[graeme]

I could be mistaken but I think your micro biome mostly doesn’t depend on external input in the form of microbes.

Rather, you have microbes, and these depend on external input in the form of nutrients.

There are exceptions such as yogurt and sauerkraut etc. but those are kept in a fridge and would not be exposed to far uvc most of the time. It would be interesting to know how they are affected during meals.

Skin micro biome might be more affected. I could not find much information on this point.