Fig. 1

A Microbial composition at the species level of the top 20 most abundant species in obese and lean donors, highlighting the differences in species distribution between the two groups. B Microbial composition at the species level of the top 20 most abundant species in pooled fecal samples from lean and obese donors, illustrating the integration and overall community structure in pooled samples. C NMDS plot displaying microbial community structure at the species level for individual donors (donor 1, donor 2, donor 3) and pooled samples (pool R1, pool R2, pool R3) at two time points (0 h and 24 h). PERMANOVA analysis indicates no significant change due to the pooling process (\(R^2 = 0.338\), \(p = 0.26\)). D Microbial composition at the species level of the top 20 most abundant species at 0 h across various feeding conditions and controls, demonstrating the initial community structure. E Microbial composition at the species level of the top 20 most abundant species after 24 h exposed to the feeding conditions, showing the effects of different dietary fibers over time. F The NMDS plot shows significant differences between lean and obese samples under various feeding conditions. PERMANOVA analysis reveals the effects of feeding conditions (\(R^2 = 14\%\), \(p = 0.025\)), obesity status (\(R^2 = 18\%\), \(p = 0.001\)), and time points (\(R^2 = 47\%\), \(p = 0.001\)) on the composition of microbial communities. Data are representative of three independent fermentation experiments (\(n=3\)) using pooled fecal inoculum from either lean or obese groups