Postnatal gut microbiota does not directly impact the obesity of caesarean offspring of GF mother

GF IQI mice were housed in vinyl isolators under a 12-h light-dark cycle, and given regular chow. On day 18.5, pregnant GF ICR or IQI mice were transferred faecal samples of each SPF control mice to prevent overgrowth of unfavorable microbes. For caesarean section experiments, progesterone was subcutaneously injected into the pregnant IQI mice on day 17.5 and 18.5. On day 19.5, pregnant IQI mice were delivered by caesarean section, and the foetuses were bred by conventional foster IQI mice for 4 weeks. Sequencing of the 16S rRNA variable regions 3 and 4 was performed as described previously. The libraries were sequenced using Miseq system (Illumina) with a 2 ? 300 base-pair protocols.