Prebiotic effects of yacon (Smallanthus sonchifolius Poepp. & Endl), a source of fructooligosaccharides and phenolic compounds with antioxidant activity

► Different bioactives such FOS and phenolics were evaluated in 35 yacon accessions. ► High variability in the content of the evaluated compounds was found. ► Promising yacon cultivars were identified as rich sources of FOS, AC and FOS/AC. ► Prebiotic effect of yacon FOS was confirmed in vivo with a guinea pig model. ► Yacon FOS enhanced beneficial bacteria, SCFAs and other properties in caecum tissue.