Peking University researchers in collaboration with the NIH have discovered a new biochemical pathway related to a bacterium that eliminates nicotine in the intestine. The findings could lead to new ways to improve nonalcoholic fatty liver disease (NAFLD) in smokers. In addition to the lung and the brain, nicotine can accumulate in the intestine, where the bacteria Bacteroides xylanisolvens could reduce its concentration and the severity of NAFLD. In their study, published in Nature Oct. 19, 2022, the researchers described the enzymes involved in this process and a new undiscovered pathway.