I can't say for sure beyond firstly, no root canals. You don't want to keep the dead tooth partially intact. This has been linked to health issues. Get it pulled.
Secondly, I'd say, maybe. Especially if the symptoms began similarly to when the tooth worsened. However, this is unlikely, due to the stomach acid and the long journey from mouth to intestines including all enzymes etc.
It sounds more like fat accumulation/malabsorption, which could be an issue with your liver. Could the liver be ailing from an infected tooth, I do not know.
Last thought that comes to mind is Candida yeast overgrowth. No idea if this could be connected to the tooth, also. The only way to truly know is talk with a doctor and have tests done.