Effect of acupuncture on cognitive impairment and gut microbiota in patients with subjective cognitive decline

Subjective cognitive decline (SCD), the earliest manifestations of preclinical stage of dementia, is the core criterion for the diagnosis of mild cognitive impairment (MCI) and prodromal alzheimer's disease (AD). In patients with SCD, changes in the gut microbiome may cause cognitive impairment, and vice versa. Acupuncture has been demonstrated to alleviate cognitive impairment in people with SCD in prior trials. However, it is unclear whether the compositions of gut microbiota in SCD patients change after acupuncture treatment. In this study, we aim to investigate the therapeutic efficacy of acupuncture on cognitive function and the gut microbiota in patients with SCD. A total of 64 participants were recruited, including 12 matched healthy controls (HCs) and 52 patients with SCD. The SCD patients were randomly divided into acupuncture (n=26) and sham acupuncture (SA) (n=26) groups, each received twice-weekly treatment for 12 weeks. Clinical information and stool samples were collected at baseline (week T0) and completion of treatment (week T12) in SCD patients. Additionally, stool samples were sequenced for the V3-V4 regions of the 16S rRNA gene.Following 12 weeks of treatment, the comprehensive Z score (p=0.045) and Montreal Cognitive Assessment (MoCA) (p=0.007) of the acupuncture group significantly increased compared with the SA group. Additionally, acupuncture could modulate the disordered gut microbiota of patients with SCD. After acupuncture treatment, the abundance of pathogenic bacteria, Proteobacteria (Klebsiella) has reduced dramatically approaching levels seen in HCs and the abundance of beneficial bacteria, such as Firmicutes (Ruminococcus_2) have increased. As a result of the Phylogenetic Investigation of Communities by Reconstruction of Unobserved States test (PICRUSt), the totally functional orthologs of SCD patients was lower compared with that of HCs. Our findings demonstrate that acupuncture contributes to the improvement of cognitive impairment in SCD patients and that the gut microbiota could be a potential therapeutic target.