Effects of Lactiplantibacillus plantarum CCFM1214 and Ligilactobacillus salivarius CCFM1215 on halitosis: a double-blind, randomized controlled trial.

The purpose of this study was to evaluate the effects of known probiotic species Lactiplantibacillus plantarum CCFM1214 and Ligilactobacillus salivarius CCFM1215 on halitosis, the oral status, and the oral microbiome. In a double-blind, randomized controlled trial that lasted for five weeks, 43 participants were divided into an oral probiotics group and a control group and given probiotics or control powder for the first four weeks, with the fifth week being the discontinuation period. 33 participants (probiotics group = 21, control group = 12) completed the entire experiment in the end. Oral samples were taken as part of oral health examinations during the baseline period (day 0) and four weeks after (day 28). The nucleotide sequence of the V3-V4 region of 16S rRNA was determined to examine the impact of intervention and time on the oral microbiome. The effects of L. plantarum CCFM1214 and L. salivarius CCFM1215 on the number of Fusobacterium nucleatum in gingival crevicular fluid (GCF) samples of participants were detected by quantitative PCR. After the intervention, L. plantarum CCFM1214 and L. salivarius CCFM1215 significantly reduced the levels of volatile sulfur compounds (VSCs) and the quantity of F. nucleatum in GCF samples, where the average DNA copy number per ng (log) of F. nucleatum decreased from 7.12 ± 0.04 to 6.01 ± 0.09. The β diversity of the probiotics group, on the whole, tended to be more concentrated and stable after the intervention. In addition, after probiotic intervention, the abundance of Lactobacillus and Bifidobacterium increased, while the abundance of Fusobacterium , Acinetobacter , Porphyromonas , and Aggregatibacter decreased significantly. In general, L. plantarum CCFM1214 and L. salivarius CCFM1215 can alleviate halitosis and considerably lower the value of VSCs and improve the oral microbiota in participants with halitosis.