Strengths and limitations of this study
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Summary
Background
Halitosis is defined as a bad odor emitted by the oral cavity. Many interventions have been used to control halitosis, from mouthwashes to chewing gum. Probiotics have been reported as an alternative method to relieve halitosis.
Aim
The present study aimed to investigate the effect of probiotics on halitosis from a temporal perspective.
Design and methods
This is a meta-analysis study conducted on indexed databases up to February 2021. Randomized controlled trials comparing the effects of probiotics and placebo on primary outcomes (organoleptic scores (OLP) and volatile sulfur compound (VSC) levels) ) and secondary outcomes (tongue coating scores (TCS) and plaque index (PI)) were included. Two reviewers independently performed data extraction and quality assessment. Publication and exclusion bias analyzes were performed.
Results
Standardized mean difference (SMD) and 95% CI were calculated to synthesize the data. Data were subgrouped and analyzed in the short term (≤4 weeks) and long term (>4 weeks) based on follow-up time.
Seven articles were included in this meta-analysis. Primary outcomes, OLP scores (SMD=−0.58; 95% CI −0.87 to −0.30, p<0.0001) and VSC levels (SMD=−0.26; 95% CI −0.51 to −0.01, p=0.04), both were significantly decreased in the probiotic group compared to the placebo group in the short term.
However, a significant reduction in OLP scores (SMD = −0.45, 95% CI −0.85 to −0.04, p = 0.03) was only observed in the long term. No significant differences were observed in secondary outcomes.
There was no evidence of publication bias. Leave-one-out analysis confirmed that the pooled estimate was stable.
Conclusions
Based on the results of this work, it appears that probiotics (e.g., Lactobacillus salivarius, Lactobacillus reuteri, Streptococcus salivarius, and Weissella cibaria) can alleviate halitosis in the short term (≤ 4 weeks). Biased evaluation results, limited data and heterogeneity of the included clinical trials could reduce the reliability of the conclusions.
Comments
Lactobacillus salivarius and reuteri, Streptococcus salivarius, Weissella cibaria can work
Probiotic bacteria typically found in fermented foods, such as yogurt, sourdough bread, and miso soup, could help dispel the embarrassment of persistent bad breath (halitosis), according to a pooled data analysis of the evidence. available, published in the open access journal BMJ Open.
Lactobacillus salivarius, Lactobacillus reuteri, Streptococcus salivarius, Weissella cibaria, taken as supplements in this study, may help freshen breath, but more good-quality research is needed, the researchers say.
Volatile sulfuric compounds are the main cause of persistent bad breath.
These compounds are produced by bacteria in the mouth as a result of the mixing of bacteria and food debris associated with poor dental and gum hygiene.
Options used to address the problem include mouthwashes, chewing gum, tooth scraping, and tongue scraping. Emerging evidence suggests that probiotic bacteria could offer a simpler alternative.
To explore this further and find out how long such effects could last, the researchers scoured research databases of relevant randomized clinical trials published up to February 2021.
From an initial run of 238 records, duplication and incomplete data reduced the number of clinical trials eligible for pooled data analysis to 7, with a total of 278 people. The number of participants in each study was small, ranging from 23 to 68, with an age range between 19 and 70. Follow-up periods spanned 2 to 12 weeks.
The severity of bad breath was defined by the levels of volatile sulfur compounds detected in the mouth or the OLP score, which measures breath odor at various distances from the mouth.
Tongue coating (3 studies) and plaque index (3 studies) scores were also included in the analysis because a dirty tongue and tartar buildup between the teeth are often considered the main causes of bad breath.
Pooled data analysis showed that OLP scores fell significantly in those receiving probiotics compared to those in the comparison study arms, regardless of the length of the follow-up period.
A similar result was observed for the levels of volatile sulfuric compounds detected, although these varied substantially in the individual studies, and the effects observed were of relatively short duration, up to 4 weeks, after which there was no notable difference.
But there were no significant differences in tongue coating score or plaque index between those who received probiotics and those who did not.
Probiotics can inhibit the breakdown of amino acids and proteins by anaerobic bacteria in the mouth, reducing the production of smelly byproducts, the researchers explain.
But they sound a note of caution in interpreting their findings. The sample sizes of the included studies were small and some of the data were incomplete. These factors, in addition to differences in detection methods, bacterial species, and wide variations in clinical trial design and methodology, weaken the findings.
“This systematic review and meta-analysis indicates that probiotics (e.g., Lactobacillus salivarius, Lactobacillus reuteri, Streptococcus salivarius, and Weissella cibaria) can alleviate halitosis by reducing concentration levels [of the volatile sulfuric compound] in the short term, but not “There is a significant effect on the main causes of halitosis, such as plaque and tongue coating,” the authors state.
“More high-quality randomized clinical trials are required in the future to verify the results and provide evidence of the effectiveness of probiotics in the management of halitosis,” they add.
Summary of findings
This meta-analysis showed that probiotics significantly reduced OLP scores compared to the placebo group, regardless of the duration of observation, confirming the benefits of probiotics for the treatment of halitosis.
The probiotic group showed a significant reduction in CVS concentrations in the short term (≤4 weeks), with no appreciable difference in the long term (>4 weeks). Meta-analyses were also performed on the H2S, CH3SH, and C2H6S subgroups to evaluate the specific difference in VSC levels. The results showed that only H2S levels were markedly reduced in the short term when probiotic treatment was administered.
For TCS and PI, results showed no significant differences between the experimental and placebo groups in the short term. There was no evidence of publication bias. Sensitivity analysis confirmed that the pooled estimate was stable.
