Certain tree species can reach ages of centuries, whereas lifespan of species like apple are markedly shorter. The latter is caused by negative plant-soil feedback that results in microbiome changes. We hypothesized that tree species with a long lifespan will be able to avoid such negative feedback and their root-associated microbiomes will be similar in trees of different ages. To test this, we used Chinese chestnut (Castanea mollissima) trees, ranging from 8 to 830 years old from a Ming orchard at the Great Wall. Their root-associated microbiomes were analysed by using meta-amplicon sequencing analysis. Their root-associated bacterial microbiomes were rather similar although based on linear regression models we cannot exclude that age has a weak correlation with microbiome compositions. When chestnut seedlings were grown for 3 months in soil associated with young or old trees, the plants were healthy and their growth was similar. This strongly supported that negative feedback had not occurred. Pseudomonas OTU1, a member of the core microbiome and representing >
50 % of the rhizosphere community, strongly inhibited growth of chestnut pathogens and stimulated plant growth. Such properties of the microbiome, in combination with a high number of resistance genes can contribute to longevity of chestnut.