire and a validated pain scale. RESULTS: Ninety-five children were included in the study, and 66.3% had a positive HBT. Diarrhea and flatulence during the test were significantly more frequent in the group with a positive HBT compared to those with a negative test (31.7% vs. 9.4%, P = 0.016 and 69.8% vs. 40.6%, P = 0.006, respectively). The frequency of abdominal pain and bloating was similar. CONCLUSIONS: Diarrhea and flatulence during the HBT are the most specific symptoms of lactose intolerance. Abdominal pain should not be automatically attributed to lactose intolerance even in the presence of lactose malabsorption. Coupling the HBT with a real-time questionnaire facilitates interpretation of results and subsequent recommendations.

Lactose Intolerance: Common Misunderstandings.

Lactose intolerance primarily refers to a syndrome having different symptoms upon the consumption of foods containing lactose. It is one of the most common form of food intolerance and occurs when lactase activity is reduced in the brush border of the small bowel mucosa. Individuals may be lactose intolerant to varying degrees, depending on the severity of these symptoms. When lactose is not digested, it can be fermented by gut microbiota leading to symptoms of lactose intolerance that include abdominal pain, bloating, flatulence, and diarrhea with a considerable intraindividual and interindividual variability in the severity of clinical manifestations. These gastrointestinal symptoms could be similar to cow's milk allergy and could be wrongly labeled as symptoms of "milk allergy." There are important differences between lactose intolerance and cow's milk allergy; therefore, a better knowledge of these differences could limit misunderstandings in the diagnostic approach and in the management of these conditions.

Digestive side-effects with teriflunomide: Thoughts on lactose.

INTRODUCTION: Teriflunomide, a novel, orally bioavailable, active metabolite of leflunomide, has anti-inflammatory activity. It is prescribed as a first-line treatment for relapsing-remitting multiple sclerosis (RRMS) at a dose of one 14mg tablet per day. Common adverse reactions observed in placebo-controlled trials with a frequency≥10% and a rate twofold or more than reported with placebo, include digestive disorders. As teriflunomide tablets also contain lactose, the official recommendations are clear about not prescribing this drug to patients with known lactose intolerance and those with rare hereditary problems due to galactose intolerance. METHODS: Our study systematically collected, from our MS clinical practice, all adverse events presenting in the first 100 patients treated with teriflunomide. All of these patients were systematically asked if they were known to have lactose intolerance. RESULTS: None of these 100 patients declared having known, documented lactose intolerance. Yet, after starting teriflunomide, 14 reported mild-to-moderate diarrhea, which resolved within a month, but four of these patients continued to have daily diarrhea (grade 2 WHO classification), prompting us to perform a lactose breath test (LBT) for malabsorption. All four tested positive and were therefore diagnosed with lactose intolerance. Digestive symptoms were resolved with probiotics, and teriflunomide was maintained in three cases; the fourth patient decided, despite the adverse event being resolved, to stop taking teriflunomide. CONCLUSION: In cases of prolonged digestive side-effects after the introduction of teriflunomide, a lactose-malabsorption breath test should be proposed to confirm the culpability or not of an enzymatic defect in the occurrence of adverse events.

Lactose Intolerance (LCT-13910C>T) Genotype Is Associated with Plasma 25-Hydroxyvitamin D Concentrations in Caucasians: A Mendelian Randomization Study.

Background: The LCT-13910C>T gene variant is associated with lactose intolerance (LI) in different ethnic groups. Individuals with LI often limit or avoid dairy consumption, a major dietary source of vitamin D in North America, which may lead to inadequate vitamin D intake.Objective: The objective was to determine the prevalence of genotypes predictive of LI in different ethnic groups living in Canada and to determine whether the LCT genotype is associated with plasma 25(OH)D concentrations.Methods: Blood samples were drawn from a total of 1495 men and women aged 20-29 y from the Toronto Nutrigenomics and Health Study for genotyping and plasma 25(OH)D analysis. Intakes of dairy were assessed by using a 196-item food frequency questionnaire. The prevalence of LCT-13910C>T genotypes was compared by using χ2 analysis. Using a Mendelian randomization approach, we examined the association between LCT genotypes and 25(OH)D concentrations.Results: Approximately 32% of Caucasians, 99% of East Asians, 74% of South Asians, and 59% of those with other or mixed ethnicities had the CC genotype associated with LI. Compared with those with the TT genotype, those with the CC genotype had a lower mean ± SE total dairy intake (2.15 ± 0.09 compared with 2.67 ± 0.12 servings/d, P = 0.003), a lower skim-milk intake (0.20 ± 0.03 compared with 0.46 ± 0.06 servings/d, P = 0.0004), and a lower plasma 25(OH)D concentration (63 ± 1.9 compared with 75.8 ± 2.4 nmol/L, P < 0.0001). The CT and CC genotypes were associated with a 50% and a 2-fold increased risk, respectively, of a suboptimal plasma 25(OH)D concentration (<75 nmol/L).Conclusions: In Caucasians, the CC genotype that predicts LI is associated with a lower plasma 25(OH)D concentration, which is attributable at least in part to a lower intake of dairy, particularly skim milk. Increased risk of suboptimal concentrations of vitamin D was also observed among those with the CT genotype, suggesting an intermediate effect of the heterozygous genotype.

Lactase Non-persistence and Lactose Intolerance.

PURPOSE OF REVIEW: To evaluate the clinical and nutritional significance of genetically determined lactase non-persistence and potential lactose and milk intolerance in 65-70% of the world's adult population. RECENT FINDINGS: Milk consumption is decreasing in the USA and is the lowest in countries with a high prevalence of lactase non-persistence. The dairy industry and Minnesota investigators have made efforts to minimize the influence of lactose intolerance on milk consumption. Some lactose intolerant individuals, without co-existent irritable bowel syndrome, are able to consume a glass of milk with a meal with no or minor symptoms. The high frequency of lactase persistence in offspring of Northern European countries and in some nomadic African tribes is due to mutations in the promoter of the lactase gene in association with survival advantage of milk drinking. Educational and commercial efforts to improve calcium and Vitamin D intake have focused on urging consumption of tolerable amounts of milk with a meal, use of lowered lactose-content foods including hard cheeses, yogurt, and lactose-hydrolyzed milk products.

Effects of cow's milk beta-casein variants on symptoms of milk intolerance in Chinese adults: a multicentre, randomised controlled study.

BACKGROUND: A major protein component of cow's milk is ß-casein. The most frequent variants in dairy herds are A1 and A2. Recent studies showed that milk containing A1 ß-casein promoted intestinal inflammation and exacerbated gastrointestinal symptoms. However, the acute gastrointestinal effects of A1 ß-casein have not been investigated. This study compared the gastrointestinal effects of milk containing A1 and A2 ß-casein versus A2 ß-casein alone in Chinese adults with self-reported lactose intolerance. METHODS: In this randomised, crossover, double-blind trial, with a 3-day dairy washout period at baseline, subjects were randomised to consume 300 mL of milk containing A1 and A2 ß-casein (ratio 58:42; conventional milk) or A2 ß-casein alone; subjects consumed the alternative product after a 7-day washout period. Urine galactose was measured at baseline after a 15 g lactose load. Subjects completed 9-point visual analogue scales for gastrointestinal symptoms (borborygmus, flatulence, bloating, abdominal pain, stool frequency, and stool consistency) at baseline and at 1, 3, and 12 h after milk consumption. RESULTS: A total of 600 subjects were included. All six symptom scores at 1 and 3 h were significantly lower after consuming A2 ß-casein versus conventional milk (all P<0.0001). At 12 h, significant differences remained for bloating, abdominal pain, stool frequency, and stool consistency (all P<0.0001). Symptom scores were consistently lower with A2 ß-casein in both lactose absorbers (urinary galactose ≥0.27 mmol/L) and lactose malabsorbers (urinary galactose <0.27 mmol/L). CONCLUSION: Milk containing A2 ß-casein attenuated acute gastrointestinal symptoms of milk intolerance, while conventional milk containing A1 ß-casein reduced lactase activity and increased gastrointestinal symptoms compared with milk containing A2 ß-casein. Thus, milk-related gastrointestinal symptoms may result from the ingestion of A1 ß-casein rather than lactose in some individuals. TRIAL REGISTRATION: NCT02878876 , registered August 16, 2016. Retrospectively registered.

Frequency and Cause of Persistent Symptoms in Celiac Disease Patients on a Long-term Gluten-free Diet.

GOALS: To estimate the frequency and cause of nonresponsive celiac disease (CD). BACKGROUND: Treatment of CD is based on life-long adherence to a gluten-free diet (GFD). Some celiac patients experience persistence of symptoms despite a GFD. This condition is defined as nonresponsive CD. STUDY: Celiac patients on a GFD for at least 12 months underwent diet compliance assessment, laboratory tests, breath tests, endoscopic, and histologic evaluations according to the symptoms/signs reported. RESULTS: Seventy of 321 (21.8%) patients had persistent or recurrent symptoms/signs. The cause of symptom persistence was evaluated in 56 of 70 patients. Thirteen of 56 (23%) patients were antiendomysial antibody positive. Among the patients with negative serology, 1 had fibromyalgia, and 3 had evidence that disproved the diagnosis of CD. The remaining 39 patients with negative serology underwent duodenal biopsy sampling, which evidenced histologic alterations in 24 patients. Among the 15 patients with normal histology 3 were lactose intolerant, 9 had irritable bowel syndrome, 2 had gastroesophageal reflux disease, and in 1 patient a cause for the persistent symptom was not identified. In patients with confirmed diagnosis of CD, exposure to dietary gluten was the main cause of persistence of symptoms/signs, and consistently after dietary modification, symptoms resolved in 63% of the patients at later time points during follow-up. CONCLUSION: Nonresponsive CD occurs in nearly one fifth of celiac patients on GFD and its occurrence suggests further investigations to optimize the management of celiac patients.

Undernourished Children and Milk Lactose.

BACKGROUND: Lactose is an important energy source in young mammals, and in fully breast-fed human infants, it constitutes around 40% of the total daily energy intake. The role of lactose in feeding of undernourished infants and young children is not well described. OBJECTIVE: A narrative review of the potential positive and negative effects of lactose in the treatment of undernourished children. METHODS: Searches were conducted using PUBMED and Web of Science up to July 2015. Relevant references in the retrieved articles were included. RESULTS: Lactose may exhibit several health benefits in young children, including a prebiotic effect on the gut microbiota and a positive effect on mineral absorption. Studies in piglets suggest there might also be a stimulating effect on growth, relative to other carbohydrates. Lactose intolerance is a potential concern for undernourished children. Most undernourished children seem to tolerate the currently recommended (low lactose level) therapeutic foods well. However, a subgroup of severely undernourished children with secondary lactase deficiency due to severe diarrhea or severe enteropathy may benefit from products with even more restricted lactose content. At limited extra costs, lactose or lactose-containing milk ingredients may have beneficial effects if added to food products for undernourished children. CONCLUSIONS: Lactose may be an overlooked beneficial nutrient for young and undernourished children. Research is needed to define the balance between beneficial and detrimental effects of lactose in undernourished children at different ages and with different degrees of diarrhea and intestinal integrity.

[Gastrointestinal and hepatic diseases]. / Enfermedades gastrointestinales y hepáticas.

Diet is considered an important triggering factor for gastrointestinal symptoms whose physiopathology includes not only measurable, inflammatory reactions, but also functional disorders, where no organic effects may be measured or demonstrated. Moreover, the prevalence of the perceived intolerance to certain foods ranges from 20-25% (within the general population) to 50-70% in diseases like irritable bowel syndrome. This intolerance has been observed particularly after the consumption of milk and dairy products, which are frequently considered as causative of gastrointestinal symptoms, thus limiting their ingestion. However, this behavior reduces the dietary sources of calcium and consequently may lead to malnutrition and bone decalcification, amongst other complications. The true dairy intolerance (intestinal lactase deficiency) explains most of the symptoms ensuing their consumption, but the frequency of such alteration on the different gastrointestinal diseases has not been determined. This review focuses on the most frequent gastrointestinal diseases and the existing evidence regarding the alterations and symptoms related to the consumption of milk or dairy products.

Diagnosis and clinical observation of lactose-free milk powder on treatment of neonatal diarrhea.

Neonatal lactose intolerance syndrome is a series of digestive system symptoms caused by the lack of lactase, and could not fully digest the lactose in breast milk or cow milk. Lactose is one of the disaccharides mainly existed in mammalian milk. Lactose content in breast milk is 7.2g/100ml, cow milk is 4.7g/100ml. Dairy products are the main energy sources for the newborn, and lactose provides 20% energy for infants. During the growth of the newborn, lactose not only play a significant role in energy supply, but also involve in the development of the brain growing. This study mainly studied the lactose development features, the reasons for lactose intolerance, and the measures to treat lactose deficiency.

The incidence of infants with rotavirus enteritis combined with lactose intolerance.

UNLABELLED: This study was to research the incidence of infants with rotavirus enteritis combined with lactose intolerance and the clinical effect of low lactose milk powder for infantile rotavirus enteritis with lactose intolerance. The control groups were 126 cases of infants with diarrhea randomly collected from our hospital at the same period, which their rotavirus detection was negative. The observation group was 185 cases of infants with rotavirus, which was tested to be positive. Through the urine galactose determination, 62 cases of the control group were positive and 124 cases of the observation group were positive. Then 124 cases of infants with rotavirus combined with lactose intolerance were randomly divided into two groups. 60 cases in the control group were given rehydration, correction of acidosis, oral smecta, Intestinal probiotics and other conventional treatment, then continued to the original feeding method. While, 64 cases in the treatment group, on the basis of routine treatment, applied the low lactose milk feeding. To observe the total effective rate for the two groups. The incidence of lactose intolerance in children with rotavirus enteritis (67.03%) was significantly higher than that of children with diarrhea (49.2%), which was tested to be negative. And the difference was statistically significant (p<0.5). In the aspect of reducing the frequency of diarrhea, and diarrhea stool forming time, the treatment group has the obvious superiority. The total effective rate was 95.4% for treatment group, which was higher than that in the control group (76.7%), the difference was statistically significant (P<0.05). CONCLUSION: Infants with rotavirus enteritis was easier to merge with lactose intolerance. The low lactose milk powder could improve the therapeutic effectively and could reduce the duration of disease, and restored to normal diet for 2 weeks feeding time.

[Lactose intolerance in neonates with non-infectious diarrhea].

OBJECTIVE: To investigate the development of lactose intolerance in neonates with non-infectious diarrhea and its association with diarrhea, and to evaluate the diagnostic values of fecal pH value and urine galactose determination for neonatal lactase deficiency. METHODS: Seventy hospitalized neonates who developed non-infectious diarrhea between October 2012 and June 2015 were enrolled as the diarrhea group, and 162 hospitalized neonates without non-infectious diarrhea were enrolled as the non-diarrhea group. Test paper was used to determine fecal pH value. The galactose oxidase method was used to detect urine galactose. The neonates with positive galactose oxidase were diagnosed with lactase deficiency, and those with lactase deficiency and diarrhea were diagnosed with lactose intolerance. According to the results of urine galactose detection, 69 neonates in the diarrhea group who underwent urine galactose detection were classified into lactose intolerance group (45 neonates) and lactose tolerance group (24 neonates), and their conditions after treatment were compared between the two groups. The follow-up visits were performed for neonates with diarrhea at 3 months after discharge. RESULTS: Fecal pH value and positive rate of urine galactose (65% vs 54%) showed no significant differences between the diarrhea and non-diarrhea groups (P>0.05). Fecal pH value showed no significant difference between the lactose intolerance and lactose tolerance groups (P>0.05), while the neonates in the lactose intolerance group had a significantly longer time to recovery of defecation than those in the lactose tolerance group (P<0.05). CONCLUSIONS: The incidence of lactase deficiency is high in neonates, and diarrhea due to lactose intolerance tends to occur. Determination of fecal pH value has no significance in the diagnosis of lactose intolerance in neonates with diarrhea.

Vitamin D Status and Adiposity in Pediatric Malabsorption Syndromes.

BACKGROUND: The combined effects of nutrient malabsorption and adiposity on vitamin D status are unclear in pediatric malabsorption syndromes. AIM: To determine the relationship between adiposity and serum 25-hydroxyvitamin D (25(OH)D) in malabsorption disorders. METHODS: Prepubertal children of ages 3-12 with either lactose intolerance (LI) (n = 38, age 8.61 ± 3.08, male/female 19/19), or celiac disease (CD) (n = 24) were compared to healthy controls (n = 49, age 7.95 ± 2.64, male/female 28/21). A separate cohort of combined prepubertal and pubertal subjects with inflammatory bowel disease (IBD) (n = 59, age 16.4 ± 2.2, male/female 31/27) were also compared to healthy controls (n = 116, male/female 49/67, age 14.6 ± 4.4). Vitamin D deficiency was defined as 25(OH)D of <50 nmol/l, overweight as body mass index (BMI) of ≥ 85th but <95th percentile, and obesity as BMI ≥ 95th percentile. RESULTS: Among the controls, 25(OH)D was significantly higher in the normal-weight prepubertal controls vs. the overweight/obese controls (p = 0.001), and similarly so for the combined cohort of prepubertal and pubertal controls (p = 0.031). In contrast, there was no significant difference in 25(OH)D concentration between the normal-weight vs. overweight/obese patients with LI (p = 0.335), CD (p = 0.387), and IBD (p = 0.883). CONCLUSION: There is no association between adiposity and serum 25(OH)D in pediatric malabsorption syndromes.

An insight into the gastrointestinal component of fibromyalgia: clinical manifestations and potential underlying mechanisms.

Fibromyalgia syndrome is characterized by chronic generalized pain accompanied by a broad symptomatologic spectrum. Besides chronic fatigue, sleep disturbances, headaches and cognitive dysfunction that are extensively described in the literature, a considerable proportion of patients with fibromyalgia experience gastrointestinal symptoms that are commonly overlooked in the studies that are not specifically dedicated to evaluate these manifestations. Nevertheless, various attempts were undertaken to explore the gastrointestinal dimension of fibromyalgia. Several studies have demonstrated an elevated comorbidity of irritable bowel syndrome (IBS) among patients with fibromyalgia. Other studies have investigated the frequency of presentation of gastrointestinal symptoms in fibromyalgia in a nonspecific approach describing several gastrointestinal complaints frequently reported by these patients such as abdominal pain, dyspepsia and bowel changes, among others. Several underlying mechanisms that require further investigation could serve as potential explanatory hypotheses for the appearance of such manifestations. These include sensitivity to dietary constituents such as gluten, lactose or FODMAPs or alterations in the brain-gut axis as a result of small intestinal bacterial overgrowth or subclinical enteric infections such as giardiasis. The gastrointestinal component of fibromyalgia constitutes a relevant element of the multidisciplinary pathophysiologic mechanisms underlying fibromyalgia that need to be unveiled, as this would contribute to the adequate designation of relevant treatment alternatives corresponding to these manifestations.

[Lactose intolerance: past and present. Part 1]. / A laktózintoleranciáról: Múlt és jelen - I. rész.

Lactose intolerance is the most prevalent intestinal malabsorption disorder. After presentation of its history, the author describes the emergence of lactose intolerance during the evolution of species, and the biochemistry of lactose as well as features of human and bacterial lactase enzymes are then described. The unequal distribution of lactose intolerance in different continents and population is discussed, followed by presentation of past and present prevalence data in Hungary. Adult-type hypolactasia is caused by a polymorphism of the MCM6 gene located upstream from the lactase gene on the long arm of the chromosome 2. It can be determined with the polymerase chain reaction. The intestinal symptoms of lactose intolerance are well known, but its extra-intestinal manifestations are less recognised. Invasive diagnostic methods (determination of lactase activity from small intestinal biopsies, lactose tolerance test), are accurate, but have been replaced by the non-invasive methods; their gold standard is the H2 breath test. Genetic testing is being used more and more frequently in Hungary too, and, presumably, the methane breath test will be also available in the near future. Lactose intolerance can be accompanied by inflammatory bowel diseases, coeliac disease and irritable bowel syndrome; it could be established whether this association is causal or not in order to start a correct diet and therapy.

[Lactose intolerance: past and present. Part II]. / A laktózintoleranciáról: Múlt és jelen - II. rész.

The author summarises the interrelations between lactose intolerance, calcium and vitamin D metabolism and osteoporosis. Lactose intolerance enhances the risk of forearm and hip fractures in some patients. Lactase gene genotype and fracture risk are related in some populations. Calcium and vitamin D supplementation increase bone mineral content and they are justified in children, during pregnancy and lactation, and in postmenopausal women. The intake of milk and milk products could increase the risk of ovarian carcinoma. CC genotype of the lactase gene increased the risk of colorectal carcinoma in Finns; no such effect was observed in British, Spanish and Italian patients. Even small quantities of lactose in drugs (10-750 mg) could elicit intolerance symptoms due to individual susceptibility. In spite of public knowledge and advertising, controlled studies did not prove the beneficial effect of either a lactose-free diet, enzyme supplementation or probiotics in an evidence-based manner. While accepted guidelines are lacking, a personalised therapy is mandatory. In spite of increasing public interest in lactose intolerance, many unknown factors must still be studied.

Protein-losing enteropathy following the Fontan procedure in a child with intestinal lactase deficiency treated with lactose-free diet.

UNLABELLED: A 12-year-old girl presented with a protein-losing enteropathy. Symptoms started 4 weeks after undergoing the Fontan procedure at the age of 1.5 years for mitral atresia, ventricular septal defect, and double-outlet right ventricle. Upon referral for 3 weeks of rehabilitation after multiple interventional measures and drug treatments, she appeared in a dystrophic state, with decreased plasma protein and electrolyte levels along with occasional tetanic convulsions. Blood glucose levels after a lactose tolerance test were markedly reduced. The introduction of a lactose-free diet was quickly effective, with plasma protein and electrolyte levels raised to normal levels, and the girl's body weight increased without ascites or oedema. Molecular genetic examination revealed a homozygous C/C13910 polymorphism in the LCT gene. CONCLUSION: Protein-losing enteropathy in the Fontan circulation may be provoked by lactase deficiency and should therefore be ruled out to exclude this rather common condition.