Halitosis or bad breath can affect anyone, regardless of their age. Often, bad breath is blamed on the foods we just ate. However, chronic bad breath in children could indicate a deeper root issue than eating stinky foods. Halitosis is ultimately caused by bacteria that live in the mouth. These bacteria colonies feed on leftover food, fluid and plaque — as they eat, they produce hydrogen sulfide, which leads to a bad smell in the mouth. As with adults, bad breath is most common in children in the morning, after they wake up. During the night, bacteria multiply in the mouth, leading to a case of “morning breath.” However, if your child’s bad breath persists throughout the day, it probably indicates a larger issue.