Hi.. Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concerns.. As per your complain H.Pylori infection can be a cause for bad breath but in case a long standing case of having bad breath for ten years does not seems to be due to h.pylori as if it would have been due to it there must be other symptoms also associated with it like stomach upset, burning,hyperacidity, ulcers etc.. It seems more to be due to sinus infection causing sinusitis and inflammation and infection in sinuses can cause chronic bas smell.. Other causes can be upper respiratory infection, tonsil stones, poor oral hygiene etc.. You should consult an Oral Physician and get evaluated and a thorough clinical evaluation can help in confirming the cause and treatment of the cause can help in resolution of bad breath.. As of now you can do steam inhalations with a few drops of eucalyptus oil in boiling water, use saline nasal sprays and chew flavoured sugar free chewing gum especially when you are around people to mask bad breath.. Doing mouthwash gargles can also help.. Avoid intake of high smelly foods like onion and garlic and maintain a good oral hygiene.. Hope this information helps.. Thanks and regards. Dr. Honey Nandwani Arora.