Classification of cultures

Structures were classified according to the presence of rounded or immature cells and budding between the harvesting and the 6 days of culture, as described by the intestinal stem cell consortium (Stelzner et al., 2012) (a nomenclature for intestinal in vitro cultures). With regard to columnar structures, the cell polarity was defined by the polarized labelling of β‐actin and β‐catenin. A columnar cell was defined by a thickness >18 μm. Releasing structures were defined by a broken epithelium and the presence of cell debris inside and outside of the structure. For all structures, the diameters around the structure were measured four times, and measurements obtained were averaged. For budding structures, only the rounded core of the structure was measured for diameter; individual budding zones were not included in the diameter measurements.