Probiotics in fermented foods such as yogurt may provide short-term relief for halitosis, according to a recent study published in BMJ Open.
Researchers at Sichuan University in Chengdu, China, investigated the effect of probiotics on halitosis from a time perspective. They analyzed previous studies that compared the effects of oral probiotics and placebo on primary halitosis outcomes (organoleptic [OLP] scores and volatile sulfur compound levels) and secondary outcomes (tongue coating scores and plaque index).
They identified seven trials involving 278 people that met the criteria for the study. The number of participants in each study was small, ranging from 23 to 68, with an age range between 19 and 70. Monitoring periods spanned from two to 12 weeks.
According to the analysis, the pooled data showed that OLP scores fell significantly in participants given probiotics compared with those in the comparison study arms, irrespective of the length of the monitoring period (BMJ Open, December 20, 2022, Vol. 12: e060753).
A similar result was observed for the levels of volatile sulfuric compounds detected, although these varied substantially in the individual studies, and the observed effects were relatively short-lived (up to four weeks), after which there was no noticeable difference.
Importantly, there were no significant differences in the tongue coating score or plaque index between those who were given probiotics and those who weren't, the authors noted.
The researchers explained that probiotics may inhibit the decomposition of amino acids and proteins by anaerobic bacteria in the mouth, thus curbing the production of smelly byproducts, the researchers explained.
"This systematic review and meta-analysis indicates that probiotics (eg, Lactobacillus salivarius, Lactobacillus reuteri, Streptococcus salivarius and Weissella cibaria) may ease halitosis by reducing the [volatile sulfuric compound] concentration levels in the short term, but there is no significant effect on the major causes of halitosis, such as plaque and tongue coating," the authors concluded.