Fig 1.

Copy numbers of mcrA gene in the feces of rats (A: control and treatment groups during the pre-experiment period; B: control and treatment groups during the first experimental period; C: group continued with BCM treatment (CO), group stopped with BCM treatment (ST) and group inoculated with faecal mixture of methanogens from healthy rats (IN) during the second experimental period). For each experimental time, P value was added when significant difference was observed among different groups.