Abstract:[Objective] To provide the basis for its treatment, the effect of ultra-micro powder Dendrobium officinale on the molecular diversity of intestinal Lactobacillus in mice with spleen-deficiency constipation was studied. [Methods] The mice with spleen-deficiency constipation in treatment groups were respectively given the traditional decoction of Dendrobium officinale and 50% dose of ultra-micro powder Dendrobium officinale. The metagenome DNA of intestinal microflora was extracted from intestinal contents. Then ARDRA analysis was made after PCR by specific primer of Lactobacillus. [Results] The results showed that OTUs, Shannon index and Brillouin index in the normal group, the traditional decoction group and the 50% dose of ultra-micro powder group were the same, and all were larger than which in the model group. Compared with Lactobacillus community structure in normal group, the similarity coefficient was 0.333 3 in the 50% dose of ultra-micro powder group, 0.181 8 in the model group, 0.166 7 in the traditional decoction group. The cluster analysis and principal components analysis suggested that molecular diversity of intestinal Lactobacillus in mice changed by the effect of spleen-deficiency constipation model, and the two kinds of decoction of Dendrobium officinale regulated it in different ways. The Dendrobium officinale had obvious effect on the molecular diversity of intestinal Lactobacillus in mice with spleen-deficiency constipation. [Conclusion] The efficacy of 50% dose of ultra-micro powder Dendrobium officinale was the best in all treatment groups, and the molecular diversity of intestinal Lactobacillus in 50% dose of ultra-micro powder Dendrobium officinale group was closer to the normal group.