This study investigates microbial community imbalances in human inflammatory bowel diseases (IBD), specifically Crohn's disease (CD) and ulcerative colitis (UC), using culture-independent rRNA sequence analysis. The research analyzed tissue samples from IBD patients and non-IBD controls, revealing significant differences in microbiota composition between the groups. CD and UC patients showed reduced diversity in their gut microbiota, characterized by a depletion of commensal bacteria, particularly from the phyla Firmicutes and Bacteroidetes. These findings suggest that microbial imbalances may contribute to the pathogenesis of IBD. The study also highlights that IBD patients exhibit distinct microbial communities compared to healthy controls, with significant differences in the abundance of certain bacterial groups. The results indicate that restoring microbial balance could be a potential therapeutic approach for IBD. The study underscores the importance of the gut-associated microbiota in IBD pathogenesis and suggests that microbial imbalances may be a key factor in disease progression. The research provides a comprehensive molecular characterization of the human small intestine microbiota, revealing that the gut microbiota is highly diverse and plays a critical role in maintaining host health. The findings have important implications for understanding the etiology and treatment of IBD.This study investigates microbial community imbalances in human inflammatory bowel diseases (IBD), specifically Crohn's disease (CD) and ulcerative colitis (UC), using culture-independent rRNA sequence analysis. The research analyzed tissue samples from IBD patients and non-IBD controls, revealing significant differences in microbiota composition between the groups. CD and UC patients showed reduced diversity in their gut microbiota, characterized by a depletion of commensal bacteria, particularly from the phyla Firmicutes and Bacteroidetes. These findings suggest that microbial imbalances may contribute to the pathogenesis of IBD. The study also highlights that IBD patients exhibit distinct microbial communities compared to healthy controls, with significant differences in the abundance of certain bacterial groups. The results indicate that restoring microbial balance could be a potential therapeutic approach for IBD. The study underscores the importance of the gut-associated microbiota in IBD pathogenesis and suggests that microbial imbalances may be a key factor in disease progression. The research provides a comprehensive molecular characterization of the human small intestine microbiota, revealing that the gut microbiota is highly diverse and plays a critical role in maintaining host health. The findings have important implications for understanding the etiology and treatment of IBD.