Intestinal Barrier Dysfunction and Microbiota–Gut–Brain Axis: Possible Implications in the Pathogenesis and Treatment of Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder with multifactorial etiology, characterized by impairment in two main functional areas: (1) communication and social interactions, and (2) skills, interests and activities. ASD patients often suffer from gastrointestinal symptoms associated with dysbiotic states and a “leaky gut.” A key role in the pathogenesis of ASD has been attributed to the gut microbiota, as it influences central nervous system development and neuropsychological and gastrointestinal homeostasis through the microbiota–gut–brain axis. A state of dysbiosis with a reduction in the Bacteroidetes/Firmicutes ratio and Bacteroidetes level and other imbalances is common in ASD. In recent decades, many authors have tried to study and identify the microbial signature of ASD through in vivo and ex vivo studies. In this regard, the advent of metabolomics has also been of great help. Based on these data, several therapeutic strategies, primarily the use of probiotics, are investigated to improve the symptoms of ASD through the modulation of the microbiota. However, although the results are promising, the heterogeneity of the studies precludes concrete evidence. The aim of this review is to explore the role of intestinal barrier dysfunction, the gut–brain axis and microbiota alterations in ASD and the possible role of probiotic supplementation in these patients.

Probiotics and gastrointestinal diseases

During the past decades, scientists have discovered the intimate role of the gut microbiome in human health, and since then, several papers have been published to investigate if the use of biotics (probiotics, prebiotics, synbiotics, and postbiotics) may have a beneficial impact on human health both in treatment and prevention. We now ask ourselves whether we have reached the finish line or just a new starting point, as the evidence supporting the use of biotics in several conditions still needs a lot of work. Many questions remain unanswered today because the evidence differs depending on the indication, used strain, and amount and duration of administration. Herein we will summarize the evidence on probiotics in some gastrointestinal diseases such as infantile colic, functional abdominal pain disorders, celiac disease, acute gastroenteritis, inflammatory bowel disease, and Helicobacter pylori infection.

Case report: Late-onset hypertrophic pyloric stenosis in a 3-year-old boy: It is never too late

Hypertrophic Pyloric Stenosis (HPS) represents a relatively rare occurrence beyond infancy. Here, we present the case of a barely 3-year-old boy diagnosed with late-onset HPS and successfully treated with extra-mucosal pyloromyotomy. We review the literature, challenging the principle that more aggressive surgical approaches should be preferred over less invasive ones.

Esophageal Eosinophilia and Eosinophilic Esophagitis in Celiac Children: A Ten Year Prospective Observational Study

The association between eosinophilic esophagitis and celiac disease is still controversial and its prevalence is highly variable. We aimed to investigate the prevalence of esophageal eosinophilia and eosinophilic esophagitis in a large group of children with celiac disease, prospectively followed over 11 years.

METHODS

Prospective observational study performed between 2008 and 2019. Celiac disease diagnosis was based on ESPGHAN criteria. At least four esophageal biopsies were sampled in patients who underwent endoscopy. The presence of at least 15 eosinophils/HPF on esophageal biopsies was considered suggestive of esophageal eosinophilia; at the same time, eosinophilic esophagitis was diagnosed according to the International Consensus Diagnostic Criteria for Eosinophilic Esophagitis.

RESULTS

A total of 465 children (M 42% mean age 7.1 years (range: 1-16)) were diagnosed with celiac disease. Three hundred and seventy patients underwent endoscopy, and esophageal biopsies were available in 313. The prevalence of esophageal eosinophilia in children with celiac disease was 1.6% (95% CI: 0.54-2.9%). Only one child was diagnosed as eosinophilic esophagitis; we calculated a prevalence of 0.3% (95% CI: 0.2-0.5%). The odds ratio for an association between eosinophilic esophagitis and celiac disease was at least 6.5 times higher (95% CI: 0.89-47.7%; p = 0.06) than in the general population.

CONCLUSION

The finding of an increased number of eosinophils (>15/HPF) in celiac patients does not have a clinical implication or warrant intervention, and therefore we do not recommend routine esophageal biopsies unless clinically indicated.

Clinical and Microbiological Effect of a Multispecies Probiotic Supplementation in Celiac Patients With Persistent IBS-type Symptoms: A Randomized, Double-Blind, Placebo-controlled, Multicenter Trial

GOALS

The goals of this study were to evaluate the efficacy and safety of a probiotic mixture in patients with celiac disease (CD) with irritable bowel syndrome (IBS)-type symptoms despite a strict gluten-free diet (GFD).

BACKGROUND

About 30% of patients with CD adherent to a GFD suffer from IBS-type symptoms; a possible cause resides in the imbalances of the intestinal microbiota in CD. Probiotics may represent a potential treatment.

STUDY

CD patients with IBS-type symptoms entered a prospective, double-blind, randomized placebo-controlled study. A 6-week treatment period was preceded by a 2-week run-in and followed by a 6-week follow-up phase. Clinical data were monitored throughout the study by validated questionnaires: IBS Severity Scoring System (IBS-SSS); Gastrointestinal Symptom Rating Scale (GSRS); Bristol Stool Form Scale (BSFS); and IBS Quality of Life Questionnaire (IBS-QOL). The fecal microbiota were assayed using plate counts and 16S rRNA gene-based analysis.

RESULTS

In total, 109 patients were randomized to probiotics (n=54) or placebo (n=55). IBS-SSS and GSRS decreased significantly in probiotics, as compared with placebo [(-15.9%±14.8% vs. 8.2%±25.9%; P<0.001) and (-19.8%±16.6% vs. 12.9%±31.6%; P<0.001)], respectively. Treatment success was significantly higher in patients receiving probiotics, as compared with placebo (15.3% vs. 3.8%; P<0.04). Presumptive lactic acid bacteria, Staphylococcus and Bifidobacterium, increased in patients receiving probiotic treatment. No adverse events were reported.

CONCLUSIONS

A 6-week probiotic treatment is effective in improving the severity of IBS-type symptoms, in CD patients on strict GFD, and is associated with a modification of gut microbiota, characterized by an increase of bifidobacteria.

Randomized Double-Blind Placebo-Controlled Crossover Trial for the Diagnosis of Non-Celiac Gluten Sensitivity in Children

OBJECTIVES

Non-celiac gluten sensitivity (NCGS) is characterized by intestinal and extra-intestinal symptoms that are related to the ingestion of gluten in subjects who are not affected by either celiac disease (CD) or wheat allergy (WA). In this multicenter study, we aim for the first time to evaluate the prevalence of NCGS in pediatric subjects with chronic functional gastrointestinal symptoms associated with gluten ingestion using a double-blind placebo-controlled (DBPC) gluten challenge with crossover.

METHODS

Among 1,114 children with chronic gastrointestinal symptoms (negative CD and WA), those exhibiting a positive correlation between symptoms and gluten ingestion were eligible for a diagnostic challenge including the following phases: run-in, open gluten-free diet (GFD) and DBPC crossover gluten challenge. Patients were randomized to gluten (10 g/daily) and placebo (rice starch) for 2 weeks each, separated by a washout week. The gluten challenge was considered positive in the presence of a minimum 30% decrease of global visual analogue scale between gluten and placebo.

RESULTS

Out of 1,114 children, 96.7% did not exhibit any correlation with gluten ingestion. Thirty-six children were eligible; after the run-in and open GFD, 28 patients entered the gluten challenge. Eleven children (39.2%; 95% CI: 23.6-53.6%) tested positive.

CONCLUSIONS

This is the first demonstration of the existence of NCGS in children that reinforce the need for a DBPC for the diagnosis as the diagnosis is ruled out in >60% of cases. The registration identifier in ClinicalsTrials.gov is NCT02431585.

Mode of Delivery and Risk of Celiac Disease: Risk of Celiac Disease and Age at Gluten Introduction Cohort Study

OBJECTIVE

To determine whether the mode of delivery is associated with the risk of celiac disease (CD) in a cohort of children genetically predisposed to CD prospectively followed from birth.

STUDY DESIGN

By telephone interview, we recorded information on the mode of delivery of children participating in the Risk of Celiac Disease and Age at Gluten Introduction study, a multicenter, prospective intervention trial that compared early and delayed introduction of gluten in infants with at least 1 first-degree relative affected with CD. The human leukocyte antigen genotype was determined at 15 months of age, and serologic screening for CD was performed at 15, 24, and 36 months of age and at 5, 8, and 10 years of age. Patients with positive serologic findings underwent intestinal biopsy. The primary outcome of the current study was the prevalence of CD autoimmunity and overt CD at 5 years of age, according to the mode of delivery.

RESULTS

The study-group included 553 children at CD risk because of positivity for human leukocyte antigen-DQ2, -DQ8, or both. We obtained data on the mode of delivery from 431 of 553 children; 233 of 431 children were born by vaginal delivery (54%). At 5 years of age, the prevalence of CD autoimmunity or overt CD was not different between children born by cesarean or vaginal delivery (24% and 19%, P = .2; 19% and 14%, P = .2 respectively, by the log-rank test).

CONCLUSIONS

In this cohort of children genetically predisposed to CD, the mode of delivery did not influence the risk of developing CD.

Impact of the birth's season on the development of celiac disease in Italy

Celiac disease (CD) is an immune-mediated systemic disorder induced by a trigger factor in genetically susceptible individuals. There is emerging evidence about the impact of the month of birth on the development of several autoimmune diseases. Our aim was to investigate whether, in Italian CD children, the season of birth is associated with development of CD later in life. We report a survey conducted at two Italian referral centers for CD in Rome and Bari. The CD database was created to enable retrospective examination of the data of all the consecutive patients, born between 2003 and 2010, who had received a diagnosis of CD. This CD patient group comprising 596 children was compared with a reference group that included all subjects born in the same period and in the same cities (439,990 controls). Overall, there was a summer birth preponderance in CD patients compared to controls (28.2 % of CD patients vs 23.0 % of the control population; OR 1.315; 95 % CI 1.100 to 1.572). Stratifying the caseload by gender and age, the summer birth preponderance was maintained for females (28.6 % CD females vs 22.6 % control females; OR 1.368; 95 % CI 1.069 to 1.750).

CONCLUSIONS

our survey confirms that in Italy, children born in summer are at higher risk to develop CD than subjects born in other seasons. The identification of a responsible seasonal factor or factors, such as timing of the first introduction of gluten and/or acute viral gastrointestinal infections, would be very important for disease prevention strategies.

WHAT IS KNOWN

• Environmental factors could be involved in the pathogenesis of CD. • Data about the impact of season of birth on CD development is so far derived from North American, Northern European and Israeli surveys.

WHAT IS NEW

• This is the first study in Southern Europe to find a relationship between season of birth (summer) and development of CD. • Summer-born infants are introduced to complementary feeding (gluten) in winter, when the rotavirus infection is at its highest peak; this may be the link between season of birth and development of CD.

The overweight: a rare presentation of celiac disease

We describe the nutritional status of a cohort of celiac disease (CD) children at presentation and during follow-up on gluten-free diet (GFD). Two Italian centers (Rome and Bari) prospectively enrolled 445 biopsy-confirmed CD children, diagnosed between 2009 and 2013. Body Mass Index was used as a measure of nutritional status according to Italian growth charts of Cacciari. The overweight/obese subject was 7.8% at onset and did not significantly increase during follow-up (9.8% at final assessment). The prevalence of overweight/obesity was significantly higher among males than females. Furthermore, overweight/obesity children as compared with those with normal weight were significantly older and had significantly lower levels of tTG antibodies. This study shows that some CD children are obese/overweight at diagnosis; therefore, overweight/obesity can be considered a rare but a possible mode of CD presentation. Thus, CD diagnosis must be considered even in overweight/obese children where this diagnosis can be easily missed.

High rate of spontaneous normalization of celiac serology in a cohort of 446 children with type 1 diabetes: a prospective study

OBJECTIVE

In children with type 1 diabetes mellitus (T1DM), elevated levels of antitissue transglutaminase (anti-tTG) antibody may spontaneously normalize, despite continued consumption of gluten. We aimed to investigate the prevalence of spontaneous normalization of anti-tTG levels and the existence of factors predictive for this outcome.

RESEARCH DESIGN AND METHODS

All children referred from 2002 to 2012 were screened for celiac disease (CD) at diabetes onset and at specific intervals. In the presence of a high anti-tTG titer or clinical symptoms, children were offered endoscopy, and asymptomatic patients with a low anti-tTG titer were invited to a second serological test after 6 months of eating a gluten-containing diet.

RESULTS

The study included 446 children. Of these, 65 (14.5%) became positive for celiac serology: 38 (58%) had a persistently elevated anti-tTG titer and 27 (41%) fluctuating anti-tTG titer; 18 (28%) became negative. The prevalence of positive CD autoimmunity and overt CD was 14.3% (95% CI 11-17) and 8.5% (95% CI 5-10), 15- and 8-times higher than the general pediatric population, respectively. Asymptomatic children older than 9.1 years at T1DM onset had the lowest risk to develop CD.

CONCLUSIONS

Serum anti-tTG levels decreased spontaneously in 40% of children with T1DM and became negative in 20%, despite gluten consumption. This finding supports the hypothesis of a state of temporary positivity of celiac serology in children with diabetes. In absence of clinical symptoms or signs of CD, histological confirmation of the disease and the gluten-free diet should be postponed to avoid unnecessary procedures and reduce an additional psychological burden.

Introduction of gluten, HLA status, and the risk of celiac disease in children

BACKGROUND

The relationship between the risk of celiac disease and both the age at which gluten is introduced to a child's diet and a child's early dietary pattern is unclear.

METHODS

We randomly assigned 832 newborns who had a first-degree relative with celiac disease to the introduction of dietary gluten at 6 months (group A) or 12 months (group B). The HLA genotype was determined at 15 months of age, and serologic screening for celiac disease was evaluated at 15, 24, and 36 months and at 5, 8, and 10 years. Patients with positive serologic findings underwent intestinal biopsies. The primary outcome was the prevalence of celiac disease autoimmunity and of overt celiac disease among the children at 5 years of age.

RESULTS

Of the 707 participants who remained in the trial at 36 months, 553 had a standard-risk or high-risk HLA genotype and completed the study. At 2 years of age, significantly higher proportions of children in group A than in group B had celiac disease autoimmunity (16% vs. 7%, P=0.002) and overt celiac disease (12% vs. 5%, P=0.01). At 5 years of age, the between-group differences were no longer significant for autoimmunity (21% in group A and 20% in group B, P=0.59) or overt disease (16% and 16%, P=0.78 by the log-rank test). At 10 years, the risk of celiac disease autoimmunity was far higher among children with high-risk HLA than among those with standard-risk HLA (38% vs. 19%, P=0.001), as was the risk of overt celiac disease (26% vs. 16%, P=0.05). Other variables, including breast-feeding, were not associated with the development of celiac disease.

CONCLUSIONS

Neither the delayed introduction of gluten nor breast-feeding modified the risk of celiac disease among at-risk infants, although the later introduction of gluten was associated with a delayed onset of disease. A high-risk HLA genotype was an important predictor of disease. (Funded by the Fondazione Celiachia of the Italian Society for Celiac Disease; CELIPREV ClinicalTrials.gov number, NCT00639444.).

Treatment of celiac disease: from gluten-free diet to novel therapies

Gluten-free diet (GFD) is the cornerstone treatment for celiac disease (CD). This diet excludes the protein gluten a protein forum in in grains such as wheat, barley, rye and triticale. Gluten causes small intestines inflammation in patients with CD and eating a GFD helps these patients in controlling signs and symptoms and prevent complications. Following a GFD may be frustrating, however, it is important to know that plenty of foods are naturally gluten-free and nowadays is relatively easy to find substitutes for gluten-containing foods. Certain grains, such as oats, are generally safe but can be contaminated with wheat during growing and processing stages of production. For this reason, it is generally recommended avoiding oats unless they are specifically labelled gluten-free. Other products that may contain gluten include food additives, such as malt flavouring, modified food starch and some supplement and/or vitamins that use gluten as a binding agent. Cross-contamination occurs when gluten-free foods come into contact with foods that contain gluten. It can happen during the manufacturing process or if the same equipment is used to make a variety of products. Cross-contamination can also occur at home if foods are prepared on common surfaces or with utensils that have not been cleaned after being used to prepare gluten-containing foods (using a toaster for gluten-free and regular bread). Although safe and effective, the GFD is not ideal: it is expensive, of limited nutritional value, and not readily available in many countries. Consequently, a need exists for novel, non-dietary therapies for celiac disease. Advances in understanding the immunopathogenesis of CD have suggested several types of therapeutic strategies alternative to the GFD. Some of these strategies attempt to decrease the immunogenicity of gluten-containing grains by manipulating the grain itself or by using oral enzymes to break down immunogenic peptides that normally remain intact during digestion. Other strategies focus on preventing the absorption of these peptides, preventing tissue transglutaminase from rendering gluten peptides more immunogenic, or inhibiting their binding to CD-specific antigen-presenting molecules. Strategies that limit T cell migration to the small intestine or that re-establish mucosal homeostasis and tolerance to gluten antigens are also being explored.

Increased prevalence of celiac disease among pediatric patients with irritable bowel syndrome: a 6-year prospective cohort study

IMPORTANCE

Recurrent abdominal pain is a prevalent health issue in childhood. Clinical criteria (ie, the Rome criteria) have been established to aid diagnosis. Studies of adults have shown an increased prevalence of celiac disease among patients with irritable bowel syndrome (IBS); few data are available with regard to children.

OBJECTIVE

To assess the prevalence of celiac disease among children with abdominal pain-related functional gastrointestinal disorders classified according to the Rome criteria.

DESIGN, SETTING, PARTICIPANTS

Six-year (2006-2012) prospective cohort study conducted in a tertiary referral center for the diagnosis and follow-up of gastrointestinal disorders in southern Italy (ie, Bari, Italy). A total of 992 children (42.8% male; median age, 6.8 years) consecutively referred for recurrent abdominal pain by their primary care physicians without previous investigation were evaluated.

EXPOSURE

Patients were classified according to Rome III criteria as having IBS, functional dyspepsia, functional abdominal pain, or abdominal migraine.

MAIN OUTCOMES AND MEASURES

Prevalence of celiac disease in each category of abdominal pain-related functional gastrointestinal disorder. Concentrations of IgA, IgA antitissue transglutaminase, and endomysial antibodies were measured, and a duodenal biopsy was performed in case of antibody positivity.

RESULTS

A total of 992 children were evaluated: 270 were classified as having IBS, 201 as having functional dyspepsia, and 311 as having functional abdominal pain, and 210 children were excluded from the study because they had an organic disorder or some other functional gastrointestinal disorder (not related to abdominal pain). Serologic testing was performed for all 782 children included in the study, and 15 patients tested positive for celiac disease (12 of 270 patients with IBS [4.4%], 2 of 201 patients with functional dyspepsia [1%], and 1 of 311 patients with functional abdominal pain [0.3%]). Children presenting with IBS have a 4 times higher risk of having celiac disease than children without IBS (odds ratio, 4.19 [95% CI, 2.03-8.49]; P < .001).

CONCLUSIONS AND RELEVANCE

The prevalence of celiac disease among children with IBS is 4 times higher than among the general pediatric population. Rome III classification of abdominal pain-related functional gastrointestinal disorders might help to select children who deserve screening for celiac disease.

Clinical, serologic, and histologic features of gluten sensitivity in children

OBJECTIVE

To describe the clinical, serologic, and histologic characteristics of children with gluten sensitivity (GS).

STUDY DESIGN

We studied 15 children (10 males and 5 females; mean age, 9.6 ± 3.9 years) with GS who were diagnosed based on a clear-cut relationship between wheat consumption and development of symptoms, after excluding celiac disease (CD) and wheat allergy, along with 15 children with active CD (5 males and 10 females; mean age, 9.1 ± 3.1 years) and 15 controls with a functional gastrointestinal disorder (6 males and 9 females; mean age, 8.6 ± 2.7 years). All children underwent CD panel testing (native antigliadin antibodies IgG and IgA, anti-tissue transglutaminase antibody IgA and IgG, and anti-endomysial antibody IgA), hematologic assessment (hemoglobin, iron, ferritin, aspartate aminotransferase, erythrocyte sedimentation rate), HLA typing, and small intestinal biopsy (on a voluntary basis in the children with GS).

RESULTS

Abdominal pain was the most prevalent symptom in the children with GS (80%), followed by chronic diarrhea in (73%), tiredness (33%), bloating (26%), limb pain, vomiting, constipation, headache (20%), and failure to thrive (13%). Native antigliadin antibodies IgG was positive in 66% of the children with GS. No differences in nutritional, biochemical, or inflammatory markers were found between the children with GS and controls. HLA-DQ2 was found in 7 children with GS. Histology revealed normal to mildly inflamed mucosa (Marsh stage 0-1) in the children with GS.

CONCLUSION

Our findings support the existence of GS in children across all ages with clinical, serologic, genetic, and histologic features similar to those of adults.

Prevalence and natural history of potential celiac disease in at-family-risk infants prospectively investigated from birth

OBJECTIVE

To evaluate the frequency and the natural history of potential (serology positive/Marsh 0-1 histology) celiac disease (CD) in children with a family risk of CD and factors associated with potential instead of overt (serology positive/Marsh 2-3 histology) CD expression.

STUDY DESIGN

Two-year follow-up study of 96 children (57 females; mean age: 29 ± 12 months) prospectively investigated from birth with: (1) a CD-affected first-degree relative; (2) positivity of serum IgA anti-tissue transglutaminase (tTG) or IgG antigliadin and IgA deficiency; and (3) the results of small intestinal biopsy. Children with potential CD were advised to remain on a gluten containing diet, repeat the celiac antibodies every 6 months, and to have an intestinal biopsy performed in case of persistently high anti-tTG level. Factors discriminating between potential and overt CD were analyzed by decision tree analysis based on the C4.5 algorithm.

RESULTS

Twenty-four children had potential and 72 overt CD. The stronger predictors of potential CD were lack of symptoms, anti-tTG level lower than 11-fold the upper normal limit, age lower than 24 months, and breastfeeding longer than 8 months. Eighteen out of 21 (86%) patients with potential CD continuing a gluten-containing diet became antibody negative, 1/21 (5%) developed overt CD, and 2/21 (9%) had fluctuating antibodies levels after 2 years.

CONCLUSIONS

The prevalence of potential CD and the percentage of short-term loss of CD-related-antibodies are high in infants at-family-risk for CD. In symptomless children with a positive celiac serology, the decision of performing an intestinal biopsy should be preceded by a period of repeated serological testing.

Randomised clinical trial: Lactobacillus reuteri DSM 17938 vs. placebo in children with acute diarrhoea--a double-blind study

BACKGROUND

Probiotics may be of help for the management of acute diarrhoea, however, the effect is strain specific and efficacy needs to be proven.

AIM

To test the efficacy and safety of Lactobacillus reuteri DSM 17938 derived from L. reuteri ATCC 55730 in children with acute diarrhoea. Primary outcomes were the rate of unresolved diarrhoea after 3 days of treatment and duration of diarrhoea.

METHODS

Children (6-36 months), hospitalised in three paediatric hospitals in Southern Italy for acute diarrhoea with clinical signs of dehydration were randomised to receive in a double-blind fashion either L. reuteri (dose of 4 × 10(8) colony-forming units/die) or placebo.

RESULTS

Out of 96 eligible children, 74 were enrolled, five patients were withdrawn; 35 in the L. reuteri group and 34 in the placebo group. Lactobacillus reuteri significantly reduced the duration of watery diarrhoea as compared with placebo (2.1 ± 1.7 days vs. 3.3 ± 2.1 days; P < 0.03); on day two and three of treatment watery diarrhoea persisted in 82% and 74% of the placebo and 55% and 45% of the L. reuteri recipients respectively (P < 0.01; P < 0.03). Finally, children receiving L. reuteri had a significantly lower relapse rate of diarrhoea (15% vs. 42%; P < 0.03). There was not a significant difference in hospital stay between the groups. No adverse events were recorded.

CONCLUSION

Our study shows that L . reuteri DSM 17938 as an adjunct to rehydration therapy is efficacious in the treatment of acute diarrhoea reducing the frequency, duration and recrudescence rate of the disease.

A randomized controlled trial of Lactobacillus GG in children with functional abdominal pain

OBJECTIVE

Our aim was to determine whether Lactobacillus rhamnosus GG (LGG) relieves symptoms in children with recurrent abdominal pain.

PATIENTS AND METHODS

A total of 141 children with irritable bowel syndrome (IBS) or functional pain were enrolled in 9 primary care sites and a referral center. Children entered a randomized, double-blind, placebo-controlled trial and received LGG or placebo for 8 weeks and entered follow-up for 8 weeks. The primary outcome was overall pain at the end of the intervention period. At entry and at the end of the trial, children underwent a double-sugar intestinal permeability test.

RESULTS

Compared with baseline, LGG, but not placebo, caused a significant reduction of both frequency (P < .01) and severity (P < .01) of abdominal pain. These differences still were significant at the end of follow-up (P < .02 and P < .001, respectively). At week 12, treatment success was achieved in 48 children in the LGG group compared with 37 children in the placebo group (P < .03); this difference still was present at the end of follow-up (P < .03). At entry, 59% of the children had abnormal results from the intestinal permeability test; LGG, but not placebo, determined a significant decrease in the number of patients with abnormal results from the intestinal permeability testing (P < .03). These effects mainly were in children with IBS.

CONCLUSIONS

LGG significantly reduces the frequency and severity of abdominal pain in children with IBS; this effect is sustained and may be secondary to improvement of the gut barrier.

Clarithromycin-resistant genotypes and eradication of Helicobacter pylori

OBJECTIVE

To compare the eradication rates among the different point mutations and the efficacy of triple therapy and a sequential regimen according to genotypic resistance.

STUDY DESIGN

Post hoc retrospective cohort study in a tertiary referral center for pediatric gastroenterology in southern Italy. All 168 children who were positive for Helicobacter pylori were enrolled. Patients had received clarithromycin-based 7-day triple therapy (73 children) or 10-day sequential therapy regimen (95 children). Real-time polymerase chain reaction for assessing clarithromycin resistance was performed on sections of paraffin-embedded gastric biopsy samples.

RESULTS

H pylori eradication was achieved in 16 of 32 (50%) children with the A2143G mutation, in 8 of 10 patients with either A2142G or A2142C strains (80%), and in 112 of 116 children with susceptible strains (88.9%). The presence of A2143G mutation was associated with a lower cure rate compared with the rate in the absence of this mutation (50% vs. 89%; P = .001). The sequential regimen achieved a higher cure rate than triple therapy in patients with A2143G mutant strains (80% vs nil; P < .001).

CONCLUSIONS

The A2143G mutation confers higher risk of treatment failure. Sequential regimen has higher efficacy than standard therapy, even in children with A2143G mutatant strains.

Helicobacter pylori status and symptom assessment two years after eradication in pediatric patients from a high prevalence area

OBJECTIVES

To establish the rate of Helicobacter pylori reinfection in children from an H. pylori high prevalence area, possible clinical features predictive of reinfection and the usefulness of re-treatment.

METHODS

65 consecutive children attending the authors' department between 1998 and 2000 who had proven successful H. pylori eradication were enrolled; 52 took part. Patients and family members were invited to undergo C-urea breath testing and to complete a simple questionnaire regarding symptoms and socioeconomic status. Patients with H. pylori reinfection were offered treatment; eradication was assessed by C-urea breath test 8 weeks after completion of treatment.

RESULTS

Of 52 children, 15 (28.8%) were H. pylori positive. Variables predictive of reinfection were age at primary infection and presence of an infected sibling. Although reinfected children were more frequently symptomatic than non-reinfected patients, no specific symptom was associated with reinfection. Of the nine re-treated patients who returned 8 weeks after completing therapy, the bacterium was eradicated in five (56%).

CONCLUSIONS

The 12.8% per year reinfection rate in childhood at 2 years that we observed should prompt a re-evaluation of H. pylori status even after a successful eradication. Living in an H. pylori high prevalence area increases the annual risk of reinfection by approximately fourfold over the annual risk in H. pylori low prevalence areas.

Genomic heterogeneity of hepatitis B virus (HBV) and outcome of perinatal HBV infection

BACKGROUND/AIMS

Data regarding hepatitis B virus (HBV) genomic heterogeneity in perinatal infection are incomplete, although HBV variants might be involved in neonatal fulminant hepatitis (ALF). We investigated HBV variability in infected babies showing different clinical courses.

METHODS

We analyzed HBV genomes isolated from nine vertically infected babies and the mothers of four of them. Two infants born to HBe-antigen (HBeAg)-positive women developed a chronic infection; seven babies (six born to anti-HBe mothers) developed acute hepatitis that had a fulminant course in four cases and a benign course in three. Two babies developing ALF received anti-HBV immunoprophylaxis at birth.

RESULTS

Viruses carrying no significant mutation infected infants born to HBeAg-positive women. HBeAg-defective viruses were detected both in children with benign and fulminant hepatitis and their mothers. A double nucleotide mutation at positions 1762 and 1764 of the HBV core-promoter was found in two of the four infants with ALF, although it was not detected in isolates from the mother of one of them. No significant S gene mutation was found in HBV from any of the babies.

CONCLUSIONS

This study indicates that HBV genomic heterogeneity is not primarily involved either in the evolution of the infection or the failure of neonatal HBV immunoprophylaxis.

Helicobacter pylori and nonulcer dyspepsia in childhood: clinical pattern, diagnostic techniques, and bacterial strains

BACKGROUND

This is a report of the results of a multicenter study performed in children with dyspepsia from five pediatric centers in Puglia, a region in southern Italy. In the study, clinical features of Helicobacter pylori infection, the reliability of diagnostic techniques, and the involvement of bacterial strains were examined.

METHODS

Fifty-three outpatients with dyspepsia enrolled in our study and compiled a diary recording clinical symptoms in patients before they underwent the following diagnostic techniques: endoscopy, biopsy for histologic analysis, rapid urease test, 13C urea breath test, serology specific for immunoglobulin (Ig)G and anti-CagA and VacA.

RESULTS

H. pylori showed a prevalence of 30.2% (n = 16). Histologic positivity was seen in all patients at the antral level (H. pylori-associated chronic gastritis). In the gastric body, bacterial chronic active gastritis was present only in six patients (H. pylori-associated chronic pangastritis). Clinical evaluation showed a significant difference in favor of subjects positive for H. pylori only for epigastric burning and/or pain (p < 0.001). The comparison of results of diagnostic tests, using histology as the gold standard, showed sensitivity and specificity of more than 93% for 13C urea breath test and more than 85% for rapid urease test and serology. Anti-CagA antibodies were found in 64.3% and anti-VacA antibodies in 42.8% of H. pylori-positive patients.

CONCLUSIONS

H. pylori prevalence in children with dyspepsia from the geographic area studied is comparable with that found in other developed countries. Approximately 50% of the studied patients were infected by cytotoxic strains. The urea breath test was the most reliable noninvasive diagnostic tool and is suitable for routine use, although endoscopy with histologic assessment remains the definitive investigation and is particularly important in patients with positive serology for CagA and VacA. Finally, the frequency of aggressive strains in our region seems to affect the clinical pattern; this emphasizes the importance of definitive diagnosis in children and offers a new role for serology.

Halitosis and Helicobacter pylori: a possible relationship

With the aim of investigating a possible relationship between "objective" halitosis (established by sulfide levels in the breath) and Helicobacter pylori, we performed a study in 58 dyspeptic patients reported to suffer from "bad breath." Furthermore, we evaluated the effects on halitosis of eradication therapy (only for H. pylori-positive patients) and chlorhexidine antiseptic mouth rinses (in all patients). Sulfide compound assay indicated objective halitosis in 52/58 patients, 30 of whom were positive and 22 negative for H. pylori. In 19/30 eradication by double therapy provoked a decrease to below the cutoff value of sulfide levels in 15. In the other 11 of the 30 subjects, in whom H. pylori positivity persisted, halitosis parameters did not change. Chlorexidine reduced sulfides to below the cutoff value in 16/22 H. pylori-negative patients, but did not provoke any change in the 11 unsuccessfully treated H. pylori-positive subjects. In these, objective halitosis disappeared only after a successful eradication by triple therapy (9/11). Our results show a possible association between halitosis and H. pylori since bacterial eradication may resolve the symptom. Antiseptic mouthwashes may be effective only in absence of H. pylori, when halitosis may be due to oral putrefactive microbial activity. In a small number of subjects the cause and treatment of halitosis need to be clarified.