Bifidobacteria, a genus of probiotic bacteria commonly found in the human gastrointestinal tract and vagina, have been investigated for their potential role in supporting or treating vaginitis, particularly bacterial vaginosis (BV) and vulvovaginal candidiasis (VVC). Scientific studies suggest that Bifidobacteria, along with Lactobacillus species, are important in maintaining a healthy vaginal microbiota by producing lactic acid and lowering vaginal pH, which inhibits the growth of pathogenic microorganisms. Clinical trials have assessed the use of oral and vaginal Bifidobacteria-containing probiotics as adjunctive therapy to standard antimicrobial treatments for vaginitis. Some randomized controlled trials (RCTs) and meta-analyses report that these probiotics can help restore microbiota balance, reduce recurrence rates, and alleviate symptoms, though the evidence is more robust for Lactobacillus than for Bifidobacteria specifically.

Overall, while there is a scientific rationale and growing body of clinical research supporting the use of Bifidobacteria for vaginitis, the quality and consistency of evidence are moderate. Guidelines do not universally recommend Bifidobacteria-based probiotics as primary therapy, but they may be considered as complementary interventions. More large-scale, high-quality RCTs are needed to clarify optimal strains, dosages, and treatment protocols. Nonetheless, the current evidence base is sufficient to rate the scientific support as moderate (3/5).