The response to dietary treatment of patients with chronic post-infectious diarrhea and lactose intolerance

Routine disaccharidase testing: are we there yet?

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.

Interventions for post-infectious irritable bowel syndrome: a systematic review of treatment efficacy

Background

Post-infectious irritable bowel syndrome (PI-IBS) due to traveler’s diarrhea is the second most common illness seen in post-travel clinics, yet its optimal management remains unknown. We performed a systematic review to evaluate treatment efficacy in PI-IBS.

Methods

We searched Medline, EMBASE, LILACS, CINAHL, CAB abstracts, and the Cochrane Library to February 3, 2014 for intervention studies of the pharmacologic and non-pharmacologic management of PI-IBS and examined the evidence according to a modified Grading of Recommendations Assessment, Development, and Evaluation (GRADE) scale.

Results

Of 336 records, 9 studies were included. Eight studies of pharmacologic interventions examined 5 agents (mesalazine or mesalamine, ondansetron, prednisolone, cholestyramine, and metronidazole). One study examined the non-pharmacologic intervention of different infant nutritional formulas following acute gastroenteritis. The quality of the evidence to date was low, with small sample size (fewer than 50 participants) and short duration of follow-up. Overall, the efficacy of pharmacological treatment ranged from no benefit (ondansetron and prednisolone) to moderately beneficial (cholestyramine and metronidazole). The evidence for mesalazine was equivocal: one study showed benefit, two others showed none.

Conclusions

Heterogeneity in outcome measures and low strength of evidence preclude recommendations on the optimal management of PI-IBS by a specific agent. More comparative intervention research into PI-IBS treatment is needed for consistent best practice in PI-IBS management. Clinicians may elect to pursue therapeutic trials of mesalazine, cholestyramine, or metronidazole in individual patients, but should be aware that data supporting the efficacy of these agents is limited.

Electronic supplementary material

The online version of this article (doi:10.1186/s40794-015-0002-9) contains supplementary material, which is available to authorized users.

Chronic T cell-mediated enteropathy in rural west African children: relationship with nutritional status and small bowel function

Previous studies from The Gambia have shown that poor childhood growth is resistant to all but the most intense nutritional intervention and highly dependent on small bowel permeability related to enteropathy. We thus aimed to characterize the mucosal inflammatory response in rural Gambian children in relation to intestinal permeability and nutritional status. Small bowel biopsies were taken from 38 rural Gambian children (age, 0.5-3 y) with a range of nutritional and clinical states (median weight z score, -4.6; range, 0.5 to -6.4), 75% of whom had diarrhea. Morphometry was performed with immunohistochemical analysis for a range of lineage and activation markers, including proinflammatory and regulatory cytokines, and related to current clinical status and gut permeability. Comparison was made with 19 age-matched U.K. controls. All Gambian children, regardless of nutritional status, had evidence of chronic cell-mediated enteropathy with crypt hyperplasia, villous stunting, and high numbers of intraepithelial lymphocytes. CD25+ cells were 20-fold higher than in U.K. controls. Although small bowel architecture was independent of nutritional status, T cell numbers rose and B cell numbers fell with worsening nutrition, and mucosal cytokine production became biased toward a proinflammatory response, with progressive decrease of transforming growth factor-beta expression. Tropical enteropathy predates the onset of marasmus and is characterized by a cell-mediated TH1 response. Protein-energy malnutrition is associated with reduction of regulatory immune responses in the mucosal microenvironment, potentially impairing the mechanisms of oral tolerance.

A consistent pattern of minor immunodeficiency and subtle enteropathy in children with multiple food allergy

OBJECTIVE

Although immunoglobulin (Ig)E-mediated allergies are readily identifiable, non-IgE-mediated allergies present more diagnostic difficulty. We performed a formal retrospective analysis to determine whether there is a recognizable clinical pattern in children.

METHODS

We studied 121 children (mean age, 17.3 months) with multiple food allergies who were recruited on the basis of adequate immunological assessment by using case notes and parental questionnaire.

RESULTS

Group 1 (n=44) had rapid reactions to dietary antigens, of whom 41 also showed delayed reactions. Group 2 (n=77) had delayed reactions only. Mean IgE was increased in group 1 but both groups otherwise shared a pattern of increased IgG1, decreased IgG2/4, and low-normal IgA. Lymphocyte subsets were skewed, with an increased percentage of CD4 and CD19 and decreased CD8 and natural killer cells. Gastroesophageal reflux, esophagitis, subtle enteropathy, and constipation were frequent in both groups. Of 55 exclusively breast-fed infants, 44 sensitized before weaning. Twenty-one of the mothers suffered from autoimmunity.

CONCLUSIONS

There appears to be a recognizable pattern of immune deviation and minor enteropathy in children with multiple food allergy, irrespective of the speed of reactions. Disturbed gut motility is particularly common, as is a maternal history of autoimmunity.

Carbohydrate intolerance after acute gastroenteritis--a disappearing problem in Polish children

The prevalence of carbohydrate intolerance in Polish children during an acute episode of gastroenteritis was determined. One hundred and seven consecutive children, less than 3 years old, with acute diarrhoea were enrolled into the study. Carbohydrate intolerance (diagnostic criteria: >0.5% reducing substances and stool pH less than 5.5) was diagnosed in 14/107 (13.08%) children: lactose intolerance was present in 12 (11.2%) patients; glucose polymer intolerance in 1 (0.93%) and monosaccharide intolerance in 1 (0.93%). The most important predisposing factor was rotavirus. In all cases the carbohydrate intolerance was transient, resolving within 5 days. Carbohydrate intolerance is also an infrequent problem in Polish children. Restriction of lactose-containing foods (use of lactose-free or low lactose formulas) for the majority of children with gastroenteritis does not seem to be justified.

Refeeding of infants with acute diarrheal disease

The purpose of this study was to determine which infant formula among five would be the most efficacious for the refeeding of infants during an acute episode of diarrhea. Fifty male infants less than 12 months of age with severe diarrhea and at least 5% dehydration were admitted to a metabolic unit and studied in a prospective, single-blind protocol. Ten infants randomly received one of five types of formula: two-thirds diluted cow milk, cow milk formula (Nanon, Nestle, Inc., São Paulo, Brazil), Portagen, Pregestimil, or Prosobee (Mead Johnson & Co. Division, Evansville, Ind.). They continued to receive the same formula for 72 hours unless dehydration occurred. There were no associated infections, and they received no prior antibiotic treatment. Oral hydration together with intravenous fluid therapy was given to all patients during the initial treatment. During the first 72 hours of refeeding, patients fed Portagen excreted the least amount of stool and required reduced quantities of intravenous fluids or oral hydration. In contrast, patients fed diluted cow milk or any other formula had more severe diarrhea. Nine of the 10 patients fed Portagen completed the 72-hour treatment, whereas only 2 of 10 fed diluted cow milk tolerated it. Similarly, the cumulative proportions for high purging rate, dehydration, carbohydrate intolerance, and vomiting were more favorable for Portagen and least acceptable for diluted cow milk. No differences were found among the remaining three formulas tested. These data show that diluted cow milk is poorly tolerated by infants with severe diarrhea, whereas Portagen is more effective.