The root rhizosphere as a functional analog to the gut microbiome: Cases for microbial symbiosis and dysbiosis in parallel contexts

Microbiomes associated with both the human gut and plant root rhizosphere are essential for the maintenance of host health and function as holobionts where both the host and microbiome operate as an integrated unit. Though substantial differences exist in both host biology and environment, these systems share functional parallels: both are enriched by host-derived nutrients, undergo successional shifts during development, and maintain core microbiomes that are taxonomically variable yet functionally redundant. Central to both systems is the balance that is maintained where beneficial microbes regulate nutrient cycling, modulate host immune response, and suppress pathogens in the presence of biotic and abiotic influences that may serve to disrupt this equilibrium. When dysbiosis occurs, there is a disruption in the composition and/or function of the associated microbiome and a loss of beneficial functional guilds, which results in a reduction in host fitness. These shared dynamics underscore dysbiosis as a cross-kingdom pathology that may be treated with similar interventions. Probiotics and prebiotics mirror microbial inoculants and organic amendments; synbiotics incorporate both biotic and abiotic factors, while fecal and soil microbiome transplants represent parallel strategies to restore a beneficial microbiome. By framing dysbiosis within a "One Health" perspective and illustrating the connectedness between human and plant health, this review advocates for microbial stewardship as a unifying strategy to mitigate disease, enhance resilience, and ensure sustainable health across both systems.