Figure 4.

Co-housing from birth shows that the skin microbiome directly influences healing outcome. Newborn WT and Nod2^–/– litters were mixed from birth with a Nod2^–/– mother and then wounded in adulthood. (a) Representative hematoxylin and eosin-stained sections of excisional wounds (day 5) from WT and Nod2^–/–control (non-mix), and co-housed (mix) cages. Arrows denote wound margins. (b) Quantification showed significantly delayed healing in WT mice co-housed with Nod2^–/– mice, with (c) increased local neutrophil influx. All data are representative of two independent experiments with n = 6 mice/non-mix groups and n = 5 mice/mix group. ^∗P < 0.05. Mean + standard error of the mean. Scale bar in a = 200 μm. WT, wild type.