The community structure and diversity of the gut microbiota are associated with human diseases. However, the analysis of different community structure might be influenced by experimental approaches such as the quality of DNA extraction. Therefore, evaluating the efficiency of different DNA extraction methods for specific intestinal species is a guideline for obtaining a comprehensive human gut microbial profile, which may assist the in-depth investigation into the structure of the gut microbial community. The aim of this study was to perform a comparative analysis of five different DNA extraction methods. With the aid of qPCR, the efficiency of five DNA extraction kits was evaluated in terms of the purity of the extracted DNA, the DNA concentration, and the abundance of genomic DNA extracted from specific intestinal species. The results showed that the kit Q gave the best extraction results, especially for Gram-positive bacteria such as Lactobacillus and Bifidobacterium. The average DNA concentration of the N kit was lower than that of the Q kit, but there was no significant difference between the two in terms of the purity. Compared to the other three commercial kits (M, PSP, TG), the efficiency of the N kit in extracting the genomic DNA of the specified microorganisms were the least different from those of the Q kit. In contrast, the DNA extracted by the M kit was of higher quality but of lower concentration, and was not very efficient for Gram-positive bacteria. The DNA extracted by the TG and PSP kits was inferior to the other validated kits in terms of the concentration, quality and bacterial abundance. These results provide a basis for the selection of genomic DNA extraction methods in microecological research experiments.
Keywords: feces; genomic DNA; gut microbiota; quantified PCR.