SRP195763 PRJNA541440 Mus musculus Metagenome Gut microbiome in P10 pups showed few Gammaproteobacteria. To simulate the relative abundances of Gammaproteobacteria in premature infants, we colonized these pups with a non-pathogenic strain of Serratia marcescens on P7 and checked the microbiome on P10 Mus musculus