ABSTRACT
Crohn's disease causes chronic inflammation in the gastrointestinal tract and its pathogenesis remains unclear. In the intestine of Crohn's disease patients, CD14+CD11+CD163low macrophages contribute to inflammation through the induction of Th17 cells and production of inflammatory cytokines; the CD14+CD11c+163high fraction is anti-inflammatory through the production of IL-10 in normal cases. In this report, the 16S rRNA gene amplicon sequencing method was used to identify bacteria that are specifically present in intestinal CD14+CD11c+ macrophages of Crohn's disease patients. Bacteria present in intestinal CD14+CD11c+ macrophages and mucus of Crohn's disease patients were separated into different clusters in principal coordinates analysis. There was a statistically significant increase in the relative composition of CD14+CD11c+ macrophages from mucus in two phyla (Proteobacteria [p = 0.01] and Actinobacteria [p = 0.02]) and two families (Moraxellaceae [p < 0.001] and Pseudomonadaceae [p = 0.01]). In addition, OTU-1: Acinetobacter and OTU-8: Pseudomonadaceae tended to concentrate in the CD14+CD11c+CD163low subset, whereas OTU-10: Proteus, OTU-15: Collinsella tended to concentrate more in the CD14+CD11c+CD163high subset than the other subset and mucus.