Fig. 5

PEG treatment in Enterocloster mono-colonized mice impacts cecal osmolality, bacterial abundance and inovirus secretion in a species-dependent manner. A Experimental schematic: germ-free Swiss Webster mice were gavaged with E. bolteae or E. clostridioformis 538, equilibrated for 4 weeks, and treated with 10% and 15% (w/v) PEG drinking water for 6 days, respectively. B Cecal contents were collected from untreated and PEG-treated mice and centrifuged, and cecal osmolalities were measured from the resulting cecal supernatant. C The effects of PEG treatment on bacterial density were measured by quantifying bacterial colony-forming units (CFU/mL) from cecal contents. D, E Relative qPCR quantification of inovirus production in cecal contents after PEG treatment. A primer pair was designed to quantify the conserved circularization region of the inovirus genome from E. bolteae and E. clostridioformis 538 using absolute qPCR (inovirus copies). Similarly, primers were designed to target the unique integration sites of the inovirus genome in the E. bolteae and E. clostridioformis 538 genomes (gDNA copies). To account for changes in bacterial abundance after PEG treatment, inovirus copy numbers were normalized by the bacterial genomic copy number (inovirus copies/10⁶ gDNA copies). To test for significance, a Student’s t test was performed between each experimental group and their control after accounting for group variances using Bartlett's test; **p < 0.01, ***p < 0.001, ****p < 1 × 10^–4