UNASSIGNED: Reduced activity of the sucrase-isomaltase (SI) enzyme can cause gastrointestinal symptoms. Biochemical measurement of SI activity in small intestinal biopsies is presently considered the gold standard for the diagnosis of SI deficiency, but this invasive test is not suitable as a routine diagnostic tool.
UNASSIGNED: To evaluate a 13C-sucrose-breath test (13CSBT) as a diagnostic tool for SI deficiency in an adult population.
UNASSIGNED: 13CSBT results were compared to sucrase activity measured in duodenal biopsies.
UNASSIGNED: Forty patients with gastrointestinal symptoms were included in the study, 4 of whom had celiac disease and the rest (n = 36) had normal histological findings. Nine patients (22.5%) had low sucrase activity measured using duodenal biopsies. No correlation was observed between enzymatic sucrase activity and the 13CSBT results. The 13CSBT-curves for the celiac patients versus patients with normal duodenal histology demonstrated that the patients with celiac disease were within the lower range of the distribution.
UNASSIGNED: We observed a mismatch between the 13CSBT results and the biochemically measured sucrase activity, suggesting that SI activity is not uniformly distributed throughout the small intestines. This methodological discrepancy should be acknowledged when diagnosing SI deficiency.

UNASSIGNED: Congenital sucrase-isomaltase deficiency (CSID) is a rare inherited carbohydrate malabsorption disorder caused by sucrase-isomaltase (SI) gene variants. In CSID, an autosomal recessively inherited disease, symptoms can also be seen in individuals with heterozygous mutations.
UNASSIGNED: The variant spectrum was evaluated retrospectively in individuals who presented with chronic diarrhea between 2014 and 2022 and had undergone genetic testing of the SI gene considering CSID due to diet-related complaints.
UNASSIGNED: Ten patients with chronic diarrhea were genetically evaluated with SI gene sequencing. In patients diagnosed with CSID and whose symptoms improved with enzyme replacement therapy, the genetic mutation zygosity was found to be heterozygous at a rate of 90%. In 10% of the patients, the mutation was homozygous. Limiting consuming sucrose and isomaltose foods reduced the patients\' complaints, but the symptoms did not disappear completely. With the initiation of sacrosidase enzyme replacement therapy, the patient\'s complaints completely disappeared.
UNASSIGNED: In CSID, defined as an autosomal recessive disease, clinical symptoms can also be seen in heterozygous cases previously described as carriers, and these patients also benefit from sacrosidase enzyme replacement therapy. In light of these findings, the autosomal recessive definition of CSID does not fully characterize the disease.What is Known:CSID is a rare inherited carbohydrate malabsorption disorder caused by sucrase-isomaltase gene variants.In congenital sucrase-isomaltase deficiency, an autosomal recessively inherited disorder, symptoms can also be seen in individuals with heterozygous mutations.What is new:Severe disease symptoms can also be seen in heterozygous cases, which were thought to be carriers because the disease was previously described as autosomal recessive.Sacrosidase enzyme replacement therapy also eliminates the disease symptoms in patients with heterozygous CSID mutations.This is the second study on sucrase-isomaltase enzyme deficiency pediatric groups in Türkiye and Europe.
This is the study to evaluate the congenital sucrase-isomaltase enzyme deficiency in chronic diarrhea cases covering adults and childhood in our country and the clinical features and treatment response characteristics of the variants detected in these patients.In addition, another aim of our study is that sucrase–isomaltase enzyme deficiency should be considered in the differential diagnosis and should be kept in mind, especially in cases with chronic diarrhea whose cause cannot be determined in childhood.

Background: Congenital sucrase-isomaltase deficiency (CSID) is an autosomal recessive inherited disease that leads to the maldigestion of disaccharides and is associated with mutation of the sucrase-isomaltase (SI) gene. Cases of CSID are not very prevalent in China or worldwide but are gradually being identified and reported. Case Presentation: We report a case involving a 14-month-old male who presented with failure to thrive that had begun after food diversification and was admitted for chronic diarrhea. We used a whole-exome sequencing (WES) approach to identify mutations in this patient\'s genome. WES revealed two novel heterozygous mutations in the SI gene, c.2626C > T (p.Q876*) and c.2872C > T (p.R958C), which were confirmed by Sanger DNA sequencing. With a strict sucrose- and starch-restricted diet, the patient\'s diarrhea was resolved, and he began to gain weight. Conclusions: We report a case of novel variants in the SI gene that caused CSID. This report provides valuable information for the clinical field, especially in China.

Patients with irritable bowel syndrome (IBS) frequently perceive eating food as a trigger to their gastrointestinal (GI) distress. Several factors involved in driving GI symptoms include malabsorption and fermentation of food substrates, gut microbiota alterations, nocebo and placebo response, and mast cell activation. Nutritional interventions require individualization based on the heterogeneity of symptoms as well as the risk for maladaptive eating patterns that present in those with IBS. Despite the variety of interventions marketed to individuals with IBS, the low Fermentable, Oligo-, Di-Mono-saccharide, and Polyol diet has the most evidence for efficacy in symptom management.

Chronic diarrhoea affects up to 14% of adults, it impacts on quality of life and its cause can be variable. Patients with chronic diarrhoea are presented with a plethora of dietary recommendations, often sought from the internet or provided by those who are untrained or inexperienced. In this review, we summarise the possible causes of chronic diarrhoea that can be managed by diet, the symptom improvement and quality of life benefits but also the potential risks of such dietary treatments. Clinicians need to consider both the benefits and risks of dietary treatments before making dietary recommendations to manage chronic diarrhoea. The pivotal role that dietitians have in ensuring optimal symptom improvement without jeopardising nutritional and overall health is discussed.

Disaccharidase assay is used for assessing carbohydrate intolerance in children, but its usefulness in adults is not known. The aim of this study is to assess the prevalence of disaccharidase deficiency in patients with unexplained gastrointestinal symptoms.
A retrospective review of adults with chronic (> 1 year) abdominal symptoms and negative imaging and endoscopy/colonoscopy and who completed bowel symptom questionnaire and duodenal biopsy for lactase, maltase, sucrase, and palatinase was performed. A subset also underwent 25 g lactose breath test (LBT).
One hundred twenty patients (females = 83) were evaluated, of whom 48 also underwent LBT. Fifty-six (46.7%) patients had enzyme deficiency; 44 (36.7%) had single (either lactase or maltase), 1 had 3 enzyme deficiencies, 11 (9.2 %) had all 4 disaccharidase enzyme (pan-disaccharidase) deficiency, and 64 (53.0%) had normal enzyme levels. Baseline prevalence and severity of 11 gastrointestinal symptoms were similar between normal and single enzyme deficiency groups. The sensitivity and specificity of LBT was 78.3% and 72.0%, respectively and overall agreement with lactase deficiency was 75.0%.
Isolated disaccharidase deficiency occurs in adults, usually lactase and rarely maltase, and pan-disaccharidase deficiency is rare. Baseline symptoms or its severity did not predict enzyme deficiency.

Patients with irritable bowel syndrome (IBS) frequently have meal-related symptoms and can recognize specific trigger foods. Lactose intolerance is a well-established carbohydrate malabsorption syndrome that causes symptoms similar to IBS such as bloating, abdominal pain, and diarrhea. However, the prevalence of sucrase-isomaltase deficiency (SID) in this population is poorly defined. SID is a condition in which sucrase-isomaltase, an enzyme produced by brush border of small intestine to metabolize sucrose, is deficient. Just like lactase deficiency, SID causes symptoms of maldigestion syndromes including abdominal pain, bloating, gas, and diarrhea. In this study, we aim to determine the prevalence of SID in patients with presumed IBS-D/M and characterize its clinical presentation.
Patients with a presumed diagnosis of IBS-D/M based on symptoms of abdominal pain, diarrhea, and/or bloating who underwent esophagogastroduodenoscopy with duodenal biopsies and testing for disaccharidase deficiency were included. Patients with a history of inflammatory bowel disease, gastrointestinal malignancy, or celiac disease were excluded. Odds ratio was calculated for abdominal pain, diarrhea, and bloating in patients with versus without SID.
A total of 31 patients with clinical suspicion for IBS-D/M were included with a median age of 46 years (IQR 30.5-60) and with 61% females. SID was present in 35% of patients. Among patients with SID, 63.6% had diarrhea, 45.4% had abdominal pain, and 36.4% had bloating. Patients with SID were less likely than controls to have abdominal pain (OR 0.16, 95% CI 0.03-0.81, p = 0.04) although no difference in diarrhea or bloating was found. Only two patients with SID underwent sucrose breath testing of which only one had a positive result. However, this patient also had a positive glucose breath test and may have had small intestinal bacterial overgrowth as a confounder.
SID was found in 35% of patients with presumed IBS-D/M and should be considered in the differential diagnosis of patients presenting with abdominal pain, diarrhea, or bloating. Further studies should better characterize the clinical features of SID and investigate the effects of dietary modification in this group of patients.

Disaccharidase (DS) activity in duodenal biopsy specimens is the gold standard for diagnosing DS deficiency. We investigated strategies to reduce the need for DS testing and whether clinical or histopathologic factors predict DS deficiency.
A retrospective chart review analyzed 1,678 DS results in children, biopsy indication(s), and duodenal histopathology.
One or more DSs were abnormal in 42.8%. Sufficient lactase predicted sucrase, palatinase, and maltase sufficiency (negative predictive value 97.7%). Three patients had sucrase-isomaltase deficiency (0.2%). DS deficiency was more common in biopsy specimens for positive celiac serology (78.0%). Villous blunting, intraepithelial lymphocytosis, and active inflammation predicted DS deficiency; a combination of any two had an 81.4% positive predictive value.
Utilization could be reduced by only testing cases with normal duodenal histopathology and ongoing clinical suspicion for DS deficiency after reviewing pathology. In cases with suspected celiac disease and/or mucosal injury, DS deficiency is common and likely secondary, limiting test utility.

Background and Aims: Patients with a disaccharidase deficiency typically present with abdominal discomfort and often with diarrhea. However, disaccharidase deficiency is often overlooked as a cause of these complaints. Therefore, we sought to determine the prevalence of lactase and sucrase deficiencies in a pediatric population undergoing diagnostic esophagogastroduodenoscopy (EGD) and to describe disaccharidase testing practices among pediatric gastroenterologists. Methods: Endoscopic records from patients undergoing diagnostic EGD and disaccharidase analysis (DA) were retrospectively reviewed. Diagnostic EGDs performed over a 5-year period (2010 through 2014) at a freestanding endoscopy center serving 13 pediatric gastroenterologists were assessed. Demographic and clinical data on patients were collected and grouped; patients with primary sucrase-isomaltase deficiency (SID) were the main focus. The data were stratified by the physician performing the procedures. Results: Over the 5-year study period, 5368 EGDs were performed, with abdominal pain as the primary indication in 3235 cases (60.2%). DAs were performed on 963 patients (17.9% of the total cohort; 29.8% of those with abdominal pain). Lactase deficiencies, sucrase deficiencies, and primary SID were found in 44.7%, 7.6%, and 3.5% of DAs, respectively. The number of DAs performed varied widely among physicians, ranging from 1.6% to 64.5% of EGDs evaluating patients with abdominal pain. Univariate regression analysis revealed significant correlations between the number of DAs performed and the number of SID and lactase deficiencies found (P<.001 for both). Conclusion: Rates of DAs vary widely among pediatric gastroenterologists performing diagnostic EGDs in children with abdominal pain. Physician education and clinical practice guidelines regarding the use of DAs are warranted.

Feijoa sellowiana fruit has been shown to possess various biological activities, such as anti-bacterial and anti-cancer properties, in a variety of cellular models, but its activity on human intestinal epithelial cells has never been tested. The purpose of this study was to investigate the effects of the acetonic extract of F. sellowiana fruits on the viability, membrane peroxidation, disaccharidases activities and proliferation of in vitro models of human intestinal epithelial cells. To obtain this goal, Caco-2 and HT-29 cells were exposed to the acetonic extract for 24 h. Cell proliferation, viability, lactase and sucrase-isomaltase activity and H2 O2 -induced membrane lipid peroxidation were tested. We found that, compared to control conditions, the acetonic extract significantly increased lactase and sucrase-isomaltase activity in Caco-2, but not HT-29, cells, decreased proliferation, had no effects on viability and restored lipid peroxidation in both cell models. This study suggests that the acetonic extract improves lactase and sucrase-isomaltase activity, inhibits cell proliferation, have no cytotoxic effects and prevent lipid peroxidation of intestinal epithelial cells. These effects may be exploited in case of disaccharidases deficit and also as an adjuvant treatment of diseases related to oxidative stress. Copyright © 2016 John Wiley & Sons, Ltd.