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Current Opinion in Gastroenterology Mar 2020Disaccharidase testing, as applied to the evaluation of gastrointestinal disturbances is available but it is not routinely considered in the diagnostic work-up. The... (Review)
Review
PURPOSE OF REVIEW
Disaccharidase testing, as applied to the evaluation of gastrointestinal disturbances is available but it is not routinely considered in the diagnostic work-up. The purpose of this review was to determine if disaccharidase testing is clinically useful and to consider how the results could alter patient management.
RECENT FINDINGS
Indicate that carbohydrate maldigestion could contribute functional bowel disorders and negatively impact the fecal microbiome. Diagnostic techniques include enzyme activity assays performed on random endoscopically obtained small intestinal biopsies, immunohistochemistry, stable isotope tracer and nonenriched substrate load breath testing, and genetic testing for mutations. More than 40 sucrase--isomaltase gene variants coding for defective or reduced enzymatic activity have been reported and deficiency conditions are more common than previously thought.
SUMMARY
The rationale for disaccharidase activity testing relates to a need to fully assess unexplained recurrent abdominal discomfort and associated symptoms. All disaccharidases share the same basic mechanism of mucosal expression and deficiency has far reaching consequences. Testing for disaccharidase expression appears to have an important role in symptom evaluation, but there are accuracy and logistical issues that should be considered. It is likely that specific recommendations for patient management, dietary modification, and enzyme supplementation would come from better testing methods.
Topics: Disaccharidases; Fermentation; Gastrointestinal Diseases; Gastrointestinal Microbiome; Humans; Malabsorption Syndromes
PubMed: 31990709
DOI: 10.1097/MOG.0000000000000614 -
Critical Reviews in Food Science and... Aug 2011Concern exists that increasing fructose consumption, particularly in the form of high-fructose corn syrup, is resulting in increasing rates of fructose intolerance and... (Review)
Review
Concern exists that increasing fructose consumption, particularly in the form of high-fructose corn syrup, is resulting in increasing rates of fructose intolerance and aggravation of clinical symptoms in individuals with irritable bowel syndrome. Most clinical trials designed to test this hypothesis have used pure fructose, a form not commonly found in the food supply, often in quantities and concentrations that exceed typical fructose intake levels. In addition, the amount of fructose provided in tests for malabsorption, which is thought to be a key cause of intolerance, often exceeds the normal physiological absorption capacity for this sugar. To help health professionals accurately identify and treat this condition, this article reviews clinical data related to understanding fructose malabsorption and intolerance (i.e., malabsorption that manifests with symptoms) relative to usual fructose and other carbohydrate intake. Because simultaneous consumption of glucose attenuates fructose malabsorption, information on the fructose and glucose content of foods, beverages, and ingredients representing a variety of food categories is provided.
Topics: Beverages; Breath Tests; Clinical Trials as Topic; Dietary Carbohydrates; Eating; Fructose; Fructose Intolerance; Glucose; Humans; Malabsorption Syndromes; Sweetening Agents
PubMed: 21793722
DOI: 10.1080/10408398.2011.566646 -
Deutsches Arzteblatt International Nov 2013Adverse food reactions (AFR) have has recently attracted increased attention from the media and are now more commonly reported by patients. Its classification,... (Review)
Review
BACKGROUND
Adverse food reactions (AFR) have has recently attracted increased attention from the media and are now more commonly reported by patients. Its classification, diagnostic evaluation, and treatment are complex and present a considerable challenge in clinical practice. Non-immune-mediated types of food intolerance have a cumulative prevalence of 30% to 40%, while true (immune-mediated) food allergies affect only 2% to 5% of the German population.
METHOD
We selectively searched the literature for pertinent publications on carbohydrate malabsorption, with special attention to published guidelines and position papers.
RESULTS
Carbohydrate intolerance can be the result of a rare, systemic metabolic defect (e.g., fructose intolerance, with a prevalence of 1 in 25,000 persons) or of gastrointestinal carbohydrate malabsorption. The malabsorption of simple carbohydrates is the most common type of non-immune-mediated food intolerance, affecting 20% to 30% of the European population. This condition is caused either by deficient digestion of lactose or by malabsorption of fructose and/or sorbitol. Half of all cases of gastrointestinal carbohydrate intolerance have nonspecific manifestations, with a differential diagnosis including irritable bowel syndrome, intolerance reactions, chronic infections, bacterial overgrowth, drug side effects, and other diseases. The diagnostic evaluation includes a nutritional history, an H2 breath test, ultrasonography, endoscopy, and stool culture.
CONCLUSION
The goals of treatment for carbohydrate malabsorption are to eliminate the intake of the responsible carbohydrate substance or reduce it to a tolerable amount and to assure the physiological nutritional composition of the patient's diet. In parallel with these goals, the patient should receive extensive information about the condition, and any underlying disease should be adequately treated.
Topics: Breath Tests; Carbohydrate Metabolism, Inborn Errors; Diagnosis, Differential; Dietary Carbohydrates; Endoscopy, Gastrointestinal; Feces; Humans; Malabsorption Syndromes; Medical History Taking; Ultrasonography
PubMed: 24300825
DOI: 10.3238/arztebl.2013.0775 -
Food and Nutrition Bulletin Mar 2015Environmental enteric dysfunction (EED) refers to an incompletely defined syndrome of inflammation, reduced absorptive capacity, and reduced barrier function in the... (Review)
Review
BACKGROUND
Environmental enteric dysfunction (EED) refers to an incompletely defined syndrome of inflammation, reduced absorptive capacity, and reduced barrier function in the small intestine. It is widespread among children and adults in low- and middle-income countries. Understanding of EED and its possible consequences for health is currently limited.
OBJECTIVE
A narrative review of the current understanding of EED: epidemiology, pathogenesis, therapies, and relevance to child health.
METHODS
Searches for key papers and ongoing trials were conducted using PUBMED 1966-June 2014; ClinicalTrials.gov; the WHO Clinical Trials Registry; the Cochrane Library; hand searches of the references of retrieved literature; discussions with experts; and personal experience from the field.
RESULTS
EED is established during infancy and is associated with poor sanitation, certain gut infections, and micronutrient deficiencies. Helicobacter pylori infection, small intestinal bacterial overgrowth (SIBO), abnormal gut microbiota, undernutrition, and toxins may all play a role. EED is usually asymptomatic, but it is important due to its association with stunting. Diagnosis is frequently by the dual sugar absorption test, although other biomarkers are emerging. EED may partly explain the reduced efficacy of oral vaccines in low- and middle-income countries and the increased risk of serious infection seen in children with undernutrition.
CONCLUSIONS
Despite its potentially significant impacts, it is currently unclear exactly what causes EED and how it can be treated or prevented. Ongoing trials involve nutritional supplements, water and sanitation interventions, and immunomodulators. Further research is needed to better understand this condition, which is of likely crucial importance for child health and development in low- and middle-income settings.
Topics: Adult; Bacterial Infections; Blind Loop Syndrome; Child, Preschool; Environment; Growth Disorders; Humans; Infant; Inflammation; Intestinal Diseases; Intestines; Malabsorption Syndromes; Poverty; Sanitation
PubMed: 25902619
DOI: 10.1177/15648265150361S113 -
Molecular Aspects of Medicine Feb 2017The proton-coupled folate transporter (PCFT-SLC46A1) is the mechanism by which folates are absorbed across the brush-border membrane of the small intestine. The... (Review)
Review
The proton-coupled folate transporter (PCFT-SLC46A1) is the mechanism by which folates are absorbed across the brush-border membrane of the small intestine. The transporter is also expressed in the choroid plexus and is required for transport of folates into the cerebrospinal fluid. Loss of PCFT function, as occurs in the autosomal recessive disorder "hereditary folate malabsorption" (HFM), results in a syndrome characterized by severe systemic and cerebral folate deficiency. Folate-receptor alpha (FRα) is expressed in the choroid plexus, and loss of function of this protein, as also occurs in an autosomal recessive disorder, results solely in "cerebral folate deficiency" (CFD), the designation for this disorder. This paper reviews the current understanding of the functional and structural properties and regulation of PCFT, an electrogenic proton symporter, and contrasts PCFT properties with those of the reduced folate carrier (RFC), an organic anion antiporter, that is the major route of folate transport to systemic tissues. The clinical characteristics of HFM and its treatment, based upon the thirty-seven known cases with the clinical syndrome, of which thirty have been verified by genotype, are presented. The ways in which PCFT and FRα might interact at the level of the choroid plexus such that each is required for folate transport from blood to cerebrospinal fluid are considered along with the different clinical presentations of HFM and CFD.
Topics: Animals; Biological Transport; Folic Acid Deficiency; Humans; Intestinal Absorption; Malabsorption Syndromes; Models, Molecular; Proton-Coupled Folate Transporter
PubMed: 27664775
DOI: 10.1016/j.mam.2016.09.002 -
Postgraduate Medical Journal Apr 1999Hypokalaemic paralysis is a relatively uncommon but potentially life-threatening clinical syndrome. If recognised and treated appropriately, patients recover without any... (Review)
Review
Hypokalaemic paralysis is a relatively uncommon but potentially life-threatening clinical syndrome. If recognised and treated appropriately, patients recover without any clinical sequellae. The syndrome of hypokalaemic paralysis represents a heterogeneous group of disorders characterised clinically by hypokalaemia and acute systemic weakness. Most cases are due to familial or primary hypokalaemic periodic paralysis; sporadic cases are associated with numerous other conditions including barium poisoning, hyperthyroidism, renal disorders, certain endocrinopathies and gastrointestinal potassium losses. The age of onset, race, family history, medications, and underlying disease states can help in identifying the cause of hypokalaemic paralysis. Initial therapy of the patient with hypokalaemic paralysis includes potassium replacement and search for underlying aetiology. Further management depends on the aetiology of hypokalaemia, severity of symptoms, and duration of disease. This review presents the differential diagnosis for hypokalaemic paralysis and discusses management of the syndrome.
Topics: Acidosis, Renal Tubular; Acute Disease; Adult; Algorithms; Barium; Chromosome Aberrations; Chromosomes, Human, Pair 1; Diagnosis, Differential; Female; Humans; Hyperaldosteronism; Hyperkalemia; Hypokalemic Periodic Paralysis; Malabsorption Syndromes; Male; Thyrotoxicosis
PubMed: 10715756
DOI: 10.1136/pgmj.75.882.193 -
Nutrients Mar 2021Carbohydrate malabsorption is a frequent digestive problem associated with abdominal pain, bloating and diarrhea. Hydrogen breath testing (BT) represents the most... (Review)
Review
BACKGROUND
Carbohydrate malabsorption is a frequent digestive problem associated with abdominal pain, bloating and diarrhea. Hydrogen breath testing (BT) represents the most reliable and validated diagnostic technique. The aim of this manuscript was to clarify the usefulness of BTs in the nutritional management of these disorders.
METHODS
A literature search for BT related to carbohydrate malabsorption was carried out using the online databases of Pubmed, Medline and Cochrane.
RESULTS
Lactose BT showed good sensitivity and optimal specificity for lactose malabsorption. However, an accurate diagnosis of lactose intolerance should require blind lactose challenge although this method is difficult to utilize in clinical practice. Regarding dose-depending fructose and sorbitol malabsorption, BTs could not add diagnostic advantage compared with a direct dietary intervention. In addition, carbohydrates are fundamental components of fermentable oligo-, di- and monosaccharides and polyols (FODMAPs). Before starting a low FODMAP diet, lactose BT should be suggested in a population with low prevalence of hypolactasia.
CONCLUSIONS
BTs represent a valid and noninvasive technique in many digestive conditions. Regarding the management of carbohydrate intolerance, lactose BT can be recommended with some limitations. No sufficient evidence is available about the usefulness of BTs for other sugars in clinical practice.
Topics: Breath Tests; Carbohydrate Metabolism; Humans; Hydrogen; Malabsorption Syndromes
PubMed: 33802839
DOI: 10.3390/nu13030974 -
International Journal of Clinical... Feb 2018In exocrine pancreatic insufficiency (EPI), the quantity and/or activity of pancreatic digestive enzymes are below the levels required for normal digestion, leading to... (Review)
Review
AIMS
In exocrine pancreatic insufficiency (EPI), the quantity and/or activity of pancreatic digestive enzymes are below the levels required for normal digestion, leading to maldigestion and malabsorption. Diagnosis of EPI is often challenging because the characteristic signs and symptoms overlap with those of other gastrointestinal conditions. Additionally, there is no single convenient, or specific diagnostic test for EPI. The aim of this review is to provide a framework for differential diagnosis of EPI vs other malabsorptive conditions.
METHODS
This is a non-systematic narrative review summarising information pertaining to the aetiology, diagnosis and management of EPI.
RESULTS
Exocrine pancreatic insufficiency may be caused by pancreatic disorders, including chronic pancreatitis, cystic fibrosis, pancreatic resection and pancreatic cancer. EPI may also result from extra-pancreatic conditions, including coeliac disease, Zollinger-Ellison syndrome and gastric surgery. Timely and accurate diagnosis of EPI is important, as delays in treatment prolong maldigestion and malabsorption, with potentially serious consequences for malnutrition, overall health and quality of life. Symptoms of EPI are non-specific; therefore, a high index of clinical suspicion is required to make a correct diagnosis.
Topics: Diagnosis, Differential; Exocrine Pancreatic Insufficiency; Humans; Malabsorption Syndromes; Quality of Life
PubMed: 29405509
DOI: 10.1111/ijcp.13066 -
Digestion 2014Longtime chronic malabsorption may among other things cause a lack of liposoluble vitamins. Vitamin E deficiency can lead to formation of lipofuscin aggregates. Its... (Review)
Review
BACKGROUND/AIMS
Longtime chronic malabsorption may among other things cause a lack of liposoluble vitamins. Vitamin E deficiency can lead to formation of lipofuscin aggregates. Its deficiency is also associated with an increased lipofuscinosis of the bowel, i.e. brown bowel syndrome.
METHODS
Systematic research via Medline on brown bowel syndrome, lipofuscinosis, and vitamin E deficiency was performed. We combined our own clinical experience and a review of the literature for this paper. Its goal is to inform about the possible consequences of severe malabsorption and brown bowel syndrome.
RESULTS
Systematic data about the occurrence of severe malabsorption and brown bowel syndrome are rare. Only about 27 scientific reports can be found on this subject. Brown bowel syndrome is found mostly in conjunction with vitamin E deficiency and lipofuscinosis of the bowel. The clinical findings are caused by both malabsorption and lipofuscinosis. Case reports show a therapeutic effect of vitamin E.
CONCLUSION
Vitamin deficiency caused by longtime chronic malabsorption can lead to the development of brown bowel syndrome, which is seen as the expression of lipofuscinosis of the bowel, and can cause further clinical disorders. Patients with malabsorption should therefore be monitored regarding their vitamin E levels.
Topics: Chronic Disease; Gastrointestinal Neoplasms; Humans; Lipofuscin; Malabsorption Syndromes; Vitamin E; Vitamin E Deficiency
PubMed: 24503572
DOI: 10.1159/000357228 -
American Journal of Physiology.... Feb 2011Fructose is a hexose sugar that is being increasingly consumed in its monosaccharide form. Patients who exhibit fructose malabsorption can present with gastrointestinal... (Review)
Review
Fructose is a hexose sugar that is being increasingly consumed in its monosaccharide form. Patients who exhibit fructose malabsorption can present with gastrointestinal symptoms that include chronic diarrhea and abdominal pain. However, with no clearly established gastrointestinal mechanism for fructose malabsorption, patient analysis by the proxy of a breath hydrogen test (BHT) is controversial. The major transporter for fructose in intestinal epithelial cells is thought to be the facilitative transporter GLUT5. Consistent with a facilitative transport system, we show here by analysis of past studies on healthy adults that there is a significant relationship between fructose malabsorption and fructose dose (r = 0.86, P < 0.001). Thus there is a dose-dependent and limited absorption capacity even in healthy individuals. Changes in fructose malabsorption with age have been observed in human infants, and this may parallel the developmental regulation of GLUT5 expression. Moreover, a GLUT5 knockout mouse has displayed the hallmarks associated with profound fructose malabsorption. Fructose malabsorption appears to be partially modulated by the amount of glucose ingested. Although solvent drag and passive diffusion have been proposed to explain the effect of glucose on fructose malabsorption, this could possibly be a result of the facilitative transporter GLUT2. GLUT5 and GLUT2 mRNA have been shown to be rapidly upregulated by the presence of fructose and GLUT2 mRNA is also upregulated by glucose, but in humans the distribution and role of GLUT2 in the brush border membrane are yet to be definitively decided. Understanding the relative roles of these transporters in humans will be crucial for establishing a mechanistic basis for fructose malabsorption in gastrointestinal patients.
Topics: Absorption; Aging; Animals; Biological Transport; Breath Tests; Exhalation; Fructose; Glucose; Glucose Transporter Type 2; Glucose Transporter Type 5; Humans; Hydrogen; Intestinal Mucosa; Malabsorption Syndromes; Mutation
PubMed: 21148401
DOI: 10.1152/ajpgi.00457.2010