Fig. 4

Volcano plots demonstrating the fold-change (FC) in the differential abundance analysis of gut bacteria at the species level (a) at week 4 compared to week 0 in the synbiotic group (n = 23); b at week 4 compared to week 0 in the placebo group (n = 19); and c at week 6 compared to week 0 in the synbiotic group (n = 21). Vertical dashed lines show log₂FC at 1 and − 1 (i.e. FC at 2 and − 2). Horizontal dashed line shows -log₁₀(adjusted p) = 2 (i.e. adjusted p = 0.01). Each point represents a different species and points are colored by phylum