There is an old saying in China: You can make up what you eat. The paper published in Cell Research by Professor Zhang Chenyu from School of Life Sciences of Nanjing University provides a scientific basis for this sentence. The research team found that some RNA in plants can be directly absorbed by the human body through the digestive tract, thus regulating the expression of related target genes, and then affecting a series of physiological functions of the human body.

MicroRNA is a kind of noncoding single-stranded RNA molecule with a length of about 22 nucleotides encoded by endogenous genes, which plays a role in gene expression regulation by affecting the stability of messenger RNA transcribed by target genes. MicroRNA found at present mainly exists in animals and plants, and is also expressed in some viruses.

Before the research results of Professor Zhang's team were published, most of the microRNAs reported in the study came from their own tissues and belonged to endogenous self-regulation. Professor Zhang's team's research shows that the human body can obtain exogenous micrornas by eating, which can resist the ultra-low PH environment of the digestive tract and the degradation of various digestive enzymes, and directly enter the blood circulation of the human body and reach the corresponding tissues to play a role.

The researchers found that MicroRNA RNA168A is abundant not only in rice, but also in the serum of China people. This microRNA can bind to the messenger RNA of human and mouse low density lipoprotein receptor adapter protein 1, thus inhibiting the expression of this protein in the liver and further prolonging the existence time of low density lipoprotein in plasma, indicating that microRNA ingested through food can really affect the physiological function of human body.

The research team also found that only 40 to 50 kinds of plant micrornas were found in human blood and tissues, which indicates that most other plant micrornas can be digested and degraded by human beings, but the impact of these undegraded micrornas on our human bodies is still unclear, and the specific mechanism of action remains to be explored by scientists. But there is no doubt that food not only provides us with raw materials and energy, but also shapes us to some extent.

Professor Zhang's team's research provides us with a new perspective on food. We not only ingest six traditional nutrient elements (water, protein, fatty acids, sugars, microorganisms and trace elements) from food, but also ingest microRNA from food, which has more specific effects on human body. The difference between southerners and northerners can be explained by microRNA expression profiles of wheat and rice. At the same time, this study also provides scientific basis and research direction for dietotherapy.