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Abstract: Background: Lactose intolerance is a frequent condition in certain populations. Different methods for diagnosis exist. There is scarce literature regarding Lactose Quick Test (LQT) and concordance with other methods for lactose intolerance diagnosis in children. Methods: Prospectively, we included children who underwent gastroduodenoscopy for evaluation of abdominal pain. We obtained a duodenal sample for LQT and blood sample for genetic test to evaluate LCT C>T‐13910 variant. Later, patients underwent breath test with lactose, to evaluate malabsorption. We evaluated the concordance between the three different tests. Key Results: We included 46 patients, 56.5% women. Mean age was 13.2 years (range 9‐18 years). 66.6% of patients had lactose malabsorption according to breath test; 64.4% were homozygous CC; and 91.3% had hypolactasia (mild or severe) according to LQT. None of the patients with normolactasia had altered breath test. Genetic test had a substantial agreement (k = 0.675) with breath test and fair agreement (k = 0.301) with LQT. LQT had fair agreement (k = 0.348) with breath test. Conclusions & Inferences: Genetic test had better concordance with breath test than LQT to diagnose lactose malabsorption, however, none of the patients with normal LQT had lactose malabsorption. In patients who undergo gastroduodenoscopy to study abdominal pain, it seems reasonable to perform LQT, and, in those with hypolactasia, to perform breath test. [ABSTRACT FROM AUTHOR]

Background There are no studies on systemic sclerosis ( SSc) assessing the relationship between food intake, especially lactose, and gastrointestinal dysfunction. Aim To determine the prevalence of lactose malabsorption, using lactose breath test, in patients with SSc. To evaluate the correlation between lactose malabsorption and gastrointestinal involvement. To predict which SSc patients exhibit lactose malabsorption. Methods Seventy-seven consecutive Caucasian patients with SSc and 20 control subjects underwent lactose breath test. All patients also completed a questionnaire on digestive symptoms, and a global symptom score ( GSS) was calculated. Results The prevalence of lactose malabsorption was higher in SSc patients than in controls (44.3% vs. 10%; P = 0.004). We observed a marked correlation between the presence of lactose malabsorption and: higher values of GSS ( P < 0.0001); severe oesophageal ( P = 0.018) and small intestinal ( P = 0.04) motor disorders; and joint involvement ( P = 0.019). Furthermore, in SSc patients with symptomatic lactose malabsorption, the median value of GSS of digestive symptoms was lower after initiation of lactose-free diet ( P < 0.0001). Conclusions Our study underscores the fact that lactose malabsorption often occurs in patients with systemic sclerosis. Furthermore, our findings highlight the fact that lactose breath test is a helpful, noninvasive method, by identifying the group of patients with systemic sclerosis with symptomatic lactose malabsorption that may benefit from a reduction in lactose intake. [ABSTRACT FROM AUTHOR]

Aim: To determine the prevalence of lactose malabsorption in young Lithuanian atopic dermatitis children; to evaluate the relationship between lactose malabsorption and the duration of exclusive breastfeeding, and the relationship between lactose malabsorption and cow's milk intolerance in parents and grandparents. Methods: 144 children with atopic dermatitis aged 1.5-24 mo (study group) and 32 children without symptoms of allergic diseases aged 1.5-23 mo (control group) were investigated. Lactose and glucose-galactose absorption tests based on serial blood glucose determination, culture of stool, latex agglutination test for rotavirus and microscopic examination of stool for parasites were performed. Results: Lactose malabsorption was determined in 59 (40.9%) and glucose-galactose malabsorption in 17 (11.8%) children with atopic dermatitis. The risk of developing lactose malabsorption was higher in children fed exclusively on breast milk up to 1 mo of age than in children fed exclusively on breast milk for 4 to 6 mo (OR: 2.62; 95% CI: 1.02-6.75). Lactose malabsorption was significantly more frequent in patients whose mothers did not tolerate cow's milk (20/30; 66.7%) than in patients whose mothers were tolerant to it (39/95; 41.1%) ( p = 0.02). Conclusion: Lactose malabsorption was determined in 40.9% of Lithuanian atopic dermatitis children aged under 2 y. Lactose malabsorption appeared to be associated with the duration of exclusive breastfeeding up to only 1 mo and mothers' milk intolerance. [ABSTRACT FROM AUTHOR]

Objective. To establish whether supplementation with a standard oral dose of Beta-Galactosidase affects hydrogen breath excretion in patients presenting with lactose malabsorption. Methods. Ninety-six consecutive patients positive to H2 Lactose Breath Test were enrolled. Mean peak H2 levels, the time to reach the peak H2, the time to reach the cut-off value of 20 ppm, the cumulative breath H2 excretion, the areas under the curve, and a Visual Analogical 10-point Scale for symptoms were calculated. Genotyping of the C/T-13910 variant was carried out. Results. Following the oral administration of Beta-Galactosidase, in 21.88% of the cases, H2 Lactose Breath Test became negative (Group A), while mean peak H2 levels (74.95 ppm versus 7.85),p < 0.0000, in 17.71% (Group B) were still positive, with the H2 level 20 ppm above the baseline, but the peak H2 levels were significantly lower than those observed at the baseline test (186.7 ppmversus 66.64), p < 0.0000, while in 60.41% (Group C) they were still positive with the peak H2 levels similar to those observed at the baseline test (94.43 versus 81.60 ppm). All 96 individuals tested presented the C/C-13910 genotype nonpersistence. Conclusions. The response to oral administration of Beta-Galactosidase in patients with symptoms of lactose malabsorption presents a significant variability. [ABSTRACT FROM AUTHOR]

The aim of this study was to establish a retrospective evaluation and comparison of the hydrogen/methane (H2/CH4) breath test and genetic test (C/T-13910 polymorphism) results in lactose malabsorption testing. In total 263 consecutive patients with suspected lactose malabsorption were included in this study. They underwent the H2/CH4 breath test following the ingestion of 50 g lactose and were tested for the C/T-13910 polymorphism. In total 51 patients (19.4%) had a C/C-13910 genotype, indicating primary lactose malabsorption. Only 19 patients (7.2%) also had a positive H2/CH4 breath test. All in all 136 patients (51.69%) had a C/T-13910 and 76 patients (28.91%) a T/T-13910 genotype, indicating lactase persistence. Four patients (1.5%) with the C/T-13910 genotype and one patient (0.4%) with the T/T-13910 genotype had a positive H2/CH4 breath test result, indicating secondary lactose malabsorption. Cohen's Kappa measuring agreement between the two methods was 0.44. Twenty patients (7.6%) with a positive H2/CH4 peak within 60 minutes after lactose ingestion were classified as patients with lactose-dependent small intestinal bacterial overgrowth (SIBO). In conclusion, only moderate agreement between the breath test and the genetic test was shown. Secondary lactose malabsorption as well as preanalytical limitations of the combined H2/CH4 breath test procedure can cause discrepant results. This trial is registered with K-42-13. [ABSTRACT FROM AUTHOR]

Lactose malabsorption is not always associated with intolerance symptoms. The factors responsible for symptom onset are not yet completely known. As differences in visceral sensitivity may play a role in the pathogenesis of functional symptoms, we evaluated whether an alteration of visceral sensitivity is present in subjects with lactose intolerance. Thirty subjects, recruited regardless of whether they were aware of their capacity to absorb lactose, underwent an evaluation of intestinal hydrogen production capacity by lactulose breath test, followed by an evaluation of lactose absorption by hydrogen breath test after lactose administration and subsequently an evaluation of recto-sigmoid sensitivity threshold during fasting and after lactulose administration, to ascertain whether fermentation modifies intestinal sensitivity. The role of differences in gastrointestinal transit was excluded by gastric emptying and mouth-to-caecum transit time by 13C-octanoic and lactulose breath tests. Lactulose administration induced a significant reduction of discomfort threshold in subjects with lactose intolerance but not in malabsorbers without intolerance symptoms or in subjects with normal lactose absorption. Perception threshold showed no changes after lactulose administration. Severity of symptoms in intolerant subjects was significantly correlated with the reduction of discomfort thresholds. Visceral hypersensitivity should be considered in the induction of intolerance symptoms in subjects with lactose malabsorption. [ABSTRACT FROM AUTHOR]

Background Lactose malabsorption ( LM), diagnosed currently using lactose hydrogen breath and tolerance tests ( LHBT, LTT) with a high, nonphysiological dose (50-g), may mimic irritable bowel syndrome ( IBS). In LM-endemic areas, clinically significant malabsorption (lactose intolerance) may be better diagnosed using a lesser dose, and positive results so obtained may predict response to milk withdrawal more effectively. Methods Fifty patients each with IBS (Rome III) were evaluated using LHBT and LTT with 50-g, 25-g, and 12-g lactose. Sensitivity and specificity of LHBT and LTT with different dosages (gold standard: lactase gene C/ T-13910 polymorphism) and symptom development were evaluated. Effect of milk withdrawal was studied. Result Of 150 patients, 37/50 (74%) and 28/50 (56%) had LM by LHBT and LTT using 50-g lactose; 41/50 (82%) and 31/50 (62%) had LM using 25-g lactose, and 14/50 (28%) and 29/50 (58%) using 12-g lactose, respectively. Sensitivity and specificity of LHBT using 50-g, 25-g, and 12-g lactose were 92.6%, 52.0%, and 94%, 60%, and 36.4%, 88.2%, and those of LTT, 92%, 80.0%, and 84.8%, 82.4%, and 66.7%, 58.8%, respectively. Breath hydrogen correlated with lactose dose. Though patients developing symptoms with 50-g lactose exhaled more hydrogen than those remaining asymptomatic, hydrogen levels did not differ following 25-g and 12-g dosages in relation to symptom development. Patients' milk intake was 335 ± 92 mL/d (≈ 16.7 ± 9.6-g lactose). Positive LHBT using 25-g dose better predicted symptom resolution than by 50-g and 12-g lactose. Conclusion Twenty-five gram is the ideal dose of lactose for LHBT and LTT in LM-endemic areas. [ABSTRACT FROM AUTHOR]

Background Fructose malabsorption, lactose malabsorption and an early rise in breath hydrogen after lactulose (ERBHAL) may play roles in induction of symptoms in gastrointestinal conditions. Aim To compare prevalence and interactions of fructose malabsorption, lactose malabsorption and ERBHAL among healthy subjects and those with chronic intestinal disorders using consistent breath hydrogen testing methodologies. Methods Consecutive series of Caucasian patients with Crohn’s disease ( n = 91), ulcerative colitis (56), functional gastrointestinal disorders (FGID) (201), coeliac disease (136) and 71 healthy volunteers underwent breath hydrogen testing using lactulose, fructose and lactose. Results Early rise in breath hydrogen after lactulose occurred more commonly in healthy controls (39%) than in Crohn’s disease (20%) and untreated coeliac disease (14%; P < 0.008), but not FGID (27%), ulcerative colitis (26%) or treated coeliac disease (29%). Fructose malabsorption was more frequent in Crohn’s disease (61%) than other groups (33–44%, P < 0.05). Lactose malabsorption was most common in Crohn’s disease (42%) and ulcerative colitis (40%) and uncommon (10%) in 79 patients with newly diagnosed coeliac disease. In Crohn’s disease, concurrent Fructose malabsorption and lactose malabsorption was most common (29%), and the association of fructose malabsorption with ERBHAL seen overall (62%) was not observed (36%, P < 0.0001). Conclusions Carbohydrate malabsorption and ERBHAL are normal physiological phenomena. The abnormal patterns observed in Crohn’s disease may have pathogenic importance. [ABSTRACT FROM AUTHOR]

Background. Insufficient vitamin D and calcium intake associated with the restricted intake of milk and dairy products can lead to poor health outcomes like malnutrition and abnormal bone mineralization. The aim of the study was to estimate the prevalence of primary and secondary lactose intolerance in children with IBD. Methods. The study included 107 patients (mean age 14.07±3.58 years; 46.7% boys) which includes 43 patients with Crohn's disease (CD), 31 with ulcerative colitis (UC), and 33 children with functional abdominal pain (AP-FGID). We analysed the result of the hydrogen breath test with lactose loading, two single nucleotide polymorphisms of the LCT gene (LCT-13910CC and LCT-22018GG). The results were analysed with MedCalc Statistical Software. Results. Adult-type hypolactasia (ATH) was found in 31% of patients with IBD and 42.4% of AP-FGID (p=0.2). Lactose malabsorption (LM) was found in 27.9% of patients with CD, in 22.6% with UC, and in 24.2% with AP-FGID (p=0.8). Lactose intolerance (LI) was diagnosed in a similar percentage of patients in each group (p=0.9). Secondary LI in IBD patients does not depend on the location, duration, and activity of the disease and the number of relapses (p>0.05). The median time of lactose-free diet in CD was 10 months and in CU 24 months. Conclusions. The incidence of LI, LM, and ATH does not differ among children with IBD from the population. [ABSTRACT FROM AUTHOR]

Background and Aim Lactase non-persistence is common in India. We evaluated: (i) frequency of lactase gene ( C/ T-13910 and G/ A-22018) polymorphisms in irritable bowel syndrome ( IBS) and healthy controls ( HC), (ii) association between these polymorphisms and IBS-subtypes and symptoms. Methods A total of 150 IBS patients ( Rome- III criteria) and 252 age and gender-matched HC were evaluated for C/ T-13910 and G/ A-22018 genotypes using polymerase chain reaction-restriction fragment length polymorphism ( PCR-RFLP). Results Totals of 79 (52%), 52 (35%) and 19 (13%) patients had diarrhea-predominant IBS ( D- IBS), constipation predominant IBS ( C- IBS) and alternating diarrhea and constipation IBS ( A- IBS), respectively ( Rome- III). Frequency of C/ T-13910 [genotypes: CC 102 (68%), CT 43 (29%), TT 5 (3%) vs CC 155 (61%), CT 83 (33%), TT 14 (6%), P > 0.05] and G/ A-22018 [ GG 97 (65%), GA 41 (27%), AA 12 (8%) vs GG 154 (61%), GA 78 (31%), AA 20 (8%), P > 0.05] were similar among IBS and HC. Patients with D- IBS more often had C/ T-13910 and G/ A-22018 genotypes than C- IBS ( CC 71 [90%], CT 6 [8%], TT 2 [2%]) versus (24 [46%], 25 [48%], 3 [6%]), A- IBS (7 [39%], 12 [63%], 0, [0%]) and HC (155 [61%], 83 [33%], 14 [6%]), P < 0.0001 and ( GG 69 [87%], GA 6 [8%], AA 4 [5%]) vs (22 [42%], 24 [46%], 6 [12%]) vs (6 [32%], 11 [58%], 2 [10%]), P < 0.0001. IBS with CC and GG genotypes more often had abdominal pain ( P = 0.005), distension ( P = 0.031) and higher stool frequency ( P = 0.003) and reported symptoms following dairy products than non- CC ( P < 0.0001). Conclusion Though C/ T-13910 and G/ A-22018 polymorphisms were comparable among IBS and HC, these were more common among D- IBS and reported some symptoms like abdominal pain, bloating and exacerbation by dairy products. [ABSTRACT FROM AUTHOR]

Background Symptoms of lactose intolerance are often attributed to lactose malabsorption but, as this relationship has not been demonstrated when a small dose of lactose similar to that contained in one cup of milk is ingested by intolerant patients, psychological factors may play a role in altered symptom perception. Aim To assess the hypothesis that the psychological profile influences the symptoms of lactose intolerance. Methods One hundred and two consecutive patients underwent a 15 g lactose hydrogen breath test to assess lactose malabsorption. The patients recorded the presence and severity of symptoms of lactose intolerance during the breath test using visual analogue scales. The psychological profile was assessed using a psychological symptom checklist, and health-related quality of life by means of the short-form health survey. Results Lactose malabsorption and intolerance were diagnosed in, respectively, 18% and 29% of the patients. The two conditions were not associated, and the severity of intolerance was even less in the patients with malabsorption. Multivariate logistic analysis showed that a high somatisation t-score was significantly associated with lactose intolerance (odds ratio 4.184; 1.704-10.309); the effects of the other psychological variables and of lactose malabsorption were not statistically significant. Health-related quality of life was significantly reduced in the patients with somatisation, but not in those with lactose malabsorption. Conclusions The symptoms of lactose intolerance during hydrogen breath testing at a low physiological lactose load, are unrelated to lactose malabsorption, but may reveal a tendency towards somatisation that could impair the quality of life. [ABSTRACT FROM AUTHOR]

Confirmation of the diagnosis of coeliac disease requires unequivocal evidence of recovery on a gluten-free diet. The lactose H[sub 2] breath test is a non-invasive technique for detecting lactose malabsorption, and this may occur in untreated coeliac disease. The utility of this test was investigated in objectively confirming a response to gluten exclusion. The study included 44 children from 0.9 to 14.75 y of age (median 3.2) with coeliac disease. Five children were asymptomatic, being identified through coeliac antibody screening. Breath tests were performed prior to dietary treatment. If positive, they were repeated at 4-wk intervals following gluten exclusion. Overall, 21/44 (48%) children had positive breath tests at presentation. In 18/21 children on a gluten-free diet, this became negative after 4 wk (86%) and in all the children by 8 wk. In two children with positive tests at 4 wk, problems with dietary adherence were identified. A positive test before treatment was not associated with significant differences in individual symptoms, height, weight and body mass index standard deviation scores, serum haemoglobin or albumin. However, no positive results were found in the asymptomatic patients (p = 0.05). Lactose malabsorption was associated with earlier age of presentation (p = 0.008). Conclusion: The lactose H[sub 2] breath test objectively confirms a response to gluten exclusion. In selected cases it can help confirm a diagnosis of coeliac disease. However, the test tends to be less informative in asymptomatic patients, and in older children. [ABSTRACT FROM AUTHOR]

Lactase persistence/persistent (LP), the ability to express the lactase enzyme in adults, is one of the most strongly selected phenotypes in humans. It is encoded by at least five genetic variants that have rapidly become widespread in various human populations. The underlying selective mechanism is not clear however, because dairy products in general are well tolerated in adults, even by lactase non‐persistence/persistent (LNP) individuals. Cultural adaptations to milk consumption, notably fermentation and transformation, which can provide most of the energy (protein, fat) to both LP and LNP individuals without any associated cost seem to have been common in ancient societies. Here, we propose that selection for LP occurred through increased glucose/galactose (energy) from fresh milk intake in early childhood, a crucial period for growth. At the age of weaning indeed, lactase activity has already begun to decline in LNP individuals so the gain in energy from fresh milk by LP children represents a major fitness increase. [ABSTRACT FROM AUTHOR]

Summary: Irritable bowel syndrome (IBS) is a common disorder of gut‐brain interaction. It is defined by the Rome criteria as the presence of abdominal pain, related to defaecation, associated with a change in stool form and/or frequency. The approach to diagnosis and investigation of suspected IBS varies between clinicians and, due in part to the uncertainty that can surround the diagnosis, many still consider it to be a diagnosis of exclusion. However, exhaustive investigation is both unnecessary and costly, and may also be counterproductive. Instead, physicians should aim to make a positive diagnosis, based on their clinical assessment of symptoms, and limit their use of investigations. The yield of routine blood tests in suspected IBS is low overall, but normal inflammatory markers may be reassuring. All patients should have serological testing for coeliac disease, irrespective of their predominant stool form. Routine testing of stool microbiology or faecal elastase is unnecessary; however, all patients with diarrhoea aged <45 should have a faecal calprotectin or a similar marker measured which, if positive, should lead to colonoscopy to exclude possible inflammatory bowel disease. Colonoscopy should also be undertaken in any patient reporting alarm symptoms suggestive of colorectal cancer, and in those whose presentation raises suspicion for microscopic colitis. Testing for bile acid diarrhoea should be considered for patients with IBS with diarrhoea where available. Hydrogen breath tests for lactose malabsorption or small intestinal bacterial overgrowth have no role in the routine assessment of suspected IBS. Adopting a standardised approach to the diagnosis and investigation of IBS will help to promote high‐quality and high‐value care for patients overall. [ABSTRACT FROM AUTHOR]

Aim: To investigate malabsorption of lactose and fructose as causes of recurrent abdominal pain (RAP). Methods: In 220 children (128 girls, mean age 8,8 [4.1-16.0] years) with RAP, hydrogen breath tests (H2BT; abnormal if ΔH2 > 30 ppm) were performed with lactose and fructose. Disappearance of RAP with elimination, recurrence with provocation and disappearance with re-elimination, followed by a 6-month pain-free follow-up, were considered indicative of a causal relation with RAP. For definite proof, a double-blinded placebo-controlled (DBPC) provocation was performed. Results: Malabsorption of lactose was found in 57 of 210, of fructose in 79 of 121 patients. Pain disappeared upon elimination in 24/38 patients with lactose malabsorption, and in 32/49 with fructose malabsorption. Open provocation with lactose and fructose was positive in 7/23 and 13/31 patients. DBPC provocation in 6/7 and 8/13 patients was negative in all. However, several children continued to report abdominal symptoms upon intake of milk or fructose. Conclusion: Lactose intolerance nor fructose intolerance could be established as causes of RAP, according to preset criteria including elimination, open provocation and DBPC provocation. However, in clinical practice, persistent feeling of intolerance in some patients should be taken seriously and could warrant extended elimination with repeated challenges. [ABSTRACT FROM AUTHOR]

Aliment Pharmacol Ther 31, 892–900 Background Many studies report a high prevalence of lactose intolerance in patients with functional, gastrointestinal disease. Aim To evaluate the role of small intestinal bacterial overgrowth (SIBO) in condition of lactose intolerance and the mechanism by which SIBO may impact lactose tolerance in affected patients. Methods Consecutive out-patients with chronic functional diarrhoea (CFD) and healthy controls underwent a validated 20 g lactose hydrogen breath test (HBT). Patients completed also a 10 g lactulose HBT with concurrent assessment of small bowel transit by scintigraphy. Results Lactose malabsorption was present in 27/31 (87%) patients with CFD and 29/32 (91%) healthy controls ( P = 0.708). From the patient group 14/27 (52%) had lactose intolerance and 13/27 (48%) experienced no symptoms (lactose malabsorption controls). Only 5 (17%) healthy controls reported symptoms ( P < 0.01). The oro-caecal transit time was similar between patient groups with or without symptoms ( P = 0.969). SIBO was present in 11 (41%) subjects and was more prevalent in lactose intolerance than in lactose malabsorption [9/14 (64%) vs. 2/13 (15%), P = 0.018]. Symptom severity was similar in lactose intolerance patients with and without SIBO ( P = 0.344). Conclusions Small intestinal bacterial overgrowth increases the likelihood of lactose intolerance in patients with CFD as a direct result of lactose fermentation in the small intestine, independent of oro-caecal transit time and visceral sensitivity. [ABSTRACT FROM AUTHOR]

Summary: Dairy products are essential to ensure calcium recommendations to achieve optimal peak bone mass and avoid bone loss. However, high prevalence of lactose malabsorption decreases milk‐derived foods consumption. The use of β‐galactosidase, which hydrolyses lactose to galactooligosaccharides (GOS) is an alternative to develop a low‐lactose yoghurt (EY) where prebiotics (GOS) and probiotics (Lactobacilli) coexist. The effects of two diets based on EY or standard yoghurt without GOS (Y) on calcium absorption and bone retention were evaluated and compared, in growing rats. Control group received AIN 93‐G diet. Male weaning rats were fed one of these three diets for 28 days. EY group showed the highest increase in faecal Lactobacillus colonies, in short‐chain fatty acids production, in intestinal crypt deep, and the lowest caecum pH. Calcium absorption (%) increased significantly as follows: EY>Y>control (P < 0.05). EY and control showed similar calcium content in femur, bone mineral content and density, and total epiphyseal cartilage while Y showed the lowest value (P < 0.05). Conclusion: YE presented some advantages compared to Y regarding calcium absorption and bone retention since Y could not match bone growth and quality of control group. EY was an effective low lactose‐dairy product for delivering prebiotics and probiotics into gut, to enhance gut health and calcium bioavailability that improved bone development in a period of high calcium requirements as growth stage. Even more important is that EY could represent an efficient therapeutic strategy to achieve calcium recommendations in people who avoid dairy product consumption due to unpleasant symptoms of lactose intolerance. [ABSTRACT FROM AUTHOR]

Lactase (LCT) deficiency affects approximately 75% of the world's adult population and may lead to lactose malabsorption and intolerance. Currently, the regulation of LCT gene expression remains poorly known. Peroxisome proliferator activator receptorγ (PPARγ) is a key player in carbohydrate metabolism. While the intestine is essential for carbohydrate digestion and absorption, the role of PPARγ in enterocyte metabolic functions has been poorly investigated. This study aims at characterizing PPARγ target genes involved in intestinal metabolic functions. In microarray analysis, the LCT gene was the most upregulated by PPARγ agonists in Caco-2 cells. We confirmed that PPARγ agonists were able to increase the expression and activity of LCT both in vitro and in vivo in the proximal small bowel of rodents. The functional response element activated by PPARγ was identified in the promoter of the human LCT gene. PPARγ modulation was able to improve symptoms induced by lactose-enriched diet in weaned rats. Our results demonstrate that PPARγ regulates LCT expression, and suggest that modulating intestinal PPARγ activity might constitute a new therapeutic strategy for lactose malabsorption. [ABSTRACT FROM AUTHOR]

Background and Aim A major use of breath hydrogen testing is to assess absorptive capacity for sugars to assist dietary design for management of gut symptoms. Qualitative reporting takes no account of the vigor of hydrogen response and provides little insight into degrees of malabsorption. This study aimed to describe a semiquantitative reporting method and to compare results with those reported qualitatively. Methods In consecutive Caucasian patients with Crohn's disease ( n = 87), ulcerative colitis (59), functional gastrointestinal disorders ( FGID) (162), and healthy controls (76), area under the curve was calculated for lactulose (15 g). This was compared with that for lactose (50 g) and fructose (35 g). Degree of malabsorption was categorized into arbitrary groups. Results Semiquantitative results for ≥ 30% (designated 'convincing') malabsorption was most similar to those using a qualitative cutoff value of 20 ppm, but in 38% and 21% of patients, the classification of malabsorption (nil or clinically significant) changed for fructose and lactose, respectively. Using a cutoff of 10 ppm, 49% and 5% were classified differently. Crohn's disease had a higher prevalence (42%) of convincing fructose malabsorption than controls (24%) or patients with FGID (33%) ( P < 0.02). Highest prevalence of convincing lactose malabsorption (38%) was in ulcerative colitis, greater than controls (18%) and FGID (18%) ( P < 0.02). Conclusions Semiquantitative assessment provides different results with different clinical implications in more than one third of patients, but disease-related alterations in prevalence are similar to those defined qualitatively. This method may be preferable because it lessens the confounding influence of the vigor of the hydrogen response. [ABSTRACT FROM AUTHOR]

Dairy milk is a core food in many food‐based guides to healthy eating. However, plant‐based milk alternatives are becoming increasingly available as substitutes. While these products serve a subset of the population unable or unwilling to consume milk, plant‐based milk alternatives can be perceived by consumers as direct equivalents, or even more healthful alternatives to dairy milk. This commentary addresses the significant differences in nutrient content that may have implications for the intake of key nutrients in the case of direct substitutions. Furthermore, while there is a significant body of knowledge demonstrating the significant health benefits associated with dairy milk consumption and a small number of potentially negative associations, there is a paucity of data on the health benefits of plant‐based milk alternatives directly. A "health halo" may exist based on matching individual nutrients through fortification, lower energy levels, and the health properties of the unprocessed raw characterizing ingredients of plant‐based milk alternatives. This may mislead consumers regarding healthfulness. Similarly, environmental attributes based on volumes of production, without considering contribution to nutrients, may also skew consumer perception. Positioning of plant‐based milk alternatives in food‐based dietary guidelines, marketing, and personal recommendations should acknowledge the differences in nutritional, bioactive, and health properties between plant‐based milk alternatives and dairy milk to ensure appropriate adaptations are made to account for shortfalls in nutrients. [ABSTRACT FROM AUTHOR]

Background and Aim It has been reported that small intestinal bacterial overgrowth ( SIBO) may lead to false positive diagnoses of lactose malabsorption ( LM) in irritable bowel syndrome patients. The aim of this study was to determine the influence of SIBO on lactose hydrogen breath test ( HBT) results in these patients. Methods Diarrhea-predominant irritable bowel syndrome patients with abnormal lactose HBTs ingested a test meal containing 99m Tc and lactose. The location of the test meal and the breath levels of hydrogen were recorded simultaneously by scintigraphic scanning and lactose HBT, respectively. The increase in hydrogen concentration was not considered to be caused by SIBO if ≥ 10% of 99m Tc accumulated in the cecal region at the time or before of abnormal lactose HBT. Results LM was present in 84% (31/37) of irritable bowel syndrome patients. Twenty of these patients agreed to measurement of oro-cecal transit time. Only three patients (15%) with abnormal lactose HBT might have had SIBO. The median oro-cecal transit time between LM and lactose intolerance patients were 75 min and 45 min, respectively (Z = 2.545, P = 0.011). Conclusions Most of irritable bowel syndrome patients with an abnormal lactose HBT had LM. SIBO had little impact on the interpretation of lactose HBTs. The patients with lactose intolerance had faster small intestinal transit than LM patients. [ABSTRACT FROM AUTHOR]

Background Irritable bowel syndrome patients with diarrhoea ( IBS-D) often report intolerance to milk; however, the mechanism underlying these symptoms is unknown. Aim To assess the role of psychological factors, immune activation and visceral sensitivity on the development of lactose intolerance ( LI) in IBS-D patients. Methods Fifty-five IBS-D patients and 18 healthy controls ( HCs) with lactase deficiency underwent a 20-g lactose hydrogen breath test ( LHBT). Patients were categorised as lactose malabsorption ( LM; malabsorption only) or LI [malabsorption plus increase in total symptom score ( TSS). Measurements included (i) psychological status; (ii) enteric biopsies with quantification of mast cells ( MCs), T-lymphocytes and enterochromaffin cells; (iii) serum cytokines; (iv) rectal sensitivity before and after lactose ingestion. Results LI was more prevalent in IBS-D patients than HCs [25/55 (46%) vs. 3/18 (17%), P = 0.029]. IBS-D patients with LI had (i) higher levels of anxiety than those with LM ( P = 0.017) or HCs ( P = 0.006); (ii) increased mucosal MCs compared with LM ( P = 0.006) and HCs ( P < 0.001); (iii) raised serum TNF- α compared with LM ( P = 0.034) and HCs ( P < 0.001) and (iv) increased rectal sensitivity after lactose ingestion compared with LM ( P < 0.001) or HCs ( P < 0.001). Severity of abdominal symptoms after lactose ingestion was associated with the increase in visceral sensitivity after lactose intake ( r = 0.629, P < 0.001), MCs ( r = 0.650, P < 0.001) and anxiety ( r = 0.519, P < 0.001). Conclusions IBS-D patients with lactose intolerence are characterised by anxiety, mucosal immune activation and increased visceral sensitivity after lactose ingestion. The presence of these biomarkers may indicate an IBS phenotype that responds to dietary therapy and/or mast cell stabilisers (ClinicalTrials.gov Identifier: NCT01286597). [ABSTRACT FROM AUTHOR]

Background and Aims: There have been few reports on lactase deficiency (LD) and lactose intolerance (LI) in Malaysia, which has a peculiar mix of three distinct major Asian races—Malay, Chinese, and Indian. The aim of this study was to determine the prevalence of LD and LI in a young multiethnic Malaysian population. Methods: Lactase activity was measured with a 13CO2 lactose breath test using an infrared spectrometer. Each subject took 25 g of lactose naturally enriched in 13CO2 together with 250 mL of water after an overnight fast. Breath samples were collected at baseline and at 15‐min intervals for 180 min. Subjects were asked to report gastrointestinal (GI) symptoms following ingestion of the lactose test meal. Results: Of the 248 subjects tested, 216 (87.1%) were lactase deficient. We found no significant differences in the presentation of LD between gender and races. LD was found in 87.5% of males and 86.8% of females (P = 0.975) and in different races: Chinese (88.5%) versus Malay (83.1%) (P = 0.399), Indian (90.5%) versus Malay (P = 0.295), and Chinese versus Indian (P = 0.902). LI was diagnosed in only 49 (19.8%) subjects; 35 patients had diarrhea, while the remainder had at least two other GI symptoms after the lactose meal. Conclusion: The prevalence of LD was high in all three major ethnic groups—Malays, Chinese, and Indians. Ironically, the prevalence of LI was low overall. The aim of this study was to determine the prevalence of lactase deficiency (LD) and lactose intolerance (LI) in a young multi‐ethnic Malaysian population. The prevalence of LD was high in all three major ethnic groups–Malays, Chinese and Indians. The prevalence of LI, however, was low. [ABSTRACT FROM AUTHOR]

Diet therapy in disorders of gut–brain interaction (DGBI) is rapidly advancing, with accumulating evidence to support two innovative therapies—manipulation of dietary fibers and enzyme supplementation—that target specific DGBI pathophysiology and modulate digestion. Dietary fibers escape digestion in the upper gastrointestinal tract and can influence gut function by impacting digestion, improving laxation, and interacting with the microbiota. A more nuanced understanding of different fiber types and their ability to impact gut function in highly specific ways has shown that fibers can impact distinct gut symptoms and pathophysiology. By considering their functional characteristics of bulking, gel‐forming, and fermentability, restriction or supplementation of specific fibers can offer clinical value in DGBI. Similarly to fiber specificity, emerging evidence suggests that supplemental digestive enzymes may be targeted to known food triggers with consideration that enzymes are substrate specific. Limited evidence supports use of lactase to target lactose, and α‐galactosidase to target galacto‐oligosaccharides. Application of enzymes during manufacturing of food products may prove to be an additional strategy, although evidence is scant. Both innovative therapies may be utilized in isolation or in combination with other diet and nondiet therapies. Implementation can be guided by the principles that fiber modulation can be targeted to specific symptomology or requirement for alterations to gut function, and digestive enzymes can be targeted to known food triggers. This review aims to summarize recent literature of these two innovative concepts and provide practical suggestions for their implementation in clinical practice. [ABSTRACT FROM AUTHOR]