Structural characteristics of Ficus carica L. dietary fibers and their in vitro fermentation properties in modulating gut microbiota and metabolites

In this study, we extracted three kinds of dietary fibers (DFs) from Ficus carica L. (FDFs) including soluble FDF (FSDF), insoluble FDF (FIDF) and total FDF (FTDF) by multiple-enzyme method. After 24 h of in vitro fecal fermentation, galacturonic acid and arabinose in FSDF were positively correlated with Parasutterella ( r = 0.82, p < 0.05; r = 0.88, p < 0.05), which was also associated with valeric acid ( r = 0.94, p < 0.05). Xylose in FIDF showed a positive correlation with Megamonas (r = 0.94, p < 0.05), and Megamonas was positively correlated with acetic acid (r = 0.94, p < 0.05). FSDF and FIDF all showed downregulatory effect on Fusobacterium , this effect was associated with the elevation of acetic acid level. Although FTDF had a regulatory effect on Fusobacterium , it had no significant regulatory effect on acetic acid. Our data suggest that FDFs exerted distinct effects on gut microbiota and its metabolites, providing a basis for future functional food design incorporating FDFs. • Three kinds of dietary fibers were extracted from Ficus carica L. (FDFs). • FDFs facilitated the production of SCFAs during in vitro fecal fermentation. • FDFs reshaped the gut microbiota composition and microbial metabolites. • Gut microbiota can utilize FDFs to modulate microbial metabolites including SCFAs.