Jamie,
You're right about gut health but also some people for what ever reason, get food trapped in the gums where it rots causing bad breath. I worked with a guy with this issue years ago and you could not stand near when he breathed.
He had no idea and at some point he discovered dentistry

which was the answer.
Another possibility is dental powder, the precurser to toothpaste. It is a powder that you put on your finger and then rub it on your gums. The rubbing of course stimulates blood flow which is a good thing. The resulting liquid is normally held in the mouth for a minute or so so it can disinfect.
I suspect that a poor diet may be causing the issue, probably containing sugar and flour, however hunose.
If this is the problem the social problem is only the tip of the iceberg because if it is a dental infection you may lose your teeth and that is definitely not good.