Figure 1: Published F. prausnitzii's mechanisms of action.
Anti-inflammatory properties attributed to the F. prausnitzii species, include (1-3):
- Induction of a tolerogenic cytokine profile on immune cells, in particular antigen presenting cells (dendritic cells, macrophages) and CD4CD8aa+ regulatory T cells, with elevated secretion of the anti-inflammatory cytokine IL10 and very low secretion of pro-inflammatory cytokines like IL12 and IFNγ-.
- Butyrate production: Butyrate (a short chain fatty acid) can reduce intestinal mucosa inflammation through inhibiting nuclear factor-κB transcription factor activation, up-regulating peroxisome proliferator-activated receptor-γ, inhibiting IFN-γ, and promoting Foxp3+ regulatory T cells.
- Production of the MAM protein which exhibits anti-inflammatory signalling in intestinal epithelial cells.
Furthermore, F. prausnitzii cells have been reported to reduce the severity of acute (4-6), chronic (7) and low grade (8) chemically induced inflammation in murine models.
In murine models of TNBS and DNBS induced colitis, intragastric administration of F. prausnitzii decreased the colitis severity in both severe and moderate chronic colitis models. The lower severity of colitis was associated with down regulation of myeloperoxidase, proinflammatory cytokines (IL12, IL6, and IFNγ) and effector T cell levels (5, 7).
Together, these findings indicate that F. prausnitzii plays a crucial role in maintaining gut physiology and host wellbeing. Due to the importance of the microbiota in the development of IBD, there is increasing interest in the development of microbiota modulating therapies, and F. prausnitzii represents an ideal candidate. It is a well characterised, extremely oxygen-sensitive, commensal, anti-inflammatory bacteria, which colonises the area of the gastro-intestinal tract in healthy individuals and is affected by inflammation in Crohn’s disease.