Associations Between Gut Microbiota and Immune Profiles in Community‐Dwelling Older Adults and the Regulatory Role of Polygonatum odoratum
Tingting Xia, Hongmei Wu, Tianyi Cui, Wenzhi Yang, Min Zhang, Yuhong Huang, Shengyuan Zhou, Yongsheng Wu, Donglan Yan, Fan Jia, Lin Zhang, Zhi Cui, Jiayao An, Xinqin Zhong, Bin Lv, Xin Zhao, Kaijun Niu, Xiumei GaoABSTRACT
Aging is often associated with intestinal microbiota imbalance and immune system degeneration. The dysregulation and crosstalk of these two factors markedly elevate the elderly's susceptibility to infections and age‐related diseases. Polygonatum odoratum , a traditional Chinese medicinal herb, is widely used in geriatric care for its lung‐moistening and nourishing effects. However, its potential regulatory roles on the microbiota and immunity in the aging context remain unreported. A total of 140 independently living elderly individuals aged 60 and above were recruited for this study. The randomized, double‐blinded study including YZG ( P. odoratum ) and placebo groups was performed for 90 days' intervention. Peripheral blood immune cell subsets were analyzed by flow cytometry, and microbial diversity in fecal samples was assessed by 16S rRNA sequencing. Baseline correlation analysis revealed that alterations in gut microbiota were predominantly associated with T cell subsets. Specifically, Akkermansia showed a significant negative correlation with age‐related memory T cells, including CD4 + and CD8 + TEMRA. Additionally, Klebsiella exhibited a significant positive correlation with partial subsets of CD4 + TEMRA. After 90‐day YZG intervention, the percentage of TEMRA and CD28 − CD57 + TEMRA cells were reduced in elderly subjects. The relative abundance of Prevotella 9 and Akkermansia were increased, and the abundance of Klebsiella in the gut microbiota were significantly decreased. Correlation analysis linked YZG‐induced gut microbiota changes to improved immunity and fewer respiratory infections. This study demonstrates significant correlations that exist between immunosenescence in T‐cell compartments and gut microbial composition, suggesting a potential interplay between microbial health and immune aging.
Trial Registration: UMIN Clinical Trials Registry identifier: UMIN000052572