Gut virome profile in healthy Saudi children.

Background: The role of viruses is well known in health and disease. The aim of this report was to describe the profile of viruses in the gut of healthy Saudi children. Methods: In 20 randomly selected school age children from Riyadh, stool samples were collected in cryovials and stored at -80° C. At the time of analysis, the samples were sent by express mail in a temperature-controlled container to the laboratory in the USA, Viral DNA was isolated and shotgun metagenomic sequencing was performed. The abundance of each organism was expressed as an average relative percentage across the viral phylogenetic tree from phyla to species. Results: The median age of the children was 11.3 (range 6.8-15.4) years, and 35% were males. Caudovirales were the most abundant bacteriophage order (77%) and Siphoviridae, Myoviridae, and Podoviridae families predominated, accounting for 41%, 25%, and 11%, respectively. Among the viral bacteriophage species, the most abundant were the Enterobacteria phages. Conclusion: The profile and abundance of the gut virome in healthy Saudi children reveal important differences from the literature. Further studies from different populations with larger sample sizes are needed to understand the role of gut viruses in the pathogenesis of disease in general and in the response to fecal microbiota therapy in particular.

Bacterial dysbiosis predicts the diagnosis of Crohn's disease in Saudi children.

BACKGROUND: Studies have reached different conclusions regarding the accuracy of dysbiosis in predicting the diagnosis of Crohn's disease (CD). The aim of this report is to assess the utility of mucosal and fecal microbial dysbiosis as predictors in the diagnosis of this condition in Saudi children. METHODS: Tissue and fecal samples were collected prospectively from children with final diagnosis of CD and from controls. Bacterial DNA was extracted and sequenced using Illumina MiSeq chemistry. The abundance and diversity of bacteria in tissue and fecal samples were determined in relation to controls. Sparse logistic regression was calculated to predict the diagnosis of CD based on subject's microbiota profile. RESULTS: There were 17 children with CD and 18 controls. All children were Saudis. The median age was 13.9 and 16.3 years for children with CD and controls respectively. Sex distribution showed that 11/17 (65%) of the CD and 12/18 (67%) of the control subjects were boys. The mean area under the curve (AUC) was significantly higher in stool (AUC = 0.97 ± 0.029) than in tissue samples (AUC = 0.83 ±0.055) (P < 0.001). CONCLUSIONS: We found high AUC in mucosal and fecal samples. The higher AUC for fecal samples suggests higher accuracy in predicting the diagnosis of CD.

Regional variation of pediatric inflammatory bowel disease in Saudi Arabia: Results from a multicenter study.

BACKGROUND: Incidence and severity variations of inflammatory bowel disease (IBD) have been reported from Western populations between continents and regions of the same countries. However, no data were available from other countries. AIM: To investigate the regional differences in the IBD profiles of pediatric patients from the Kingdom of Saudi Arabia. METHODS: Data from a national multicenter IBD study were used. The incidence, time trend, and clinical presentation of Crohn's disease (CD) and ulcerative colitis (UC) in the Central region (CR), Western region (WR), and Eastern region (ER) were analyzed and compared. Statistical analysis included Poisson regression analysis for incidence variation and Chi-square test for demographic and clinical parameters. A P < 0.05 was considered significant. RESULTS: The prevalence of positive family history was lower in children with CD from the ER than the CR or the WR. Consanguinity rate was higher in children with CD and UC from the CR and the ER, respectively. The incidences and time trends of CD and UC were not significantly different between regions. In the ER, a significantly higher percentage of children with CD presented with abdominal pain (P < 0.001), blood in stools (P = 0.048), stricturing or penetrating disease (P = 0.029), higher erythrocyte sedimentation rate (P < 0.001), higher C-reactive protein (P < 0.001), higher anemia (P = 0.017), and lower albumin level (P = 0.014). For children with UC from the ER, a significantly higher percentage presented with anemia (P = 0.006) and a lower percentage with pancolitis (P < 0.001). CONCLUSION: The most important finding is the identification of significantly more severe presentation of CD in the ER of the Kingdom of Saudi Arabia. Prospective studies are needed to explain such variations.

Diagnostic delay of pediatric inflammatory bowel disease in Saudi Arabia.

BACKGROUND/AIM: Delay in the diagnosis of inflammatory bowel disease (IBD) is associated with complications. Our aim was to describe the pattern and risk factors associated with delay in the diagnosis of IBD in Saudi children. PATIENTS AND METHODS: This was a multicenter study with a retrospective/prospective design. Data on diagnostic delay in children with Crohn's disease (CD) and ulcerative colitis (UC) were retrieved from physician's notes. Multivariate regression analysis was used to assess the risk factors associated with long delay in diagnosis. RESULTS: There were 240 and 183 Saudi children with CD and UC, respectively. The median delays in diagnosis were 8 and 5 months in CD and UC, respectively, significantly longer in children with CD than UC (P < 0.001). Long diagnostic delays (>75th percentile) were 24 and 8.8 months for CD and UC, respectively. Ileal location was a significant risk factor in CD and the age of onset above 10 years was protective in UC. CONCLUSIONS: Long diagnostic delay in IBD was mainly due to the longer delay in gastroenterologist consultation. Review of the referral system is needed to focus on measures to reduce long delays in diagnosis. The ileal location as a risk factor in CD and age older than 10 years as protective in UC should help recognition and early referral.

Fungal dysbiosis predicts the diagnosis of pediatric Crohn's disease.

AIM: To investigate the accuracy of fungal dysbiosis in mucosa and stool for predicting the diagnosis of Crohn's disease (CD). METHODS: Children were prospectively enrolled in two medical centers: one university hospital and one private gastroenterology clinic in the city of Riyadh, Kingdom of Saudi Arabia. The children with confirmed diagnosis of CD by standard guidelines were considered cases, and the others were considered non-inflammatory bowel disease controls. Mucosal and stool samples were sequenced utilizing Illumina MiSeq chemistry following the manufacturer's protocols, and abundance and diversity of fungal taxa in mucosa and stool were analyzed. Sparse logistic regression was used to predict the diagnosis of CD. The accuracy of the classifier was tested by computing the receiver operating characteristic curves with 5-fold stratified cross-validation under 100 permutations of the training data partition and the mean area under the curve (AUC) was calculated. RESULTS: All the children were Saudi nationals. There were 15 children with CD and 20 controls. The mean age was 13.9 (range: 6.7-17.8) years for CD children and 13.9 (3.25-18.6) years for controls, and 10/15 (67%) of the CD and 13/20 (65%) of the control subjects were boys. CD locations at diagnosis were ileal (L1) in 4 and colonic (L3) in 11 children, while CD behavior was non-stricturing and non-penetrating (B1) in 12 and stricturing (B2) in 3 children. The mean AUC for the fungal dysbiosis classifier was significantly higher in stools (AUC = 0.85 ± 0.057) than in mucosa (AUC = 0.71 ± 0.067) (P < 0.001). Most fungal species were significantly more depleted in stools than mucosal samples, except for Saccharomyces cerevisiae and S. bayanus, which were significantly more abundant. Diversity was significantly more reduced in stools than in mucosa. CONCLUSION: We found high AUC of fungal dysbiosis in fecal samples of children with CD, suggesting high accuracy in predicting diagnosis of CD.