Meta-environment No1: blood is the main organ of a person

Blood is traditionally considered as a transport medium Modern scientific data require a fundamental revision of this idea. In the blood plasma of each person, 1-5 thousand metabolites circulate, forming a dynamic ensemble, the balanced state of which is a necessary and sufficient condition for the normal functioning of all cells, tissues and organs. It is the imbalance of this metabolic background that underlies most symptoms, including pain, fatigue, cognitive impairment, and chronic inflammation. Blood contains extracellular vesicles that carry RNA, proteins, and lipids between cells and organs, as well as free nucleic acids that reflect the state of tissues. It has its own mechanisms of autoregulation, such as buffer systems that work faster than any organ responses, and the ability to preserve epigenetic memory of past events. In this article, we substantiate that blood is an active meta-medium No1 that meets all four criteria of meta-environments. We show that changes in the blood long precede clinical symptoms in type 2 diabetes, atherosclerosis, autoimmune diseases, cancer, and neurodegeneration. Understanding blood as a meta-medium, and especially its metabolic composition, opens up new opportunities for early diagnosis (5–15 years before the onset of symptoms) and systemic therapies aimed at restoring metabolic homeostasis. Particular attention is paid to the systemic restoration of blood using the Quatotron method, the first engineering system that reproduces the rejuvenating effect of heterochronic parabiosis without surgical intervention on humans. The data of single-cell transcriptome analysis and clinical observations confirming the effectiveness of the approach are presented. Blood is the meta-environmentNo1 that connects everything to everything, and its systemic repair is key to preventing chronic diseases and prolonging an active life.