scholarly journals Congruency of Genetic Predisposition to Lactase Persistence and Lactose Breath Test

Nutrients ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1383 ◽  
Author(s):  
Enza Coluccia ◽  
Patrizia Iardino ◽  
Diego Pappalardo ◽  
Anna Lisa Brigida ◽  
Vincenzo Formicola ◽  
...  
Keyword(s):  
Breath Test ◽  
Lactose Intolerance ◽  
Genetic Test ◽  
Gastrointestinal Symptoms ◽  
Diagnostic Procedures ◽  
Clinical Syndrome ◽  
Clinical Use ◽  
Genotype C ◽  
Lactase Gene ◽  
Genotype A

The physiological decline of lactase production in adulthood, in some individuals, is responsible for the so-called “Lactose Intolerance.” This clinical syndrome presents with gastrointestinal and non-gastrointestinal symptoms following the consumption of dairy containing food. Lactose intolerance can be evaluated by means of the Lactose Breath Test (phenotype) and/or genetic evaluation of lactase-gene polymorphism (genotype). A comparison of the two tests was carried out in a large number of symptomatic adult subjects, which are selected and not representative of the general population. Congruency was as high as 88.6%. Among lactase non-persistent (genotype C/C), 14 subjects showed a negative Lactose Breath Test (LBT), possibly due to young age. Among lactase-persistent (genotype C/T), four subjects showed a positive LBT, which helps to diagnose secondary lactose intolerance. Symptoms, both gastrointestinal and extra-gastrointestinal, were reported by 90% of patients during the breath test. Clinical use of both tests in the same patients could be taken into consideration as a sharp diagnostic tool. We suggest considering the use of the genetic test after LBT administration, when secondary hypolactasia is suspected, for completion of diagnostic procedures.

Milk consumption and gastrointestinal symptoms in preschool girls with different lactase genotypes

2021 ◽  
Vol 29 (3) ◽  
pp. 379-388
Author(s):  
Alina A. Bezrukova ◽  
Mariya I. Yarmolinskaya ◽  
Olga V. Sazonova ◽  
Marina V. Komarova ◽  
Spiridonova Natalia V Spiridonova Natalia V
Keyword(s):  
Abdominal Pain ◽  
Significant Relationship ◽  
Dairy Products ◽  
Lactose Intolerance ◽  
Polymorphic Locus ◽  
Gastrointestinal Symptoms ◽  
Milk Consumption ◽  
Subjective Symptoms ◽  
Lactase Gene

AIM: To analyze the frequency of milk consumption and subjective symptoms of intolerance to dairy products in the population of three- to six-year-old girls (born and resident in Samara) based on the genotype of the lactase gene. MATERIALS AND METHODS: We included 103 preschool girls ranging three to six years of age. Parents were questioned about the frequency of milk consumption by the child (per week), as well as the presence of gastrointestinal symptoms in their children (abdominal pain, bloating, flatulence and diarrhea) and the suspected association of symptoms with milk consumption (according to the parents). Buccal samples were taken from all girls to determine the polymorphism of the lactase genes (determination of C/T-13910 variant of the MCM6 gene). RESULTS: A significant relationship between the frequency of milk consumption and the variant of the polymorphic locus of the lactase gene, MCM6 [C 13910T; which affects the expression of the lactase gene (LCT)] has not been established. There is no correlation in the enlarged gradation of frequent milk consumption (47 times a week) and rare milk consumption (23 times a week or less): of 53 girls with the CC genotype 27 (51%) often drink milk, 26 (49%) rarely drink milk; of 39 girls with CT genotype 23 (59%) often consume milk, 16 (41%) rarely consume milk; of 11 girls with the TT genotype, 8 (73%) often consume milk, 3 (27%) rarely consume milk (c2 1.94, p = 0.379). There was no significant relationship between the frequency of milk consumption, subjective symptoms of lactose intolerance (abdominal pain, bloating, flatulence and diarrhea) and the genotype; these symptoms were found only in four girls carrying the C allele (CC and CT genotypes) though not detected in girls with TT genotype. CONCLUSION: In girls of 36 years old, there is no relationship between the frequency of milk consumption, subjective symptoms of lactose intolerance and genotype of lactase gene.

scholarly journals Laktózintolerancia: a laktázgén C/T-13910 polimorfizmusának és a hidrogénkilégzési teszt pontosságának retrospektív kiértékelése gasztroenterológiai szakrendelésen

2016 ◽  
Vol 157 (25) ◽  
pp. 1007-1012 ◽  
Author(s):  
György Buzás ◽  
Flóra Fodor ◽  
Béla Csókay
Keyword(s):  
Positive Predictive Value ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Breath Test ◽  
Genetic Test ◽  
Kappa Index ◽  
Adult Type ◽  
Breath Tests ◽  
Set Up ◽  
Lactase Gene

Introduction: Adult type hypolactasia is the most prevalent carbohydrate malabsorption. Aim: To assess the distribution of lactase gene C/T-13910 polymorphism and the accuracy and concordance of a genetic test and H2 breath test in the diagnosis of adult type hypolactasia. Method: 496 patients with symptoms of lactose intolerance were enrolled in a retrospective study who underwent genetic test using TaqMan polymerase chain reaction and H2 breath test. Results: The prevalence of C/T-13910 genotypes was: CC 48.1%, TC: 40.5%, and TT: 11.4%. When the genetic test was taken as reference, the sensitivity of the breath test was 84.3%, with a specificity of 95.7%, a positive predictive value of 96.7% and negative predictive value of 80.4%. Conversely, the accuracy of genetic test was: sensitivity 96.6%, specificity 80.4%, positive predictive value 84.3% and negative predictive value 95.7%. The concordance value between the two tests (kappa index) was 0.78. The results were discordant in 11.1% of the cases. Conclusions: In symptomatic patients, the lactase non-persistence genotype CC occurred in almost half of the patients. Both the genetic and the breath tests are sufficiently accurate, with good predictive value and they can be used to set up the diagnosis. Discordant results should be carefully interpreted. Orv. Hetil., 2016, 157(25), 1007–1112.

scholarly journals ANALYSIS OF LACTOSE INTOLERANCE IN STUDENTS WITH SUGGESTIVE SYMPTOMS OF IRRITABLE BOWEL SYNDROME

2019 ◽  
Vol 56 (3) ◽  
pp. 304-311
Author(s):  
Cleise de Jesus SILVA ◽  
Ingrid Dantas Sampaio LEITE ◽  
José Weberton RODRIGUES ◽  
Samara Pereira de ALMEIDA ◽  
Bruna Pessoa NÓBREGA ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Irritable Bowel Syndrome ◽  
Breath Test ◽  
Gastrointestinal Symptom ◽  
Lactose Intolerance ◽  
Gastrointestinal Symptoms ◽  
Bacterial Overgrowth ◽  
Irritable Bowel ◽  
Carbohydrate Intolerance

ABSTRACT BACKGROUND: Irritable bowel syndrome is a clinical condition presenting pain, distension and abdominal fullness, diarrhea, constipation, and other symptoms. It generates significant impacts on the quality of life of those affected. The pathophysiology is uncertain, but the role of various food types has been established in bowel sensitivity and its clinical manifestations. Carbohydrate intolerance, particularly to lactose, generates similar and sometimes indistinguishable symptoms from irritable bowel syndrome, and in clinical practice is both a frequent and underdiagnosed condition. Carbohydrate intolerance is related to enzymatic deficiencies, alterations of intestinal microbiota and even genetic change. The principal test for a diagnosis of lactose intolerance is the breath test, which measures hydrogen emission (produced only by bacteria), after ingestion of the corresponding substrate. OBJECTIVE: The present work aims to verify the prevalence of lactose intolerance in university students, presenting gastrointestinal symptoms suggestive of irritable bowel syndrome. METHODS: In a transversal study, to screen for those with suggestive symptoms, 124 medicine students participated by responding to a form. Those with abdominal pain were referred for anti-parasite treatment in order to exclude intestinal parasites as a secondary cause. Subsequently, using the hydrogen breath test, bacterial overgrowth was investigated, and if negative, lactose intolerance testing would be performed. Patients presenting high hydrogen concentrations of ≥20 ppm above the basal level were considered lactose intolerant. RESULTS: Of the total of students researched (n=124), 7 were excluded because they did not completing all study phases. From those 117 individuals effectively included in the survey; 8 (6.8%) were diagnosed with lactose intolerance and 2 (1.7%) with bacterial overgrowth. Intolerance was more frequent in; female individuals (75%), age range 18 to 25 years (62.5%), being colored (50%), and in their 5th semester of studies (37.5%). The presence of at least one gastrointestinal symptom among those presenting intolerance (100%), and those not presenting intolerance (42.2%) was found (P=0.002). In addition to abdominal pain (100%) (P<0.001), the most recurrent gastrointestinal symptom in the lactose intolerant students was the distension/flatulence (62.5%) (P=0.026). In relation to life habits and food patterns, there was no statistical difference between lactose tolerant and intolerant individuals, or for symptom frequencies. The more advanced students, completing more periods towards graduation, demonstrated more occurrences of gastrointestinal symptoms, yet without presenting significant statistical discrepancies. CONCLUSION: In view of the test sample quantity (n=21), a high prevalence of lactose intolerance (6.8%) in the academic environment, with epidemiological characteristics compatible to those found the literature is demonstrated, generating knowledge with understanding to prevent, diagnose, alleviate and treat lactose intolerant university students, and generate positive impacts towards well-being, improving the quality of life of these individuals.

scholarly journals Lactose intolerance, lactose malabsorption and genetic predisposition to adult-type hypolactasia in patients after restorative proctocolectomy

2019 ◽  
Author(s):  
Jarosław Walkowiak ◽  
Ewa Fidler-Witoń ◽  
Aleksandra Glapa ◽  
Jacek Paszkowski ◽  
Maciej Borejsza-Wysocki ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
Restorative Proctocolectomy ◽  
Genetic Predisposition ◽  
Breath Test ◽  
Lactose Intolerance ◽  
Adenomatous Polyposis ◽  
Adult Type ◽  
Lactose Malabsorption ◽  
Significant Difference ◽  
Lactase Gene

This study provides up-to-date findings on lactose malabsorption, lactose intolerance and genetic predisposition to adult-type hypolactasia in 72 patients after restorative proctocolectomy (RPC). The lactose malabsorption was assessed by hydrogen-methane breath test. Genetic predisposition to adult-type hypolactasia was assessed by detecting –13910T/C polymorphism in the lactase gene. Lactose intolerance was more frequent in UC (ulcerative colitis) patients than FAP (familial adenomatous polyposis) patients (77.5% vs. 55.2%; p=0.01). The C/C genotype of the lactase gene was observed in 39.1% subjects with no significant difference between UC and FAP patients. Lactose malabsorption occurred in 10.1% of subjects and almost only in patients with genetic predisposition, with the same frequency in UC and FAP patients.

scholarly journals A laktózintoleranciáról: Múlt és jelen – I. rész

2015 ◽  
Vol 156 (38) ◽  
pp. 1532-1539
Author(s):  
György Miklós Buzás
Keyword(s):  
Breath Test ◽  
Lactose Intolerance ◽  
Tolerance Test ◽  
Diagnostic Methods ◽  
Chromosome 2 ◽  
Adult Type ◽  
Unequal Distribution ◽  
Bowel Diseases ◽  
Irritable Bowel ◽  
Lactase Gene

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. Orv. Hetil., 2015, 156(38), 1532–1539.

The Molecular basis of Lactose Intolerance

2005 ◽  
Vol 88 (3) ◽  
pp. 157-202 ◽  
Author(s):  
Anthony K. Campbell ◽  
Jonathan P. Waud ◽  
Stephanie B. Matthews
Keyword(s):  
Rheumatoid Arthritis ◽  
Multiple Sclerosis ◽  
Molecular Basis ◽  
Charles Darwin ◽  
Lactose Intolerance ◽  
Anaerobic Bacteria ◽  
Bacterial Toxins ◽  
Systemic Symptoms ◽  
Lactase Gene ◽  
Over 40 Years

A staggering 4000 million people cannot digest lactose, the sugar in milk, properly. All mammals, apart from white Northern Europeans and few tribes in Africa and Asia, lose most of their lactase, the enzyme that cleaves lactose into galactose and glucose, after weaning. Lactose intolerance causes gut and a range of systemic symptoms, though the threshold to lactose varies considerably between ethnic groups and individuals within a group. The molecular basis of inherited hypolactasia has yet to be identified, though two polymorphisms in the introns of a helicase upstream from the lactase gene correlate closely with hypolactasia, and thus lactose intolerance. The symptoms of lactose intolerance are caused by gases and toxins produced by anaerobic bacteria in the large intestine. Bacterial toxins may play a key role in several other diseases, such as diabetes, rheumatoid arthritis, multiple sclerosis and some cancers. The problem of lactose intolerance has been exacerbated because of the addition of products containing lactose to various foods and drinks without being on the label. Lactose intolerance fits exactly the illness that Charles Darwin suffered from for over 40 years, and yet was never diagnosed. Darwin missed something else – the key to our own evolution – the Rubicon some 300 million years ago that produced lactose and lactase in sufficient amounts to be susceptible to natural selection.

S2067 A Comparison Between Lactose Breath Test and a Quick Test On Duodenal Biopsies for Lactase Deficiency, in Patients with a Self Reported Lactose Intolerance

2009 ◽  
Vol 136 (5) ◽  
pp. A-323
Author(s):  
Franzè Jolanda ◽  
Andrea Parodi ◽  
Edoardo Savarino ◽  
Ester Morana ◽  
Anna Bertelè ◽  
...  
Keyword(s):  
Breath Test ◽  
Lactose Intolerance ◽  
Lactase Deficiency ◽  
Quick Test ◽  
Duodenal Biopsies

scholarly journals Comparative Analysis of 22 Coronavirus HKU1 Genomes Reveals a Novel Genotype and Evidence of Natural Recombination in Coronavirus HKU1

2006 ◽  
Vol 80 (14) ◽  
pp. 7136-7145 ◽  
Author(s):  
Patrick C. Y. Woo ◽  
Susanna K. P. Lau ◽  
Cyril C. Y. Yip ◽  
Yi Huang ◽  
Hoi-Wah Tsoi ◽  
...  
Keyword(s):  
Respiratory Tract Infections ◽  
Single Gene ◽  
Human Infection ◽  
Bootscan Analysis ◽  
Acidic Domain ◽  
Multiple Alignments ◽  
Genotype C ◽  
Natural Recombination ◽  
Tract Infections ◽  
Genotype A

ABSTRACT We sequenced and compared the complete genomes of 22 strains of coronavirus HKU1 (CoV HKU1) obtained from nasopharyngeal aspirates of patients with respiratory tract infections over a 2-year period. Phylogenetic analysis of 24 putative proteins and polypeptides showed that the 22 CoV HKU1 strains fell into three clusters (genotype A, 13 strains; genotype B, 3 strains and genotype C, 6 strains). However, different phylogenetic relationships among the three clusters were observed in different regions of their genomes. From nsp4 to nsp6, the genotype A strains were clustered with the genotype B strains. For nsp7 and nsp8 and from nsp10 to nsp16, the genotype A strains were clustered with the genotype C strains. From hemagglutinin esterase (HE) to nucleocapsid (N), the genotype B strains were clustered closely with the genotype C strains. Bootscan analysis showed possible recombination between genotypes B and C from nucleotide positions 11500 to 13000, corresponding to the nsp6-nsp7 junction, giving rise to genotype A, and between genotypes A and B from nucleotide positions 21500 to 22500, corresponding to the nsp16-HE junction, giving rise to genotype C. Multiple alignments further narrowed the sites of crossover to a 143-bp region between nucleotide positions 11750 and 11892 and a 29-bp region between nucleotide positions 21502 and 21530. Genome analysis also revealed various numbers of tandem copies of a perfect 30-base acidic tandem repeat (ATR) which encodes NDDEDVVTGD and various numbers and sequences of imperfect repeats in the N terminus of nsp3 inside the acidic domain upstream of papain-like protease 1 among the 22 genomes. All 10 CoV HKU1 strains with incomplete imperfect repeats (1.4 and 4.4) belonged to genotype A. The present study represents the first evidence for natural recombination in coronavirus associated with human infection. Analysis of a single gene is not sufficient for the genotyping of CoV HKU1 strains but requires amplification and sequencing of at least two gene loci, one from nsp10 to nsp16 (e.g., pol or helicase) and another from HE to N (e.g., spike or N). Further studies will delineate whether the ATR is useful for the molecular typing of CoV HKU1.

scholarly journals TREATMENT OF LACTASE DEFICIENCY IN CHILDREN’S OBESITY WITH GENOTYPE C/C 13910 OF LACTASE GENE

2019 ◽  
Vol 72 (1) ◽  
pp. 17-21
Author(s):  
Alexandr Ye. Abaturov ◽  
Yuri M. Stepanov ◽  
Anna A. Nikulina
Keyword(s):  
Insulin Resistance ◽  
Healthy Children ◽  
Lactase Deficiency ◽  
Obese Children ◽  
Hydrogen Breath Test ◽  
Lactose Maldigestion ◽  
Group I ◽  
Comparison Groups ◽  
Genotype C ◽  
Lactase Gene

Introduction: Excess lactose in the diet of modern man causes the development of not only lactase deficiency, but it can be a factor that contributes to obesity. The aim: To study associations between obesity and genotype C/C 13910 of lactase gene (LCT) in children, to investigate the effectiveness of treatment using drug exogenous lactase and a low-lactose diet. Materials and methods: genotyping of lactase gene by real-time polymerase chain reaction, determining the level of lactose maldigestion by hydrogen breath test (HBT), estimating the insulin resistance with the HOMA-IR index in 70 obese children and 40 healthy children 6 - 18 years. Obese children with genotype C/C 13910 and lactose maldigestion (n=40) were randomized in two groups: children from group I (n=20) received an exogenous lactase preparation, and children from group II (n=20) - low-lactose diet. Results: in obese children, the genotype C/C 13910 is 2 times more often than in healthy children. Obese children with genotype C/C 13910 have a significantly higher value of HBT (32.8–39.8 ppm) compared to healthy children (p<0.05), and an increased value of the HOMA-IR index. After treatment, there was a significant decrease in HBT and the HOMA-IR index in the two comparison groups. Conclusions: signs of insulin resistance are observed in children with obesity, genotype C/C 13910 and lactose maldigestion. The use of exogenous lactase in the therapy or the administration of a low-lactose diet cause approximately the same decrease in the HOMA-IR index.

Lactose Intolerance

2021 ◽  
pp. 115-134
Author(s):  
Jomanah Abduljalil H. Bakhsh
Keyword(s):  
Lactose Intolerance ◽  
Gastrointestinal Symptoms ◽  
Monitoring And Evaluation ◽  
Nutrition Therapy ◽  
Nutritional Deficiencies ◽  
Medical Nutrition Therapy ◽  
Case Scenario ◽  
Therapy Goals ◽  
Medical Nutrition

This chapter presents a case scenario of lactose intolerance. Lactose intolerance is the inability to digest and absorb lactose, which is the sugar in milk, due to deficiency of the enzyme lactase. This condition commonly occurs after weaning, and it results in various gastrointestinal symptoms such as diarrhea. In addition, it may result in nutritional deficiencies. Management of lactose intolerance requires diet manipulations. This case study provides the needed information to implement the appropriate intervention such as patient's details and case history. Moreover, the case analysis section discusses in detail the disease pathophysiology and the medical nutrition therapy goals. This comprehensive analysis will allow the dietetic professional to follow the nutrition care process (NCP) framework (assessment, diagnosis, intervention, and monitoring and evaluation) to properly intervene and deal with the case. This case study will show the importance of the medical nutrition therapy for the management of lactose intolerance.

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