Effects of gut microbiota on the differentiation into activated macrophages

Abstract

Specific intestinal bacteria are recognized as key modulators of host homeostasis and disease susceptibility through complex pathways in the gut. Macrophages are involved in the initial immune response by producing a spectrum of cytokines, whose expression pattern could vary among bacterial strains. In this study, we evaluated the immunomodulatory capacities of nine representative intestinal bacteria strains in an in vitro macrophage model using THP-1 cells. Akkermansia muciniphila, Bacteroides uniformis and Parabacteroides distasonis elicited higher levels of TNF-α, IL-10, CCL5 and CXCL10 than did other strains. Moreover, cytokine induction by these strains correlated positively with bacterial concentration. These findings highlight the potential strain-specific effect of intestinal bacteria on macrophage activation and suggest the importance of analyzing interactions between host and microbiota at the single-bacterium level for therapeutic insights.