Among the genes with impact in IBD, a significant association stands between Caspase recruitment domain family member 9 (CARD9), Nucleotide-binding oligomerization domain containing 2 (NOD2), Autophagy related 16 like 1 (ATG16L) and Fucosyltransferase 2 (FUT2), and the low abundance of the protective Roseburia species that switches acetate into butyrate [63]. Here, CARD9 is linked to inflammatory bowel disease.