Particularly, the identification in FAP patients of a specific microbiota composition with some taxa found both in mucosal and faecal specimens and associated with the specific derangement of Wnt/β-catenin and PI3K/mTOR signallings may help in developing assays to differentiate patients with early-stage adenomas often missed by FIT screening. The gene discussed is PIK3CA; the disease is Familial adenomatous polyposis.