Extended Data 6. Fetal meconium Micrococcus isolate exhibits adaptation to the fetal environment.

Effects of 10⁻⁵ M progesterone (P4) and 10⁻⁶ M β-Estradiol (E2) on the growth a. MicroRef1 or b. MicroRef2 in carbon limiting media or of c. MicroRef1, d. MicroRef2, e. Micro36 with indicated concentrations of P4 and E2 or f. combinations of hormones compared to ethanol vehicle control, in carbon-rich media at 37 °C. Representative growth curves of three independent experiments measured by optical density at 600nm (OD600), error bars denote standard error of the mean (SEM) between three technical experiments. For carbon-rich media conditions, integral of logistic regression model fitting was used to calculate area under the curve (auc) and change with respect to vehicle control is reported as Δauc. g. Intracellular survival of Micro36 or MicroRef1 or E. coli in RAW264.3 cells. ANOVA of generalized linear model of log(CFU+1) against E. coli for each timepoint was used to calculate significance. Error bars indicate SEM around center mean of n=3 independent cell culture experiments. Growth of indicated strains on media with (+) or without (−) gentamycin (10μg mL⁻¹) following 24–50 hours of intracellular growth in h. RAW264.7 cells or i. primary human fetal intestinal antigen presenting cells.