FAS and fatty liver disease: The prevention of MetS and fatty liver by LWE is associated with the increase of bacterial diversity and abundance of some bacterial groups producing short-chain fatty acids, such as Ruminococcaceae, Faecalibaculum, Intestinimonas, and Alistipes, and the suppression of the SIRT6/SREBP1/FAS/DGAT1 hepatic lipogenesis pathway.