Study evaluation: For chewing or sucking: Probiotic bacteria reduce bad breath

Taking probiotic bacteria can reduce bad breath.

Study evaluation: For chewing or sucking: Probiotic bacteria reduce bad breath

Taking probiotic bacteria can reduce bad breath. This is the result of an analysis of several studies that have examined the effect of probiotics on perceptible and measurable bad breath. Accordingly, the probiotics administered through chewing gum or lozenges primarily reduce the formation of volatile - and musty - sulfur compounds, especially hydrogen sulfide. The group led by Longjiang Li from Sichuan University in Chengdu (China) has published their study in the specialist journal "BMJ Open".

"Halitosis has a significant impact on patients' daily work and social activities and can even lead to common mental health problems, such as anxiety, depression and social isolation," the researchers write. Around a quarter of all people worldwide suffer at least temporarily from unpleasant bad breath, medically known as halitosis. Bad breath is chronic in about six percent of people. In more than 90 percent of cases, microorganisms in the oral cavity are responsible for the odor; Diseases of the ear and nose area or the gastrointestinal tract are also possible causes.

In the mouth, on the other hand, it is mainly bacteria in the recesses of the tongue that produce foul-smelling gases by breaking down organic substances. However, the microorganisms can also sit on the teeth and in gum pockets. Such bacteria can cause inflammation of the gums (gingivitis) and the periodontium (periodontitis). Unless there is an underlying condition outside of the oral cavity, halitosis is often treated with tartar removal, professional teeth cleaning, and tongue cleaning. Patients are usually shown how to improve their daily oral hygiene. In some cases, mouthwashes, antibiotics and, for some years now, probiotics are also used.

Li and colleagues found 238 studies examining the effect of probiotics on bad breath in medical databases. For the analysis, however, they only used high-quality studies with a control group, which also had to contain certain data. This left seven studies with a total of 278 participants. In the studies, people assessed the extent of bad breath, and some also measured volatile sulfur compounds in the breath. In addition, the coatings on the tongue and on the teeth were partially examined.

The statistical evaluation of the study results showed a significant reduction in the perceptible bad breath when the patients had been administered probiotic bacteria. These bacteria included Lactobacillus salivarius, Lactobacillus reuteri, Streptococcus salivarius, and Weissella cibaria. Volatile sulfur compounds also decreased, but only up to about four weeks after starting treatment; after that, the differences between the probiotic group and the placebo group shrank. Tooth and tongue coatings did not change as a result of the therapy.

"According to the available studies, probiotic therapy reduces the concentrations of odorants by inhibiting the breakdown of amino acids and proteins by anaerobic bacteria," the study authors write. Anaerobic bacteria get by without oxygen for their metabolism and can lodge deep in the tongue crevices and other cracks in the mouth. Their growth is inhibited by the probiotic bacteria. However, Li's team also writes that the study results were weakened in their validity because different methods and procedures were used in the studies considered.