Fecal Microbiota Transplantation for Clostridioides difficile Infection in Immunocompromised Pediatric Patients.

OBJECTIVES: We sought to evaluate the safety and effectiveness of fecal microbiota transplantation (FMT) for recurrent Clostridioides difficile infection (CDI) in pediatric immunocompromised (IC) patients. METHODS: This is a multicenter retrospective cohort study of pediatric participants who underwent FMT between March 2013 and April 2020 with 12-week follow-up. Pediatric patients were included if they met the definition of IC and were treated with FMT for an indication of recurrent CDI. We excluded patients over 18 years of age, those with incomplete records, insufficient follow-up, or not meeting study definition of IC. We also excluded those treated for Clostridioides difficile recurrence without meeting the study definition and those with inflammatory bowel disease without another immunocompromising condition. RESULTS: Of 59 pediatric patients identified at 9 centers, there were 42 who met inclusion and no exclusion criteria. Included patients had a median age of 6.7 years. Etiology of IC included: solid organ transplantation (18, 43%), malignancy (12, 28%), primary immunodeficiency (10, 24%), or other chronic conditions (2, 5%). Success rate was 79% after first FMT and 86% after 1 or more FMT. There were no statistically significant differences in patient characteristics or procedural components when patients with a failed FMT were compared to those with a successful FMT. There were 15 total serious adverse events (SAEs) in 13 out of 42 (31%) patients that occurred during the follow-up period; 4 (9.5%) of which were likely treatment-related. There were no deaths or infections with multidrug resistant organisms during follow-up and all patients with a SAE fully recovered. CONCLUSIONS: The success rate of FMT for recurrent CDI in this pediatric IC cohort is high and mirrors data for IC adults and immunocompetent children. FMT-related SAEs do occur (9.5%) and highlight the need for careful consideration of risk and benefit.

Efficacy of Fecal Microbiota Transplantation for Clostridium difficile Infection in Children.

BACKGROUND & AIMS: Fecal microbiota transplantation (FMT) is commonly used to treat Clostridium difficile infection (CDI). CDI is an increasing cause of diarrheal illness in pediatric patients, but the effects of FMT have not been well studied in children. We performed a multi-center retrospective cohort study of pediatric and young adult patients to evaluate the efficacy, safety, and factors associated with a successful FMT for the treatment of CDI. METHODS: We performed a retrospective study of 372 patients, 11 months to 23 years old, who underwent FMT at 18 pediatric centers, from February 1, 2004, to February 28, 2017; 2-month outcome data were available from 335 patients. Successful FMT was defined as no recurrence of CDI in the 2 months following FMT. We performed stepwise logistic regression to identify factors associated with successful FMT. RESULTS: Of 335 patients who underwent FMT and were followed for 2 months or more, 271 (81%) had a successful outcome following a single FMT and 86.6% had a successful outcome following a first or repeated FMT. Patients who received FMT with fresh donor stool (odds ratio [OR], 2.66; 95% CI, 1.39-5.08), underwent FMT via colonoscopy (OR, 2.41; 95% CI, 1.26-4.61), did not have a feeding tube (OR, 2.08; 95% CI, 1.05-4.11), or had 1 less episode of CDI before FMT (OR, 1.20; 95% CI, 1.04-1.39) had increased odds for successful FMT. Seventeen patients (4.7%) had a severe adverse event during the 3-month follow-up period, including 10 hospitalizations. CONCLUSIONS: Based on the findings from a large multi-center retrospective cohort, FMT is effective and safe for the treatment of CDI in children and young adults. Further studies are required to optimize the timing and method of FMT for pediatric patients-factors associated with success differ from those of adult patients.

Fecal Microbiota Transplantation for Recurrent Clostridium difficile Infection and Other Conditions in Children: A Joint Position Paper From the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition.

Fecal microbiota transplantation (FMT) is becoming part of the treatment algorithms against recurrent Clostridium difficile infection (rCDI) both in adult and pediatric gastroenterology practice. With our increasing recognition of the critical role the microbiome plays in human health and disease, FMT is also being considered as a potential therapy for other disorders, including inflammatory bowel disease (Crohn disease, ulcerative colitis), graft versus host disease, neuropsychiatric diseases, and metabolic syndrome. Controlled trials with FMT for rCDI have not been performed in children, and numerous clinical and regulatory considerations have to be considered when using this untraditional therapy. This report is intended to provide guidance for FMT in the treatment of rCDI in pediatric patients.

Baseline Analysis of a Young α-1-Antitrypsin Deficiency Liver Disease Cohort Reveals Frequent Portal Hypertension.

OBJECTIVES: α-1-Antitrypsin (A1AT) deficiency is a common genetic disease with an unpredictable and highly variable course. The Childhood Liver Disease Research and Education Network is a National Institutes of Health, multicenter, longitudinal consortium studying pediatric liver diseases, with the objective of prospectively defining natural history and identifying disease modifiers. METHODS: Longitudinal, cohort study of A1AT patients' birth through 25 years diagnosed as having liver disease, type PIZZ or PISZ. Medical history, physical examination, laboratory, imaging, and standardized survey tool data were collected during the provision of standard of care. RESULTS: In the present report of the cohort at baseline, 269 subjects were enrolled between November 2008 and October 2012 (208 with their native livers and 61 postliver transplant). Subjects with mild disease (native livers and no portal hypertension [PHT]) compared to severe disease (with PHT or postliver transplant) were not different in age at presentation. A total of 57% of subjects with mild disease and 76% with severe disease were jaundiced at presentation (P = 0.0024). A total of 29% of subjects with native livers had PHT, but age at diagnosis and growth were not different between the no-PHT and PHT groups (P > 0.05). Subjects with native livers and PHT were more likely to have elevated bilirubin, ALT, AST, INR, and GGTP than the no-PHT group (P << 0.001), but overlap was large. Chemistries alone could not identify PHT. CONCLUSIONS: Many subjects with A1AT presenting with elevated liver tests and jaundice improve spontaneously. Subjects with PHT have few symptoms and normal growth. Longitudinal cohort follow-up will identify genetic and environmental disease modifiers.

Medical status of 219 children with biliary atresia surviving long-term with their native livers: results from a North American multicenter consortium.

OBJECTIVES: To examine the medical status of children with biliary atresia (BA) with their native livers after hepato- portoenterostomy (HPE) surgery. STUDY DESIGN: The Childhood Liver Disease Research and Education Network database was utilized to examine subjects with BA living with their native livers 5 or more years after HPE and to describe the prevalence of subjects with BA with an "ideal" outcome, defined as no clinical evidence of chronic liver disease, normal liver biochemical indices (aspartate aminotransferase, alanine aminotransferase, γ-glutamyl transpeptidase, platelet count, total bilirubin, international normalized ratio, and albumin), and normal health-related quality of life 5 or more years after HPE. RESULTS: Children with BA (n = 219; 43% male) with median age 9.7 years were studied. Median age at HPE was 56 (range 7-125) days. Median age- and sex-adjusted height and weight z-scores at 5-year follow-up were 0.487 (IQR -0.27 to 1.02) and 0.00 (IQR -0.74 to 0.70), respectively. During the 12 preceding months, cholangitis and bone fractures occurred in 17% and 5.5%, respectively. Health-related quality of life was reported normal by 53% of patients. However, only 1.8% met the study definition of "ideal" outcome. Individual tests of liver synthetic function (total bilirubin, albumin, and international normalized ratio) were normal in 75%, 85%, and 73% of the study cohort. CONCLUSION: Cholangitis and fractures in long-term survivors underscore the importance of ongoing medical surveillance. Over 98% of this North American cohort of subjects with BA living with native livers 5 or more years after HPE have clinical or biochemical evidence of chronic liver disease.

Differences in gut microbiota and fecal bile acids between Caucasian and Hispanic children and young adults with ulcerative colitis.

Ulcerative Colitis (UC) is an inflammatory bowel disease (IBD) that has been associated with gut dysbiosis. Changes in the gut microbiome lead to changes in bile acids (BA) metabolism, which changes the BA profiles in patients with UC. We conducted this study to investigate the differences in bile acids and gut microbiota between Hispanic and Caucasian children and young adults with UC. Twenty-seven Caucasian and 20 Hispanic children and young adults with UC were enrolled in the study. BAs were extracted from the subjects' stool samples and analyzed by liquid chromatography-mass spectrometry. Microbial DNA was also extracted from the stool samples to perform 16s rRNA amplicon sequencing. The median levels of cholic acid and taurolithocholic acid were found to be significantly higher in Hispanic children and young adults with UC compared to their Caucasian counterparts. The abundance of the gut microbiota that metabolizes BAs such as Proteobacteria, Pseudomonadaceae, Pseudomonas, Ruminococcus gnavus, and Escherichia coli were also all significantly higher in Hispanic children and young adults as well. The distinct BA profile that we found in Hispanic children and young adults with UC, in addition to the unique composition of their gut microbiome, provide them with a protective gut environment against inflammation, which is contrary to the common believe that Hispanics have worse IBD.

Short-Chain Fatty Acid Levels after Fecal Microbiota Transplantation in a Pediatric Cohort with Recurrent Clostridioides difficile Infection.

Though antibiotics are the mainstay treatment for Clostridioides difficile, a large population of individuals infected will experience recurrence. In turn, fecal microbiota transplantation (FMT) has emerged as a promising treatment for recurrent C. difficile infection (rCDI). Mechanistically, by providing a healthy, diverse flora to the infected individual, FMT "resets" the underlying gut microbiome dysbiosis associated with rCDI. A proposed mechanism through which this occurs is via microbiome metabolites such as short-chain fatty acids (SCFAs); however, this has not been previously studied in pediatric patients. Using mass spectroscopy, we quantified pre- and post-transplant levels of acetate, isovalerate, butyrate, formate, and propionate in pediatric patients diagnosed with rCDI (n = 9). We compared pre- and post-transplant levels within the rCDI cohort at 1, 3, 6, and 12 months post-transplant and correlated these levels with healthy controls (n = 19). We witnessed a significant difference in the combined SCFA levels and the individual levels of acetate, butyrate, isovalerate, and propionate in the pre-treatment rCDI cohort compared to the healthy controls. In addition, there was a significant increase in combined SCFA levels at 12 months post-transplant within the rCDI group compared to that of their pre-transplant levels, and, more specifically, acetate, propionate, and isovalerate increased from pre-transplant to 12 months post-transplant. The longitudinal aspect of this study allowed us to identify mechanisms that contribute to the durability of responses to FMT, as well as characterize the unique patterns of short-chain fatty acid level recovery in rCDI pediatric patients.

Gut metabolomic profiles in paediatric ulcerative colitis patients prior to and after receiving faecal microbiota transplants.

Ulcerative colitis (UC) is an immune-mediated inflammation of the colonic mucosa. Gut microbiota dysbiosis may play a significant role in disease pathogenesis by causing shifts in metabolomic profiles within the gut. To identify differences and trends in the metabolomic profile of paediatric UC patients pre- and post-faecal microbiota transplants (FMT). Forty-six paediatric patients with mild-to-moderate UC and 30 healthy paediatric patients were enrolled in this study. Baseline stool samples were collected prior to FMT initiation and at months 1, 3, 6, and 12 post-FMT. Pediatric Ulcerative Colitis Activity Index (PUCAI) scores were calculated at baseline and months 1, 3, 6, and 12 after FMT. The average Bray-Curtis dissimilarities to healthy subjects decreased after FMT. In principal coordinate analysis plots, UC patients' centroids drew nearer to healthy individuals. The variance explained by phenotype (Healthy versus UC) reduced and remained significant. From 1 to 3 months after FMT, PUCAI trends were statistically significant and decreasing. PUCAI scores remain flat starting 6 months after FMT. This study concludes that paediatric UC patients have a significantly different baseline metabolite profile than healthy controls. Although being time limited, FMT significantly altered these metabolite profiles and shifted them towards that of healthy controls.

Quantitative profiling of gut microbiota of children with diarrhea-predominant irritable bowel syndrome.

OBJECTIVES: Human intestinal microbiota has a number of important roles in human health and is also implicated in several gastrointestinal disorders. The goal of this study was to determine the gut microbiota in two groups of pre- and adolescent children: healthy volunteers and children diagnosed with diarrhea predominant irritable bowel syndrome (IBS-D). METHODS: Phylogenetic Microbiota Array was used to obtain quantitative measurements of bacterial presence and abundance in subjects ' fecal samples. We utilized high-throughput DNA sequencing, quantitative PCR, and fluorescent in situ hybridization to confirm microarray findings. RESULTS: Both sample groups were dominated by the phyla Firmicutes, Bacteroidetes, and Actinobacteria, which cumulatively constituted 91 % of overall sample composition on average. A core microbiome shared among analyzed samples encompassed 55 bacterial phylotypes dominated by genus Ruminococcus ; members of genera Clostridium , Faecalibacterium, Roseburia, Streptococcus , and Bacteroides were also present. Several genera were found to be differentially abundant in the gut of healthy and IBS groups: levels of Veillonella , Prevotella , Lactobacillus , and Parasporo bacterium were increased in children diagnosed with IBS, whereas members of Bifidobacterium and Verrucomicrobium were less abundant in those individuals. By calculating a nonparametric correlation matrix among abundances of different genera in all samples, we also examined potential associations among intestinal microbes. Strong positive correlations were found between abundances of Veillonella and both Haemophilus and Streptococcus , between Anaerovorax and Verrucomicrobium , and between Tannerella and Anaerophaga . CONCLUSIONS: Although at the higher taxonomical level gut microbiota was similar between healthy and IBS-D children, specific differences in the abundances of several bacterial genera were revealed. Core microbiome in children was dominated by Clostridia. Putative relationships identified among microbial genera provide testable hypotheses of cross-species associations among members of human gut microbiota

Metagenomic Analyses of Multiple Gut Datasets Revealed the Association of Phage Signatures in Colorectal Cancer.

The association of colorectal cancer (CRC) and the human gut microbiome dysbiosis has been the focus of several studies in the past. Many bacterial taxa have been shown to have differential abundance among CRC patients compared to healthy controls. However, the relationship between CRC and non-bacterial gut microbiome such as the gut virome is under-studied and not well understood. In this study we conducted a comprehensive analysis of the association of viral abundances with CRC using metagenomic shotgun sequencing data of 462 CRC subjects and 449 healthy controls from 7 studies performed in 8 different countries. Despite the high heterogeneity, our results showed that the virome alpha diversity was consistently higher in CRC patients than in healthy controls (p-value <0.001). This finding is in sharp contrast to previous reports of low alpha diversity of prokaryotes in CRC compared to healthy controls. In addition to the previously known association of Podoviridae, Siphoviridae and Myoviridae with CRC, we further demonstrate that Herelleviridae, a newly constructed viral family, is significantly depleted in CRC subjects. Our interkingdom association analysis reveals a less intertwined correlation between the gut virome and bacteriome in CRC compared to healthy controls. Furthermore, we show that the viral abundance profiles can be used to accurately predict CRC disease status (AUROC >0.8) in both within-study and cross-study settings. The combination of training sets resulted in rather generalized and accurate prediction models. Our study clearly shows that subjects with colorectal cancer harbor a distinct human gut virome profile which may have an important role in this disease.

16S rRNA and metagenomic shotgun sequencing data revealed consistent patterns of gut microbiome signature in pediatric ulcerative colitis.

Dysbiosis of human gut microbiota has been reported in association with ulcerative colitis (UC) in both children and adults using either 16S rRNA gene or shotgun sequencing data. However, these studies used either 16S rRNA or metagenomic shotgun sequencing but not both. We sequenced feces samples from 19 pediatric UC and 23 healthy children ages between 7 to 21 years using both 16S rRNA and metagenomic shotgun sequencing. The samples were analyzed using three different types of data: 16S rRNA genus level abundance, microbial species and pathway abundance profiles. We demonstrated that (a) the alpha diversity of pediatric UC cases is lower than that of healthy controls; (b) the beta diversity within children with UC is more variable than within the healthy children; (c) several microbial families including Akkermansiaceae, Clostridiaceae, Eggerthellaceae, Lachnospiraceae, and Oscillospiraceae, contain species that are depleted in pediatric UC compared to controls; (d) a few associated species unique to pediatric UC, but not adult UC, were also identified, e.g. some species in the Christensenellaceae family were found to be depleted and some species in the Enterobacteriaceae family were found to be enriched in pediatric UC; and (e) both 16S rRNA and shotgun sequencing data can predict pediatric UC status with area under the receiver operating characteristic curve (AUROC) of close to 0.90 based on cross validation. We showed that 16S rRNA data yielded similar results as shotgun data in terms of alpha diversity, beta diversity, and prediction accuracy. Our study demonstrated that pediatric UC subjects harbor a dysbiotic and less diverse gut microbial population with distinct differences from healthy children. We also showed that 16S rRNA data yielded accurate disease prediction results in comparison to shotgun data, which can be more expensive and laborious. These conclusions were confirmed in an independent data set of 7 pediatric UC cases and 8 controls.

Efficacy and Outcomes of Faecal Microbiota Transplantation for Recurrent Clostridioides difficile Infection in Children with Inflammatory Bowel Disease.

BACKGROUND: Children with inflammatory bowel disease [IBD] are disproportionally affected by recurrent Clostridioides difficile infection [rCDI]. Although faecal microbiota transplantation [FMT] has been used with good efficacy in adults with IBD, little is known about outcomes associated with FMT in paediatric IBD. METHODS: We performed a retrospective review of FMT at 20 paediatric centres in the USA from March 2012 to March 2020. Children with and without IBD were compared with determined differences in the efficacy of FMT for rCDI. In addition, children with IBD with and without a successful outcome were compared with determined predictors of success. Safety data and IBD-specific outcomes were obtained. RESULTS: A total of 396 paediatric patients, including 148 with IBD, were included. Children with IBD were no less likely to have a successful first FMT then the non-IBD affected cohort [76% vs 81%, p = 0.17]. Among children with IBD, patients were more likely to have a successful FMT if they received FMT with fresh stool [p = 0.03], were without diarrhoea prior to FMT [p = 0.03], or had a shorter time from rCDI diagnosis until FMT [p = 0.04]. Children with a failed FMT were more likely to have clinically active IBD post-FMT [p = 0.002] and 19 [13%] patients had an IBD-related hospitalisation in the 3-month follow-up. CONCLUSIONS: Based on the findings from this large US multicentre cohort, the efficacy of FMT for the treatment of rCDI did not differ in children with IBD. Failed FMT among children with IBD was possibly related to the presence of clinically active IBD.

Outcome following thiopurine use in children with ulcerative colitis: a prospective multicenter registry study.

OBJECTIVES: Despite little supporting data, thiopurine use is common in pediatric ulcerative colitis (UC). Our aim was to determine outcome following thiopurine use in a multicenter inception cohort of children diagnosed with UC. METHODS: Data were obtained from a prospective observational study of newly diagnosed children <16 years of age. Data are recorded at diagnosis, 30 days, and quarterly. Patients are managed by physician dictates not protocol. Disease activity is classified by physician global assessment. The primary outcome was corticosteroid (CS)-free inactive UC at 1 year following thiopurine initiation without the need for rescue therapy (infliximab, calcineurin inhibitors, or colectomy). RESULTS: Of 1,490 patients in our registry, 394 have UC (mean age at diagnosis 11.3±3.7 years); 197 (50%) received thiopurine (49% ≤3 months from diagnosis). Also, 84% were receiving CSs and 60% 5-aminosalicylates at thiopurine start. Of the 197 patients, there was insufficient follow-up (41), previous or concomitant use of infliximab (16), or calcineurin inhibitor (7), leaving 133 patients evaluable at 1 year. Of these, 65 (49%) had CS-free inactive UC without rescue therapy. CS-free inactive disease at 1 year after initiating thiopurine was not affected by starting thiopurine ≤3 months vs. >3 months from diagnosis, gender, age, or concomitant treatment with 5-aminosalicylates. Kaplan-Meier analysis showed that the likelihood of remaining free of rescue therapy in the thiopurine-treated patients was 73% at 1 year. CONCLUSIONS: Approximately 50% of children with UC starting thiopurine without previous or concomitant biologic or calcineurin inhibitor therapy have CS-free inactive disease 1 year later without the need for rescue therapy.

Decreased secondary faecal bile acids in children with ulcerative colitis and Clostridioides difficile infection.

BACKGROUND: Patients with ulcerative colitis (UC) have an increased risk of Clostridioides difficile infection (CDI). There is a well-documented relationship between bile acids and CDI. AIMS: To evaluate faecal bile acid profiles and gut microbial changes associated with CDI in children with UC. METHODS: This study was conducted at Children's Hospital Los Angeles. Faecal bile acids and gut microbial genes related to bile acid metabolism were measured in 29 healthy children, 23 children with mild to moderate UC without prior CDI (UC group), 16 children with mild to moderate UC with prior CDI (UC+CDI group) and 10 children without UC with prior CDI (CDI group). RESULTS: Secondary faecal bile acids, especially lithocholic acid (3.296 vs 10.793, P ≤ 0.001) and ursodeoxycholic acid (7.414 vs 10.617, P ≤ 0.0001), were significantly lower in children with UC+CDI when compared to UC alone. Secondary faecal bile acids can predict disease status between these groups with 84.6% accuracy. Additionally, gut microbial genes coding for bile salt hydrolase, 7α-hydroxysteroid dehydrogenase and 7α/ß-dehydroxylation were all diminished in children with UC+CDI compared to children with UC alone. CONCLUSIONS: Bile acids can distinguish between children with UC based on their prior CDI status. Bile acid profile changes can be explained by gut microbial genes encoding for bile salt hydrolase, 7α-hydroxysteroid dehydrogenase and 7α/ß-dehydroxylation. Bile acid profiles may be helpful as biomarkers to identify UC children who have had CDI and may serve as future therapeutic targets.

Reduced fecal short-chain fatty acids in hispanic children with ulcerative colitis.

BACKGROUND: It is known that patients with ulcerative colitis (UC) have reduced numbers of short-chain fatty acid (SCFA) producing bacteria and reduced SCFA concentration in feces. There is also evidence that Hispanic patients have increased incidence of UC and increased likelihood of developing disease at a younger age. To understand why this might be, we compared fiber intake and fecal SCFA concentrations in Hispanic children with UC and non-Hispanic children with UC. METHODS: In this cross-sectional study conducted at the Children's Hospital of Los Angeles, stool was collected from 22 Hispanic and 31 non-Hispanic children with UC. SCFAs in the stool were quantified using mass spectrometry. Diet information was collected at the time of stool collection using food frequency questionnaires. RESULTS: Acetic acid, butyric acid, isovaleric acid, and propionic acid concentrations are significantly lower in Hispanic children with UC compared to age, gender, and disease activity matched non-Hispanic children with UC (p < 0.001). Butyric acid showed the most significant decrease (p = 1.6e-7) There was no significant difference in fiber intake between Hispanic and non-Hispanic children with UC. CONCLUSION: To our knowledge, this is the first study to find that Hispanic children with UC had further reduced SCFAs, independent of disease activity and fiber intake. It is possible that the reduction in SCFAs is related to the colonic disease in Hispanic patients with UC. This may provide more evidence to support the use of SCFA targeted therapies for UC.

Chronic diarrhea.

Chronic diarrhea is a complex and common problem faced by primary care clinicians. Its causes can range from the common and relatively benign excessive juice consumption to the more alarming inflammatory bowel disease (IBD). This paper will review the definition and etiology of chronic diarrhea and aims to provide a simple approach to its diagnosis and management including when, if appropriate, to refer to GI specialist.

Rebaudioside affords hepatoprotection ameliorating sugar sweetened beverage- induced nonalcoholic steatohepatitis.

Sugar-sweetened beverage consumption is a known independent risk factor for nonalcoholic steatohepatitis (NASH). Non-caloric sweeteners (NCS) are food additives providing sweetness without calories and are considered safe and/or not metabolized by the liver. The potential role of newer NCS in the regulation of NASH, however, remain unknown. Our study aimed to determine the impact of newer NCS including Rebaudioside A and sucralose on NASH using high fat diet induced obesity mouse model by substituting fructose and sucrose with NCS in the drinking water. We characterized the phenotype of NCS- treated obesity and investigated the alterations of hepatic function and underlying mechanisms. We found that NCS have no impact on weight gain and energy balance in high fat diet induced obesity. However, in comparison to fructose and sucrose, Rebaudioside A significantly improved liver enzymes, hepatic steatosis and hepatic fibrosis. Additionally, Rebaudioside A improved endoplasmic reticulum (ER) stress related gene expressions, fasting glucose levels, insulin sensitivity and restored pancreatic islet cell mass, neuronal innervation and microbiome composition. We concluded that Rebaudioside A significantly ameliorated murine NASH, while the underlying mechanisms requires further investigation.

High-throughput quantitative analysis of the human intestinal microbiota with a phylogenetic microarray.

Gut microbiota carry out key functions in health and participate in the pathogenesis of a growing number of diseases. The aim of this study was to develop a custom microarray that is able to identify hundreds of intestinal bacterial species. We used the Entrez nucleotide database to compile a data set of bacterial 16S rRNA gene sequences isolated from human intestinal and fecal samples. Identified sequences were clustered into separate phylospecies groups. Representative sequences from each phylospecies were used to develop a microbiota microarray based on the Affymetrix GeneChip platform. The designed microbiota array contains probes to 775 different bacterial phylospecies. In our validation experiments, the array correctly identified genomic DNA from all 15 bacterial species used. Microbiota array has a detection sensitivity of at least 1 pg of genomic DNA and can detect bacteria present at a 0.00025% level of overall sample. Using the developed microarray, fecal samples from two healthy children and two healthy adults were analyzed for bacterial presence. Between 227 and 232 species were detected in fecal samples from children, whereas 191 to 208 species were found in adult stools. The majority of identified phylospecies belonged to the classes Clostridia and Bacteroidetes. The microarray revealed putative differences between the gut microbiota of healthy children and adults: fecal samples from adults had more Clostridia and less Bacteroidetes and Proteobacteria than those from children. A number of other putative differences were found at the genus level.

Rapunzel syndrome-a rare cause of multiple jejunal intussusception.

Trichobezoars are usually without symptoms until they reach a large size. The "Rapunzel" syndrome is a trichobezoar with a long tail extending from the stomach to small bowel. We report the case of a 6-year-old girl with a history of trichotillomania and hair ingestion for three years, who presented with multiple jejunojejunal intussusceptions due to a trichobezoar with a long, 90-cm tail into the small bowel. To our knowledge, this is the first report of trichobezoars as a cause of jejunal intussusceptions, which should be suspected in the appropriate clinical circumstances.