Host-microbe associations underlie many key processes of host development, immunity, and life history. Yet, none of the current research on the central model species Caenorhabditis elegans considers the worm's natural microbiome. Instead, almost all laboratories exclusively use the canonical strain N2 and derived mutants, maintained through routine bleach sterilization in monoxenic cultures with an E. coli strain as food. Here, we characterize for the first time the native microbiome of C. elegans and assess its influence on nematode life history characteristics via transcriptomics. Overall design: mRNA profiles of wild type (WT) C.elegans fed to either Ochrobactrum strain MYb65, MYb71, mixture of MYb65 and MYb71 or standard lab food E. coli OP50 at different life stages (from L2 to adults) were generated by deep sequencing, in triplicate, using Illumina HiSeq2000.