To minimize the waste of active ingredients present in herb residues, in the present study, probiotics of Bacillus subtilis, Aspergillus oryzae and Lactobacillus plantarum M3 were selected to reuse herb residues from Jianweixiaoshi tablets, and the therapeutic effects of the herb residue fermentation supernatant were evaluated using a spleen‑deficient mouse model. The results of the present study indicated that the fermentation supernatant may effectively improve the immunity of mice, as measured by body weight, spleen and thymus index, and inflammatory cytokines, including interleukin (IL)‑2, IL‑4 and interferon‑γ. The viable cell count and denaturing gradient gel electrophoresis results indicated that the fermentation supernatant markedly enhanced bacterial diversity and the number of lactobacilli in mouse intestines. Therefore, the combination of the Jianweixiaoshi herb residue and probiotics provided a novel method to reuse herb residues and may in the future contribute to the treatment of spleen deficiency.