The infrequency of the stomach ' s being such a source was central to a recent court case in which i participated as an expert witness [ see box on page 79 ] 然而，正因为胃很少成为口臭的主因，让我最近变成一件法庭诉讼的专家证人（见口臭之战一文） 。
Bacteria that live in the mouth break down proteins in food , releasing sulphur compounds . it ' s these that smell . people with gum disease and dental decay are more likely to suffer 许多长期有口臭的人，是因为吸烟和过度饮酒引起的，而引起口臭的最主要原因是? ?不注意口腔卫生。
While foods such as garlic can be the culprit , as can a tooth infection , the most common cause of bad breath ( halitosis ) is an overgrowth of the bacteria which normally live in the mouth or throat 虽然导致口臭的原因可以归咎于象大蒜这样的食物，又或者是因为牙龈发炎，但是最为常见的口臭原因是在于，口腔和喉咙内的细菌过渡滋长。
Because a steady flow of saliva washes away bacteria and their smelly chemical products , anything that promotes dryness ? mouth breathing , fasting , prolonged talking , stress and hundreds of medications ? can exacerbate the situation 由于唾液的持续流动会冲走细菌及其发臭的化学产物，因此任何促使口腔乾燥的动作，像是用嘴巴呼吸、禁食、长时间说话、压力以及数百种用药，都会让口臭的情况恶化。
Other possible causes include a dry mouth , which can sometimes be linked to a medical condition such as an underactive thyroid , or it can be associated with alcohol , smoking , stress or medications such as some antihypertensives ( that lower blood pressure ) 其他可能引起口臭的原因包括：口腔发干，这种情况有时候是与像似甲状腺功能失调的医疗症状有关；或者是可以由于喝酒、吸烟、精神压力或服用某些抗高血压药物而造成的口臭。
