Professor Nie's research spans across food science and life sciences, focusing on the impact of dietary fiber on gut microbiota, the mechanisms of action and translational studies of microbiota-derived metabolites in metabolic diseases. The representative work includes the systematic evaluation and identification of specific types of dietary fibers that enhance glucose metabolism, as well as their associated gut functional bacteria; Elucidated the underlying mechanisms through which dietary fibers improve glucose metabolism via the “gut microbiota-bacterial metabolites-host receptor” axis. Furthermore, he also developed an innovative system for mining bacteria-derived metabolites, which has revealed the mechanistic pathway through which gut Bacteroides uniformis produces novel succinylated bile acids to improve metabolic dysfunction associated steatohepatitis.