Individuals with H. pylori infection of the stomach can have increased amounts of the following substances in the breath:
Sulfides: hydrogen sulfide (rotten eggs smell), dimethyl sulfide (cabbage-like smell), methyl mercaptane (rotten cabbage smell)
Isobutane (petroleum-like odor), 2-butanone (pungent sweet odor) and ethyl acetate (fruity odor)
The first question I would ask in response to your question on gum disease is "Have you spoken with your dentist about the health of your gums?"
Looking at the NHS webpage on Halitosis, it sounds that most of the possibilities have been ruled out, but not oral hygiene completely.
The most common cause of bad breath is poor oral hygiene. Bacteria that ...