Spent coffee grounds extract rich in manooligosaccharides promote a healthier gut microbial community in a dose dependent manner

Abstract

Coffee is one of the most consumed beverages around the world and as a consequence, spent coffee grounds are a massively produced residue that is causing environmental problems. Reusing them is a major focus of interest nowadays. We extracted mannoligosaccharides (MOS) from spent coffee grounds and submitted them to an in vitro fermentation with human feces. Results obtained suggest that MOS are able to exert a prebiotic effect on gut microbiota by stimulating the growth of some beneficial genera such as Barnesiella, Odoribacter, Coprococcus, Butyricicoccus, Intestinimonas, Pseudoflavonifractor, or Veillonella. Moreover, SCFA production also increased in a dose dependent manner. However, we observed that 5-hydroxymethylfurfural, furfural and polyphenols (which are either produced or released from spent coffee grounds matrix during hydrolysis) could have an inhibitory effect on some beneficial genera such as Faecalibacterium, Ruminococcus, Blautia, Butyricimonas, Dialister, Collinsella, or Anaerostipes which could affect negatively to the prebiotic activity of MOS.