Effect of berberine analogues on functional profiles of human gut microbiomes

The understanding of the effects of compounds on the gut microbiome is limited and in particular we don’t know whether structurally similar compounds have similar or distinct effects on the gut microbiome. Here we selected berberine (BBR), an isoquinoline quaternary alkaloid, and sixteen structural analogues, and evaluated their effects on in vitro cultured individual gut microbiomes. The responses of the individual microbiomes were evaluated by metaproteomic profiles and by assessing butyrate production. BBR and eight analogues led to changes in proteins involved in microbial defense and stress responses, and enrichment of proteins from Verrumicrobia, Proteobacteria and Bacteroides phyla. It also led to a decrease in proteins from the Firmicutes phylum and its Clostridiales order which correlated to decrease proteins involved in the butyrate production pathway and butyrate concentration. Three of the compounds, Sanguinarine, Chelerythrine and Ethoxysanguinarine activated bacterial protective mechanisms, enriched Proteobacteria, increased opacity proteins and markedly reduced butyrate production. Dihydroberberine had a similar function to BBR in enriching the Akkermansia genus. In addition, it showed less overall adverse impacts on the functionality of the gut microbiome, including a better maintenance of the butyrate level. Our study shows that ex vivo microbiome assay can assess differential regulating effects of compounds with subtle differences and reveals that compound analogues can have distinct effects on the microbiome.