The gut microbiota seems to have a major influence in the body in which they reside. Cat + human is only one of the examples of this symbiosis. The same can be

The gut microbiota seems to have a major influence in the body in which they reside. Cat + human is only one of the examples of this symbiosis. The same can be said for any animal + human. Human + human is also true. A couple will tend to resemble each other in looks when living together for a while. If you think about it, the skin is just the outer layer of the gut. One can think of the body as a tubular structure with a couple of openings. The inside, includes the gut where most of the microbiota reside, but also on the skin, in the hair, in the mouth, etc. So when we kiss or touch, we are exchanging microbiota. Animals in this regard form a sort of proxy. They facilitate the transfer of the microbiota from human to human, including animal to human and human to animal. Overall it seems that diversity is preferable. That's one of the reasons that it's not good to be alone for too long as the microbiota diversity gets compromised. So getting a pet does actually work, be it a cat or dog.