Evaluation of liquid yeast-derived sucrase enzyme replacement in patients with sucrase-isomaltase deficiency

Diet management in congenital diarrheas and enteropathies - general concepts and disease-specific approach, a narrative review

Congenital diarrheas and enteropathies (CODE) are a group of rare, heterogenous, monogenic disorders that lead to chronic diarrhea in infancy. Definitive treatment is rarely available, and supportive treatment is the mainstay. Nutritional management in the form of either specialized formulas, restrictive diet, or parenteral nutrition support in CODE with poor enteral tolerance is the cornerstone of CODE treatment and long-term growth. The evidence to support the use of specific diet regimens and nutritional approaches in most CODE disorders is limited due to the rarity of these diseases and the scant published clinical experience. The goal of this review was to create a comprehensive guide for nutritional management in CODE, based on the currently available literature, disease mechanism, and the PediCODE group experience. Enteral diet management in CODE can be divided into 3 distinct conceptual frameworks: nutrient elimination, nutrient supplementation, and generalized nutrient restriction. Response to nutrient elimination or supplementation can lead to resolution or significant improvement in the chronic diarrhea of CODE and resumption of normal growth. This pattern can be seen in CODE due to carbohydrate malabsorption, defects in fat absorption, and occasionally in electrolyte transport defects. In contrast, general diet restriction is mainly supportive. However, occasionally it allows parenteral nutrition weaning or reduction over time, mainly in enteroendocrine defects and rarely in epithelial trafficking and polarity defects. Further research is required to better elucidate the role of diet in the treatment of CODE and the appropriate diet management for each disease.

The patient journey to diagnosis and treatment of congenital sucrase-isomaltase deficiency

Purpose

Congenital sucrase-isomaltase deficiency (CSID) is a rare genetic disorder characterized by a deficiency of the sucrase-isomaltase (SI) enzyme complex within the brush border membrane of the small intestine. Mutations in the SI gene result in abnormal synthesis and/or incorrect transport of the SI enzyme. Patients with CSID generally have reduced sucrase activity, but levels of isomaltase activity range from absent to almost normal. This study sought to better understand the experience of patients with CSID prior to, during, and after their diagnosis and its subsequent treatment with sacrosidase.

Methods

This was a cross-sectional interview study conducted in conjunction with a longitudinal, observational study of US patients prescribed and taking sacrosidase for at least three consecutive months as treatment for CSID. The observational study included both children and adults.

Results

This qualitative interview study explored the experiences of 43 adult and pediatric patients (n = 8 adults and n = 35 children/adolescents) with CSID pre-, during, and post-diagnosis. Findings suggest that a CSID diagnosis is particularly problematic given the disparate range of more commonly understood gastrointestinal (GI) disorders. After diagnosis and treatment with sacrosidase, participants reported considerable improvement in symptoms and health-related quality of life (HRQL), yet symptoms persist that continue to affect daily life, indicating areas of potential unmet need.

Conclusion

Educating clinicians about CSID may help improve the overall diagnosis experience. As this research is the first of its kind in CSID, additional research, qualitative and quantitative, will be important to furthering the understanding of HRQL impact and unmet need experienced by this population and identifying ways to best meet those needs.

From Birth and Throughout Life: Fungal Microbiota in Nutrition and Metabolic Health

The human gastrointestinal tract is home to a vibrant, diverse ecosystem of prokaryotic and eukaryotic microorganisms. The gut fungi (mycobiota) have recently risen to prominence due to their ability to modulate host immunity. Colonization of the gut occurs through a combination of vertical transmission from the maternal mycobiota and environmental and dietary exposure. Data from human and animal studies demonstrate that nutrition strongly affects the mycobiota composition and that changes in the fungal communities can aggravate metabolic diseases. The mechanisms pertaining to the mycobiota's influence on host health, pathology, and resident gastrointestinal communities through intrakingdom, transkingdom, and immune cross talk are beginning to come into focus, setting the stage for a new chapter in microbiota-host interactions. Herein, we examine the inception, maturation, and dietary modulation of gastrointestinal and nutritional fungal communities and inspect their impact on metabolic diseases in humans.

Hypomorphic SI genetic variants are associated with childhood chronic loose stools

OBJECTIVE

The SI gene encodes the sucrase-isomaltase enzyme, a disaccharidase expressed in the intestinal brush border. Hypomorphic SI variants cause recessive congenital sucrase-isomaltase deficiency (CSID) and related gastrointestinal (GI) symptoms. Among children presenting with chronic, idiopathic loose stools, we assessed the prevalence of CSID-associated SI variants relative to the general population and the relative GI symptom burden associated with SI genotype within the study population.

METHODS

A prospective study conducted at 18 centers enrolled 308 non-Hispanic white children ≤18 years old who were experiencing chronic, idiopathic, loose stools at least once per week for >4 weeks. Data on demographics, GI symptoms, and genotyping for 37 SI hypomorphic variants were collected. Race/ethnicity-matched SI data from the Exome Aggregation Consortium (ExAC) database was used as the general population reference.

RESULTS

Compared with the general population, the cumulative prevalence of hypomorphic SI variants was significantly higher in the study population (4.5% vs. 1.3%, P < .01; OR = 3.5 [95% CI: 6.1, 2.0]). Within the study population, children with a hypomorphic SI variant had a more severe GI symptom burden than those without, including: more frequent episodes of loose stools (P < .01), higher overall stool frequency (P < .01), looser stool form (P = .01) and increased flatulence (P = .02).

CONCLUSION

Non-Hispanic white children with chronic idiopathic loose stools have a higher prevalence of CSID-associated hypomorphic SI variants than the general population. The GI symptom burden was greater among the study subjects with a hypomorphic SI variant than those without hypomorphic SI variants.

Relationships among Dietary Intakes and Persistent Gastrointestinal Symptoms in Patients Receiving Enzyme Treatment for Genetic Sucrase-Isomaltase Deficiency

BACKGROUND

Sucrose-isomaltase deficiency (SID) remains underdiagnosed. Absent or reduced enzyme activity promotes diarrhea, abdominal bloating, and flatulence from undigested and malabsorbed disaccharides. Frequency and severity of gastrointestinal symptoms may be associated with the type of carbohydrates consumed.

OBJECTIVE

To characterize the dietary intakes of patients treated with sacrosidase (Sucraid; QOL Medical) for SID and determine relationships between type of carbohydrates, sacrosidase dose, and gastrointestinal symptoms.

DESIGN

A prospective 30-day observational study.

PARTICIPANTS/SETTING

Forty-nine patients treated with sacrosidase for ≥3 months were recruited from the enzyme manufacturer's nationwide clinical database between November 2014 and August 2015.

MAIN OUTCOME MEASURES

Dietary energy and nutrient intakes reported during 24-hour diet recall interviews, frequency and severity of gastrointestinal (GI) symptoms, and sacrosidase dose.

STATISTICAL ANALYSES PERFORMED

Relationships between nutrient intakes, sacrosidase dose, and GI symptoms were evaluated using Spearman ρ correlation coefficients.

RESULTS

Sacrosidase dose averaged 5.2±3.1 mL/day. Participants reported 1.3±0.9 bowel movements daily. Having less frequent GI symptoms was associated with higher sacrosidase intake. Energy intakes averaged 1,562.5±411.5 kcal/day in children, 1,964.7±823.6 kcal/day in adolescents, and 1,952.6±546.5 kcal/day in adults. Macronutrient composition averaged 44% carbohydrate, 39% fat, and 17% protein. Average carbohydrate composition was 35% starch, 8% fiber, and 59% sugars. Sucrose and fructose intakes were not associated with GI symptoms. Lactose intake was associated with diarrhea. Maltose intake was associated with nausea, distension, and reflux.

CONCLUSIONS

Intakes were lower in carbohydrates and higher in fat compared with the Acceptable Macronutrient Distribution Ranges. Sucrose and fructose intakes were not associated with GI symptoms. Higher maltose and lactose intakes were associated with GI symptom frequency and severity. These findings provide evidence to guide nutrition counseling for patients treated for SID.

Improved Starch Digestion of Sucrase-deficient Shrews Treated With Oral Glucoamylase Enzyme Supplements

BACKGROUND AND OBJECTIVE

Although named because of its sucrose hydrolytic activity, this mucosal enzyme plays a leading role in starch digestion because of its maltase and glucoamylase activities. Sucrase-deficient mutant shrews, Suncus murinus, were used as a model to investigate starch digestion in patients with congenital sucrase-isomaltase deficiency.Starch digestion is much more complex than sucrose digestion. Six enzyme activities, 2 α-amylases (Amy), and 4 mucosal α-glucosidases (maltases), including maltase-glucoamylase (Mgam) and sucrase-isomaltase (Si) subunit activities, are needed to digest starch to absorbable free glucose. Amy breaks down insoluble starch to soluble dextrins; mucosal Mgam and Si can either directly digest starch to glucose or convert the post-α-amylolytic dextrins to glucose. Starch digestion is reduced because of sucrase deficiency and oral glucoamylase enzyme supplement can correct the starch maldigestion. The aim of the present study was to measure glucogenesis in suc/suc shrews after feeding of starch and improvement of glucogenesis by oral glucoamylase supplements.

METHODS

Sucrase mutant (suc/suc) and heterozygous (+/suc) shrews were fed with C-enriched starch diets. Glucogenesis derived from starch was measured as blood C-glucose enrichment and oral recombinant C-terminal Mgam glucoamylase (M20) was supplemented to improve starch digestion.

RESULTS

After feedings, suc/suc and +/suc shrews had different starch digestions as shown by blood glucose enrichment and the suc/suc had lower total glucose concentrations. Oral supplements of glucoamylase increased suc/suc total blood glucose and quantitative starch digestion to glucose.

CONCLUSIONS

Sucrase deficiency, in this model of congenital sucrase-isomaltase deficiency, reduces blood glucose response to starch feeding. Supplementing the diet with oral recombinant glucoamylase significantly improved starch digestion in the sucrase-deficient shrew.

Improving the stability and activity of oral therapeutic enzymes-recent advances and perspectives

Exogenous, orally-administered enzymes are currently in clinical use or under development for the treatment of pathologies, such as celiac disease and phenylketonuria. However, the administration of therapeutic enzymes via the oral route remains challenging due to potential inactivation of these fragile macromolecular entities in the harsh environment of the gastrointestinal tract. Enzymes are particularly sensitive because both proteolysis and unfolding can lead to their inactivation. Current efforts to overcome these shortcomings involve the application of gastro-resistant delivery systems and the modification of enzyme structures by polymer conjugation or protein engineering. This perspective manuscript reviews and critically discusses recent progress in the oral delivery of therapeutic enzymes, whose substrate is localized in the gastrointestinal tract.

Tinospora cordifolia, a novel source of extracellular disaccharidases, useful for human disaccharidase deficiency therapy

Disaccharide intolerance is the inability to digest certain carbohydrates due to a lack of one or more intestinal disaccharidases (e.g., lactase, maltase, isomaltase and sucrase). Symptoms include diarrhea, abdominal distention and flatulence. Management of the disorder by external enzymes supplementation has not yet been attempted. We report that the medicinal plant Tinospora cordifolia contains substantial amounts of all disaccharidases required for intestinal digestion of carbohydrates. The plant is also a rich source of saccharifying amylase. We recovered (units/100 g fresh stem) amylase: 49,000+500, maltase: 400+50, isomaltase: 130+50, sucrase: 4500+500, acid lactase: 350+30, cellobiase: 35+10 and trehalase: 40+10 by buffer extraction of the blended stem. Crude enzymes in the forms of stem powder, lyophilized aqueous extract and ethanol precipitated protein were found to be stable. Disaccharidases were optimally active at 50 (0) C in the pH range of 4-5. Lactase was an acid lactase similar to the type linked with human lactose intolerance. Enzymes were catalytically stable in the pH range of 2-7 and temperature range of up to 40 (0) C. T. cordifolia enzyme was non-toxic up to a dose of 200 mg protein/kg body weight.

Ranitidine induces inhibition and structural changes in sucrase

Ranitidine is an antagonist of histamine-2 (H(2)) receptor. It is employed to treat peptic ulcer and other conditions in which gastric acidity must be reduced. Sucrase is a hydrolytic enzyme that catalyzes the breakdown of sucrose to its monomer content. A liquid of yeast sucrase was developed for treatment of congenital sucrase-isomaltase deficiency (CSID) in human. In this study, the effect of ranitidine on yeast sucrase activity was investigated. Our results showed that ranitidine binds to sucrase and inhibits the enzyme in a noncompetitive manner. The K(i) and IC(50) values were measured to be about 2.3 and 2.2 mM, respectively. Fluorescence measurement showed conformational changes after binding of ranitidine to the enzyme. The fluorescence spectra showed that ranitidine could bind to both free enzyme and enzyme-substrate complex, which was accompanied with reduction of emission intensity and red shift production.

13C-breath tests for sucrose digestion in congenital sucrase isomaltase-deficient and sacrosidase-supplemented patients

BACKGROUND

Congenital sucrase-isomaltase deficiency (CSID) is characterized by absence or deficiency of the mucosal sucrase-isomaltase enzyme. Specific diagnosis requires upper gastrointestinal biopsy with evidence of low to absent sucrase enzyme activity and normal histology. The hydrogen breath test (BT) is useful, but is not specific for confirmation of CSID. We investigated a more specific 13C-sucrose labeled BT.

OBJECTIVES

Determine whether CSID can be detected with the 13C-sucrose BT without duodenal biopsy sucrase assay, and if the 13C-sucrose BT can document restoration of sucrose digestion by CSID patients after oral supplementation with sacrosidase (Sucraid).

METHODS

Ten CSID patients were diagnosed by low biopsy sucrase activity. Ten controls were children who underwent endoscopy and biopsy because of dyspepsia or chronic diarrhea with normal mucosal enzymes activity and histology. Uniformly labeled 13C-glucose and 13C-sucrose loads were orally administered. 13CO2 breath enrichments were assayed using an infrared spectrophotometer. In CSID patients, the 13C-sucrose load was repeated adding Sucraid. Sucrose digestion and oxidation were calculated as a mean percent coefficient of glucose oxidation averaged between 30 and 90 minutes.

RESULTS

Classification of patients by 13C-sucrose BT percent coefficient of glucose oxidation agreed with biopsy sucrase activity. The breath test also documented the return to normal of sucrose digestion and oxidation after supplementation of CSID patients with Sucraid.

CONCLUSIONS

13C-sucrose BT is an accurate and specific noninvasive confirmatory test for CSID and for enzyme replacement management.

Probiotics: what are they? What are their effects on gut physiology?

Probiotics can be defined as microbial cells that have a beneficial effect on the health and well-being of the host. Since the gastrointestinal mucosa is the surface of contact with probiotics, it seems evident that the first effects of probiotics relate to digestive function. A brief review of the literature indicates that probiotics have very few effects on the main physiological functions of the gastrointestinal tract, which are digestion, absorption and propulsion. The main action of probiotics can be summarised as a reinforcement of the intestinal mucosal barrier against deleterious agents. Experimental data indicate that some probiotics reduce pathological alterations in paracellular permeability to large molecules or bacteria, stimulate mucosal immunity, display a trophic action on the mucosa, reduce mucus degradation and interact with mediators of inflammation. Yoghurt may help lactose digestion, and some data needing confirmation indicate a stimulation of water absorption and an acceleration of intestinal transit by some bacteria.

Sacrosidase therapy for congenital sucrase-isomaltase deficiency

BACKGROUND

The purpose of this study was to determine if sacrosidase, a liquid produced from Saccharomyces cerevisiae containing 6000 IU of sucrase activity per mg protein, prevented symptoms of diarrhea, abdominal cramps, gas, and bloating in patients with congenital sucrase-isomaltase deficiency (CSID) consuming a normal sucrose and carbohydrate-containing diet.

METHODS

Twenty-eight children (aged 5 months to 11 years) underwent a randomized, double-blind trial consisting of two phases: 1) three sucrose breath H2 tests with three single-dose treatments (placebo, sacrosidase, and sacrosidase plus milk), and 2) a dose-response phase consisting of four multidose treatments, each for 10 days of full-strength sacrosidase, 1:10 dilution, 1:100 dilution, and 1:1000 dilution. Patients who weighed less than or equal to 15 kg received a dose of sacrosidase and those who weighed more than 15 kg received 2 ml. For the dose-response phase each patient consumed a normal diet. The number of stools and severity of symptoms were recorded daily for each concentration of sacrosidase administered and compared to a baseline period during which the patient took no sacrosidase and consumed a sucrose/starch-free diet. Data were analyzed using an ANOVA model and the nonparameter Wilcoxon signed-rank test.

RESULTS

Breath H2 excretion decreased significantly when patients received sacrosidase or sacrosidase plus milk compared to placebo during sucrose breath tests. During the dose-response phase significant treatment differences were observed between the two higher concentrations and the two lower concentrations of sacrosidase for both total stools (p < 0.001) and total symptom score (p = 0.003). Higher concentrations of sacrosidase were associated with fewer stools and a greater number of formed or hard stools compared to lower concentrations and compared to the baseline period. Higher concentrations were also associated with fewer symptoms of gas, abdominal cramps, or bloating, but no differences in vomiting. The only significant adverse event was wheezing in one child with a history of asthma.

CONCLUSIONS

Sacrosidase is a safe, effective, well-accepted treatment to prevent gastrointestinal symptoms in patients with CSID consuming a normal diet.

Analytical methods and stability assessment of liquid yeast derived sucrase

Two independent analytical methods for determining the activity and stability profile of liquid yeast derived sucrase (YS) were established and validated in order to conduct preliminary stability studies as a function of temperature. The methods included a hexokinase-based (HK) enzymatic assay for determining the formation of glucose upon hydrolysis of sucrose by YS, and a direct polarimetric procedure to quantitate YS hydrolysis of sucrose. Both assays were validated with respect to YS dilution, incubation time, sucrose or glucose concentration, linearity of response and within- and between-day variability. A preliminary stability study was conducted over a 24 week period with liquid YS samples stored at -20, 4, 30, 40 and 50 degrees C. Enzymatic activity was monitored as a function of time using both the HK and polarimetric assays. Liquid YS samples stored at -20, 4 and 30 degrees C retained 100% activity after 24 weeks storage, while the samples stored at 40 degrees C lost approximately 70% activity over the same storage period and samples stored at 50 degrees C lost approximately 95% activity after 12 weeks storage. The two methods of analysis gave consistent results over the course of the study.

Gastrointestinal gas formation and infantile colic

Gastrointestinal gas causes distress in many patients and their parents. Most often, patients do not have an actual increase in gastrointestinal gas volume, but rather their complaints derive from a misunderstanding of normal physiology, a misinterpretation of symptoms (colic), or an increase in intestinal sensitivity (irritable bowel syndrome). Symptoms from actual increases in intestinal gas volume are seen most frequently in children who swallow excessive amounts of air, have a dysmotility syndrome, or consume foods containing poorly absorbed carbohydrates. Although many therapies are used in the treatment of gas-related symptoms, under close scrutiny, the commonly recommended agents (e.g. simethicone) do not have proven efficacy. An understanding of the physiology of gas production and disposal is of practical use to pediatricians in determining the appropriate method of intervention for patients with these complaints.