Preliminary study of gut microbiome influence on black Ivory coffee fermentation in Asian elephants

Black Ivory Coffee (BIC), produced through the digestion of Arabica coffee beans by Asian elephants, is recognized for its smooth, chocolaty flavor and low bitterness. However, the biological mechanisms underlying its unique taste remain poorly understood. In this study, we conducted a preliminary analysis of the gut microbiome of BIC-producing elephants and compared it with that of control elephants. 16S rRNA gene sequencing analysis revealed significant differences in microbial community structure, including the enrichment of specific bacterial genera such as Acinetobacter and family such as Izemoplasmataceae in the BIC group. Functional prediction using PICRUSt2 indicated that the BIC elephant gut microbiome harbors key enzymes involved in the degradation and utilization of pectin and cellulose-major components of coffee cherries and beans. Notably, genes related to pectin transport and downstream metabolism, including K08191 and K01812, were significantly more abundant in BIC elephants. These pathways may contribute to the degradation of specific compounds, such as 2-furfuryl furan, which has been previously shown to decrease after gastrointestinal passage. Comparative analysis with other animals revealed that only elephants harbored a complete set of pectin-degrading genes. Our findings suggest that the gut microbiota of BIC elephants facilitates microbial fermentation of coffee components, potentially influencing the chemical profiles of Black Ivory Coffee.