This study by Indian scholars was recently published in Science Progress, a sub-journal of Science magazine. The topic of the paper is: high-salt diet mediates the interaction between NK cells and intestinal microflora to induce potential tumor immunity 1.
Dietary components profoundly affect human health by regulating immune homeostasis and intestinal microbial composition. It is worth noting that high-salt diet (HSD) is considered to be an effective immunomodulator related to strong inflammatory response, and some recent studies have also shown that high-salt diet can inhibit the growth of tumors.
On April 7th, 2020, Professor Dong Lei from School of Life Sciences of Nanjing University published a research paper entitled "High-salt diet inhibits tumor growth in mice by regulating marrow-derived cell differentiation".
This study shows that high-salt diet can activate anti-tumor immune monitoring by regulating the activity of bone marrow-derived suppressor cells (MDSCs), thus inhibiting the growth of mice tumors.
Detailed report: Subverting cognition! Nanjing University found that a high-salt diet can actually inhibit tumor growth.
Interestingly, tumor microenvironment is usually characterized by ion imbalance, so some tumor patients often have hyponatremia, which is related to the change of intestinal permeability and the ecological imbalance of intestinal microbial community. In addition, previous reports showed that high-salt diet induced changes in the composition and metabolism of intestinal flora in rodents.
These evidences indicate that the tumor immunity induced by high-salt diet may be closely related to intestinal flora, and may affect other components of the immune system that are crucial to anti-tumor function.
In this study, the research team of the Institute of Transforming Health Science and Technology in Haryana, India, fed tumor-bearing mice with a high-salt diet. Researchers found that high-salt diet can effectively inhibit tumor growth by up-regulating the number of NK cells and activation markers and down-regulating NK cell inhibition signals (especially PD- 1 molecule). In contrast, the absence of NK cells can block the tumor immunity of high-salt diet, which is mediated by NK-dependent interferon-γ (IFN-γ).
The tumor immunity of high-salt diet is mediated by increasing the number and activation of NK cells.
The research team further confirmed that high-salt diet can lead to a significant increase in serum hippuric acid in mice.