The use of specific bacteria, primarily in the form of probiotics, to support or treat gingivitis is supported by scientific evidence. Gingivitis is an inflammatory condition of the gums commonly caused by the accumulation of dental plaque. Recent research has explored the role of beneficial bacteria (probiotics) in modulating the oral microbiome to reduce inflammation and pathogenic bacterial load.

Several randomized controlled trials and systematic reviews have shown that probiotic strains such as Lactobacillus reuteri, Lactobacillus casei, and Bifidobacterium animalis can help reduce gingival inflammation and plaque when used as adjuncts to standard oral hygiene. Mechanistically, these probiotics may compete with pathogenic bacteria, modulate immune responses, and produce antimicrobial substances that inhibit the growth of harmful species associated with gingivitis.

A 2020 systematic review in the Journal of Periodontology concluded that probiotic supplementation led to significant reductions in gingival index and bleeding on probing compared to placebo. However, while the evidence is promising and growing, there remains variability in study designs, strains tested, and durations, so further high-quality research is warranted for definitive recommendations. Overall, the scientific basis for using beneficial bacteria (probiotics) in managing gingivitis is well-supported, with evidence pointing toward a positive adjunctive effect.