Hi Dear, Welcome to Health Care Magic Team. Understanding concern about your health. Leaky gut syndrome occur because of imbalance between useful and harmful bacteria of gut ,when number of harmful bacteria increases ,they cause damage to the gut and lead to leaky gut syndrome due to which fungal infection caused by candida fungus proliferate and start causing damage . Because of action of candida fungus candidiasis/oral thrush develop in mouth . The probable reason for the bad breath is oral thrush ,there can also be white patches present along with bad breath . So its treatment would be use of lystatin mouth wash , maintenance of oral hygiene , foods contining sugar and yeast content should be avoided . You should visit a dentist who can prescribe you some anti fungal medication . Hope your concern has been resolved. Get well soon. Best wishes, Dr. Harry Maheshwari