FFAR2 and inflammatory bowel disease: Of the aforementioned receptors that were upregulated in the inflamed mucosa of IBD, only FFAR2 (FR = 1.60, padj = 0.029) and S1PR4 (FR = 1.81, padj = 0.025) were found to be upregulated in colonic samples of C. jejuni-infected individuals when compared to hIs.