Mauro Batista de Morais

Measurement of low dietary fiber Intake as a risk factor for chronic constipation in children

BACKGROUND Scarce information exists regarding dietary fiber intake in children with chronic constipation. The objective of this case-control study was to evaluate the intake of fiber as a risk factor for chronic constipation. METHODS Fifty-two children with a mean age of 6.8+/-3.2 years who had chronic constipation were age and gender matched with 52 children with normal intestinal habits. The fiber content of the diet was evaluated with a 24-hour dietary recall. Two tables of fiber composition in foods were used: a Brazilian table, and a table based on the method of the Association of Official Agricultural Chemists (AOAC). RESULTS According to the Brazilian table, the median intake of fiber (in grams per day) by the constipated and the control groups was 13.8 and 17.3, respectively, for total fiber (p = 0.020), 6.8 and 9.7 for insoluble fiber (p = 0.004), and 6.5 and 7.6 for soluble fiber (p = 0.104). According to the AOAC table, the constipation group (9.7 g/day) also had lower (p = 0.0022) intake of total fiber than the control group (12.6 g/day). The coefficient of correlation between the two tables on fiber content of food was +0.82 (p < 0.001) in the constipation group and +0.86 (p < 0.001) in the control group. The intake of fiber was less than the minimum recommendation (age + 5 g) and statistically associated (p = 0.001) with the constipation group (75.0%) in comparison with the controls (42.5%). The odds ratio was 4.1 (95% confidence limits, 1.64-10.32). CONCLUSION Intake of fiber below the minimum recommendation is a risk factor for chronic constipation in children.

Diffusely Adherent Escherichia coli as a Cause of Acute Diarrhea in Young Children in Northeast Brazil: a Case-Control Study

ABSTRACT In a prospective study carried out in two urban centers in northeastern Brazil, 195 HEp-2-adherent Escherichia coli strains were isolated; 110 were identified as the only pathogen in stools of children with diarrhea, and 85 were from controls. Enteropathogenic E. coli isolates were identified in 21 children with diarrhea (8.9%) and 7 children without diarrhea (3.0%), and they were significantly associated with diarrhea (P < 0.01). Enteroaggregative E. coli strains were isolated from 40 children with diarrhea (16.9%) and 38 children without diarrhea (16.4%) and showed no correlation with diarrhea (P > 0.5). In 49 children with diarrhea (20.7%) and 40 children without diarrhea (17.3%), diffusely adherent E. coli (DAEC) isolates were detected and were not found to be associated with diarrhea (P = 0.41). However, after stratification, for children older than 12 months of age a significant correlation between DAEC infection and diarrhea was detected (P = 0.01). These results suggest that DAEC isolates should be considered potential pathogens in northeastern Brazil and also confirm the association of DAEC with age-dependent diarrhea.

Cow's milk protein intolerance and chronic constipation in children

Cows milk protein (CMP) allergy was investigated in 25 children (age‐range 3 months to 11 years) with chronic constipation. A diagnosis of constipation was made on the basis of a history of painful elimination of hard stools for at least 1 month, whether or not associated with a reduced frequency of stools or soiling. The children were evaluated using clinical parameters and the following laboratory tests: total serum immunoglobulin E (IgE); specific IgE (radioallergosorbent test [RAST]) for whole cows milk, α‐lactoalbumin, β‐lactoglobulin, and a food group; and skin‐prick tests with whole milk, α‐lactoalbumin, β‐lactoglobulin, and casein. Following the evaluation, the children were submitted to a CMP‐free diet for a period of 4 weeks. In seven patients (28%), constipation disappeared during the CMP‐free diet and reappeared within 48–72 h following challenge with cows milk. In two infants a rectal biopsy revealed allergic colitis and they therefore did not undergo the challenge. High serum levels of total IgE were observed in five of the children who showed a clinical improvement (71%), a positive skin‐test in two (29%), and detectable specific IgE in two (29%). These results suggest that CMP allergy or intolerance should be considered as a cause of chronic refractory constipation in children, although the underlying mechanism still require further investigation.

HEp-2-adherent Escherichia coli strains associated with acute infantile diarrhea, São Paulo, Brazil.

In this paired case-control study of infants with diarrhea in São Paulo, we examined the association between HEp-2–adherent Escherichia coli strains and diarrhea. We tested isolates from stool specimens of infants with diarrhea and matched controls in an HEp-2 cell adherence assay; we then hybridized isolates with DNA probes and identified enteropathogenic E. coli (EPEC), enteroaggregative E. coli (EAEC), and diffusely adherent E. coli (DAEC). From 100 patient-control pairs, we isolated 78 HEp-2–adherent strains; of these, 61 strains were single pathogens identified in stools of infants with diarrhea. While typical EPEC was significantly associated with diarrhea (p<0.001), EAEC was more frequently associated with diarrhea in clinical cases (20%) compared with healthy controls (3%) (p<0.001). Atypical EPEC, showing a localized adherence-like pattern, was also more common in patients than controls (p>0.1). DAEC was isolated with equal frequency from patients and controls (p>0.1).

Comparison of DNA Hybridization and PCR Assays for Detection of Putative Pathogenic Enteroadherent Escherichia coli

ABSTRACT The correlation of the different adherence patterns with DNA probes and PCR primers for the identification of Escherichia coli was analyzed in isolates from children, less than 2 years of age with or without diarrhea, from different regions of Brazil. A total of 1,428 isolates obtained from 338 patients and 322 control children were studied. The enteropathogenic E. coli (EPEC) adherence factor (EAF) probe was shown to be as good as the HEp-2 adhesion assay for the detection of typical EPEC strains. The DNA probes used to detect diffusely adhering E. coli and enteroaggregative E. coli (EAEC) showed low sensitivities (64 and 50%, respectively), and the best method of identifying these organisms in clinical research remains the HEp-2 adherence assay. The “bundle-forming pilus” (BFP) and the EAEC PCR assays could be used instead of the DNA probes as a screening method for typical EPEC and EAEC carrying the EAEC probe sequence in the clinical laboratory. In our study, only typical EPEC strains that carried EAF and BFP were associated with acute diarrhea.

The impact of antibiotics on growth in children in low and middle income countries: systematic review and meta-analysis of randomised controlled trials

Objectives To determine whether antibiotic treatment leads to improvements in growth in prepubertal children in low and middle income countries, to determine the magnitude of improvements in growth, and to identify moderators of this treatment effect. Design Systematic review and meta-analysis. Data sources Medline, Embase, Scopus, the Cochrane central register of controlled trials, and Web of Science. Study selection Randomised controlled trials conducted in low or middle income countries in which an orally administered antibacterial agent was allocated by randomisation or minimisation and growth was measured as an outcome. Participants aged 1 month to 12 years were included. Control was placebo or non-antimicrobial intervention. Results Data were pooled from 10 randomised controlled trials representing 4316 children, across a variety of antibiotics, indications for treatment, treatment regimens, and countries. In random effects models, antibiotic use increased height by 0.04 cm/month (95% confidence interval 0.00 to 0.07) and weight by 23.8 g/month (95% confidence interval 4.3 to 43.3). After adjusting for age, effects on height were larger in younger populations and effects on weight were larger in African studies compared with other regions. Conclusion Antibiotics have a growth promoting effect in prepubertal children in low and middle income countries. This effect was more pronounced for ponderal than for linear growth. The antibiotic growth promoting effect may be mediated by treatment of clinical or subclinical infections or possibly by modulation of the intestinal microbiota. Better definition of the mechanisms underlying this effect will be important to inform optimal and safe approaches to achieving healthy growth in vulnerable populations.

A survey on clinical presentation and nutritional status of infants with suspected cow' milk allergy.

BackgroundCows milk is the most common food allergen in infants and the diagnosis of cows milk allergy is difficult, even with the use of several diagnostic tests. Therefore, elimination diets and challenge tests are essential for the diagnosis and treatment of this disorder. The aim of this study is to report the clinical presentation and nutritional status of children evaluated by pediatric gastroenterologists for the assessment of symptoms suggestive of cows milk allergy.MethodsAn observational cross-sectional study was performed among 9,478 patients evaluated by 30 pediatric gastroenterologists for 40 days in 5 different geographical regions in Brazil. Clinical data were collected from patients with symptoms suggestive of cows milk allergy. The nutritional status of infants (age ≤ 24 months) seen for the first time was evaluated according to z-scores for weight-for-age, weight-for-height, and height-for-age. Epi-Info (CDC-NCHS, 2000) software was used to calculate z-scores.ResultsThe prevalence of suspected cows milk allergy in the study population was 5.4% (513/9,478), and the incidence was 2.2% (211/9,478). Among 159 infants seen at first evaluation, 15.1% presented with a low weight-for-age z score (< -2.0 standard deviation - SD), 8.7% with a low weight-for-height z score (< -2.0 SD), and 23.9% with a low height-for-age z score (< -2.0 SD).ConclusionThe high prevalence of nutritional deficits among infants with symptoms suggestive of cows milk allergy indicates that effective elimination diets should be prescribed to control allergy symptoms and to prevent or treat malnutrition.

Breath methane associated with slow colonic transit time in children with chronic constipation.

Objective: This study analyzed the relationship between methane production and colonic transit time in children with chronic constipation. Methodology: Forty children, from 3 to 13 years of age, suffering from chronic constipation were included. Methane production was defined when the breath methane concentration was greater than 3 ppm. The total and segmental colonic transit times were measured with radio-opaque markers. Results: Soiling was present in 34 (85.0%) of 40 patients with constipation. Methane production was present in 25 of 34 (73.5%) patients with constipation and soiling and only in 1 (16.7%) of 6 with constipation but without soiling (P = 0.014). The medians of total colonic transit time were 80.5 and 61.0 hours, respectively (P = 0.04), in methane and nonmethane producers. Segmental colonic transit times were 17.5 and 10.5 hours, respectively (P = 0.580), in right colon, 29.5 and 10.5 hours (P = 0.001), respectively, in left colon, and 31.5 and 27.0 hours (P = 0.202), respectively, in the rectosigmoid. By the sixth week of treatment, the reduction in the total colonic transit time was greater in patients who had become nonmethane producers. Conclusion: The presence of breath methane in children with chronic constipation may suggest the possibility of prolonged colonic transit time.

Functional Gastrointestinal Disorders: Working Group Report of the First World Congress of Pediatric Gastroenterology, Hepatology, and Nutrition

Functional gastrointestinal disorders are defined as conditions in which a variable combination of chronic or recurrent gastrointestinal symptoms are present in the absence of known structural or biochemical abnormalities. There is no apparent organic disease or objective evidence of a pathologic condition. In clinical practice, most children with chronic gastrointestinal complaints have functional disorders. Despite their common occurrence, we know very little about the pathophysiology of most of these conditions. A diagnosis of a functional disorder is largely based on a patient’s report of symptoms. Whereas adults can offer accurate histories, this is not necessarily the case in children, especially those who are young. Moreover, parents often play a large role in reporting their child’s symptoms as well as in making the decision about whether to seek health care. Often the child–parent unit must be evaluated when addressing functional disorders. Considerable effort has been spent in defining pediatric functional gastrointestinal disorders. A multinational team of senior clinicians suggested working definitions (1). A recent monograph has described the spectrum of these disorders (2). It has been observed that some pediatric functional gastrointestinal disorders accompany normal development (e.g., infant regurgitation), or may be triggered by behavioral responses to age-appropriate activities (functional fecal retention during toilet training). It was also suggested that some children could inherit a temperament characterized by a predilection to gastrointestinal reactivity to stress, thereby constituting a genetic susceptibility to functional gastrointestinal disorders. At the same time it is recognized that environmental factors (parental health care seeking, stress, culture, geographic location) might play a role in the pathogenesis of functional gastrointestinal disorders. In the biopsychosocial model of clinical practice, symptoms represent the end result of autonomic nervous system reactivity and recovery, environmental stressors, and the child’s ability to cope. They are also influenced by parental responses and coping. In this report, we address functional gastrointestinal disorders associated with vomiting, abdominal pain, and disordered defecation. We have not considered infant regurgitation, which is discussed in another Working Group report.

Effect of Resistant and Digestible Starch on Intestinal Absorption of Calcium, Iron, and Zinc in Infant Pigs

The first nonmilk foods that are given to infants contain high levels of starch, a fraction of which is resistant to enzyme hydrolysis. Incomplete digestion of starch may interfere with the absorption of certain minerals. A fraction of dietary starch which is resistant to in vitro enzymatic hydrolysis has been termed resistant starch. The aim of this study was to compare the intestinal apparent absorption of calcium, phosphorus, iron, and zinc in the presence of either resistant or digestible starch. Twelve 7-10-d-old piglets were fitted with a T-tube inserted into the intestine approximately 3 m distal to the duodenum. Animals received in random order 200 mL of a test meal of cooked, cooled, high amylose corn starch (16.4% resistant starch), or cooked rice starch (digestible starch) administered by an orogastric tube. Both meals contained the same amount of calcium, phosphorus, iron, and zinc. The test meal also contained tracer amounts of 59Fe and65 Zn, as well as polyethylene glycol 3350, as a nonabsorbable marker. Intestinal apparent absorption of starch was greater after the meal with digestible starch (71.0 ± 17.0%) than after the meal with resistant starch (49.2 ± 10.3) (p < 0.001). After feeding the meals with resistant and digestible starch, mineral apparent absorption was, respectively: calcium, 40.2 ± 11.8% versus 28.1 ± 16.4% (p < 0.05); phosphorus, 73.2 ± 14.0%versus 67.8 ± 18% (NS); iron, 24.1 ± 12.2%versus 12.6 ± 10.6% (p < 0.01), and zinc, 35.0± 13.0% versus 30.6 ± 8.22% (NS). In conclusion, a meal containing 16.4% resistant starch resulted in a greater apparent absorption of calcium and iron compared with a completely digestible starch meal. If this finding holds true for the whole bowel, administration of resistant starches could have a positive effect on intestinal calcium and iron absorption.