Normal Disaccharidase Activity and Disaccharidase Activity in Patients with Functional Enteropathies

Objective of the Review: To demonstrate the role of changes in disaccharidase activity in aetiology and pathogenesis of functional enteropathies (FEP). Key Points. In mid-20th century, Russian scientists found out that jejunum diseases can be caused by impaired membrane digestion (MD). Not it is known that irritable bowel syndrome and other FEPs can mask enteropathies with impaired MD. Conclusion. Measurements of disaccharidase activity in duodenum mucosa are a method of choice in diagnosing enteropathies with impaired MD. The information on disaccharidase activity in ileum have not been described in any references. It is assumed that disaccharidase measurements in distal jejunum can be of extra diagnostic significance in examination of patients with FEP. Available information will make it possible to propose an up-to-date concept of aetiology, pathogenesis, clinical course, diagnosis and management of disaccharidase deficiency. Keywords: irritable bowel syndrome, disaccharidases, membrane digestion, A. M. Ugolev, Dahlquist method, FODMAP diet, Rebamipide, probiotics.

A retrospective study on the association of gastrointestinal symptoms in children with low lactase activity and low activity of other disaccharidases

Background Disaccharides such as lactose and sucrose are sugars commonly found in human diet. They are broken down by mucosal disaccharidases in the duodenum. Previous small studies found no associations between gastrointestinal (GI) symptoms and combined low disaccharidase activity. We aim to explore the associations of low activity of disaccharidase and combinations of low activity of different disaccharidases with general GI symptom presentations in a large cohort of pediatric patients. Methods We examined a cohort (0–21 yrs.) who have undergone esophagogastroduodenoscopy and received disaccharidase activity assay from duodenal biopsy in the time period 2010 to 2012. Disaccharidase assays tested for activity of lactase, sucrase, maltase, and palatinase. GI symptoms were grouped into four categories, abdominal pain, diarrhea, weight loss, and gastroesophageal reflux. Results Of the 347 subjects, we found an association between low lactase activity and abdominal pain (OR = 1.78; 95% CI = 1.07–2.97; p < 0.05). Subjects with a lactase/sucrase ratio < 0.2 were found to be associated with abdominal pain (OR = 2.25; 95% CI = 1.25–4.04; p < 0.05), Subjects with low pandisaccharidase may be correlated with abdominal pain and have a unique frequency of GI symptoms due to low frequency of diarrhea and weight loss, but they were not statistically significant. Conclusions Low activities of certain disaccharidase combinations may be associated with GI symptoms in subjects; a prospective study may be needed to investigate further.

Stool Reducing Sugars and Stool pH Are Poor Screening Tests for Intestinal Disaccharidase Deficiencies in Children

Background Tests for stool reducing sugars and stool pH are ordered for children with osmotic diarrhea to screen for carbohydrate malabsorption. Methods We compared the results of the two screening tests, stool reducing sugars and stool pH, with a more definitive result from an intestinal tissue disaccharidase activity assay ordered for pediatric patients (&lt;18 years old). Overall, 159 patients had results for tissue disaccharidase and stool reducing sugars, but only 115 had additional results of stool pH. Forty-six of the 159 patients had mild, moderate, or severe disaccharidase deficiencies. The sensitivity and specificity of the screening tests were calculated for individual disaccharidase deficiencies. In addition, trends of abnormal tissue disaccharidase, stool reducing sugars, and stool pH results were examined in different age groups. Results The sensitivities for stool reducing sugars and stool pH were 9% to 28% and specificities were 74% to 81% for individual disaccharidase deficiencies. Infants (0 years of age) had the highest percentage of abnormal results across all three tests; however, the positive predicative values were 54% and 50% for stool reducing sugars and stool pH, respectively. Conclusions The screening tests, stool reducing sugars and stool pH, had low sensitivity compared with results of measured tissue disaccharidase activity in pediatric patients. Infants had the highest percentage of abnormal results for all three tests, but the screening tests still performed poorly in that age group. This study suggests that stool reducing sugars and stool pH should not be used as screening tests for carbohydrate malabsorption due to disaccharidase deficiencies in pediatric patients.

Diet composition modulates intestinal hydrolytic enzymes in white-footed mice (Peromyscus leucopus)

We tested whether white-footed mice (Peromyscus leucopus) modulate the activity of three key intestinal digestive enzymes (maltase, sucrase, and aminopeptidase-N [APN]) based on diet composition. To test the adaptive modulation hypothesis (AMH), we fed mice either of three kinds of synthetic diet, high starch (HS, 50% carbohydrate), high protein (HP, 60% protein), and high lipid (HL, 25% lipid), and determined their digestive responses. First, there was no effect of either diet itself, or time eating the diet, on body mass, or mass and length of small intestine. Second, the activity of both disaccharidases summed over the entire small intestine was highest on the HS diet, which was higher than on the HP diet by about 45% and higher than on the HL diet by 400%. This was consistent with our prediction that starch induces disaccharidase activity, and demonstrated induction of disaccharidase activities by high dietary carbohydrate in a wild mammal. Third, both summed and mass-specific activity of maltase and sucrase of HL mice were lower than those of HP mice, even though their diets had the same content of starch, which suggests that lipid in the HL diet inhibited disaccharidase activity. Finally, the summed activity of APN was highest on the HP diet, which was higher than on the HS diet or HL diet by ~100%, consistent with our prediction that high protein content induces peptidase activity. Taken together, our results support the AMH, though they also illustrate that high lipid content in the diet can confound some predicted patterns. Flexibility of digestive enzyme activity is likely important in allowing white-footed mice to cope with fluctuations in the environmental availability of different food types. Probamos si el ratón de patas blancas (Peromyscus leucopus) modula las actividades de tres enzimas digestivas intestinales claves – maltasa, sacarasa y N-aminopeptidasa- al modificarse la composición de la dieta. Para someter a prueba la hipótesis de la modulación adaptativa, se alimentaron paralelamente ratones con tres tipos de dietas semi-sintéticas, una alta en almidón (HS, 50% carbohidratos), otra alta en proteína (HP, 60% proteínas), y una alta en lípidos (HL, 25% lípidos), y se determinaron sus respuestas digestivas. No se observó un efecto de la dieta o del tiempo que la consumieron sobre la masa corporal o la masa y el largo del intestino delgado (SI). La sumatoria de las actividades de cada una de las disacaridasas a lo largo de todo el intestino delgado fue más alta con la dieta HS que con las dietas HP y HL, un 45% y un 400% mayor, respectivamente. Esto fue consistente con nuestra predicción acerca de que el almidón induce la actividad disacaridásica, constituyendo el primer estudio que demuestra inequívocamente en un animal silvestre, que la inducción de las actividades de las disacaridasas intestinales es mediada por un incremento de los carbohidratos en la dieta. Las actividades hidrolíticas totales y masa-específicas de la maltasa y sacarasa de los ratones HL fueron más bajas que las de los alimentados con dieta HP, aun cuando sus dietas tenían el mismo contenido de almidón, lo que sugiere que los lípidos en la dieta HL inhiben la actividad de las disacaridasas. La actividad hidrolítica total de la N-aminopeptidasa fue mayor con la dieta HP, ~100% más alta que para las dietas HS y HL, de manera consistente con la predicción que propone que la presencia de mayor cantidad de proteína en la dieta induce la actividad peptidásica. En conjunto nuestros resultados dan soporte a la hipótesis de la modulación adaptativa, además de ilustrar que los lípidos en las dietas pueden confundir la predicción de patrones de procesamiento de alimentos. La flexibilidad de la actividad de las enzimas digestivas es probablemente importante para los ratones de patas blancas, ya que les permite adecuarse a las fluctuaciones ambientales de disponibilidad de diferentes tipos de recursos.

Morphology and disaccharidase activity of small intes- tinal mucosa in post-weaning-induced malnourished rats and after realimentation

Background The most common cause of failure to thrive in in-fants is malnutrition which causes histological and biochemicalchanges of small intestine. Studies on histology and enzyme ac-tivity of small intestinal mucosa were not much developed.Objective To study about histology and disaccharidases activity ofsmall intestinal mucosa in post-weaning-induced malnourished rats.Methods We used Sprague-Dawley white rats as the subjects ofthis study with post test-control group design. The study was per-formed at the CentER for Research of Food and Nutrition Devel-opment from April 2003 to December 2004.Results There were a decrease of body weight (hypotrophy nor-moblastic) and an increase of disaccharidase activity of small in-testinal mucosa in post-weaning-induced malnourished rats. Afterrealimentation, there were an increase of body weight, an improve-ment of the hypotrophy, and a decrease of the enzyme but theystill cannot reach normal condition.Conclusion In malnourished rats, there are decrease of bodyweight hypotrophy normoblastic and increase of disaccharidasesactivity of intestinal mucosa that are improved after realimentation