Proteomic analysis of Bacillus subtilis WB800N under high‑concentration sugar stress. Cells were treated with D‑galactose, D‑fructose and D‑tagatose at 100–600 g/L (55°C, 30 min), with three biological replicates per condition. DIA‑based LC‑MS/MS quantified 3,049 proteins. Data provide insights into stress adaptation mechanisms relevant to whole‑cell biocatalysis of rare sugars.