Microbial dysbiosis in inflammatory bowel diseases: results of a metagenomic study in Saudi Arabia

BACKGROUND: The intestinal microbiota plays an essential role in the pathogenesis of ulcerative colitis (UC)and Crohn disease (CD). METHODS: Metagenomic studies were used to study microbiota in the diagnosed cases of UC and CD at King Fahad Medical City, Riyadh, Saudi Arabia. Each segment of the colon was flushed with distilled water during colonoscopy, and the material was aspirated, immediately frozen for the study. The patients attending for screening colonoscopies were taken as age-matched healthy controls. The UC patients were followed clinically for any signs of exacerbation relapse, and CD patients were followed for any complications. RESULTS: The metagenomic data on 46 (24 females) patients with CD were analyzed along with a group of age and gender-matched controls. Their age ranged from 14 to 65 years, mean age 25.19 +/- 10.67 years. There were 50 UC patient (28 females) mean age of 34.42 +/- 12.58, and their age ranged from 13-58 years. This study identified enrichment of 19 genera in the control group (Abiotrophia, Anaerofustis, Butyrivibrio, Campylobacter, Catenibacterium, Coprococcus, Dorea, Eubacterium, Facklamia, Klebsiella, Lactococcus, Oscillibacter, Paenibacillus, Parabacteroides, Parasutterella, Porphyromonas, Prevotella, Ruminococcus, Treponema). There was a significant enrichment of 14 genera in our CD cohort (Beggiatoa, Burkholderia, Cyanothece, Enterococcus, Escherichia, Fusobacterium, Jonquetella, Mitsuokella, Parvimonas, Peptostreptococcus, Shigella, Succinatimonas, ThermoanaerobacterVerrucomicrobiales, Vibrio). There was a significant enrichment of 7 genera in UC cohort (Beggiatoa, Burkholderia, Parascardovia, Parvimonas, Pseudoflavonifractor, Thermoanaerobacter, Verrucomicrobiales). CONCLUSIONS: A significant dysbiosis was found in UC and CD patients compared to controls.