Some Gammaproteobacteria are enriched within CD14 macrophages from intestinal lamina propria of Crohn's disease patients versus mucus.

Crohn's disease causes chronic inflammation in the gastrointestinal tract and its pathogenesis remains unclear. In the intestine of Crohn's disease patients, CD14CD11CD163 macrophages contribute to inflammation through the induction of Th17 cells and production of inflammatory cytokines; the CD14CD11c163 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 CD14CD11c macrophages of Crohn's disease patients. Bacteria present in intestinal CD14CD11c 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 CD14CD11c 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 CD14CD11cCD163 subset, whereas OTU-10: Proteus, OTU-15: Collinsella tended to concentrate more in the CD14CD11cCD163 subset than the other subset and mucus.