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Objective. In a recent study by our group, it was shown that a large proportion of patients with lactose malabsorption and with no bacterial overgrowth are affected by silent coeliac disease (CD). Our aim was to evaluate the effect of a gluten-free diet on lactose malabsorption assessed using the hydrogen lactose breath test (LBT) and also the relationship with normalization of duodenal biopsies in coeliac patients. Material and methods. Fifteen patients (11 F, 4 M; mean age 35.8±6) affected by CD with a positive LBT and negative glucose breath test were enrolled. All were started on a gluten-free diet and were re-evaluated after 6 months by LBT and after 12 months by both LBT and upper gastrointestinal endoscopy with biopsies. Results. LBT normalization was observed in 1 out of 15 patients (6.7%) after 6 months and in 9 of the remaining 14 (64.2%) after 12 months. Duodenal biopsies showed normal villi in 8 patients, partial villous atrophy in 5 and total atrophy in 2. Conclusions. The present study shows that a large proportion of CD patients experience a regression of lactose malabsorption after receiving a gluten-free diet. This may be related to normalization of the brush border with an improvement of lactase enzyme activity. LBT should be performed after 12 months in CD patients on a gluten-free diet in order to assess the persistence/disappearance of lactose malabsorption, thus avoiding an unnecessary lactose-free diet. [ABSTRACT FROM AUTHOR]

Objective. The prevalence of lactose malabsorption (LM) is increased in the elderly, although the mechanisms responsible are still a matter of speculation. The objective of this study was to investigate the possible roles of reduced functional small intestinal absorptive area, lactase deficiency and small intestinal bacterial overgrowth (SIBO). Material and methods. Twenty Caucasian (Anglo-Celtic), asymptomatic, well-nourished, elderly volunteers (median age 79 years, range 70-94 years) with no clinically apparent predisposition to SIBO underwent a 50 g lactose breath hydrogen test (LBHT) and mannitol absorption test, the latter as an index of functional small intestinal absorptive area. Those with LM additionally underwent bacteriological assessment of small intestinal secretions and mucosal biopsy, to assess the contribution of SIBO and lactase deficiency, respectively, to the pathogenesis of LM in individual cases. The prevalence of SIBO was also determined in elderly subjects without LM. Twenty asymptomatic younger subjects (median age 29 years, age range 18-35 years) served as controls. All subjects were "hydrogen producers" in response to lactulose. Results. LM was evident in 10/20 (50%) elderly subjects and 1/20 (5%) younger subjects (p=0.003). Mannitol absorption did not differ significantly in elderly and younger subjects or in elderly subjects with and without LM. SIBO was documented in 9/10 (90%) elderly subjects with LM; eradication was associated with resolution of LM. Lactase deficiency was evident in only one elderly subject with LM. SIBO was evident in 2/10 (20%) elderly subjects without LM (p=0.005 compared to those with LM). Lactulose breath hydrogen test identified only 2/11 (18%) elderly subjects with SIBO. Conclusions. Increased prevalence of LM in the elderly is mostly due to clinically non-apparent SIBO, rather than mucosal factors. The lactulose breath hydrogen test cannot be relied upon to identify elderly subjects with SIBO, even in those without an anatomical predisposition. [ABSTRACT FROM AUTHOR]

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 H[sub 2]/CH[sub 4] breath test after lactulose. After a 3-day period, an H[sub 2]/CH[sub 4] 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 H[sub 2] and CH[sub 4] excretion parameters at fasting and after lactulose did not differ between the three groups. Cumulative breath H[sub 2] 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. [ABSTRACT FROM AUTHOR]

Background: Symptoms after intake of milk are common in persons with irritable bowel syndrome (IBS). The aims of this study were to compare the prevalence of lactose malabsorption (LM) and symptoms related to intake of milk and lactose in subjects with IBS with that of healthy volunteers, and to search for symptoms that are characteristic of LM. Methods: A case-control study in a Norwegian population was initiated. Subjects with IBS were asked for symptoms related to intake of milk and lactose, tested for LM, and compared with a group of healthy volunteers. Results: The study comprised a total of 187 persons (82 with IBS and 105 volunteers), females/males: 138/49, mean age 47 years. In subjects with IBS and in healthy volunteers, LM was present in 3/74 (4.1%) and 4/105 (3.8%), respectively (ns), milk-related symptoms in 32/79 (40%) and 13/105 (12%), respectively ( P < 0.001) and symptoms after intake of lactose in 28/74 (38%) and 21/104 (20%), respectively ( P = 0.01). Borborygmi starting within 5 h after intake of lactose and lasting for more than 2 h indicated LM (OR 61 (95% CI:­8-475), P < 0.001). Conclusions: IBS and LM are unrelated disorders in a Norwegian population. Milk-related symptoms and symptoms after intake of lactose are unreliable predictors for LM. Precise symptom-based criteria might enhance the diagnostic accuracy for LM. [ABSTRACT FROM AUTHOR]

Roux-en-Y gastric bypass (RYGB) can cause multiple food intolerances and gastrointestinal complaints are frequently reported after dairy consumption. We aimed to determine the prevalence of lactose malabsorption and intolerance, and complaints associated with dairy consumption in daily life, before and after RYGB. The lactose breath test (LBT) and lactose tolerance test (LTT) was performed in 84 patients awaiting RYGB surgery and 84 patients after surgery. Gastrointestinal symptoms at baseline and after testing were recorded. Lactose malabsorption was defined as a positive LBT and/or LTT. Lactose intolerance as a positive test combined with an increase of gastrointestinal complains. Dairy consumption in daily life and successive gastrointestinal complaints were registered via a questionnaire. Results of preoperative and postoperative patients were compared. Lactose malabsorption was present in 15 (17.9%) of the preoperative patients and in 25 (29.8%) of the postoperative patients (OR 2.46; 95%CI: 1.08–5.59; p =.03). Of the preoperative patients 6 (7.1%) patients met the criteria for lactose intolerance, compared to 8 (9.5%) patients in the postoperative group (OR 1.48; 95%CI 0.48–4.57; p =.50). Twelve (14.3%) preoperative patients indicated to have gastrointestinal complaints after dairy consumption in daily life versus 45 (53.6%) postoperative patients (p <.01). This study shows no increase in patients with proven lactose intolerance after RYGB compared to preoperative patients. Gastrointestinal complaints after dairy consumption in daily life were far more frequently reported by RYGB patients. It is unlikely that all reported gastrointestinal complaints are actually caused by lactose. Other ingredients in dairy, like fat, are possibly contributory. [ABSTRACT FROM AUTHOR]

Presents a letter to the editor of the "Scandinavian Journal of Gastroenterology," about a studt of lactose malabsorption and functional gastrointestinal disorders.

Primary lactose malabsorption is characterised by a down-regulation of lactase activity after weaning and inability to digest lactose in adulthood. It has been suggested that the historical introduction of dairying led to a positive selection for lactase persistence variants in a regulatory region upstream of the LCT gene. Here, we genotyped 202 Armenian subjects for LCT-13910T, a lactase persistence variant which is widespread in Europeans. The homozygous C/C genotype associated with primary hypolactasia, the heterozygous C/T and the homozygous T/T lactase persistence genotypes were found in 191 (94.6%), 11 (5.4%), and 0 (0.0%) samples, respectively. The frequency for the LCT-13910*T allele was 2.7%. The observed allele frequency of 2.7% for LCT-13910T is even lower than previously reported and supports current phenotypic data about lactose malabsorption in Armenia. [ABSTRACT FROM AUTHOR]

Objective. Circulating immune complexes (CICs) in blood are associated with autoimmune-diseases such as systemic lupus erythematosus, immune complex glomerulonephritis, rheumatoid arthritis and vasculitis. However, slightly increased serum concentrations of such CICs are sometimes also found in healthy individuals. The objective of the current study was to assess whether food antigens could play a role in the formation of CICs. Material and methods. A total of 352 (265 F, 87 M), so far, healthy individuals were tested for CICs containing C1q and immunoglobulin G (IgG) as well as for gliadin IgG antibodies using the ELISA technique. Additionally, fructose and lactose malabsorption was assessed using hydrogen breath tests. Results. In our study, 15.3% (54/352) of the patients presented with elevated CIC concentrations (above 50 µg/ml) and 6.5% (23/352) of the study population were positive for gliadin IgG antibodies (above 20 U/ml). CIC concentration levels were significantly higher in the group with elevated gliadin IgG antibodies (CIC median: 49.0 µg/ml) compared with the group with normal levels of gliadin IgG antibodies (CIC median: 30.0 µg/ml; Mann-Whitney U-test, U=1992; p <0.001). As expected, there was no difference in CIC concentrations (Mann-Whitney U-test, U=6106; p=0.783) and gliadin IgG (Mann-Whitney U-test, U=3761; p=0.411) between patients in the fructose or lactose malabsorber groups and the subjects without malabsorption. Conclusions. The results of this study indicate that certain food antigens (e.g. gluten) could play a role in the formation of CICs. An association between CICs and fructose or lactose malabsorption seems to be improbable. [ABSTRACT FROM AUTHOR]

Presents a letter to the editor of the "Scandinavian Journal of Gastroenterology," about a routine test for lactose malabsorption.

Purpose: To correlate intestinal gas production with the intensity of symptoms experienced during a lactose breath test (LBT) and to evaluate the value of different symptoms in lactose malabsorption diagnosis as assessed by LBT, considered as the gold standard. Design: A statistical correlation between symptoms and gas production, and the prevalence of symptoms in consecutive patients screened for lactose malabsorption. Materials and Methods: All symptoms and their intensity during a 5 hour breath test after a 20 g oral lactose dose were recorded in 214 patients. A symptom score was calculated and correlated to the gases measured in expired air. Results: The most frequently experienced symptoms were: bloating in 70.3% of patients with a pathological breath test and in 22.3% of patients with a normal breath test ( p < 0.0005, odds ratio = 7.7); abdominal pain in 34.7% of patients with a pathological breath test and in 18.7% of patients with a normal breath test ( p = 0.009, odds ratio = 2.7); headache in 11.9% of patients with a pathological breath test and in 9.4% of patients with a normal breath test ( p = 0.3); nausea in 8.5% of patients with a pathological breath test and in 5.2% of patients with a normal breath test ( p = 0.3); diarrhoea in 9.3% of patients with a pathological breath test and in 5.2% of patients with a normal breath test ( p = 0.2). There was a low but significant correlation between hydrogen (H 2 ) production and symptoms ( r = 0.37, p < 0.000005), but we found no correlation between methane (CH 4 ) production and symptoms. Bloating appearing within 5 hours after an oral lactose dose had a positive predictive value of 79% and a negative predictive value of 68% in breath test results. Conclusions: Our results show that only H 2 but not CH 4 production correlates with symptoms after a 20 g lactose dose. A possible interpretation of these results is that the generation of symptoms is a complex process that involves not only gases but other... [ABSTRACT FROM AUTHOR]

The study aims to estimate the prevalence of lactase non-persistence (LNP) among Greenlandic Inuit and Scandinavians living in Nuuk and East Greenland. The C to T transition in LCT − 13910 (rs4988235) is an autosomal inherited variant that provides the ability to lifelong lactase production, necessary to digest milk. The transition is very common in North European populations. However, LNP has only been sparsely studied in Greenland and never in Eastern Greenland, and genotype data has not previously been reported. Whole blood samples were collected from 535 participants, and rs4988235 was typed using a PCR-based method. Ethnicity was defined by parents' place of birth. Results were compared between East and West Greenland and Inuit and Scandinavians using Pearson's Chi2 test. 82.2% of the participants were Inuit, and 17.8% were of Scandinavian ancestry. Among Inuit, 88.5% had LNP compared to 7.5% among Scandinavians (p < 0.001). The prevalence of LNP in Inuit varied significantly between East and West Greenland (p < 0.001). In the capital, 67.6% of Inuit had LNP compared to 98.6% in Tasiilaq and 100% in the villages around Tasiilaq. The difference in LNP between East and West Greenland and the Inuit and Scandinavian population found in our study suggests that the original Inuit population was lactose maldigesters. Our findings suggest that the −13910 T allele was introduced into the original Inuit population by the Danes. [ABSTRACT FROM AUTHOR]

Adult-type hypolactasia (lactase non-persistence; primary lactose malabsorption) is characterized by the down-regulation of the lactase enzyme activity in the intestinal wall after weaning. The down-regulation is genetically determined and a mutation has occurred that has made part of mankind tolerate milk (lactase persistence). A DNA-variant, single nucleotide polymorphism C/T-13910 located 13 910 base pairs (bp) upstream of the lactase gene (LCT) at chromosome 2q21-22 has been shown to associate with the lactase persistence/non-persistence trait both in family and case-control studies. The C/T-13910 variant is located in a non-coding region in the genome in intron 13 of the minichromosome maintenance type 6 gene (MCM6). Significant correlation between the C/T-13910-variant and lactase activity in the intestinal biopsy specimens has been demonstrated. Molecular epidemiological studies on the prevalence of the C/C-13910 genotype associated with low lactase activity are in agreement with the prevalence figures for adult type hypolactasia in>70 diverse ethnic groups studied. Recent functional studies have suggested that this variant has an enhancer effect over the lactase gene. Based on the biochemical, functional, genetic and molecular epidemiological studies of the C/T-13910 variant, genetic testing for adult type hypolactasia has been introduced into clinical practice in Finland. Identification of the genetic change has highlighted the role of non-coding variants in the regulation of common genes and created new tools to study the mechanism of lactase enzyme activation. [ABSTRACT FROM AUTHOR]

Lactose intolerance (LI) may be considered in patients with unspecific gastrointestinal symptoms, but there is no clear consensus on when and how to diagnose the disorder. The LCT-13910 CC genotype is associated with acquired primary lactase deficiency (adult-type hypolactasia; ATH). We aimed to describe the number of tests and test results in the North Denmark Region considering patient age, geographical origin and repeated testing. Retrospective evaluation of the polymerase chain reaction-based LCT-13910 genotype tests registered in the clinical laboratory information system (LABKA II) with data linkage to Danish nationwide registers. Between 18 May 2007 and 31 December 2018, a total of 23,560 individuals were tested. There was a sevenfold increase in the number of tests performed during the study period. About 9.8% of the tests performed in 2018 were repeated testing in the same individuals. Overall, 8.8% of tested individuals were younger than 5 years, 90.7% were of Danish origin and 5.5% originated from outside of Europe. The LCT-13910 CC genotype was identified in 13.3% of all tested individuals, in 16.0% of children younger than 5 years, in 6.8% of Danish individuals and in 90.9% originating from outside of Europe. In the North Denmark Region, a marked increase in the use of genetic testing for hypolactasia was observed and repeated testing was frequent. Furthermore, the use of the test and the test results were dependent on patient age and geographical origin. Results inform the debate on when and how to use genetic testing in the diagnosing of LI. [ABSTRACT FROM AUTHOR]

Background: Microscopic colitis is a disease of unknown aetiology characterized by chronic watery diarrhoea and diarrhoea can be eliminated by budesonide but frequently recurs when budesonide is stopped. We studied whether prednisolone could induce remission in patients with disabling, chronic diarrhoea due to microscopic colitis. Methods: A double-blind, randomized (3:1) trial of oral prednisolone 50 mg daily or placebo for 2 weeks. Remission was defined as stool weight &leg;200 g/day or frequency &leg;2/day; effect was defined as >50% reduction of either stool frequency or weight. Six centres screened 31 consecutive patients and included 11 with collagenous colitis and 1 with lymphocytic colitis. Median duration of diarrhoea was 9 months. Patients had a normal colonoscopy, and no evidence of coeliac disease, bile acid or lactose malabsorption. Patients with gastrointestinal infection, previous gastrointestinal surgery, abnormal biochemical screening or recent treatment with immunosuppressive agents were excluded. Results: Stool weight (grams) declined in 7 of 9 patients given prednisolone and in 1 of 3 receiving placebo; changes in median weight were from 430 to 278 and from 825 to 489, respectively. Stool frequency (per day) declined from 6 to 3 and from 8 to 5. Remission was obtained in 2 and 0, and effect in 5 and 0, respectively (NS; Fisher exact test). Conclusions: Prednisolone 50 mg daily for 2 weeks induces incomplete remission in patients with chronic diarrhoea due to collagenous colitis. [ABSTRACT FROM AUTHOR]

The validity of a newly developed diagnostic method is usually proven by comparing with a well-grounded reference method. When measurements from a new method are continuous but in different units from a reference standard and having a linear relationship, validity can be usually assessed by Pearson correlation coefficient, but it does not provide clinical guidance for judging validity. We defined a limits-ofagreement derived from regression models for assessing validity of new method, and developed a sample size formula. The sample size formula to achieve a certain probability that the limits-of-agreement is within a pre-defined, clinically acceptable range [-d, d] was derived and the result is presented as a nomogram. When a ratio of upper bound of a limits-of-agreement to d is expected to be 0.95, a sample size of approximately 300 achieves a 90% probability that the limits-ofagreement lies within± d. The simulation showed that the suggested sample size formula had the targeted coverages. The sample size determination based on a limits-of-agreement is practical for showing validity of new methods, measuring the same attribute but in different units, and the presented nomogram is useful. [ABSTRACT FROM AUTHOR]

The irritable bowel syndrome (IBS) is the best-recognized disorder of gut brain interactions (DGBI). However, it is controversial if the Rome IV criteria iteration for IBS diagnosis is fit for purpose. This review critically evaluates Rome IV criteria for diagnosis of IBS and addresses clinical considerations in IBS treatment and management, including dietary factors, biomarkers, disease mimics, symptom severity, and subtypes. The role of diet in IBS is critically reviewed along with the influence of the microbiota, including small intestinal bacterial overgrowth. Emerging data suggest the Rome IV criteria are more suitable for identifying severe IBS and least useful for sub-diagnostic patients who are still likely to benefit from IBS treatment. Despite convincing evidence that IBS symptoms are diet-driven and often postprandial, a relationship to eating is not a Rome IV diagnostic criterion. Few IBS biomarkers have been identified, suggesting the syndrome is too heterogeneous to be measured by a single marker, and combined biomarker, clinical, dietary, and microbial profiling may be needed for objective characterization. With many organic diseases mimicking and overlapping with IBS, it's important clinicians are knowledgable about this to mitigate the risk of missing comorbid organic intestinal disease and to optimally treat IBS symptoms. [ABSTRACT FROM AUTHOR]

The genetically programmed reduction in lactase activity during adulthood affects 70% of the world adult population and can cause severe digestive disorders, which are the sign of lactose intolerance. Lactose intolerance symptoms vary depending on the residual lactase activity, the small bowel transit time, and especially the amount of ingested lactose. To formulate dairy products suitable for the vast majority of lactose intolerants, it is essential to define lactose intolerance threshold. A recent meta-analysis permitted to show that almost all lactose intolerants tolerate 12 g of lactose in one intake and approximately 18 g of lactose spread over the day. The prevalence and severity of lactose intolerance are probably overestimated by the general public. This misconception usually leads to an unnecessary reduction of dairy foodstuff consumption. Nevertheless, dairy products are essential for health mainly due to their calcium content and the positive influence of probiotic bacteria. The formulation of dairy products suitable for most intolerant and suspicious subjects seems necessary. The use of exogenous enzyme preparations, as well as the consumption of lactose-free products or products rich in probiotic bacteria are proposed as symptom-reducing strategies. [ABSTRACT FROM AUTHOR]

In this study, we examine the mismatch between the anthropometric and the economic measures of human wellbeing, a fact that has gone unnoticed in the international research on anthropometric history: by 1914, Estonian males were among the tallest in the world despite the country's economic underdevelopment. We explain the anthropometric overperformance of Estonia considering the early start of the first demographic transition in relation to the special features of the agrarian reforms in the Baltic provinces. Estonian boys did grow taller than their peers in Lithuania, Finland, and even in the much richer Western countries, because their parents had smaller families. [ABSTRACT FROM AUTHOR]

There has been phenomenal interest concerning gut microbiota dysbiosis including small intestinal bacterial overgrowth (SIBO). However, the diagnostic methods for SIBO are still unsatisfactory. The current review covers the different invasive and noninvasive tests to diagnose SIBO, their methodology, interpretation, sensitivity, specificity, and limitations based on the selected articles from literature search using searchterms 'small intestinal bacterial overgrowth' AND 'digestive diseases' OR'diagnosis' OR 'hydrogen breath test' in PubMed in December 2022. The current review will cover some potential methods for diagnosis of SIBO that may be of clinical utility in the future. SIBO was conventionally defined as a total bacterial count >105 colony forming units (CFU) per mL on quantitative culture of upper gut aspirate. The threshold for the diagnosis of SIBO has been reduced to >103CFU per mL of aspirate recently. Considering the invasiveness of collecting upper gut aspirate, need for laboratory infrastructure and manpower to culture it, noninvasive hydrogen breath tests (HBT) became popular. However, due to the poor sensitivity and specificity of HBT to diagnose SIBO, their utility is being challenged. A new technology of measuring intra-luminal hydrogen gas has a potential to bring a paradigm shift in the diagnostic tests for SIBO. [ABSTRACT FROM AUTHOR]

The purpose of this article is to describe a modeling sequence about the digestive system. What happens in your body when you have lactose intolerance? is the initial question that will guide the activities. Students will build a 3D plaster cast of the digestive system as part of a modeling cycle through which they are expected to evaluate and refine their models both individually and cooperatively. Today, about two-thirds of the population in the world are known to have lactose intolerance. Besides, lactose intolerance and allergy to cow's milk are usually mistaken by the public. For those reasons, the topic seems fundamental to be taught to children in the science class. [ABSTRACT FROM AUTHOR]

Bovine viral diarrhea virus (BVDV) is a ubiquitous immunosuppressive etiological agent which is economically important for a wide host range in the livestock industry. Lactobacillus spp. has widely been using in the field of management and treatment of gastro-enteric disease for both humans and animals. The ability of Lacticaseibacillus casei MCJ protein-based metabolized to suppress BVDV infection in Madin–Darby Bovine Kidney cell line was demonstrated in this study. The protein-based metabolites were extracted from the cultured L. casei to obtain the safest and beneficial form of the probiotic bacteria. It is revealed that LPM have no cytotoxic effect and the cell viability remain more than 80% even after the cells are treated with 3000 µg/mL of LPM. The results of the plaque formation assay showed that LPM can reduce the viral infection rate. To know the mechanism of LPM for anti-BVDV activity, MDBK cells were exposed to LPM before, after and co-incubation of virus infection. The co-treatment of LPM with BVDV revealed the best results. The results suggest that the LPM has a potential anti-BVDV activity which could be a prospective candidate for the prevention and control of BVDV infection in an animal. [ABSTRACT FROM AUTHOR]

Background: Lactase activity declines during childhood in the majority of human populations leading to adult-type hypolactasia (AtH). C/T-13910 and G/A-22018 single nucleotide polymorphisms (SNPs) have been suggested to be associated with AtH in different human populations. Coeliac disease (CD) is an autoimmune condition characterized by damage to intestinal cells leading to ultimate deterioration. Aim: This study investigated the association between coeliac disease (CD) and SNPs leading to AtH in children from North India. Subjects and methods: Intestinal biopsies and saliva samples were obtained from 52 children with CD diagnosis and 102 control subjects. Biopsies were assayed for disaccharidase activities and samples were genotyped for given SNPs. Results: Prevalence of C/C and G/G genotypes of AtH was almost equal in the CD and control group. The CD group had low lactase activity compared to the control group, irrespective of genotype at C/T -13910 and G/A -22018 SNPs ( p < 0.05). For the control group, lactase activity was high in children with C/T + G/A genotypes compared to C/C + G/G ( p < 0.05). Conclusion: There appears to be no significant correlation between C/T -13910 or G/A -22018 SNPs of AtH and CD. Children with C/C or G/G genotype of AtH may not be at greater risk of CD. [ABSTRACT FROM AUTHOR]

Human breath offers several benefits for diagnostic applications, including simple, noninvasive collection. Breath is a rich source of clinically-relevant biological information; this includes a volatile fraction, where greater than 1,000 volatile organic compounds (VOCs) have been described so far, and breath aerosols that carry nucleic acids, proteins, signaling molecules, and pathogens. Many of these factors, especially VOCs, are delivered to the lung by the systemic circulation, and diffusion of candidate biomarkers from blood into breath allows systematic profiling of organismal health. Biomarkers on breath offer the capability to advance early detection and precision medicine in areas of global clinical need. Breath tests are noninvasive and can be performed at home or in a primary care setting, which makes them well-suited for the kind of public screening program that could dramatically improve the early detection of conditions such as lung cancer. Since measurements of VOCs on breath largely report on metabolic changes, this too aids in the early detection of a broader range of illnesses and can be used to detect metabolic shifts that could be targeted through precision medicine. Furthermore, the ability to perform frequent sampling has envisioned applications in monitoring treatment responses. Breath has been investigated in respiratory, liver, gut, and neurological diseases and in contexts as diverse as infectious diseases and cancer. Preclinical research studies using breath have been ongoing for some time, yet only a few breath-based diagnostics tests are currently available and in widespread clinical use. Most recently, tests assessing the gut microbiome using hydrogen and methane on breath, in addition to tests using urea to detect Helicobacter pylori infections have been released, yet there are many more applications of breath tests still to be realized. Here, we discuss the strengths of breath as a clinical sampling matrix and the technical challenges to be addressed in developing it for clinical use. Historically, a lack of standardized methodologies has delayed the discovery and validation of biomarker candidates, resulting in a proliferation of early-stage pilot studies. We will explore how advancements in breath collection and analysis are in the process of driving renewed progress in the field, particularly in the context of gastrointestinal and chronic liver disease. Finally, we will provide a forward-looking outlook for developing the next generation of clinically relevant breath tests and how they may emerge into clinical practice. [ABSTRACT FROM AUTHOR]

Background: Lactase non-persistence (LNP) has been associated with the CC genotype of −13910C > T and GG genotype of −22018G > A polymorphisms present upstream of the lactase gene. Lactose intolerance (LI) is caused when gastrointestinal symptoms develop in individuals with low lactase activity. Objective: To analyse association of LNP genotype and LI symptoms with milk intake and determine whether factors such as age, gender and genotype affect LI status. Subjects and methods: Genetic analysis and lactose tolerance test (LTT) were performed on 205 healthy Indian adults. The pattern of milk consumption was recorded using a dietary questionnaire. Results: LI was strongly associated with −13910CC genotype (OR = 10.28, 95% CI = 2.32-45.55, p = 0.002). Females were found to be at a higher risk of developing LI (OR = 2.47, 95% CI = 1.33-4.59, p = 0.004). The association of the ≥50 years age group with LI was marginally significant (OR = 1.86, 95% CI = 0.995-3.47, p = 0.05). Frequency and quantity of milk intake were lower in subjects belonging to the LNP genotype and LI groups ( p < 0.05). Conclusions: Subject study suggests that gender and genotype may be associated with development of LI. Association of age with LI was marginal. The data also indicate that LNP genotype and LI may play a role in influencing milk intake in individuals. [ABSTRACT FROM AUTHOR]

The article reports that milk was not a staple food in China; in fact, it served as a marker of racial distinction between the agricultural Han-Chinese and the non-Han nomads on the steppe. Since the nineteenth century, however, milk has increasingly become a common choice for infant feeding and adult nourishment; moreover, it has become a matter of national prosperity.

Objectives. The frequency of adult-type hypolactasia (lactase non-persistence) varies widely among different ethnic groups. The cultural historical hypothesis assumes a link between the occurrence of hypolactasia and the distribution of dairy farming. The nomadic Nenets have been reindeer herders for generations and have therefore not consumed any dairy products. The hypotheses here was that the prevalence of lactase nonpersistence (-13910 C/C genotype) among Nenets people having four Nenets grandparents is high, while the prevalence among Nenets originating from ethnically mixed families is lower. Study design. The material was collected in four typical Nenets settlements in the Nenets Autonomous Okrug in Russia. One-third of the adult Nenets population were invited to answer a questionnaire and to donate buccal samples for genotyping by a doctor from the team of medical professionals who make rounds in this area. The total number of available participants was 177. Methods. Genotyping was performed with the AbiPrism system. We used the method of concordance of grandparents' national origin to ascribe ethnicity. Results. The prevalence of adult-type hypolactasia (-13910 C/C) among Nenets who had four Nenets grandparents was found to be 90%. The figures among others reporting three, two and one grandparent of Nenets origin were 72, 60 and 28%, respectively. Conclusion. The findings are in accord with the cultural historical hypothesis. [ABSTRACT FROM AUTHOR]

Background. Adult-type hypolactasia (lactase non-persistence) is a common cause of gastrointestinal symptoms. Several DNA sequence variants have been identified for the lactase-persistence/non-persistence (LP/LNP), the most common being the C to T residing -13910 bp upstream of the lactase gene (LCT). We have analysed sequence variants of LP/LNP in subjects originating from Northern Russia. Methods. A total of 148 subjects with gastrointestinal complaints were genotyped covering about 400 bp around the -13910C/T variant using direct PCR-sequencing. All patients were interviewed about milk-related symptoms using the questionnaire. Disaccharidase activities were measured from intestinal biopsy specimens of the index person. Results. The prevalence of the -13910C/C genotype among 148 patients was 28.4%. A G to A variant residing 13914 bp upstream from the LCT gene (-13914G>A) was identified in one participant carrying the -13910C/C genotype. In two biopsy specimens her lactase activity was above the generally accepted cut off level for adult-type hypolactasia, 10U/g protein. Three other family members also carried the -13914G>A genotype. Among eight family members five had the LNP genotype -13910C/C. Conclusion. A rare variant G to A residing 13914 bp upstream of the LCT gene was identified in a subject carrying the more frequent variant -13910C/C. The -13914G>A variant in heterozygous state was associated with increased lactase activity, suggesting that the increased lactase activity is most likely to be associated with the -13914G>A variant. Further studies need to be done to confirm the functional role of this variant. [ABSTRACT FROM AUTHOR]

Lactase non-persistence (adult-type hypolactasia) is present in more than half of the human population and is caused by the down-regulation of lactase enzyme activity during childhood. Congenital lactase deficiency (CLD) is a rare severe gastrointestinal disorder of new-borns enriched in the Finnish population. Both lactase deficiencies are autosomal recessive traits and characterized by diminished expression of lactase activity in the intestine. Genetic variants underlying both forms have been identified. Here we review the current understanding of the molecular defects of human lactase deficiencies and their phenotype-genotype correlation, the implications on clinical practice, and the understanding of their function and role in human evolution. [ABSTRACT FROM AUTHOR]