Skip to main content
. Author manuscript; available in PMC: 2024 Nov 13.
Published in final edited form as: Nat Rev Gastroenterol Hepatol. 2024 Feb 21;21(5):348–364. doi: 10.1038/s41575-024-00896-2

Fig. 5|. Modulation of inflammation and immune cell differentiation and function by secondary bile acid derivatives in the gastrointestinal tract.

Fig. 5|

The illustration summarizes the latest observations on the effects of rarely measured and hence understudied microbially derived secondary bile acid derivatives on host immune cells. In general, the data indicate that particular secondary bile acid derivatives exert distinct effects on the differentiation of macrophage progenitors as well as dendritic cell antigen presentation and naive CD4+ T cell differentiation, thereby purportedly influencing the inflammatory tone in the gastrointestinal tract. For specific details on the findings illustrated, readers are referred to the original research papers26–28,57,59,145,146,178,194–196,198, which are summarized in the body of the present Review and subsequent review articles9,29,30,55,216. Briefly, iso-lithocholic acid (isoLCA) and 3-oxoLCA were shown to modulate macrophage polarization states217, iso-deoxycholic acid (isoDCA) induced FOXP3 expression in dendritic cells to diminish their immunostimulatory properties146, the planar secondary bile acid isoalloLCA enhanced regulatory T (Treg) cell differentiation through interactions with the nuclear hormone receptor NR4A1, leading to activation of FOXP3gene transcription28 .and 3-oxoLCA inhibited T helper 17 (TH17) cell differentiation26,27. Similar to 3-oxoLCA, isoLCA suppressed TH17 cell differentiation by inhibiting the canonical transcription factor retinoid-related orphan receptor γt (RORγt+)27. FXR, farnesoid X receptor; M-CSF, macrophage colony-stimulating factor. TCR, T cell receptor.