Antibiotic treatment and fecal microbiota transplantation

Eight-week-old male C57BL/6 J mice fed an HFD were supplemented with either 0.5% CMCNa (solvent) or PMFE at 120 mg/kg in the absence or presence of antibiotics [vancomycin (0.5 g/liter), neomycin sulfate (1 g/liter), metronidazole (1 g/liter), and ampicillin (1 g/liter)]. Fecal transplant was performed on the basis of an established protocol (37). Briefly, 8-week-old male donor mice were fed with HFD or HFD + PMFE (120 mg/kg). The recipient mice were fed HFD and treated daily with fresh transplant material from either PMFE-treated mice or HFD mice. Stool was collected daily from donor mice and pooled. Donor stool (100 mg) was diluted with saline and homogenized for 1 min using a vortex to achieve a liquid slurry, and then centrifuged at 500g for 3 min to remove particulate matter to facilitate administration. Fresh transplant material was prepared within 10 min before oral gavage to prevent changes in bacterial composition. There was no pretreatment of HFD and HFD + PMFE before the fecal transplantation. Oral gavage with drug or fecal transplant material was conducted daily through the 8-week experiment.