Hi.. Can understand your concern.. As per your complain foul smell in mouth can be due to a number of reasons.. It can be due to infection in gums leading to pus formation. It can also be due to cavitated teeth leading to food lodgement and bacterial growth leading to foul smell.. It can be due to diabetes leading to production of ketone bodies. It can be due to digestive problems and acid reflux. I would suggest you to maintain a good oral hygiene.. Brush twice daily one in morning and other before going to bed. Use flavoured mouthwashes to gargle like peppermint flavoured for a pleasant smell. Get checked for diseases like diabetes and digestive problems. Get treatment of infections in gums and teeth if present. Eat a balanced diet with more of fibres and green leafy vegetables. Drink plenty of water to maintain hydration and prevent dry mouth and it also flushes off debris and bacteria from mouth.. Cut down on coffee, tea,smoking , alcohol if you do. Cut down on high aroma foods like garlic and onion. Always gargle using mouthwash after meals. Hope your query is solved.. If you find the answer helpful please write a positive review and click on find this answer helpful as a token of appreciation.. Thanks and regards.. Dr.Honey Nandwani Arora.