**Abstract**

The gut microbial community has amazing effects on our immune system and nervous system through three pathways: cell signaling, electron transfer, and biological cycles. However, this relationship is two-way and has its own risks or benefits. Except for the brain, there is no place in the body that does not have cytokines (but not all of them). Cytokines are one of the most important immune molecules that play an important role in maintaining homeostasis in our body and the connection between the central nervous system and our immune system. So it is clear that many beneficial microbes in the gut are stimulated when we are hungry or when our nervous system is under pressure from external stimuli. These microbes die or damage intestinal epithelial tissues and stimulate immune molecules such as interleukins or IFNs upstream.

**Keywords:** GI-tract, microbial community, immune system, nervous systems
