“When plaque builds up, the gums can become inflamed and start to bleed, making it easier for bacteria from the mouth to enter the bloodstream. If this happens regularly, it may contribute to low-level inflammation elsewhere in the body, which can place extra demands on the immune system,” Bhogal concluded.
Article source: https://www.huffingtonpost.co.uk/entry/habits-that-weaken-immune-system_uk_6af5d394e4b01d00edac12fd