Genomic DNA extraction
Genomic DNA (gDNA) was extracted from approximately 100 mg of each fecal sample using the ZymoBIOMICSTM DNA Miniprep Kit (Zymo Research, U.S.), according to the manufacturer’s protocol. A NanoDropTM spectrophotometer was used to quantify and assess the purification of the gDNA. The expected real-time quality score had to be > 7. However, the results obtained using the given protocol showed low DNA concentrations and inadequate purification for amplification. Therefore, we adjusted the protocol to achieve a better yield and more highly purified gDNA (See supplement).