3.1 Selection of instrumental variables associated with gut microbiota
After the screening of the genome-wide significance threshold, LD test, harmonization, MR-PRESSO test, and F statistics, multiple SNPs were obtained as their proxies for these 196 bacterial taxa for further analysis, including 8 Class. Melainabacteria, 5 Genus. Butyricicoccus, 4 Genus. Catenibacterium, 9 Genus. Oscillibacter, 11 Genus.Ruminiclostridium5, 10 Genus. Ruminococcaceae UCG-003, 8 Order. Bacillales, and 8 Order. Gastranaerophilales.