Characterization of Bacterial and Fungal Microbiome in Children with Hirschsprung Disease with and without a History of Enterocolitis: A Multicenter Study

Microbiota analysis in individuals with type two diabetes mellitus and end‑stage renal disease: A pilot study

Chronic kidney disease (CKD) is a widespread health concern, which affects ~9.1% of the global population and 12-15% of individuals in upper-middle income countries. Notably, ~2% of patients with CKD progress to end-stage renal disease (ESRD), which leads to a substantial decline in the quality of life, an increased risk of mortality and significant financial burden. Patients with ESRD often still suffer from uremia and uremic syndromes, due to the accumulation of toxins between dialysis sessions and the inadequate removal of protein-bound toxins during dialysis. A number of these toxins are produced by the gut microbiota through the fermentation of dietary proteins or cholines. Furthermore, the gut microbial community serves a key role in maintaining metabolic and immune equilibrium in individuals. The present study aimed to investigate the gut microbiota patterns in individuals with type 2 diabetes mellitus (T2DM) and ESRD via quantitative PCR analysis of the 16S and 18S ribosomal RNA of selected members of the gut microbiota. Individuals affected by both T2DM and ESRD displayed distinctive features within their intestinal microbiota. Specifically, there were increased levels of Gammaproteobacteria observed in these patients, and all subjects exhibited a notably increased presence of Enterobacteriaceae compared with healthy individuals. This particular microbial community has established connections with the presence of inflammatory processes in the colon. Moreover, the elevated levels of Enterobacteriaceae may serve as an indicator of an imbalance in the intestinal microbiota, a condition known as dysbiosis. In addition, the Betaproteobacteria phylum was significantly more prevalent in the stool samples of patients with both T2DM and ESRD when compared with the control group. In conclusion, the present pilot study focused on gut microbiome alterations in T2DM and ESRD. Understanding the relationship between dysbiosis and CKD may identify new areas of research and therapeutic interventions aimed at modulating the gut microbiota to improve the health and outcomes of individuals with CKD and ESRD.

Malian Children's Core Gut Mycobiome

Because data on the fungal gut community structure of African children are scarce, we aimed to describe it by reanalysing rRNA ITS1 and ITS2 metabarcoding data from a study designed to assess the influence of microbiota in malaria susceptibility in Malian children from the Dogon country. More specifically, we aimed to establish the core gut mycobiome and compare the gut fungal community structure of breastfed children, aged 0-2 years, with other age groups. Briefly, DNA was extracted from 296 children's stool samples. Both rRNA ITS1 and ITS2 genomic barcodes were amplified and subjected to Illumina MiSeq sequencing. The ITS2 barcode generated 1,975,320 reads and 532 operational taxonomic units (OTUs), while the ITS1 barcode generated 647,816 reads and 532 OTUs. The alpha diversity was significantly higher by using the ITS1 compared to the ITS2 barcode (p < 0.05); but, regardless of the ITS barcode, we found no significant difference between breastfed children, aged 0-2 years, compared to the other age groups. The core gut mycobiome of the Malian children included Saccharomyces cerevisiae, Candida albicans, Pichia kudriavzevii, Malassezia restricta, Candida tropicalis and Aspergillus section Aspergillus, which were present in at least 50% of the 296 children. Further studies in other African countries are warranted to reach a global view of African children's core gut mycobiome.

Candida spp. in Human Intestinal Health and Disease: More than a Gut Feeling

Fungi are an essential part of the normal collection of intestinal microorganisms, even though their collective abundance comprises only 0.1-1% of all fecal microbes. The composition and role of the fungal population is often studied in relation to early-life microbial colonization and development of the (mucosal) immune system. The genus Candida is frequently described as one of the most abundant genera, and altered fungal compositions (including elevated abundance of Candida spp.) have been linked with intestinal diseases such as inflammatory bowel disease and irritable bowel syndrome. These studies are performed using both culture-dependent and genomic (metabarcoding) techniques. In this review, we aimed to summarize existing data on intestinal Candida spp. colonization in relation to intestinal disease and provide a brief overview of the biological and technical challenges in this field, including the recently described role of sub-species strain variation of intestinal Candida albicans. Together, the evidence for a contributing role of Candida spp. in pediatric and adult intestinal disease is quickly expanding, even though technical and biological challenges may limit full understanding of host-microbe interactions.

A unicentric cross-sectional observational study on chronic intestinal inflammation in total colonic aganglionosis: beware of an underestimated condition

BACKGROUND

Inflammatory Bowel Diseases (IBD) are known to occur in association with Hirschsprung disease (HSCR). Most of cases are represented by Crohn Disease (CD) occurring in patients with Total Colonic Aganglionosis (TCSA) with an estimated prevalence of around 2%. Based on these considerations and on a number of provisional data belonging to our Center for Digestive Diseases, we developed a unicentric cross-sectional observational study aimed at describing phenotype, genotype, pathology and metagenomics of all patients with TCSA and Crohn-like lesions.

RESULTS

Out of a series of 62 eligible TCSA patients, 48 fulfilled inclusion criteria and were enrolled in the study. Ten patients did not complete the study due to non-compliance or withdrawal of consent and were subsequently dropped out. A total of 38 patients completed the study. All patients were tested for chronic intestinal inflammation by a combination of fecal calprotectine (FC) or occult fecal blood (OFB) and underwent fecal metagenomics. Nineteen (50%) tested positive for FC, OFB, or both and subsequently underwent retrograde ileoscopy. Fourteen patients (36.8%) presented Crohn-like lesions, occurring after a median of 11.5 years after surgery (range 8 months - 21.5 years). No statistically significant differences regarding demographic, phenotype and genotype were observed comparing patients with and without lesions, except for need for blood transfusion that was more frequent in those with lesions. Faecal microbiome of patients with lesions (not that of caregivers) was less biodiverse and characterized by a reduction of Bacteroidetes, and an overabundance of Proteobacteria. FC tested negative in 3/14 patients with lesions (21%).

CONCLUSIONS

Our study demonstrated an impressive 10-folds higher incidence of chronic inflammation in TCSA. Up to 50% of patients may develop IBD-like lesions postoperatively. Nonetheless, we failed in identifying specific risk factors to be used to implement prevention strategies. Based on the results of our study, we suggest screening all TCSA patients with retrograde ileoscopy regardless of FC/OFB values. The frequency of endoscopic assessments and the role of FC/OFB screening in prompting endoscopy is yet to be determined.

Comparation of robotic-assisted surgery and laparoscopic‑assisted surgery in children with Hirschsprung's disease: a single-centered retrospective study

BACKGROUND

There are few studies comparing robotic-assisted surgery (RAS) and laparoscopic-assisted surgery (LAS) in Hirschsprung's disease (HSCR). This study aimed to compare intraoperative and postoperative outcomes between RAS and LAS performed during the same period.

METHODS

All consecutive 75 patients with pathologically diagnosed as HSCR who underwent Swenson pull-through surgery from April 2020 to Nov 2022, were included. Patients were divided into RAS group and LAS group and a retrospective analysis was performed based on clinical indexes and prognosis.

RESULTS

A total of 75 patients were included, among which, 31 patients received RAS and 44 received LAS. The RAS and LAS groups had similar ages, sex, weight, postoperative hospital stays, and fasting times. Compared with LAS, blood loss (p = 0.002) and the incidence of Hirschsprung-associated enterocolitis (p = 0.046) were significantly lower in the RAS group. The first onset of Hirschsprung-associated enterocolitis in patients younger than 3 months occurred significantly earlier (p = 0.043). Two patients experienced anastomotic leakage in the LAS group and one patient experienced incisional hernia in the RAS group. The cost of RAS was significantly higher than that of LAS (p < 0.0001).

CONCLUSIONS

RAS is a safe and effective alternative for HSCR children, and a delaying primary surgery until later in infancy (> 3 months) may improve outcomes.

Proton pump inhibitors induced fungal dysbiosis in patients with gastroesophageal reflux disease

Gut mycobiota inhabits human gastrointestinal lumen and plays a role in human health and disease. We investigated the influence of proton pump inhibitors (PPIs) on gastric mucosal and fecal mycobiota in patients with gastroesophageal reflux diseases (GERD) by using Internal Transcribed Spacer 1 sequencing. A total of 65 participants were included, consisting of the healthy control (HC) group, GERD patients who did not use PPIs (nt-GERD), and GERD patients who used PPIs, which were further divided into short-term (s-PPI) and long-term PPI user (l-PPI) groups based on the duration of PPI use. The alpha diversity and beta diversity of gastric mucosal mycobiota in GERD patients with PPI use were significantly different from HCs, but there were no differences between s-PPI and l-PPI groups. LEfSe analysis identified Candida at the genus level as a biomarker for the s-PPI group when compared to the nt-GERD group. Meanwhile, Candida, Nothojafnea, Rhizodermea, Ambispora, and Saccharicola were more abundant in the l-PPI group than in the nt-GERD group. Furthermore, colonization of Candida in gastric mucosa was significantly increased after PPI treatment. However, there was no significant difference in Candida colonization between patients with endoscopic esophageal mucosal breaks and those without. There were significant differences in the fecal mycobiota composition between HCs and GERD patients regardless whether or not they used PPI. As compared to nt-GERD patient samples, there was a high abundance of Alternaria, Aspergillus, Mycenella, Exserohilum, and Clitopilus in the s-PPI group. In addition, there was a significantly higher abundance of Alternaria, Aspergillus, Podospora, Phallus, and Monographella in the l-PPI group than nt-GERD patients. In conclusion, our study indicates that dysbiosis of mycobiota was presented in GERD patients in both gastric mucosal and fecal mycobiota. PPI treatment may increase the colonization of Candida in the gastric mucosa in GERD patients.

Hirschsprung's disease associated enterocolitis: A comprehensive review

Hirschsprung's disease (HSCR) is a congenital disorder characterized by failure of the neural crest cells to migrate and populate the distal bowel during gestation affecting different lengths of intestine leading to a distal functional obstruction. Surgical treatment is needed to correct HSCR once the diagnosis is confirmed by demonstrating the absence of ganglion cells or aganglionosis of the affected bowel segment. Hirschsprung's disease associated enterocolitis (HAEC) is an inflammatory complication associated with HSCR that can present either in the pre- or postoperative period and associated with increased morbidity and mortality. The pathogenesis of HAEC remains poorly understood, but intestinal dysmotility, dysbiosis and impaired mucosal defense and intestinal barrier function appear to play a significant role. There is no clear definition for HAEC, but the diagnosis is primarily clinical, and treatment is guided based on severity. Here, we aim to provide a comprehensive review of the clinical presentation, etiology, pathophysiology, and current therapeutic options for HAEC.

Update on the Pathogenesis of the Hirschsprung-Associated Enterocolitis

Despite the significant progress that has been made in terms of understanding the pathophysiology and risk factors of Hirschsprung-associated enterocolitis (HAEC), the morbidity rate has remained unsatisfactorily stable, and clinical management of the condition continues to be challenging. Therefore, in the present literature review, we summarized the up-to-date advances that have been made regarding basic research on the pathogenesis of HAEC. Original articles published between August 2013 and October 2022 were searched in a number of databases, including PubMed, Web of Science, and Scopus. The keywords "Hirschsprung enterocolitis", "Hirschsprung's enterocolitis", "Hirschsprung's-associated enterocolitis", and "Hirschsprung-associated enterocolitis" were selected and reviewed. A total of 50 eligible articles were obtained. The latest findings of these research articles were grouped into gene, microbiome, barrier function, enteric nervous system, and immune state categories. The present review concludes that HAEC is shown to be a multifactorial clinical syndrome. Only deep insights into this syndrome, with an accrual of knowledge in terms of understanding its pathogenesis, will elicit the necessary changes that are required for managing this disease.

Microcytic hypochromic Anemia is a risk factor for postoperative HAEC: A retrospective study

Background

Hirschsprung-associated enterocolitis (HAEC) is a common and life-threatening complication of Hirschsprung's disease (HSCR), which can occur before and after surgery. The aim of this study was to identify the risk factors associated with the development of HAEC.

Methods

We retrospectively reviewed the medical records of HSCR patients admitted to the Children's Hospital of Shanxi Province, China, between January 2011 and August 2021. Diagnosis of HAEC was made using a scoring system with cutoff values ≥4 and included the patient's history, physical examination, and radiological and laboratory findings. The results are shown as frequency (%). The chi-square test was used to analyze a single factor with a significance level of P < 0.05. Logistic regression analysis was used to analyze multiple factors.

Results

A total of 324 patients were included in this study, with 266 males and 58 females. In total, 34.3% (111/324) of patients had HAEC, including 85 males and 26 females; 18.9% (61/324) of patients had preoperative HAEC; and 15.4% (50/324) of patients had postoperative HAEC within one year after surgery. Gender, age at definitive therapy, and feeding methods were not found to be associated with preoperative HAEC in univariate analysis. Respiratory infection was associated with preoperative HAEC (P = 0.00003). No association was found between gender and age at definitive therapy and postoperative HAEC. Postoperative HAEC was associated with microcytic hypochromic anemia (P = 0.00058), preoperative history of HAEC (P = 0.00120), the creation of a preoperative stoma (P = 0.00097), long segment or total colon HSCR (P = 0.00057), and hypoalbuminemia (P = 0.03225). Regression analysis showed that microcytic hypochromic anemia (OR=2.716, 95% CI = 1.418-5.203, P = 0.003), preoperative history of HAEC (OR=2.814, 95% CI = 1.429-5.542, P = 0.003), the creation of a preoperative stoma (OR=2.332, 95% CI = 1.003-5.420, P = 0.049), and long segment or total colon HSCR (OR=2.167, 95% CI = 1.054-4.456, P = 0.035) were associated with postoperative HAEC.

Conclusion

This study revealed that the incidence of preoperative HAEC at our hospital was associated with respiratory infections. In addition, microcytic hypochromic anemia, preoperative history of HAEC, the creation of a preoperative stoma, and long segment or total colon HSCR were risk factors of postoperative HAEC. The most important finding of this study was that microcytic hypochromic anemia was a risk factor for postoperative HAEC, which has been rarely reported. Further studies with larger sample sizes are necessary to confirm these findings.

Dysbiotic but nonpathogenic shift in the fecal mycobiota of patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is closely associated with the oral and gut microbiomes. Fungal cell wall components initiate inflammatory arthritis in mouse models. However, little is known regarding the role of the fungal community in the pathogenesis of RA. To evaluate the association between RA and the gut microbiome, investigations of bacterial and fungal communities in patients with RA are necessary. Therefore, we investigated the compositions and associations of fecal bacterial and fungal communities in 30 healthy controls and 99 patients with RA. The relative abundances of Bifidobacterium and Blautia decreased, whereas the relative abundance of Streptococcus increased, in patients with RA. The relative abundance of Candida in the fecal fungal community was higher in patients with RA than in healthy controls, while the relative abundance of Aspergillus was higher in healthy controls than in patients with RA. Candida species-specific gene amplification showed that C. albicans was the most abundant species of Candida. Ordination analysis and random forest classification models supported the findings of structural changes in bacterial and fungal communities. Aspergillus was the core fecal fungal genus in healthy controls, although Saccharomyces spp. are typically predominant in Western cohorts. In addition, bacterial-fungal association analyses showed that the hub node had shifted from fungi to bacteria in patients with RA. The finding of fungal dysbiosis in patients with RA suggests that fungi play critical roles in the fecal microbial communities and pathogenesis of RA.

Mycobiota and diet-derived fungal xenosiderophores promote Salmonella gastrointestinal colonization

The fungal gut microbiota (mycobiota) has been implicated in diseases that disturb gut homeostasis, such as inflammatory bowel disease. However, little is known about functional relationships between bacteria and fungi in the gut during infectious colitis. Here we investigated the role of fungal metabolites during infection with the intestinal pathogen Salmonella enterica serovar Typhimurium, a major cause of gastroenteritis worldwide. We found that, in the gut lumen, both the mycobiota and fungi present in the diet can be a source of siderophores, small molecules that scavenge iron from the host. The ability to use fungal siderophores, such as ferrichrome and coprogen, conferred a competitive growth advantage to Salmonella strains expressing the fungal siderophore receptors FhuA or FhuE in vitro and in a mouse model. Our study highlights the role of inter-kingdom cross-feeding between fungi and Salmonella and elucidates an additional function of the gut mycobiota, revealing the importance of these understudied members of the gut ecosystem during bacterial infection.

Risk factors for Hirschsprung-associated enterocolitis following Soave: a retrospective study over a decade

Background

Hirschsprung-associated enterocolitis (HAEC), one of the most significant causes of morbidity and mortality for patients with Hirschsprung disease (HSCR), can occur before and after radical surgery. This study aims to identify the risk factors for HAEC before and after Soave. 

Methods

A retrospective study of 145 patients with HSCR treated by transanal or combination with laparoscopic or laparotomy Soave procedure between January 2011 and June 2021 was performed. Data were retrieved from the medical records. HAEC was defined as the presence of clinical signs of bowel inflammation and requiring treatment with intravenous antibiotics and rectal irrigation for at least two days in the outpatient or inpatient department. Univariate analysis and multivariate regression models were used to identify risk factors for developing pre-and postoperative HAEC.

Results

The incidence of pre-and postoperative HAEC was 24.1% and 20.7%, respectively. More than 90% of the patients with the first episode of postoperative HAEC occurred within the first year after Soave. Long-segment aganglionosis was the independent risk factor for developing preoperative HAEC ([OR] 5.8, Cl 2.4–14.2, p < 0.001), while the history of preoperative HAEC was significantly associated with developing postoperative HAEC ([OR] 4.2, Cl 1.6–10.8, p = 0.003).

Conclusions

Long-segment aganglionosis was the independent risk factor for the development of preoperative HAEC, and the history of preoperative HAEC was strongly associated with developing HAEC after Soave.

Level of Evidence

Level III

A pilot study characterizing longitudinal changes in fecal microbiota of patients with Hirschsprung-associated enterocolitis

PURPOSE

Hirschsprung disease is a neurointestinal disease that occurs due to failure of enteric neural crest-derived cells to complete their rostrocaudal migration along the gut mesenchyme, resulting in aganglionosis along variable lengths of the distal bowel. Despite the effective surgery that removes the aganglionic segment, children with Hirschsprung disease remain at high risk for developing a potentially life-threatening enterocolitis (Hirschsprung-associated enterocolitis). Although the etiology of this enterocolitis remains poorly understood, several recent studies in both mouse models and in human subjects suggest potential involvement of gastrointestinal microbiota in the underlying pathogenesis of Hirschsprung-associated enterocolitis.

METHODS

We present the first study to exploit the Illumina MiSeq next-generation sequencing platform within a longitudinal framework focused on microbiomes of Hirschsprung-associated enterocolitis in five patients. We analyzed bacterial communities from fecal samples collected at different timepoints starting from active enterocolitis and progressing into remission.

RESULTS

We observed compositional differences between patients largely attributable to variability in age at the time of sample collection. Remission samples across patients exhibited compositional similarity, including enrichment of Blautia, while active enterocolitis samples showed substantial variability in composition.

CONCLUSIONS

Overall, our findings provide continued support for the role of GI microbiota in the pathogenesis of Hirschsprung-associated enterocolitis.

Tachygastria in Preterm Infants: A Longitudinal Cohort Study

OBJECTIVES

Tachygastria is a gastric dysrhythmia (>4 to ≤9 cycles per minute, cpm) associated with gastric hypomotility and gastrointestinal disorders. Healthy preterm infants spend more time in tachygastria than adults; however, normative values are not defined. We sought to determine the percent of time preterm infants spend in tachygastria.

METHODS

We conducted a longitudinal, prospective cohort study with weekly electrogastrography (EGG) recordings in 51 preterm <34 weeks' gestation and 5 term (reference) infants. We calculated percentage recording time in tachygastria (% tachygastria) and determined the mean ± standard deviation (SD) across EGG sessions. Mixed effects model was performed to test weekly variance in % tachygastria and gestational age effect. Successive pre- and post-prandial measurements were obtained to assess reproducibility of % tachygastria. We compared time to achieve full feeds between subjects with % tachygastria within 1 SD from the mean versus % tachygastria >1 SD from mean.

RESULTS

Three hundred seventy-six EGG sessions were completed (N = 56). Mean % tachygastria was 40% with SD ±5%. We demonstrated no change in % tachygastria across 9 postnatal weeks (P = 0.70) and no gestational age effect. No difference was demonstrated between successive pre- (P = 0.91) and post-prandial (P = 0.96) % tachygastria. Infants with 35%-45% tachygastria (within 1 SD from mean) had higher gestational age and less time to achieve full feeds than infants with <35% or >45% tachygastria.

CONCLUSIONS

EGG is a reproducible tool to assess % tachygastria in preterm infants. Clinical significance of increased or decreased % tachygastria needs further investigation to validate if 35%-45% tachygastria is safe for feeding.

Associations of Mucosal Nerve Fiber Innervation Density with Hirschsprung-Associated Enterocolitis: A Retrospective Three-Center Cohort Study

OBJECTIVE

 Hirschsprung's disease (HSCR) is a congenital intestinal neurodevelopmental disorder characterized by the absence of enteric ganglion cells in the distal colon. Although Hirschsprung-associated enterocolitis (HAEC) is the most frequent life-threatening complication in HSCR, to date reliable biomarkers predicting the likelihood of HAEC are yet to be established. We established a three-center retrospective study including 104 HSCR patients surgically treated between 1998 and 2019.

MATERIALS AND METHODS

 Patient-derived cryopreserved or paraffin-preserved colonic tissue at surgery was analyzed via βIII-tubulin immunohistochemistry. We subsequently determined extrinsic mucosal nerve fiber density in resected rectosigmoid specimens and classified HSCR patients accordingly into nerve fiber-high or fiber-low groups. We compared the distribution of clinical parameters obtained from medical records between the fiber-high (n = 36) and fiber-low (n = 68) patient groups. We assessed the association between fiber phenotype and enterocolitis using univariate and multivariate logistic regression adjusted for age at operation.

RESULTS

 Enterocolitis was more prevalent in patients with sparse mucosal nerve fiber innervation (fiber-low phenotype, 87%) compared with the fiber-high phenotype (13%; p = 0.002). In addition, patients developing enterocolitis had a younger age at surgery (3 vs. 7 months; p = 0.016). In the univariate analysis, the odds for enterocolitis development in the fiber-low phenotype was 5.26 (95% confidence interval [CI], 1.67-16.59; p = 0.005) and 4.01 (95% CI, 1.22-13.17; p = 0.022) when adjusted for age.

CONCLUSION

 Here, we showed that HSCR patients with a low mucosal nerve fiber innervation grade in the distal aganglionic colon have a higher risk of developing HAEC. Consequently, histopathologic analysis of the nerve fiber innervation grade could serve as a novel sensitive prognostic marker associated with the development of enterocolitis in HSCR patients.

Identification and validation of the common pathogenesis and hub biomarkers in Hirschsprung disease complicated with Crohn’s disease

Background

Although increasing evidence has supported that Hirschsprung disease (HSCR) is the risk factor for children developing Crohn’s disease (CD), the common mechanism of its co-occurrence remains unknown. The purpose of this study is to further explore the underlying mechanism and biomarkers for the co-occurrence of HSCR and CD.

Methods

The Gene Expression Omnibus (GEO) database was used to obtain gene expression profiles for CD (GSE95095) and HSCR (GSE98502). Following the identification of the shared differentially expressed genes (DEGs) of CD and HSCR, functional annotation, protein–protein interaction (PPI) network creation, and module assembly were performed to discover hub genes. RT-qPCR was performed to validate the expression of the hub genes in HSCR samples. The receiver operating characteristic (ROC) curve was utilized to assess the accuracy of the hub genes as biomarkers in predicting CD in both the training dataset and test dataset.

Results

A total of 103 common DEGs (50 downregulated genes and 53 upregulated genes) were chosen for further investigation. The importance of chemokines and cytokines in these two disorders is highlighted by functional analysis. MCODE plug identified three important modules, which functionally enriched the immune system process. Finally, nine hub genes were identified using cytoHubba, including IL1B, IL10, CXCL10, ICAM1, EGR1, FCGR3A, S100A12, S100A9, and FPR1. The nine hub genes were mainly enriched in immune- and inflammation-related pathways. External data profiles and RT-qPCR confirmed the expression of the nine hub genes in HSCR and CD. ROC analysis revealed that the nine hub genes had a strong diagnostic value.

Conclusion

Our study reveals the common pathogenesis of HSCR and CD. These hub genes and diagnostic models may provide novel insight for the diagnosis and treatment of HSCR complicated with CD.

A Novel Method for Identifying the Transition Zone in Long-Segment Hirschsprung Disease: Investigating the Muscle Unit to Ganglion Ratio

Hirschsprung disease (HSCR) is characterised by the absence of enteric ganglia along variable lengths of the distal bowel. Current gold standard treatment involves the surgical resection of the defective, aganglionic bowel. Clear and reliable distinction of the normoganglionated bowel from the transition zone is key for successful resection of the entire defective bowel, and the avoidance of subsequent postoperative complications. However, the intraoperative nature of the tissue analysis and the variability of patient samples, sample preparation, and operator objectivity, make reproducible identification of the transition zone difficult. Here, we have described a novel method for using muscle units as a distinctive landmark for quantifying the density of enteric ganglia in resection specimens from HSCR patients. We show that the muscle unit to ganglion ratio is greater in the transition zone when compared with the proximal, normoganglionated region for long-segment HSCR patients. Patients with short-segment HSCR were also investigated, however, the muscle unit to ganglion ratio was not significantly different in these patients. Immunohistochemical examination of individual ganglia showed that there were no differences in the proportions of either enteric neurons or glial cells through the different regions of the resected colon. In addition, we identified that the size of enteric ganglia was smaller for patients that went on to develop HSCR associated enterocolitis; although the density of ganglia, as determined by the muscle unit to ganglia ratio, was not different when compared with patients that had no further complications. This suggests that subtle changes in the enteric nervous system, even in the “normoganglionated” colon, could be involved in changes in immune function and subsequent bacterial dysbiosis.

Different Fecal Microbiota in Hirschsprung's Patients With and Without Associated Enterocolitis

Background and Objectives

Patients with Hirschsprung's disease are at risk of developing Hirschsprung-associated enterocolitis, especially in the first 2 years of life. The pathophysiology of this inflammatory disease remains unclear, and intestinal dysbiosis has been proposed in the last decade. The primary objective of this study was to evaluate in a large cohort if Hirschsprung-associated enterocolitis was associated with alterations of fecal bacterial composition compared with HD without enterocolitis in different age groups.

Methods

We analyzed the fecal microbiota structure of 103 Hirschsprung patients from 3 months to 16 years of age, all of whom had completed definitive surgery for rectosigmoid Hirschsprung. 16S rRNA gene sequencing allowed us to compare the microbiota composition between Hirschsprung's disease patients with (HAEC group) or without enterocolitis (HD group) in different age groups (0-2, 2-6, 6-12, and 12-16 years).

Results

Richness and diversity increased with age group but did not differ between HD and HAEC patients, irrespective of the age group. Relative abundance of Actinobacteria was lower in HAEC than in HD patients under 2 years of age (-66%, P = 0.045). Multivariate analysis by linear models (MaAsLin) considering sex, medications, birth mode, breast-feeding, and the Bristol stool scale, as well as surgery parameters, highlighted Flavonifractor plautii and Eggerthella lenta, as well as Ruminococcus gnavus group, as positively associated with Hirschsprung-associated enterocolitis in the 0-2 years age group.

Conclusion

Hirschsprung-associated enterocolitis was associated with features of intestinal dysbiosis in infants (0-2 years) but not in older patients. This could explain the highest rate of enterocolitis in this age group.

Clinical Trial Registration

https://clinicaltrials.gov/ct2/show/NCT02857205, MICROPRUNG, NCT02857205, 02/08/2016.

Probiotics for the prevention of Hirschsprung-associated enterocolitis

BACKGROUND

Hirschsprung-associated enterocolitis (HAEC) is a leading cause of serious morbidity and potential mortality in children with Hirschsprung's disease (HD). People with HAEC suffer from intestinal inflammation, and present with diarrhoea, explosive stools, and abdominal distension. Probiotics are live microorganisms with beneficial health effects, which can optimise gastrointestinal function and gut flora. However, the efficacy and safety of probiotic supplementation in the prevention of HAEC remains unclear.

OBJECTIVES

To assess the effects of probiotic supplements used either alone or in combination with pharmacological interventions on the prevention of Hirschsprung-associated enterocolitis.

SEARCH METHODS

We searched CENTRAL, PubMed, Embase, the China BioMedical Literature database (CBM), the World Health Organization International Clinical Trials Registry, ClinicalTrials.gov, the Chinese Clinical Trials Registry, Australian New Zealand Clinical Trials Registry, and Clinical Trials Registry-India, from database inception to 27 February 2022. We also searched the reference lists of relevant articles and reviews for any additional trails.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing probiotics and placebo, or any other non-probiotic intervention, for the prevention of HAEC were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias of the included studies; disagreements were resolved by discussion with a third review author. We assessed the certainty of evidence using the GRADE approach. We calculated odds ratios (ORs) with 95% confidence intervals (CIs) for dichotomous outcomes.

MAIN RESULTS

We included two RCTs, with a total of 122 participants. We judged the overall risk of bias as high. We downgraded the evidence due to risk of bias (random sequence generation, allocation concealment, and blinding) and small sample size. The evidence is very uncertain about the effect of probiotics on the occurrence of HAEC (OR 0.58, 95% CI 0.10 to 3.43; I² = 74%; 2 studies, 120 participants; very low-certainty evidence). We found one included study that did not measure serious adverse events and one included study that reported no serious adverse events related to probiotics. Probiotics may result in little to no difference between probiotics and placebo in relation to the severity of children with HAEC at Grade I (OR 0.66, 95% CI 0.14 to 3.16; I² = 25%; 2 studies, 120 participants; low-certainty evidence). The effects of probiotics on the severity of HAEC at Grade II are very uncertain (OR 1.14, 95% CI 0.01 to 136.58; I² = 86%; 2 studies, 120 participants; very low-certainty evidence). Similarly, the evidence suggests that probiotics results in little to no difference in relation to the severity of HAEC at Grade III (OR 0.43, 95% CI 0.05 to 3.45; I² = 0%; 2 studies, 120 participants; low-certainty evidence). No overall mortality or withdrawals due to adverse events were reported. Probiotics may result in little to no difference in the recurrence of episodes of HAEC compared to placebo (OR 0.85, 95% CI 0.24 to 3.00; 1 study, 60 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

There is currently not enough evidence to assess the efficacy or safety of probiotics for the prevention of Hirschsprung-associated enterocolitis when compared with placebo. The presence of low- to very-low certainty evidence suggests that further well-designed and sufficiently powered RCTs are needed to clarify the true efficacy of probiotics.

E. coli JM83 damages the mucosal barrier in Ednrb knockout mice to promote the development of Hirschsprung‑associated enterocolitis via activation of TLR4/p‑p38/NF‑κB signaling

Hirschsprung-associated enterocolitis (HAEC) is characterized by intestinal mucosal damage and an imbalance in the intestinal microbiota. Recent studies have indicated that the TLR4/p-p38/NF-κB signaling pathway in the intestine is of great importance to intestinal mucosal integrity. The present study aimed to investigate the role of TLR4/phosphorylated (p-)38/NF-κB signaling in the pathogenesis of HAEC in E. coli JM83-infected endothelin receptor B (Ednrb)^−/− mice. Ednrb^−/− mice were infected with E. coli JM83 by oral gavage to establish the HAEC model. Wild-type and Ednrb^−/− mice were randomly divided into uninfected and E. coli groups. The role of TLR4/p-p38/NF-κB signaling was further evaluated by in vivo and in vitro analyses. The activation of the TLR4/p-p38/NF-κB signaling pathway induced by E. coli JM83 resulted in HAEC in Ednrb^−/− mice, which was evidenced by a significant increase in the expression of TNF-α, TGF-β and IL-10, and a decreased density of F-actin protein expression. TLR4 knockdown reduced the severity of enterocolitis and attenuated the expression of IL-10, TNF-α and TGF-β, whilst increasing the density of F-actin protein in Ednrb^−/− mice after E. coli infection. These results indicated that E. coli JM83 activates TLR4/p-p38/NF-κB signaling in Ednrb^−/− to promote the development of HAEC. Thus, inhibition of this signaling pathway may benefit the treatment and prevention of HAEC.

Cholinergic Signaling Attenuates Pro-Inflammatory Interleukin-8 Response in Colonic Epithelial Cells

Infants affected by Hirschsprung disease (HSCR), a neurodevelopmental congenital disorder, lack ganglia of the intrinsic enteric nervous system (aganglionosis) in a variable length of the colon, and are prone to developing severe Hirschsprung-associated enterocolitis (HAEC). HSCR patients typically show abnormal dense innervation of extrinsic cholinergic nerve fibers throughout the aganglionic rectosigmoid. Cholinergic signaling has been reported to reduce inflammatory response. Consequently, a sparse extrinsic cholinergic innervation in the mucosa of the rectosigmoid correlates with increased inflammatory immune cell frequencies and higher incidence of HAEC in HSCR patients. However, whether cholinergic signals influence the pro-inflammatory immune response of intestinal epithelial cells (IEC) is unknown. Here, we analyzed colonic IEC isolated from 43 HSCR patients with either a low or high mucosal cholinergic innervation density (fiber-low versus fiber-high) as well as from control tissue. Compared to fiber-high samples, IEC purified from fiber-low rectosigmoid expressed significantly higher levels of IL-8 but not TNF-α, IL-10, TGF-β1, Muc-2 or tight junction proteins. IEC from fiber-low rectosigmoid showed higher IL-8 protein concentrations in cell lysates as well as prominent IL-8 immunoreactivity compared to IEC from fiber-high tissue. Using the human colonic IEC cell line SW480 we demonstrated that cholinergic signals suppress lipopolysaccharide-induced IL-8 secretion via the alpha 7 nicotinic acetylcholine receptor (a7nAChR). In conclusion, we showed for the first time that the presence of a dense mucosal cholinergic innervation is associated with decreased secretion of IEC-derived pro-inflammatory IL-8 in the rectosigmoid of HSCR patients likely dependent on a7nAChR activation. Owing to the association between IL-8 and enterocolitis-prone, fiber-low HSCR patients, targeted therapies against IL-8 might be a promising immunotherapy candidate for HAEC treatment.

Enteric nervous system modulation of luminal pH modifies the microbial environment to promote intestinal health

The enteric nervous system (ENS) controls many aspects of intestinal homeostasis, including parameters that shape the habitat of microbial residents. Previously we showed that zebrafish lacking an ENS, due to deficiency of the sox10 gene, develop intestinal inflammation and bacterial dysbiosis, with an expansion of proinflammatory Vibrio strains. To understand the primary defects resulting in dysbiosis in sox10 mutants, we investigated how the ENS shapes the intestinal environment in the absence of microbiota and associated inflammatory responses. We found that intestinal transit, intestinal permeability, and luminal pH regulation are all aberrant in sox10 mutants, independent of microbially induced inflammation. Treatment with the proton pump inhibitor, omeprazole, corrected the more acidic luminal pH of sox10 mutants to wild type levels. Omeprazole treatment also prevented overabundance of Vibrio and ameliorated inflammation in sox10 mutant intestines. Treatment with the carbonic anhydrase inhibitor, acetazolamide, caused wild type luminal pH to become more acidic, and increased both Vibrio abundance and intestinal inflammation. We conclude that a primary function of the ENS is to regulate luminal pH, which plays a critical role in shaping the resident microbial community and regulating intestinal inflammation.

Pathways and microbiome modifications related to surgery and enterocolitis in Hirschsprung disease

BACKGROUND

Hirschsprung disease (HSCR) is a congenital anomaly of the enteric nervous system. Abnormal microbiome composition was reported in HSCR patients. In this study, we addressed and analyzed microbiome modifications with relation tosurgery and HSCR associated enterocolitis (HAEC).

METHODS

The faecal microbiome of 31 HSCR patients (overall 64 samples) was analyzed. HAEC was diagnosed and classified according to a combination of Pastor's and Elhalabi's criteria. Stool samples were analyzed by 16S sequencing (7 out of 9 polymorphic regions). Compositional and relative abundance profiles, as well as the functional potentials of the microbial community, were analyzed with the marker gene sequencing profiles using PICRUSt.

RESULTS

The relative abundance of Bacteroidetes showed a severe decrease with slow recovery after surgery. Conversely, Proteobacteria transiently increased their abundance. Noteworthy, a strong linkage has been found between Proteobacteria descendants and HAEC occurrences. The inferred functional analysis indicated that virulence factors and fimbriae or pili might be associated with HAEC.

CONCLUSIONS

Our study, addressing microbiome dynamics, demonstrated relevant changes after surgical manipulation. Alpha-diversity analyses indicated that surgery deeply affects microbiome composition. Proteobacteria and Enterobacteriaceae seem to play a pivotal role in HAEC occurrences. Several virulence factors, such as fimbriae or pili, might explain the HAEC-predisposing potential of selected microbiomes. These results suggest some innovative therapeutic approaches that deserve to be tested in appropriate clinical trials.

Alterations of Gut Bacteria in Hirschsprung Disease and Hirschsprung-Associated Enterocolitis

Hirschsprung-associated enterocolitis (HAEC) is a common life-threatening complication of Hirschsprung disease (HSCR). It has been proposed that gut microbiota, which have an essential role in gut-homeostasis, are associated with HAEC. Recent studies demonstrated an increase in alpha diversity of fecal microbiota over time in HSCR mice and a decrease in diversity after surgery. In addition, clinical studies have reported a reduction in bacterial richness in HSCR children after surgery. Some studies revealed a difference in microbiota between the proximal ganglionic and distal aganglionic intestine and found a difference in bacterial character between fecal and colonic specimens. HAEC studies found an increase in Proteobacteria, especially Escherichia and Enterobacteriaceae, with a decrease in Firmicutes and Bifidobacterium in HAEC patients. However, the direction of alpha diversity in HAEC patients is still controversial. The self-comparison of microbiota in treatment periods suggested that probiotics might improve gut dysbiosis and decrease the frequency of enterocolitis, but some reported contradictory findings. This review comprehensively summarizes and discusses key findings from animal and clinical data of the distinct microbiome associated with HCSR and the association of gut dysbiosis with the development of HAEC. This information should be useful in the establishment of novel interventions to improve gut dysbiosis and prevent enterocolitis in HSCR patients.

Leclercia adecarboxylata invasive infection in a patient with Hirschsprung disease: A case report

Introduction

Leclercia adecarboxylata is a ubiquitous aerobic, motile, gram-negative bacilli. The human gastro-intestinal tract is known to harbor this rarely opportunistic microorganism. We describe a rare case of invasive infection with a gastrointestinal starting point due to L. adecarboxylata in a patient with Hirschsprung disease.

Case report

It is about a newborn female who was admitted on the 3rd day of life to the neonatal intensive care unit for intestinal obstruction. On the 9th day of life, while managing the neonatal obstruction, the patient developed febrile peaks. Cytobacteriological examination of cerebrospinal fluid, blood cultures and culture of umbilical vein catheter allowed the exclusive isolation of Leclercia adecarboxylata. It was producing extended spectrum beta-lactamase and was treated with intravenous imipenem. After favourable evolution, the patient was transferred to the pediatric surgery department. There, she was diagnosed with Hirschsprung disease.

Discussion

Knowledge of the route of transmission of L. adecarboxylata is limited and the possible source of the infection is unclear. However, the authors describe three hypotheses of contamination of our propositus. In our patient, one or more of these routes of contamination would be possible. Indeed, bacteremia could occur as a result of a bacterial translocation across the mucosal barrier of the colon altered by Hirschsprung disease, antibiotic use and feeding practices.

Conclusion

Infection with L. adecarboxylata revealed a wide range of infection. It has only recently been acknowledged as an emerging pathogen. Further studies of the pathogenesis and risk factors are required.

•

Leclercia adecarboxylata is Gram-negative bacillus as a member of the Enterobacteriaceae family.

•

Infection with this rarely pathogenic microorganism has been limited to a small number of case reports. Of these, only few reports implicate the gastrointestinal tract as the focus of infection.

•

Bacteremia could occur as a result of a bacterial translocation across the mucosal barrier of the colon altered by Hirschsprung disease, antibiotic use and feeding practices.

•

As the number of L. adecarboxylata infections continues to expand so does our insight into its pathogenicity and role in human clinical infections. Further studies of the pathogenesis and risk factors are required.

Chronic Diseases Associated with Malassezia Yeast

Malassezia are a lipid-dependent basidiomycetous yeast of the normal skin microbiome, although Malassezia DNA has been recently detected in other body sites and has been associated with certain chronic human diseases. This new perspective raises many questions. Are these yeasts truly present in the investigated body site or were they contaminated by other body sites, adjacent or not? Does this DNA contamination come from living or dead yeast? If these yeasts are alive, do they belong to the resident mycobiota or are they transient colonizers which are not permanently established within these niches? Finally, are these yeasts associated with certain chronic diseases or not? In an attempt to shed light on this knowledge gap, we critically reviewed the 31 published studies focusing on the association of Malassezia spp. with chronic human diseases, including psoriasis, atopic dermatitis (AD), chronic rhinosinusitis (CRS), asthma, cystic fibrosis (CF), HIV infection, inflammatory bowel disease (IBD), colorectal cancer (CRC), and neurodegenerative diseases.

Clinical characteristics and validation of diagnosis in individuals with Hirschsprung disease and inflammatory bowel disease

BACKGROUND/PURPOSE

Hirschsprung disease has previously been reported to be associated with inflammatory bowel disease (IBD). The aim was to clinically confirm the diagnosis and to describe characteristics among individuals with both conditions in a national populationbased cohort.

METHODS

Nationwide, population-based cohort study, including all individuals with a Hirschsprung disease diagnosis and an IBD diagnosis registered between 1964 and 2016, in which clinical data were collected from the medical records of 18 validated cases with both Hirschsprung disease and IBD. The medical record of each individual in the study cohort was reviewed for age at IBD diagnosis, type of aganglionosis, type of surgical treatment, subtype of IBD, and treatment for IBD.

RESULTS

Median age at follow up was 34 years (range 19-66), and 3 of 18 indivduals (17%) were females. Median age at first diagnosis of IBD was 21 years (range 10-46). Six patients had ulcerative colitis, ten had Crohn's disease and two had unclassified IBD. Most of the patients had pharmacological treatment for IBD and 5 (28%) individuals had surgical treatment.

CONCLUSION

Hirschsprung disease and IBD was clinically confirmed in 18 cases. Age at IBD onset and subtype of IBD is similar to IBD patients without Hirschsprung disease. Five individuals had undergone surgical treatment for IBD.

Disparities in the gut metabolome of post-operative Hirschsprung's disease patients

Hirschsprung's disease (HD) is a congenital structural abnormality of the colon seen in approximately 1 to 5000 live births. Despite surgical correction shortly after presentation, up to 60% of patients will express long-term gastrointestinal complaints, including potentially life-threatening Hirschsprung-associated enterocolitis (HAEC). In this study fecal samples from postoperative HD patients (n = 38) and their healthy siblings (n = 21) were analysed using high-resolution liquid chromatography-mass spectrometry aiming to further unravel the nature of the chronic gastrointestinal disturbances. Furthermore, within the patient group, we compared the faecal metabolome between patients with and without a history of HAEC as well as those diagnosed with short or long aganglionic segment. Targeted analysis identified several individual metabolites characteristic for all HD patients as well as those with a history of HAEC and long segment HD. Moreover, multivariate models based on untargeted data established statistically significant (p < 0.05) differences in comprehensive faecal metabolome in the patients' cohort as a whole and in patients with a history of HAEC. Pathway analysis revealed the most impact on amino sugar, lysine, sialic acid, hyaluronan and heparan sulphate metabolism in HD, as well as impaired tyrosine metabolism in HAEC group. Those changes imply disruption of intestinal mucosal barrier due to glycosaminoglycan breakdown and dysbiosis as major metabolic changes in patients' group and should be further explored for potential diagnostic or treatment targets.

Comparison of Hirschsprung Disease Characteristics between Those with a History of Postoperative Enterocolitis and Those without: Results from the Pediatric Colorectal and Pelvic Learning Consortium

INTRODUCTION

 The current understanding of Hirschsprung-associated enterocolitis (HAEC) is based mainly on single-center, retrospective studies. The aims of this study are to determine risk factors for postoperative HAEC using the Pediatric Colorectal and Pelvic Learning Consortium (PCPLC) database.

MATERIALS AND METHODS

 We performed a multicenter, retrospective, case-control study of children with Hirschsprung disease (HD) who had undergone a pull-through procedure and were evaluated at a PCPLC member site between February 2017 and March 2020. The cohort with a history of postoperative HAEC was compared with that without postoperative episodes of HAEC to determine relevant associations with postoperative HAEC.

RESULTS

 One-hundred forty of 299 (46.8%) patients enrolled had a history of postoperative HAEC. Patients with a rectosigmoid transition zone had a lower association with postoperative HAEC as compared with those with a more proximal transition zone (odds ratio [OR]: 0.46, 95% confidence interval [CI]: 0.26, 0.84, p < 0.01). Private insurance was protective against postoperative HAEC on univariate analysis (OR: 0.62, 95% CI: 0.38, 0.99, p = 0.047), but not on multivariate analysis (OR: 0.62, 95% CI: 0.37, 1.04, p = 0.07). Preoperative HAEC was not associated with the development of postoperative HAEC.

CONCLUSION

 Patients with a rectosigmoid transition zone have less postoperative HAEC compared with patients with a more proximal transition zone. Multi-institutional collection of clinical information in patients with HD may allow for the identification of additional risk factors for HAEC and afford the opportunity to improve care.

Disorders of the enteric nervous system - a holistic view

The enteric nervous system (ENS) is the largest division of the peripheral nervous system and closely resembles components and functions of the central nervous system. Although the central role of the ENS in congenital enteric neuropathic disorders, including Hirschsprung disease and inflammatory and functional bowel diseases, is well acknowledged, its role in systemic diseases is less understood. Evidence of a disordered ENS has accumulated in neurodegenerative diseases ranging from amyotrophic lateral sclerosis, Alzheimer disease and multiple sclerosis to Parkinson disease as well as neurodevelopmental disorders such as autism. The ENS is a key modulator of gut barrier function and a regulator of enteric homeostasis. A 'leaky gut' represents the gateway for bacterial and toxin translocation that might initiate downstream processes. Data indicate that changes in the gut microbiome acting in concert with the individual genetic background can modify the ENS, central nervous system and the immune system, impair barrier function, and contribute to various disorders such as irritable bowel syndrome, inflammatory bowel disease or neurodegeneration. Here, we summarize the current knowledge on the role of the ENS in gastrointestinal and systemic diseases, highlighting its interaction with various key players involved in shaping the phenotypes. Finally, current flaws and pitfalls related to ENS research in addition to future perspectives are also addressed.

Lack of Mucosal Cholinergic Innervation Is Associated With Increased Risk of Enterocolitis in Hirschsprung's Disease

BACKGROUND & AIMS

Hirschsprung's disease (HSCR) is a congenital intestinal motility disorder defined by the absence of enteric neuronal cells (ganglia) in the distal gut. The development of HSCR-associated enterocolitis remains a life-threatening complication. Absence of enteric ganglia implicates innervation of acetylcholine-secreting (cholinergic) nerve fibers. Cholinergic signals have been reported to control excessive inflammation, but the impact on HSCR-associated enterocolitis is unknown.

METHODS

We enrolled 44 HSCR patients in a prospective multicenter study and grouped them according to their degree of colonic mucosal acetylcholinesterase-positive innervation into low-fiber and high-fiber patient groups. The fiber phenotype was correlated with the tissue cytokine profile as well as immune cell frequencies using Luminex analysis and fluorescence-activated cell sorting analysis of colonic tissue and immune cells. Using confocal immunofluorescence microscopy, macrophages were identified in close proximity to nerve fibers and characterized by RNA-seq analysis. Microbial dysbiosis was analyzed in colonic tissue using 16S-rDNA gene sequencing. Finally, the fiber phenotype was correlated with postoperative enterocolitis manifestation.

RESULTS

The presence of mucosal nerve fiber innervation correlated with reduced T-helper 17 cytokines and cell frequencies. In high-fiber tissue, macrophages co-localized with nerve fibers and expressed significantly less interleukin 23 than macrophages from low-fiber tissue. HSCR patients lacking mucosal nerve fibers showed microbial dysbiosis and had a higher incidence of postoperative enterocolitis.

CONCLUSIONS

The mucosal fiber phenotype might serve as a prognostic marker for enterocolitis development in HSCR patients and may offer an approach to personalized patient care and new therapeutic options.

Evidence for Differentiation of Colon Tissue Microbiota in Patients with and without Postoperative Hirschsprung's Associated Enterocolitis: A Pilot Study

PURPOSE

To investigate the differences in the colon microbiota composition of Hirschsprung's disease (HSCR) patients with and without a history of postoperative Hirschsprung's associated enterocolitis (HAEC).

METHODS

Colon tissue microbiota was characterized by bacterial deoxyribonucleic acid (DNA) extraction and 16S rDNA sequencing for taxonomic classification and comparison.

RESULTS

The sequence diversity richness within samples was significantly higher in samples from patients with a history of postoperative HAEC. We observed an increased relative abundance of the phyla Bacteroidetes, Firmicutes and Cyanobacteria in HAEC patients and Fusobacteria, Actinobacteria and Proteobacteria in HSCR patients and, an increased relative abundance of the genera Dolosigranulum, Roseouria and Streptococcus in HAEC patients and Propionibacterium and Delftia in HSCR patients.

CONCLUSION

Our findings provide evidence that the colon tissue microbiota composition is different in HSCR patients with and without postoperative HAEC.

Eukaryotic and Prokaryotic Microbiota Interactions

The nature of the relationship between the communities of microorganisms making up the microbiota in and on a host body has been increasingly explored in recent years. Microorganisms, including bacteria, archaea, viruses, parasites and fungi, have often long co-evolved with their hosts. In human, the structure and diversity of microbiota vary according to the host’s immunity, diet, environment, age, physiological and metabolic status, medical practices (e.g., antibiotic treatment), climate, season and host genetics. The recent advent of next generation sequencing (NGS) technologies enhanced observational capacities and allowed for a better understanding of the relationship between distinct microorganisms within microbiota. The interaction between the host and their microbiota has become a field of research into microorganisms with therapeutic and preventive interest for public health applications. This review aims at assessing the current knowledge on interactions between prokaryotic and eukaryotic communities. After a brief description of the metagenomic methods used in the studies were analysed, we summarise the findings of available publications describing the interaction between the bacterial communities and protozoa, helminths and fungi, either in vitro, in experimental models, or in humans. Overall, we observed the existence of a beneficial effect in situations where some microorganisms can improve the health status of the host, while the presence of other microorganisms has been associated with pathologies, resulting in an adverse effect on human health.

Lipopolysaccharide upregulates miR-132/212 in Hirschsprung-associated enterocolitis, facilitating pyroptosis by activating NLRP3 inflammasome via targeting Sirtuin 1 (SIRT1)

Hirschsprung disease (HSCR) is a congenital disorder attributed to the failure of the neural crest derivatives migrating and/or differentiating along the hindgut. The most frequent complication in Hirschsprung disease patients is Hirschsprung-associated enterocolitis (HAEC). However, its pathogenesis has not been fully understood. This study investigated miRNAs influenced by Lipopolysaccharide (LPS) in postoperative HAEC patients, their effect on enterocolitis and the underlying mechanism. MiR-132 and miR-212 were up-regulated in HAEC dilated tissues and LPS-treated mice enteritis samples. LPS-stimulated HT29 cells showed a high expression of miR-132 and miR-212. QRT-PCR analysis, western blotting, luciferase reporter assay, and flow cytometric analysis were carried out in vitro, showing that miR-132 and miR-212 could directly inhibit Sirtuin 1 (SIRT1) expression. Consequently, SIRT1 deficiency in LPS-stimulated HT29 cell line and LPS-treated mice activated NLRP3 inflammasome and Caspase-1-mediated pyroptosis. Furthermore, the above inflammation activation was reversed by miR-132/212 inhibitor or SIRT1 overexpression plasmid transfection.In conclusion, LPS upregulated miR-132 and miR-212 expression in HAEC, suppressing SIRT1 and facilitating NLRP3 inflammasome activation, which induced pyroptosis. Our findings illustrated the role of LPS/miR-132/-212/SIRT1/NLRP3 regulatory network in the occurrence and progression of HAEC and proposed a new molecular pathway for LPS-mediated cell pyroptosis.

Gut mycobiome and its interaction with diet, gut bacteria and alzheimer's disease markers in subjects with mild cognitive impairment: A pilot study

BACKGROUND

Recently, we reported that patients with mild cognitive impairment (MCI) harbor specific signature of bacteria in their gut and that a modified Mediterranean ketogenic diet (MMKD) improves Alzheimer's disease (AD) markers in cerebrospinal fluid (CSF) and the signatures of gut bacteria. However, other microbial population such as gut fungi (mycobiome) in relation to MCI/AD pathology, gut bacteria and diet remain unknown.

METHODS

We measure gut mycobiome by sequencing of the fungal rRNA ITS1 gene in 17 older adults (11 MCI; 6 cognitively normal [CN]) in a single-center, randomized, double-blind, crossover pilot study, before and after 6 weeks intervention of MMKD and American Heart Association Diet (AHAD), and determine its correlation with AD markers in CSF and gut bacteria.

FINDINGS

Compared to CN counterparts, patients with MCI have higher proportion of families Sclerotiniaceae, Phaffomyceteceae, Trichocomaceae, Cystofilobasidiaceae, Togniniaceae and genera Botrytis, Kazachstania, Phaeoacremonium and Cladosporium and lower abundance of Meyerozyma. Specific fungal taxa exhibit distinct correlation arrays with AD markers and gut bacteria in subjects with versus without MCI. MMKD induces broader effect on fungal diversity in subjects with MCI and increases Agaricus and Mrakia while decreasing Saccharomyces and Claviceps with differential response in subjects with or without MCI.

INTERPRETATION

The study reveals MCI-specific mycobiome signatures and demonstrates that distinct diets modulate the mycobiome in association with AD markers and fungal-bacterial co-regulation networks in patients with MCI. The findings corroborate the notion of considering gut mycobiome as a unique factor that can affect cognitive health/AD by interacting with gut bacteria and diet and facilitate better understanding of the AD and related microbiome, using unique diet or microbiome modulators.

Prospective study reveals a microbiome signature that predicts the occurrence of post-operative enterocolitis in Hirschsprung disease (HSCR) patients

Hirschsprung disease (HSCR) is a birth defect with an approximate incidence of 1/5,000 live births, and up to one-third of HSCR patients develop Hirschsprung-associated enterocolitis (HAEC), the leading cause of HSCR-related death. Very little is known about the pathogenesis, prevention, and early diagnosis of HAEC. Here, we used a prospective study to investigate the enteric microbiome composition at the time of surgery as a predictor for developing postoperative HAEC. We identified a microbiome signature containing 21 operational taxonomic units (OTUs) that can potentially predict postoperative HAEC with ~85% accuracy. Furthermore, we identified exclusive breastfeeding as a novel protective factor for total HAEC (i.e., preoperative and postoperative HAEC combined). In addition, we discovered that breastfeeding was associated with a lowered risk for HAEC potentially mediated by modulating the gut microbiome composition characterized by a lower abundance of Gram-negative bacteria and lower LPS concentrations. In conclusion, modulating the gut microbiome by encouraging breastfeeding might prevent HAEC progression in HSCR patients.

ERNICA guidelines for the management of rectosigmoid Hirschsprung's disease

BACKGROUND

Hirschsprung's disease (HSCR) is a serious congenital bowel disorder with a prevalence of 1/5000. Currently, there is a lack of systematically developed guidelines to assist clinical decision-making regarding diagnostics and management.

AIMS

This guideline aims to cover the diagnostics and management of rectosigmoid HSCR up to adulthood. It aims to describe the preferred approach of ERNICA, the European Reference Network for rare inherited and congenital digestive disorders.

METHODS

Recommendations within key topics covering the care pathway for rectosigmoid HSCR were developed by an international workgroup of experts from 8 European countries within ERNICA European Reference Network from the disciplines of surgery, medicine, histopathology, microbiology, genetics, and patient organization representatives. Recommendation statements were based on a comprehensive review of the available literature and expert consensus. AGREE II and GRADE approaches were used during development. Evidence levels and levels of agreement are noted.

RESULTS

Thirty-three statements within 9 key areas were generated. Most recommendations were based on expert opinion.

CONCLUSION

In rare or low-prevalence diseases such as HSCR, there remains limited availability of high-quality clinical evidence. Consensus-based guidelines for care are presented.

Evaluating the Alimentary and Respiratory Tracts in Health and disease (EARTH) research programme: a protocol for prospective, longitudinal, controlled, observational studies in children with chronic disease at an Australian tertiary paediatric hospital

INTRODUCTION

Chronic gastrointestinal and respiratory conditions of childhood can have long-lasting physical, psychosocial and economic effects on children and their families. Alterations in diet and intestinal and respiratory microbiomes may have important implications for physical and psychosocial health. Diet influences the intestinal microbiome and should be considered when exploring disease-specific alterations. The concepts of gut-brain and gut-lung axes provide novel perspectives for examining chronic childhood disease(s). We established the 'Evaluating the Alimentary and Respiratory Tracts in Health and disease' (EARTH) research programme to provide a structured, holistic evaluation of children with chronic gastrointestinal and/or respiratory conditions.

METHODS AND ANALYSIS

The EARTH programme provides a framework for a series of prospective, longitudinal, controlled, observational studies (comprised of individual substudies), conducted at an Australian tertiary paediatric hospital (the methodology is applicable to other settings). Children with a chronic gastrointestinal and/or respiratory condition will be compared with age and gender matched healthy controls (HC) across a 12-month period. The following will be collected at baseline, 6 and 12 months: (i) stool, (ii) oropharyngeal swab/sputum, (iii) semi-quantitative food frequency questionnaire, (iv) details of disease symptomatology, (v) health-related quality of life and (vi) psychosocial factors. Data on the intestinal and respiratory microbiomes and diet will be compared between children with a condition and HC. Correlations between dietary intake (energy, macro-nutrients and micro-nutrients), intestinal and respiratory microbiomes within each group will be explored. Data on disease symptomatology, quality of life and psychosocial factors will be compared between condition and HC cohorts.Results will be hypothesis-generating and direct future focussed studies. There is future potential for direct translation into clinical care, as diet is a highly modifiable factor.

ETHICS AND DISSEMINATION

Ethics approval: Sydney Children's Hospitals Network Human Research Ethics Committee (HREC/18/SCHN/26). Results will be presented at international conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04071314.

Hirschsprung-associated enterocolitis in children treated at US children's hospitals

BACKGROUND

The incidence of and risk factors for Hirschsprung's-associated enterocolitis (HAEC) following pull-through have been limited to single institutions studies. We characterized the incidence of, risk factors for, and consequences of post-operative HAEC.

METHODS

We identified children with Hirschsprung's Disease (HD) at US Children's Hospitals from 2007 to 2017 with and an associated pull-through operation at less than 1 year of age. HAEC readmissions were identified using ICD9/10 Diagnosis Codes and antibiotic administration. Hierarchical logistic regression models were developed for the risk factors for HAEC after pull-through and effects of recurrent HAEC on HD-related reoperations.

RESULTS

We identified 2030 children with HD, and 138 (7%) who had two or more readmissions related to HAEC. The frequency of recurrent HAEC by hospital ranged from 0 to 33%. Pre-operative HAEC, history of central nervous system infection, and congenital neurologic anomalies were associated with increased risk of recurrent HAEC. Recurrent HAEC was associated with HD-specific re-operation (OR 5.2, CI 3.3-8.1, p < 0.001); however, it was not associated with risk of in-hospital mortality (OR 3.3, CI 0.88-12.1, p = 0.08).

CONCLUSIONS

HAEC following pull-through occurs in a large proportion of infants with HD and predicts reoperation. Multicenter studies are needed to develop prediction models and treatment protocols for HAEC.

LEVEL OF EVIDENCE

II TYPE OF STUDY: Retrospective cohort study.

Culture-independent and dependent evaluation of the equine paranasal sinus microbiota in health and disease

BACKGROUND

Horses with bacterial sinusitis frequently undergo empirical treatment with antimicrobials, however, in some cases bacterial culture of the affected sinus is used to direct therapy. Data regarding which organisms are part of the commensal microbiota of the equine sinus are lacking making it difficult to interpret culture results and guide empiric antimicrobial selection.

OBJECTIVES

Our objectives were to describe the bacterial and fungal microbiota of the paranasal sinuses in clinically normal horses using culture-dependent and independent approaches and to compare the bacterial culture and susceptibility patterns of normal horses with those from horses affected with primary and secondary sinusitis.

STUDY DESIGN

Experimental study and descriptive retrospective review of case records.

METHODS

Sinus washes were collected from 23 healthy horses. Washes were submitted for routine culture and susceptibility testing and DNA was isolated for next generation sequencing of bacterial and fungal marker genes. For clinical cases of sinusitis, medical records from 2010 to 2017 were reviewed and horses diagnosed with primary and/or secondary sinusitis were included.

RESULTS

The paranasal sinus cavity hosts multiple bacterial and fungal organisms. The bacterial microbiota of healthy horses consists largely of uncultivable, aerobic bacteria. While few anaerobes were isolated from normal horses, the majority of clinical cases resulted in growth of anaerobic organisms with no difference in the proportion of aerobic and anaerobic bacteria isolated from clinical cases.

MAIN LIMITATIONS

Small sample size in both populations of horses and heterogeneity of the population prevent a more in-depth analysis.

CONCLUSIONS

The microbiota of the paranasal sinuses of horses consists primarily of aerobic bacteria and fungal organisms, the majority of which are uncultivable via common clinical methods. Anaerobic bacteria are found in the majority of horses with clinical sinusitis. These findings suggest anaerobic bacteria are associated with sinusitis and their presence should be considered when treating horses with sinusitis.

Inflammatory Bowel Disease Serological Immune Markers Anti-Saccharomyces cerevisiae Mannan Antibodies and Outer Membrane Porin C are Potential Biomarkers for Hirschsprung-associated Enterocolitis

OBJECTIVE

Hirschsprung-associated enterocolitis (HAEC) is the most frequent complication in Hirschsprung disease (HSCR) patients. Currently HAEC is diagnosed clinically, leaving uncertainty in the diagnosis thereby potentially leading to over- or undertreatment of patients. The aim of this study was to identify immune biomarkers to aid in the diagnosis of HAEC.

METHODS

From 2012 to 2017, 43 children with HSCR enrolled in a multicenter study, underwent retrospective evaluation of their medical records, and questionnaire-directed parent interviews. HAEC status was determined using HAEC score with cutoff ≥4. Plasma was collected and analyzed by ELISA for the inflammatory bowel disease-associated antibodies: anti-Saccharomyces cerevisiae mannan antibodies (ASCA), outer membrane porin C (OmpC), CBir1, antineutrophil cytoplasmic antibodies. Data were analyzed using t test, univariate, multivariable, and binomial regression models.

RESULTS

Eighteen patients had at least 1 episode of HAEC, 25 had no history of HAEC. The HAEC and NO HAEC groups had similar median ages (3 years) and family histories of HSCR. The HAEC group showed markedly elevated ASCA IgA and OmpC antibody levels compared with the NO HAEC group, whereas CBir1 and antineutrophil cytoplasmic antibodies were similar between the groups. Both univariate and multivariable analysis revealed higher OmpC antibody levels associated with HAEC (odds ratio 1.39, confidence interval 1-1.92, P = 0.048), whereas univariate analysis identified a trend toward elevated IgA and immunoglobulin G ASCA levels with HAEC.

CONCLUSIONS

We identified elevated OmpC and ASCA serum antibody levels in HAEC patients, and that increased OmpC antibody levels correlated with HAEC occurrence, suggesting HAEC and Crohn disease share gut microbial-host immune responses. These antibodies may serve as potential biomarkers for HAEC, although prospective study with larger sample size is needed.

Reduced expression of the NLRP6 inflammasome in the colon of patients with Hirschsprung's disease

PURPOSE

Hirschsprung's associated enterocolitis (HAEC) is the most common cause of morbidity and mortality in Hirschsprung's Disease (HSCR). The pathogenesis of HAEC remains unsatisfactorily understood. Mounting evidence of an altered microbiome in patients with HSCR adds a new angle to the pathogenesis of HAEC. NLRP6 is a member of the nucleotide-binding domain, leucine-rich-repeat-containing (NLR) innate immune receptor family, a multiprotein complex that functions as a sensor of damage-associated molecular patterns. Known as inflammasomes they have been implicated in the regulation of colonic microbial ecology and by alteration, regulators of inflammation. We designed this study to test the hypothesis that NLRP6 expression is altered in the colon of patients with HSCR.

METHODS

We investigated NLPR6 protein expression in both the aganglionic and ganglionic regions of HSCR patients (n = 10) versus healthy control colon (n = 10). Protein distribution was assessed by using immunofluorescence and confocal microscopy. Gene and protein expressions were quantified using quantitative real-time polymerase chain reaction (qPCR), Western blot analysis, and densitometry.

MAIN RESULTS

qPCR and Western blot analysis revealed that NLRP6 is expressed in the colon of patients with HSCR. NLRP6 expression was significantly decreased (p < 0.003) in the ganglionic and aganglionic bowel in HSCR compared to controls. Confocal microscopy revealed that NLRP6 expression in colonic epithelium was markedly decreased in HSCR specimens compared to controls.

CONCLUSION

We demonstrate for the first time the expression and distribution of NLRP6 in patients with HSCR. The observed decreased expression of NLRP6 may contribute to an altered colonic microbiome in patients with HSCR and increases the susceptibility to develop HAEC.

Candida albicans Elicits Pro-Inflammatory Differential Gene Expression in Intestinal Peyer's Patches

The details of how gut-associated lymphoid tissues such as Peyer's patches (PPs) in the small intestine play a role in immune surveillance, microbial differentiation and the mucosal barrier protection in response to fungal organisms such as Candida albicans are still unclear. We particularly focus on PPs as they are the immune sensors and inductive sites of the gut that influence inflammation and tolerance. We have previously demonstrated that CD11c⁺ phagocytes that include dendritic cells and macrophages are located in the sub-epithelial dome within PPs sample C. albicans. To gain insight on how specific cells within PPs sense and respond to the sampling of fungi, we gavaged naïve mice with C. albicans strains ATCC 18804 and SC5314 as well as Saccharomyces cerevisiae. We measured the differential gene expression of sorted CD45⁺ B220⁺ B-cells, CD3⁺ T-cells and CD11c⁺ DCs within the first 24 h post-gavage using nanostring nCounter^® technology. The results reveal that at 24 h, PP phagocytes were the cell type that displayed differential gene expression. These phagocytes were able to sample C. albicans and discriminate between strains. In particular, strain ATCC 18804 upregulated fungal-specific pro-inflammatory genes pertaining to innate and adaptive immune responses. Interestingly, PP CD11c⁺ phagocytes also differentially expressed genes in response to C. albicans that were important in the protection of the mucosal barrier. These results highlight that the mucosal barrier not only responds to C. albicans, but also aids in the protection of the host.

Technologies for the Selection, Culture and Metabolic Profiling of Unique Rhizosphere Microorganisms for Natural Product Discovery

Small molecule discovery has benefitted from the development of technologies that have aided in the culture and identification of soil microorganisms and the subsequent analysis of their respective metabolomes. We report herein on the use of both culture dependent and independent approaches for evaluation of soil microbial diversity in the rhizosphere of canola, a crop known to support a diverse microbiome, including plant growth promoting rhizobacteria. Initial screening of rhizosphere soils showed that microbial diversity, particularly bacterial, was greatest at crop maturity; therefore organismal recovery was attempted with soil collected at canola harvest. Two standard media (Mueller Hinton and gellan gum) were evaluated following inoculation with soil aqueous suspensions and compared with a novel “rhizochip” prototype buried in a living canola crop rhizosphere for microbial culture in situ. Following successful recovery and identification of 375 rhizosphere microbiota of interest from all culture methods, isolates were identified by Sanger sequencing and/or characterization using morphological and biochemical traits. Three bacterial isolates of interest were randomly selected as case studies for intensive metabolic profiling. After successful culture in liquid media and solvent extraction, individual extracts were subjected to evaluation by UHPLC-DAD-QToF-MS, resulting in the rapid characterization of metabolites of interest from cultures of two isolates. After evaluation of key molecular features, unique or unusual bacterial metabolites were annotated and are reported herein.

The role of the gut microbiota in development, function and disorders of the central nervous system and the enteric nervous system

The gut microbiota has emerged as an environmental factor that modulates the development of the central nervous system (CNS) and the enteric nervous system (ENS). Before obtaining its own microbiota, eutherian foetuses are exposed to products and metabolites from the maternal microbiota. At birth, the infants are colonised by microorganisms. The microbial composition in early life is strongly influenced by the mode of delivery, the feeding method, the use of antibiotics and the maternal microbial composition. Microbial products and microbially produced metabolites act as signalling molecules that have direct or indirect effects on the CNS and the ENS. An increasing number of studies show that the gut microbiota can modulate important processes during development, including neurogenesis, myelination, glial cell function, synaptic pruning and blood-brain barrier permeability. Furthermore, numerous studies indicate that there is a developmental window early in life during which the gut microbial composition is crucial and perturbation of the gut microbiota during this period causes long-lasting effects on the development of the CNS and the ENS. However, other functions are readily modulated in adult animals, including microglia activation and neuroinflammation. Several neurobehavioural, neurodegenerative, mental and metabolic disorders, including Parkinson disease, autism spectrum disorder, schizophrenia, Alzheimer's disease, depression and obesity, have been linked to the gut microbiota. This review focuses on the role of the microorganisms in the development and function of the CNS and the ENS, as well as their potential role in pathogenesis.

Gut microbiota-mediated Gene-Environment interaction in the TashT mouse model of Hirschsprung disease

Based on the bilateral relationship between the gut microbiota and formation/function of the enteric nervous system (ENS), we sought to determine whether antibiotics-induced dysbiosis might impact the expressivity of genetically-induced ENS abnormalities. To address this, we took advantage of the TashT mouse model of Hirschsprung disease, in which colonic aganglionosis and hypoganglionosis are both much more severe in males. These defects result into two male-biased colon motility phenotypes: either megacolon that is lethal around weaning age or chronic constipation in adults, the latter being also associated with an increased proportion of nitrergic neurons in the distal ENS. Induction of dysbiosis using a cocktail of broad-spectrum antibiotics specifically impacted the colonic ENS of TashT^Tg/Tg mice in a stage-dependent manner. It further decreased the neuronal density at post-weaning age and differentially modulated the otherwise increased proportion of nitrergic neurons, which appeared normalized around weaning age and further increased at post-weaning age. These changes delayed the development of megacolon around weaning age but led to premature onset of severe constipation later on. Finally, local inhibition of nitric oxide signaling improved motility and prevented death by megacolon. We thus conclude that exposure to antibiotics can negatively influence the expressivity of a genetically-induced enteric neuropathy.

A Metagenomics Study on Hirschsprung's Disease Associated Enterocolitis: Biodiversity and Gut Microbial Homeostasis Depend on Resection Length and Patient's Clinical History

Objectives: Since 2010, several researches demonstrated that microbiota dynamics correlate and can even predispose to Hirschsprung (HSCR) associated enterocolitis (HAEC). This study aims at assessing the structure of the microbiota of HSCR patients in relation to extent of aganglionosis and HAEC status. Methods: All consecutive HSCR patients admitted to Gaslini Institute (Genova, Italy) between May 2012 and November 2014 were enrolled. Institutional review board (IRB) approval was obtained. Stools were sampled and 16S rDNA V3-V4 regions were sequenced using the Illumina-MiSeq. Taxonomy assignments were performed using QIIME RDP. Alpha diversity indexes were analyzed by Shannon and Simpson Indexes, and Phylogenetic Diversity. Results: We enrolled 20 patients. Male to female ratio was 4:1. Six patients suffered from Total Colonic Aganglionosis (TCSA). Considering sample site (i.e., extent of aganglionosis), we confirmed the known relationship between sample site and both biodiversity and composition of intestinal microbiota. Patients with TCSA showed lower biodiversity and increased Proteobacteria/Bacteroidetes relative abundance ratio. When addressing biodiversity, composition and dynamics of TCSA patients we could not find any significant relationship with regard to HAEC occurrences. Conclusions: The composition of HAEC predisposing microbiota is specific to each patient. We could confirm that total colon resections can change the composition of intestinal microbiota and to dramatically reduce microbial diversity. The subsequent reduction of system robustness could expose TCSA patients to environmental microbes that might not be part of the normal microbiota. Future long-term studies should investigate both patients and their family environment, as well as their disease history.

Urinary microbiome associated with chronic allograft dysfunction in kidney transplant recipients

BACKGROUND

We performed a study to identify differences in the urinary microbiome associated with chronic allograft dysfunction (CAD) and compared the urinary microbiome of male and female transplant recipients with CAD.

METHODS

This case-control study enrolled 67 patients within the Deterioration of Kidney Allograft Function (DeKAF) Genomics cohort at two transplant centers. CAD was defined as a greater than 25% rise in serum creatinine relative to a 3 month post-transplant baseline. Urine samples from patients with and without CAD were analyzed using 16S V4 bacterial ribosomal DNA sequences.

RESULTS

Corynebacterium was more prevalent in female and male patients with CAD compared to non-CAD female patients (P = 0.0005). A total 21 distinct Operational Taxonomic Unit (OTUs) were identified as significantly different when comparing CAD and non-CAD patients using Kruskal-Wallis (P < 0.01). A subset analysis of female patients with CAD compared to non-CAD females identified similar differentially abundant OTUs, including the genera Corynebacterium and Staphylococcus (Kruskal-Wallis; P = 0.01; P = 0.004, respectively). Male CAD vs female CAD analysis showed greater abundance of phylum Proteobacteria in males.

CONCLUSION

There were differences in the urinary microbiome when comparing female and male CAD patients with their female non-CAD counterparts and these differences persisted in the subset analysis limited to female patients only.

Hirschsprung's Associated Enterocolitis (HAEC) Personalized Treatment with Probiotics Based on Gene Sequencing Analysis of the Fecal Microbiome

Approximately 40% of children with Hirschsprung's disease (HD) suffer from Hirschsprung's associated enterocolitis (HAEC) despite correct surgery. Disturbances of the intestinal microbiome may play a role. Treatment with probiotics based on individual analyses of the fecal microbiome has not been published for HD patients with recurrent HAEC yet. A boy with trisomy 21 received transanal pull-through at the age of 6 months for rectosigmoid HD. With four years, he suffered from recurrent episodes of HAEC. The fecal microbiome was measured during three healthy and three HAEC episodes by next-generation sequencing. The patient was started on daily probiotics for 3 months; the fecal microbiome was measured weekly. The fecal microbiome differed significantly between healthy and HAEC episodes. HAEC episodes were associated with significant decreases of Actinobacteria and significant increases of Bacteroidetes and Proteobacteria. Probiotic treatment led to a significant increase of alpha diversity and a significant increase of Bifidobacterium and Streptococcus as well as decreases of Rikenellaceae, Pseudobutyrivibrio, Blautia, and Lachnospiraceae. A longitudinal observation of the microbiome has never been performed following correction of Hirschsprung's disease. Probiotic treatment significantly changed the fecal microbiome; the alterations were not limited to strains contained in the administered probiotics.