Gut Microbiota In Children Research Articles

Helicobacter pylori and the intestinal microbiome among healthy school-age children.

Helicobacterpylori (H. pylori) infection is acquired during childhood and causes chronic gastritis that remains asymptomatic in most infected people. H. pylori alters the gastric microbiota and causes peptic ulcer disease. Evidence on the relationship between asymptomatic H. pylori infection and children's gut microbiota remains elusive. We characterized the relationship between H. pylori infection and the intestinal microbiome of healthy children, adjusting for known inter-personal and environmental exposures. This cross-sectional study included stool samples obtained from 163 Israeli Arab children aged 6-9years from different socioeconomic strata. Sociodemographic information was collected through maternal interviews. H. pylori infection was determined using monoclonal antigen detection stool enzyme immunoassay. The gut microbiome was characterized by implementing 16S rRNA gene sequencing of the V4 region and a multivariate downstream analysis. Overall, 57% of the participants were positive for H. pylori infection and it was significantly associated with low socioeconomic status. There was no significant association between H. pylori infection and bacterial richness of fecal microbiome. H. pylori infection was significantly associated with intestinal bacterial composition, including a strong association with Prevotellacopri and Eubacteriumbiforme. Moreover, socioeconomic status was strongly associated with bacterial composition. H. pylori infection in healthy children was significantly associated with altered intestinal microbiome structure. Socioeconomic determinants exhibit a strong effect, related to both H. pylori infection and intestinal diversity and composition in childhood. These findings are clinically important to the understanding of the role of H. pylori infection and other intestinal microbes in health and disease.

Digestibility and Bioaccessibility of Leaf Protein Concentrates and their Impact on Children Gut Microbiota

Digestibility and Bioaccessibility of Leaf Protein Concentrates and their Impact on Children Gut Microbiota

Characteristics of Gut Microbiota in Children With Biliary Atresia After Liver Transplantation.

Background and AimsBiliary atresia (BA) is an idiopathic neonatal cholestasis and is the most common indication in pediatric liver transplantation (LT). Previous studies have suggested that the gut microbiota (GM) in BA is disordered. However, the effect of LT on gut dysbiosis in patients with BA has not yet been elucidated.MethodsPatients with BA (n = 16) and healthy controls (n = 10) were recruited. In the early life of children with BA, Kasai surgery is a typical procedure for restoring bile flow. According to whether BA patients had previously undergone Kasai surgery, we divided the post-LT patients into the with-Kasai group (n = 8) and non-Kasai group (n = 8). Fecal samples were collected in both the BA and the control group; among BA patients, samples were obtained again 6 months after LT. A total of 40 fecal samples were collected, of which 16 were pre-LT, 14 were post-LT (8 were with-Kasai, 6 were non-Kasai), and 10 were from the control group. Metagenomic sequencing was performed to evaluate the GM.ResultsThe Kruskal-Wallis test showed a statistically significant difference in the number of genes between the pre-LT and the control group, the pre-LT and the post-LT group (P < 0.05), but no statistical difference between the post-LT and the control group. Principal coordinate analysis also showed that the microbiome structure was similar between the post-LT and control group (P > 0.05). Analysis of the GM composition showed a significant decrease in Serratia, Enterobacter, Morganella, Skunalikevirus, and Phifllikevirus while short chain fatty acid (SCFA)-producing bacteria such as Roseburia, Blautia, Clostridium, Akkermansia, and Ruminococcus were increased after LT (linear discriminant analysis > 2, P < 0.05). However, they still did not reach the normal control level. Concerning functional profiles, lipopolysaccharide metabolism, multidrug resistance, polyamine biosynthesis, GABA biosynthesis, and EHEC/EPEC pathogenicity signature were more enriched in the post-LT group compared with the control group. Prior Kasai surgery had a specific influence on the postoperative GM.ConclusionLT partly improved the GM in patients with BA, which provided new insight into understanding the role of LT in BA.

Effects of Probiotic Bacteria Lactobacillaceae on the Gut Microbiota in Children With Celiac Disease Autoimmunity: A Placebo-Controlled and Randomized Clinical Trial.

Disturbances of the gut microbiota may influence the development of various autoimmune diseases. This study investigated the effects of supplementations with the probiotic bacteria, Lactiplantibacillus plantarum HEAL9 and Lacticaseibacillus paracasei 8700:2, on the microbial community in children with celiac disease autoimmunity (CDA). The study included 78 genetically predisposed children for celiac disease with elevated levels of tissue transglutaminase autoantibodies (tTGA) signaling for ongoing CDA. Among those children, 38 received a placebo and 40 received the probiotic supplement daily for 6 months. Fecal and plasma samples were collected at baseline and after 3 and 6 months, respectively. The bacterial community was investigated with 16S rRNA gene sequencing and terminal restriction fragment length polymorphism (T-RFLP), and tTGA levels were measured in radiobinding assays. In children that received probiotic supplementation, the relative abundance of Lactobacillaceae increased over time, while it remained unchanged in the placebo group. There was no overall correlation between tTGA levels and bacterial genus except for a positive correlation between Dialister and IgG-tTG in the probiotic group. The abundance of specific bacterial amplicon sequence variant (ASV:s) changed during the study in both groups, indicating that specific bacterial strains might be affected by probiotic supplementation.

A Meta-analysis of Gut Microbiota in Children with Autism.

Previous studies have reported dysbiosis in the gut microbiota (GM) of children with autism spectrum disorders (ASD), which may be a determining factor on child development through the microbiota-gut-brain axis. However, it is not clear if there is a specific group of dysbiotic bacteria in ASD. The aim of this study was to carry out a meta-analysis on the studies that analyze GM in children with ASD. 18 studies fulfilled our selection criteria. Our results showed a lower relative abundance of Streptococcus (SMD+ = -0.999; 95% CI -1.549, -0.449) and Bifidobacterium genera (SMD+ = -0.513; 95% CI -0.953, -0.073) in children with ASD. Overall, the Bifidobacterium genera is involved. However, differences found between studies are attributed to factors such as reporting bias.

Neurodevelopment correlates with gut microbiota in a cross-sectional analysis of children at 3\xa0years of age in rural China

We investigated cross-sectional associations between children’s neurodevelopment and their gut microbiota composition. Study children (36 months of age) lived in rural China (n = 46). Neurodevelopment was assessed using the Bayley Scales of Infant Development, 2nd Edition, yielding the Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI). Children's gut microbiota was assessed using 16S rRNA gene profiling. Microbial diversity was characterized using alpha diversity patterns. Additionally, 3 coabundance factors were determined for the 25 most abundant taxa. Multivariable linear regression models were constructed to examine the relationships between Bayley scores (MDI and PDI) and children's gut microbiota. In adjusted models, MDI and PDI scores were not associated with alpha diversity indices. However, in adjusted models, MDI and PDI scores were positively associated with the first coabundance factor, which captured positive loadings for the genera Faecalibacterium, Sutterella, and Clostridium cluster XIVa. For an interquartile range increase in the first coabundance factor, MDI scores increased by 3.9 points [95% confidence interval (CI): 0, 7.7], while PDI scores increased by 8.6 points (95% CI 3.1, 14). Our results highlight the potential for gut microbial compositional characteristics to be important correlates of children's Bayley Scales performance at 36 months of age.

The Composition and Diversity of the Gut Microbiota in Children Is Modifiable by the Household Dogs: Impact of a Canine-Specific Probiotic.

The development of the infant gut microbiota is initiated during pregnancy and continued through early life and childhood, guided by the immediate environment of the child. Our aim was to characterize the shared microbiota between dogs and children as well as to determine whether introduction to dogs of a dog-specific probiotic combination modifies the transfer process. We studied 31 children from allergic families with pet dog(s) and 18 control families without a dog. Altogether 37 dogs were randomized for a 4-week period in a double-blind design to receive canine-derived probiotic product containing a mixture of L. fermentum, L. plantarum, and L. rhamnosus, or placebo. Fecal samples from children and dogs were taken before and after the treatment. Distinctive gut microbiota composition was observed in children with dogs compared to those without a dog, characterized by higher abundance of Bacteroides and short-chain fatty acid producing bacteria such as Ruminococcus and Lachnospiraceae. Probiotic intervention in dogs had an impact on the composition of the gut microbiota in both dogs and children, characterized by a reduction in Bacteroides. We provide evidence for a direct effect of home environment and household pets on children microbiota and document that modification of dog microbiota by specific probiotics is reflected in children’s microbiota.

Antimicrobial Prophylaxis and Modifications of the Gut Microbiota in Children with Cancer.

In children with cancer, chemotherapy can produce cytotoxic effects, resulting in immunosuppression and an augmented risk of febrile neutropenia and bloodstream infections. This has led to widespread use of antibiotic prophylaxis which, combined with intensive chemotherapy treatment, could have a long-term effect on the gastrointestinal microbiome. In this review, we aimed to analyze the current literature about the widespread use of antibiotic prophylaxis in children experiencing infectious complications induced by chemotherapy and its effects on the gut microbiome. Our review of the literature shows that antimicrobial prophylaxis in children with cancer is still a trending topic and, at the moment, there are not enough data to define universal guidelines. Children with cancer experience long and painful medical treatments and side effects, which are associated with great economic and social burdens, important psychological consequences, and dysbiosis induced by antibiotics and also by chemotherapy. Considering the importance of a healthy gut microbiota, studies are needed to understand the impact of dysbiosis in response to therapy in these children and to define how to modulate the microbiome to favor a positive therapeutic outcome.

Effect of Antibiotics on The Gut Microbiota in Children with Chronic Pancreatitis

Objectives: Little is known about the effect of antibiotic treatment on the gut microbiota in children with chronic pancreatitis (CCP). Our objective was to identify the effect of antibiotic treatment on the gut microbiota in children with chronic pancreatitis (CCP), the main gut microbiota genera and characterize the patients’ functional mutations after using antibiotics. Methods: The 16S rRNA sequencing method was used to compare the gut microbiota of healthy controls (HCs) with CCP using and not using antibiotics. Results: All CCP demonstrated a significantly reduced alpha diversity of the gut microbiota (P＜0.01). The gut microbiota's alpha diversity and the abundance of genera’s beta diversity did not show statistical differences between the non-antibiotics and antibiotics groups. There were 15 altered genera with common abundance in the non-antibiotics and antibiotics groups compared to the HC group. The area under the curve (AUC) of the top three probiotics, i.e., Faecalibacterium, Eubacterium, and Subdoligranulum, was 0.91. Among the 13 genera altered in the non-antibiotics group, the top three genera were not appropriate as biomarkers for cases receiving antibiotics. Compared to these 13 genera, the differences between the genera and the proportion of gram-positive bacteria in the 17 genera altered only in the antibiotics group were not statistically significant. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated that the antibiotics caused alterations in the abundance of certain genera. The enriched functions and the altered gut microbiota in the two groups had their enriched functions. Conclusion: The use of antibiotics affects the gut microbiota of CCP, but the effect of disease on gut microbiota is still obvious, which may help diagnosis and further investigation into the pathogenic mechanisms of CP. Chronic pancreatitis (CP) is a persistent fibro-inflammatory process of the pancreas associated with genetic, environmental, and other pathogenic factors. This disease eventually led to the pancreas' irreversible injury and increased risk of pancreatic cancer and impaired mental health [1-3].

Respiratory and Gut Microbiota of Children with Cystic Fibrosis: A Pilot Study

Differences in the clinical presentation of cystic fibrosis (CF) may be due to microbiota components and their relationship with the host’s immune system. In this pilot study, we aimed to investigate the composition of the respiratory and gut microbiota of a cohort of clinically stable children with CF, homozygous for the p.Phe508del mutation. Oropharyngeal swabs and stool samples were obtained from these children attending the CF referral clinics at the Hospital of Clinics, Federal University Paraná (CHC – UFPR). Oropharyngeal and gut microbiota were assessed by V3-V4 sequencing of the 16S ribosomal RNA, and bioinformatics analyses were performed using a proprietary pipeline. We identified a total of 456 bacterial taxa belonging to 164 genera, of which 65 (39.6 %) were common to both the respiratory and gastrointestinal tracts. Taxa from eight genera dominated more than 75 % of the microbial composition of both the niches. Among these dominant taxa, only Prevotella spp. were common to both the sites. Overall, the respiratory and gut microbiota were homogeneous among all the patients. Longitudinal studies targeting a larger cohort are important for an improved understanding of how the composition of bacterial communities is related to changes in the clinical status of CF

This Month in Pediatric Urology

You have accessJournal of UrologyThis Month in Pediatric Urology1 Dec 2020This Month in Pediatric Urology Stacy T. Tanaka Stacy T. TanakaStacy T. Tanaka More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000001267AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail Three articles in this issue of The Journal focus on common pediatric urological diagnoses: bladder-bowel dysfunction (BBD), febrile urinary tract infection (fUTI) in infants and distal hypospadias. These authors paused while seeing these everyday cases to ask how we can improve care for patients with these routine diagnoses. Development and Validation of Symptom Score for Total Bladder-Bowel Dysfunction: Subscales for Overactive Bladder and Dysfunctional Voiding Because bladder-bowel dysfunction encompasses such a wide range of symptoms, including infrequent voiding, genital pain and urinary frequency, many clinicians take an “I know it when I see it” approach to clinical assessment. BBD negatively affects outcomes in children with vesicoureteral reflux and recurrent urinary tract infections. However, research studies on these topics are limited unless we have a standardized assessment method. Sillén et al (1333) from Sweden present a validated BBD symptom score for children 3 to 16 years old.1 Children with monosymptomatic enuresis, which is not included in the definition of BBD, were excluded. This instrument improves on existing pediatric questionnaires. It is able to distinguish between storage and emptying dysfunction, and it can assess treatment response. Currently the questionnaire has only been validated in Swedish. Use of a standardized BBD questionnaire across research studies should be a common goal of the pediatric urology community. Impact of Long-Term Low Dose Antibiotic Prophylaxis on Gut Microbiota in Children Following febrile urinary tract infection antibiotic prophylaxis is routinely started in infants with vesicoureteral reflux. There has been concern that altering the microbiome can increase the risk of obesity and pediatric allergic diseases. Akagawa et al (1320) from Japan performed 16S ribosomal gene sequencing on stool samples of infants treated for fUTI before, during and 5 to 6 months after antibiotic treatment.2 Continuous antibiotic prophylaxis with trimethoprim-sulfamethoxazole was started in those infants diagnosed with vesicoureteral reflux, while those without reflux served as controls. Although gut microbiota diversity initially decreased after treatment of fUTI, diversity recovered 1 to 2 months after treatment and was maintained in both groups. Antibiotic resistance could not be measured by this methodology. The results from this small study are reassuring and offer novel insights regarding the many infants who are started on antibiotic prophylaxis. Competency in Tubularized Incised Plate Repair for Distal Hypospadias: Cumulative Sum Learning Curve Analysis of a Single Surgeon Experience Distal hypospadias repair is a common pediatric urological procedure. Zu’bi et al (1326) from Canada and Madison, Wisconsin asked the question “How long does it take after establishing independent practice for a single surgeon to become competent and proficient?”3 They found that the complication rate and operative time started to decrease after the 234th case. The study has limitations because complications can continue to arise long after the initial procedure. Although the results are not surprising, the study prompts frank discussion of the importance of tracking our own complication rates, whether just starting or in practice for many years, and the technical modifications we can make to lower them.

Early Gut Fungal and Bacterial Microbiota and Childhood Growth.

Introduction: Childhood growth is a sensitive marker of health. Animal studies show increased height and weight velocity in the presence of fungal as well as antibiotic supplement in feed. Human studies on early gut microbiota and anthropometrics have mainly focused on bacteria only and overweight, with diverging results. We thus aimed to investigate the associations between childhood growth [height and body mass index (BMI)] and early fungal and bacterial gut microbiota.Methods: In a population-based cohort, a subset of 278 pregnant mothers was randomized to drink milk with or without probiotic bacteria during and after pregnancy. We obtained fecal samples in offspring at four time points between 0 and 2 years and anthropometric measurements 0 and 9 years. By quantitative PCR and 16S/ITS rRNA gene sequencing, children's gut microbiota abundance and diversity were analyzed against height standard deviation score (SDS) and BMI-SDS and presented as effect estimate (β) of linear mixed models.Results: From 278 included children (149 girls), 1,015 fecal samples were collected. Maternal probiotic administration did not affect childhood growth, and the groups were pooled. Fungal abundance at 2 years was positively associated with height-SDS at 2–9 years (β = 0.11 height-SDS; 95% CI, 0.00, 0.22) but not with BMI-SDS. Also, higher fungal abundance at 1 year was associated with a lower BMI-SDS at 0–1 year (β = −0.09 BMI-SDS; 95% CI, −0.18, −0.00), and both bacterial abundance and bacterial alpha diversity at 1 year were associated with lower BMI-SDS at 0–1 year (β = −0.13 BMI-SDS; 95% CI, −0.22, −0.04; and β = −0.19 BMI-SDS; 95% CI, −0.39, −0.00, respectively).Conclusions: In this prospective cohort following 0–9-year-old children, we observed that higher gut fungal abundances at 2 years were associated with taller children between 2 and 9 years. Also, higher gut fungal and bacterial abundances and higher gut bacterial diversity at 1 year were associated with lower BMI in the first year of life. The results may indicate interactions between early gut fungal microbiota and the human growth-regulating physiology, previously not reported.Clinical Trial Registration: Clinicaltrials.gov, NCT00159523.

Changes in the Gut Microbiota of Children with Autism Spectrum Disorder.

Alterations in the gut microbiota may influence gastrointestinal (GI) dysbiosis frequently reported in individuals with autism spectrum disorder (ASD). In this study, we sequenced the bacterial 16S rRNA gene to evaluate changes in fecal microbiota between 48 children with ASD and 48 healthy children in China. At the phylum level, the number of Firmicutes, Proteobacteria, and Verrucomicrobia decreased in children with ASD, while the Bacteroidetes/Firmicutes was significantly higher in autistic children due to enrichment of Bacteroidetes. At the genus level, the amount of Bacteroides, Prevotella, Lachnospiracea_incertae_sedis, and Megamonas increased, while Clostridium XlVa, Eisenbergiella, Clostridium IV, Flavonifractor, Escherichia/Shigella, Haemophilus, Akkermansia, and Dialister decreased in children with ASD relative to the controls. Significant increase was observed in the number of species synthesizing branched-chain amino acids (BCAAs), like Bacteroides vulgatus and Prevotella copri, while the numbers of Bacteroides fragilis and Akkermansia muciniphila decreased in children with ASD compared to the controls. Most importantly, the highest levels of pathogenic bacteria were different for each child with ASD in this cohort. We found that only one functional module, cellular antigens, was enriched in children with ASD, and other pathways like lysine degradation and tryptophan metabolism were significantly decreased in children with ASD. These findings provide further evidence of altered gut microbiota in Chinese ASD children and may contribute to the treatment of patients with ASD. LAY SUMMARY: This study characterized the gut bacteria composition of 48 children with ASD and 48 neurotypical children in China. The metabolic disruptions caused by altered gut microbiota may contribute significantly to the neurological pathophysiology of ASD, including significant increases in the number of species synthesizing BCAAs, and decreases in the number of probiotic species. These findings suggest that a gut microbiome-associated therapeutic intervention may provide a novel strategy for treating GI symptoms frequently seen in individuals with ASD. Autism Res 2020, 13: 1614-1625. © 2020 International Society for Autism Research, Wiley Periodicals, Inc.

Composition of Gut Microbiota in Children with Autism Spectrum Disorder: A Systematic Review and Meta-Analysis.

Background: Autism spectrum disorder (ASD) is a public health problem and has a prevalence of 0.6%–1.7% in children. As well as psychiatric symptoms, dysbiosis and gastrointestinal comorbidities are also frequently reported. The gut–brain microbiota axis suggests that there is a form of communication between microbiota and the brain underlying some neurological disabilities. The aim of this study is to describe and compare the composition of gut microbiota in children with and without ASD. Methods: Electronic databases were searched as far as February 2020. Meta-analyses were performed using RevMan5.3 to estimate the overall relative abundance of gut bacteria belonging to 8 phyla and 17 genera in children with ASD and controls. Results: We included 18 studies assessing a total of 493 ASD children and 404 controls. The microbiota was mainly composed of the phyla Bacteroidetes, Firmicutes, and Actinobacteria, all of which were more abundant in the ASD children than in the controls. Children with ASD showed a significantly higher abundance of the genera Bacteroides, Parabacteroides, Clostridium, Faecalibacterium, and Phascolarctobacterium and a lower percentage of Coprococcus and Bifidobacterium. Discussion: This meta-analysis suggests that there is a dysbiosis in ASD children which may influence the development and severity of ASD symptomatology. Further studies are required in order to obtain stronger evidence of the effectiveness of pre- or probiotics in reducing autistic behaviors.

Restitution of gut microbiota in Ugandan children administered with probiotics (Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp. lactis BB-12) during treatment for severe acute malnutrition

ABSTRACT Severe acute malnutrition (SAM) is a major challenge in low-income countries and gut microbiota (GM) dysbiosis may play a role in its etiology. Here, we determined the GM evolution during rehabilitation from SAM and the impact of probiotics (Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp. lactis BB-12) supplementation. The GM (16S rRNA gene amplicon sequencing) of children admitted to hospital with SAM showed distinct composition over admission (e.g. Klebsiella spp., and Enterobacteriaceae spp.), discharge (e.g. Clostridiaceae spp., Veilonella dispar) and follow-up (e.g. Lactobacillus ruminis, Blautia spp., Faecalibacterium prausnitzii), reaching similar β- and α-diversity as healthy individuals. Children with diarrhea had reduced distribution of Bacteroidaceae, Lachnospiraceae, increased Enterobacteriaceae and Moraxellaceae, and lower α-diversity. Children suffering from edematous SAM had diminished proportion of Prevotellaceae, Lachnospiraceae, Ruminoccaceae and a higher α-diversity when compared to non-edematous SAM. Supplementation of probiotics did not influence β-diversity upon discharge or follow-up, but it increased (p < .05) the number of observed species [SE: > 4.5]. Children where the probiotic species were detected had lower cumulative incidence (p < .001) of diarrhea during the follow-up period compared to children receiving placebo and children receiving probiotics, but where the probiotics were not detected. The GM of children with non-edematous and edematous SAM differ in composition, which might have implications for future GM targeted treatments. Probiotics treatment reduced the cumulative incidence of diarrhea during the outpatient phase, with the strongest effect in children where the administered probiotics could be detected in the GM.

Antibiotic Resistance Genes in the Gut Microbiota of Children with Autistic Spectrum Disorder as Possible Predictors of the Disease

The gut microbiota (GM), which contains thousands of bacterial species, is a reservoir of antibiotic resistance genes (ARGs) called resistome. Early life exposure to antibiotics alters significantly the composition and function of the gut microbiota of children, which may trigger symptoms of autism spectrum disorder (ASD). This is because the GM plays an important role in the bidirectional communication between the gut and the brain and influences the brain normal functioning through multiple pathways. The goal of this article is to study the distribution of ARGs in the GM of 3- to 5-year-old healthy children and children with ASD living in Moscow, Russia. The metagenomic analysis of samples from both groups revealed differences in the signatures between them. The signatures consisted of the bacterial genera and aminoglycoside, β-lactam, macrolide, and tetracycline resistance genes that they harbored. Our results show an increase in ARGs in the resistome of the GM of children with ASD. These findings emphasize the negative influence of early-life antibiotic therapy. We found three ARGs, aac(6')-aph(2''), cepA-49, and tet(40), which could serve as markers of ASD. The additional functions carried out by the enzymes, encoded by these genes, are being discussed.

An approach to gut microbiota profile in children with autism spectrum disorder.

In recent years, there has been an increase in studies on the implications of gut microbiota (GM) on the behaviour of children with autism spectrum disorders (ASD) due to a dysbiosis in GM that can trigger onset, development or progression of ASD through the microbiota-gut-brain axis. The aim of this study is to carry out a systematic review of articles from the last 6 years that analyse GM in children with ASD compared to GM in control groups. Children with ASD showed a higher abundance of Roseburia and Candida genera, and lower abundance of Dialister, Bilophila, Veillonella, Streptococcus, Coprococcus and Prevotella genera. Those differences can be attributed to factors such as different nationalities, nature of control groups, place where the sample was taken, gastrointestinal (GI) problems or bacterial detection methods. It is still too early to define a specific GM profile of children with ASD, and future studies should focus on homogenizing the characteristics of samples and control groups. Furthermore, new multicentre studies should also focus on the impact of GM on GI physiology, neurophysiology and behaviour of children with ASD, and on performing psychometric analyses of the correlation between the severity of ASD behavioural symptoms and GM profiles.

Epigenetics and Gut Microbiota in Children With Epilepsy

Epigenetics and Gut Microbiota in Children With Epilepsy

Dynamics of the Gut Microbiota in Children Receiving Selective or Total Gut Decontamination Treatment during Hematopoietic Stem Cell Transplantation.

Bloodstream infections and graft-versus-host disease are common complications after hematopoietic stem cell transplantation (HSCT) procedures, associated with the gut microbiota that acts as a reservoir for opportunistic pathogens. Selective gut decontamination (SGD) and total gut decontamination (TGD) during HSCT have been associated with a decreased risk of developing these complications after transplantation. However, because studies have shown conflicting results, the use of these treatments remains subject of debate. In addition, their impact on the gut microbiota is not well studied. The aim of this study was to elucidate the dynamics of the microbiota during and after TGD and to compare these with the dynamics of SGD. In this prospective, observational, single-center study fecal samples were longitudinally collected from 19 children eligible for allogenic HSCT (TGD, n=12; SGD, n=7), weekly during hospital admission and monthly after discharge. In addition, fecal samples were collected from 3 family stem cell donors. Fecal microbiota structure of patients and donors was determined by 16S rRNA gene amplicon sequencing. Microbiota richness and diversity markedly decreased during SGD and TGD and gradually increased after cessation of decontamination treatment. During SGD, gut microbiota composition was relatively stable and dominated by Bacteroides, whereas it showed high inter- and intraindividual variation and low Bacteroides abundance during TGD. In some children TGD allowed the genera Enterococcus and Streptococcus to thrive during treatment. A gut microbiota dominated by Bacteroides was associated with increased predicted activity of several metabolic processes. Comparing the microbiota of recipients and their donors indicated that receiving an SCT did not alter the patient's microbiota to become more similar to that of its donor. Overall, our findings indicate that SGD and TGD affect gut microbiota structure in a treatment-specific manner. Whether these treatments affect clinical outcomes via interference with the gut microbiota needs to be further elucidated.

Impact of Westernized Diet on Gut Microbiota in Children on Leyte Island.

Urbanization has changed life styles of the children in some towns and cities on Leyte island in the Philippines. To evaluate the impact of modernization in dietary habits on gut microbiota, we compared fecal microbiota of 7 to 9-year-old children from rural Baybay city (n = 24) and urban Ormoc city (n = 19), and assessed the correlation between bacterial composition and diet. A dietary survey indicated that Ormoc children consumed fast food frequently and more meat and confectionary than Baybay children, suggesting modernization/westernization of dietary habits. Fat intake accounted for 27.2% of the total energy intake in Ormoc children; this was remarkably higher than in their Baybay counterparts (18.1%) and close to the upper limit (30%) recommended by the World Health Organization. Their fecal microbiota were analyzed by high-throughput 16S rRNA gene sequencing in conjunction with a dataset from five other Asian countries. Their microbiota were classified into two enterotype-like clusters with the other countries’ children, each defined by high abundance of either Prevotellaceae (P-type) or Bacteroidaceae (BB-type), respectively. Baybay and Ormoc children mainly harbored P-type and BB-type, respectively. Redundancy analysis showed that P-type favored carbohydrates whereas BB-type preferred fats. Fat intake correlated positively with the Firmicutes-to-Bacteroidetes (F/B) ratio and negatively with the relative abundance of the family Prevotellaceae/genus Prevotella. A species-level analysis suggested that dietary fat positively correlated with an Oscillibacter species as well as a series of Bacteroides/Parabacteroides species, whereas dietary carbohydrate positively correlated with Dialister succinatiphilus known as succinate-utilizing bacteria and some succinate-producing species of family Prevotellaceae, Veillonellaceae, and Erysipelotrichaceae. We also found that a Succinivibrio species was overrepresented in the P-type community, suggesting the syntroph via hydrogen and succinate. Predicted metagenomics suggests that BB-type microbiota is well nourished and metabolically more active with simple sugars, amino acids, and lipids, while P-type community is more involved in digestion of complex carbohydrates. Overweight and obese children living in Ormoc, who consumed a high-fat diet, harbored microbiota with higher F/B ratio and low abundance of Prevotella. The altered gut microbiota may be a sign of a modern diet-associated obesity among children in developing areas.