Abstract
Coffee is globally popular beverage, renowned for its taste and stimulating properties. This study aims to explore the impact of two different types of coffee, depending on extraction methods, on the gut microbiota. Fecal samples from healthy donors (n = 20) were cultured with or without coffee using in vitro fecal incubation. Both coffee-treated groups exhibited lower microbial diversity and greater structural differences in their communities compared to the control. Notably, the Bifidobacterium genus was overrepresented in the instant coffee (IC)-treated groups, whereas the Blautia genus was underrepresented in both coffee-treated groups. Additionally, genes for TCA cycle and vitamin B6 metabolism were more prevalent in coffee-treated groups than in the control. However, the precursor pathways leading to the TCA cycle differed between the DC- and IC-treated groups, reflecting the distinct chemical compositions of each coffee type. These findings demonstrate that extraction method of coffee significantly affects its impacts on gut microbial structure. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10068-024-01717-7.