Consistently, a recent study reported that smoking-related non-alcoholic steatohepatitis (NASH) can be alleviated by the degradation of gut nicotine with a gut bacterium Bacteroides xylanisolvens J1101, whose genome encodes a nicotine-degrading enzyme (NDE), NicX [8]. This evidence concerns the gene NDE1 and metabolic dysfunction-associated steatohepatitis.