OBJECTIVE To explore the effect of acupuncture on the learning and memory ability and intestinal flora structure of senescence-accelerated mouse prone 8 (SAMP8) mice.

METHODS Eighteen 6-month-old SAMP8 mice were randomly divided into model group and acupuncture group, with 9 mice in each group, and 9 senescence-accelerated mouse resistant strain 1 (SAMR1) mice of the same month as the normal group. The acupuncture group selected Baihui and Yongquan points for acupuncture, 5 times a week, 20 min each time, for 8 consecutive weeks. Morris water maze was used to detect the learning and memory ability of mice in each group, immunofluorescence method was used to detect β-amyloid protein (Aβ) expression in the cerebral cortex, and 16S rDNA technology was used to detect changes in intestinal flora.

RESULTS The results of the water maze experiment showed that compared with the normal group, the learning and memory abilities of the mice in the model group were significantly reduced (P < 0.05), and the learning and memory abilities of the mice in the acupuncture group were significantly improved compared with the model group (P < 0.05). Immunofluorescence results showed that compared with the normal group, the model group had increased positive expression of Aβ in the cerebral cortex, and obvious Aβ plaque deposition could be seen; the acupuncture group had fewer Aβ plaques than the model group. Alpha diversity index showed that compared with the normal group, the Ace and Simpson values of the model group decreased (P < 0.05) and the Shannon value increased (P < 0.05); compared with the model group, the Ace and Chao values of the acupuncture group increased (P < 0.05, P < 0.01). In the beta diversity analysis, the results of principal component analysis (PCA) and principal coordinate analysis (PCoA) showed that the samples in each group were relatively clustered, and the distance between samples in each group was far away. The Venn diagram showed that there were 664, 689, and 649 OTUs in the normal group, model group, and acupuncture group, respectively. Results of intestinal flora structure analysis showed that compared with the normal group, the abundance of Bacteroidetes, Ruminococcaceae, and Eubacterium xylanophilum in the model group increased (P < 0.05), and the abundance of Fusobacterium, unclassified Fusobacterium, and Porphyromonas decreased (P < 0.05); compared with the model group, the abundance of Bacteroidetes and Eubacterium xylanophilum decreased in the acupuncture group (P < 0.05), and the abundance of Fusobacterium, unclassified Fusobacterium, and Porphyromonas increased (P < 0.05).

CONCLUSION Acupuncture can reduce cortical Aβ deposition and improve learning and memory abilities in SAMP8 mice, which may be related to regulating the structure of intestinal flora and increasing species diversity.