Role of probiotics in the treatment and prevention of oral malodor/halitosis: A systematic review Pragati Ishwar Shringeri, Nusrath Fareed, Hemant Battur, Sanjeev Khanagar Journal of Indian Association of Public Health Dentistry 2019 17(2):90-96 Oral malodor is a condition which impedes people's social life and self-esteem. With more widespread acceptance of the potential for probiotic intervention providing health benefits for nonintestinal body sites, application of it on alternative target tissues has increased, to obtain more specific and enduring benefits. From the periodontal perspective, several studies have revealed the role of probiotic in the reduction of gingival inflammation. However, the studies of stronger evidence pertaining to the role of probiotics in the treatment and prevention of halitosis is limited. The aim of this study was to determine the role of probiotic strains in the treatment and prevention of oral malodor. Records were searched from various databases such as PubMed/Medline, Cochrane, and EMBASE. Articles published over the past 11 years were identified using the key search terms. A total of 178 records were identified by title/abstracts/full-text articles and were retrieved. After thorough assessment, 11 manuscripts were included in qualitative synthesis in this systematic review. Analysis of studies revealed 666 participants, aged 4–76 years, and about 20 probiotic strains were assigned to the test groups and control groups with a varying follow-up period. The effect size for randomized control trials ranged from 0.08 to 0.7 which suggests low-to-moderate practical significance. The results of this systematic review confirm that more studies are necessary to evaluate the efficacy of probiotics with correct methodological design, in broader population samples, and over longer periods.