Fig. 4: Differential gut microbial proteins between the MCI patients and controls.

a Volcano plot indicating the differential proteins between the patients and controls. Proteins with fold change (FC, patients/controls) > 2 and p-value < 0.05 were colored red, while those with FC < 0.5 and p-value < 0.05 were colored blue. The p-values were given by MS1-MS2-combined statistical test in Spectronaut and adjusted by the Bonferroni method. b Distribution of taxonomy assigned to the differential proteins. c Numbers of the differential proteins in each category of clusters of orthologous groups (COG). Proteins more abundant in patients were colored red, while those more abundant in controls were colored blue.