Unless you sleep with your jaws wired shut, chances are you occasionally sleep with your mouth open, which means you have probably experienced morning breath. A distinct variation on traditional halitosis, morning breath is caused by dry mouth, although new research suggests that the pH of your tongue has something to do with it.
A study published in the Journal of Applied Oral Science found that in people with morning breath, their saliva was slightly acidic, while their tongue coating - that white stuff that appears in the back of your mouth - was basic.
The report's authors, who hail from Brazil's Bauru School of Dentistry, noted that even though these levels changed slightly after volunteers rinsed with various products, ultimately the pH of a morning-breath-afflicted mouth stays more or less the same with treatment.
Since changing the level of acidity on one's tongue may not cut it, in the short-term anyway, a long-term solution may work better. Oral care probiotics, for instance, can gradually replace the bacterial colony on the tongue with one that is less fragrant.
Over time, this method may reduce the severity of your morning breath, even if you have it every day.