In a 90-day randomized, double-blind trial of 140 independently living adults aged 60 and older, supplementation with Polygonatum odoratum reduced terminally differentiated memory T cells (TEMRA, including the CD28−CD57+ senescent subset) while increasing Akkermansia and Prevotella 9 and lowering Klebsiella abundance. Baseline analysis showed gut microbial composition correlated most strongly with T cell subsets, and the intervention-associated microbial shifts tracked with improved immune profiles and fewer respiratory infections.
Key Points
- Akkermansia abundance inversely correlated with senescent CD4+ and CD8+ TEMRA cells
- 90-day herbal intervention reduced TEMRA and CD28−CD57+ senescent T cells
- Microbial shifts accompanied improved immunity and fewer respiratory infections
Longevity Analysis
Immunosenescence — the accumulation of terminally differentiated, replication-limited T cells — is among the more reliable predictors of infection risk and mortality after age 60, and this trial places gut microbial composition upstream of that process rather than alongside it. Akkermansia, a mucin-degrading organism tied to barrier integrity, tracked inversely with the most senescent T cell populations, while Klebsiella, an opportunistic pathobiont, tracked with them. The practical implication is that reducing pathobiont pressure and supporting the intestinal lining may shift how the body defends itself against respiratory pathogens, with the caveat that a 90-day window measures immune profile change, not long-term outcome.
Original published by Wiley Aging Cell, by 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 Gao .