Dysbiosis is usually associated with either the overgrowth of a single pathobiont, such as adherent-invasive Escherichia coli in a TLR5 deficient model of spontaneous colitis [52], or the loss of a single protective strain, such as the anti-inflammatory Faecalibacterium prausnitzii that is reduced in Crohn’s disease patients [53]. The gene discussed is TLR5; the disease is colitis.