Of note, the expression of PINK1—a host gene that regulates mitochondrial homoeostasis and activates PI3-kinase/AKT signalling, contributing to intestinal inflammation in IBD and tumorigenesis32,91—is associated with the abundance of Collinsella in CRC, Peptostreptococcaceae in IBD and Blautia in IBS. The gene discussed is PINK1; the disease is inflammatory bowel disease.