Intestinal mucosal and fecal microbiota profiles in Crohn's disease in Chinese children

Imbalance in the microbiota has been identified in Crohn's disease (CD). We explored the difference of the microbiota in fecal and intestinal mucosa (including ileocecal junction, terminal ileum and transverse colon) in pediatric patients with active CD, CD patients in remission, nonspecific enteritis (NE) and the healthy children. Seven children had active CD, 5 cases of patients achieve remission (CDR), 19 were NE patients, and 11 were healthy controls (Col). A total of 168 samples were collected. Microbiota compositions were analyzed using 16 ​S rRNA sequencing. The results showed that, in fecal samples, Clostridium_sensu_stricto, Enterobacter and Akkermansia had a higher relative abundance in the CD group than that in CDR, Col and NE groups. Fusobacterium and Streptococcus showed a higher abundance in both CD and CDR than that in Col group. In intestinal mucosa samples, the bacterial communities of the three sampling sites were extremely similar. Escherichia-Shigella was the most abundant mucosal bacteria in the CD group, and the abundance of Bacillus, Ruminococcus_torques_group, Streptococcus, Faecalibacterium and Blautia was lower in the CD group than in other groups. In conclusion, as a very characteristic bacteria, the abundance of Escherichia-Shigella in the intestinal mucosa can be used as a diagnostic criterion for CD patients. Also, the Bacilus and Blautia, which were not as prominent as Escherichia-Shigella could still be used as a diagnostic candidate due to their neatness in CD patients. Mucosal samples may be better than stool samples when assessing the community and diversity of patients' intestinal microbes.