a,b Relative abundance (rarefied to 10 000 reads/sample) of bacterial taxa at the genus level in lumen, expelled stool and tissue microbiota of mice fed standard chow (SD) (a) and Western diet (WD) (b). c–e Relative abundance of Enterococcus in lumen (c), expelled stool (d) and tissue (e) microbiota. Mean values (bold lines), i.q.r. (boxes), and range (error bars) excluding outliers (dots) are shown. *P < 0.050 versus SD (analysis of composition of microbiome (ANCOM), with Benjamini–Hochberg false discovery rate correction). There was a significant difference in relative abundance of Enterococcus over time for all sample types in each group (P < 0.050, ANCOM), demonstrating a significant flux of Enterococcus at certain times in both SD and WD groups. Preop., preoperative.