gut microbiota of AD/NG
Sterile containers for fecal sample collection were provided to the 120 participants to fresh fecal samples collection. The returned samples were packaged with proper labels and stored in our lab at -80C until microbiota analysis. Fecal sample DNA extraction was performed using QIAamp Fast DNA Stool Mini Kit (51504, QIAGEN, Germany), followed by DNA quality detection. V3-V4 region of 16S rDNA was amplified, product was purified, DNA libraries were performed and libraries were sequenced on the Illumina Novaseq 6000 sequencing platform according to manufactures instruction. The decommission data distinguishes the data of each sample according to the barcode sequence and then performs chimeric filtering to obtain valid data that can be used for subsequent analysis, and the obtained sequence is clustered at 97% similarity to become out by USEARCH 10.0. OTUs were analyzed for abundance, alpha diversity, beta diversity, and the function was predicted using the FARPROTX database.