Intestinal stem cells heterogeneity and clonal dominance during aging: two faces of the same coin?

•Aging increases the cell-to-cell heterogeneity of the intestinal stem cells (ISCs).•ISC heterogeneity is driven by multiple environmental, microenvironment and cell intrinsic factors.•Intestinal crypt clonality represents a prevention mechanism to reduce fixation and spread of altered stem cells.•Altered ISCs may escape this protective mechanism during aging.