Do Probiotics Affect Vaginal Odor?

Yes, certain probiotic strains, particularly specific Lactobacillus strains, have evidence supporting their potential to improve vaginal odor associated with bacterial vaginosis by restoring normal vaginal flora and reducing odor-related symptoms.

Very low

Low

Moderate

High

Certainty not assessed

This analysis does not carry a graded certainty rating. Read the limitations section before drawing conclusions.

What the research shows

Multiple high-quality randomized controlled trials and systematic reviews indicate that probiotics, especially Lactobacillus strains such as Lactobacillus acidophilus, Lactobacillus rhamnosus (including GR-1), Lactobacillus reuteri (including RC-14), Lactobacillus crispatus, Lactiplantibacillus plantarum, and Lactobacillus fermentum, can help restore normal vaginal microbiota in women with bacterial vaginosis (BV). This restoration is associated with improvements in clinical symptoms including vaginal odor, discharge, and Nugent scores. Vaginal administration of probiotics often shows more direct effects, but oral administration also demonstrates benefits. Some studies also show that probiotics reduce recurrence rates of BV. Safety profiles are generally favorable with mild and self-limiting side effects reported. However, evidence is heterogeneous with some studies showing no significant benefit, and strain-specific effects are important. More large-scale, well-designed trials are needed to confirm optimal strains, doses, and administration routes. Probiotics have not been shown to directly treat vaginal odor unrelated to BV or other conditions.

Best studied probiotic strains

Lactobacillus acidophilus

Moderate evidence from a clinical trial (PMID 17532736) showed that vaginal douche containing L. acidophilus significantly reduced vaginal pH and odor in women with bacterial vaginosis, improving Nugent scores and whiff test results.

Effective in vaginal douche form; evidence moderate and from a pilot study.

Lacticaseibacillus rhamnosus (including GR-1)

High-quality RCTs and systematic reviews (PMIDs 17045832, 16697231, 24283058, 18854803, 18843900) demonstrate that L. rhamnosus strains improve BV cure rates, reduce recurrence, restore vaginal flora, and reduce symptoms including odor. Oral and vaginal administration both effective.

Strain-specific effects important; often combined with L. reuteri RC-14.

Lactobacillus reuteri (including RC-14)

RCTs (PMIDs 17045832, 16697231, 18854803) show that L. reuteri RC-14 combined with L. rhamnosus GR-1 improves BV treatment outcomes and reduces odor and discharge symptoms.

Usually studied in combination with L. rhamnosus GR-1.

Lactobacillus crispatus (including CTV-05)

High-quality RCTs (PMIDs 19543144, 20644497) show that vaginal administration of L. crispatus CTV-05 is safe, colonizes the vagina, and may help prevent BV recurrence and improve vaginal health.

Colonization after vaginal administration demonstrated; safety profile good.

Lactiplantibacillus plantarum

Low to moderate evidence (PMID 25291116, 35633296) supports vaginal administration of L. plantarum strains reducing Nugent scores and inhibiting Gardnerella vaginalis growth, potentially improving BV symptoms including odor.

Evidence from pilot studies; promising candidate for vaginal probiotics.

Limosilactobacillus fermentum

Low to moderate evidence (PMIDs 25291116, 20472091, 24641524) indicates L. fermentum strains can inhibit G. vaginalis and improve BV symptoms including malodor when administered vaginally.

Often studied in combination with other lactobacilli.

Bifidobacterium longum BB536

High evidence (PMID 42046285) shows BB536 improves odor-related metabolites in gut microbiota subgroups but study focused on gastrointestinal symptoms in male athletes, not vaginal odor.

No direct evidence for vaginal odor; included for completeness.

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Who may benefit

Women diagnosed with bacterial vaginosis experiencing vaginal odor Women seeking adjunctive therapy to antibiotics for bacterial vaginosis Women with recurrent bacterial vaginosis aiming to reduce recurrence Women preferring probiotic approaches for vaginal health maintenance

Safety

Probiotics studied for vaginal health are generally safe and well tolerated. Mild, self-limiting adverse events such as vaginal discharge, abdominal discomfort, or irritation have been reported. No serious adverse events or safety concerns were noted in high-quality trials. Vaginal and oral probiotic administration routes are both considered safe.

Limitations

Evidence is heterogeneous with variability in probiotic strains, doses, administration routes, and study designs. Some studies have small sample sizes or are pilot trials. Strain-specific effects are critical; not all probiotics are equally effective. Most evidence pertains to bacterial vaginosis-related odor, not other causes of vaginal odor. Long-term efficacy and optimal treatment regimens require further research. Some studies report no significant benefit over placebo or standard treatment.

PubMed sources

Study	Type	Year	PMID
Activity of a Lactobacillus acidophilus-based douche for the treatment of bacterial vaginosis. Journal of alternative and complementary medicine (New York, N.Y.)	Clinical Trial	2007	17532736
Effective probiotic regimens for bacterial vaginosis treatment and recurrence prevention: A systematic review. Narra J	Systematic Review	2025	40352249
[Effect of Lactobacillus casei var rhamnosus (Gynophilus) in restoring the vaginal flora by female patients with bacterial vaginosis--randomized, open clinical trial]. Akusherstvo i ginekologiia	Randomized Controlled Trial	2013	24294746
Comparative efficacy of oral and vaginal probiotics in reducing the recurrence of bacterial vaginosis: a double-blind clinical trial. BMC women's health	Randomized Controlled Trial	2024	39462408
Integrated analysis of characteristic volatile flavor formation mechanisms in probiotic co-fermented cheese by untargeted metabolomics and sensory predictive modeling. Food research international (Ottawa, Ont.)	Research Study	2025	40356103
Effectiveness of the two microorganisms Lactobacillus fermentum LF15 and Lactobacillus plantarum LP01, formulated in slow-release vaginal tablets, in women affected by bacterial vaginosis: a pilot study. Journal of clinical gastroenterology	Randomized Controlled Trial	2014	25291116
Comparing the effect of sucrose gel and metronidazole gel in treatment of clinical symptoms of bacterial vaginosis: a randomized controlled trial. Trials	Randomized Controlled Trial	2018	30367673
NK3 and NK49 Alleviate Bacterial Vaginosis and Osteoporosis in Mice by Suppressing NF-B-Linked TNF- Expression. Journal of medicinal food	Research Study	2019	31381476
Impact of -containing oral and vaginal probiotics on vaginal health: a randomised double-blind placebo controlled clinical trial. Beneficial microbes	Randomized Controlled Trial	2023	36856121
Probiotics--a helpful additional therapy for bacterial vaginosis. Journal of medicine and life	Clinical Trial	2013	24868256
Exploring of probiotic potential vaginal lactobacillus isolates from healthy women against Gardnerella vaginalis and Caenorhabditis elegans model testing. Journal of applied microbiology	Research Study	2022	35633296
[Efficacy of combined 5-nitroimidazole and probiotic therapy of bacterial vaginosis: randomized open trial]. Akusherstvo i ginekologiia	Randomized Controlled Trial	2013	24283058
Lactobacilli-containing vaginal probiotics to cure or prevent bacterial or fungal vaginal dysbiosis: a systematic review and recommendations for future trial designs. BJOG : an international journal of obstetrics and gynaecology	Systematic Review	2020	31299136
Continuous versus interrupted use of vaginal probiotics plus vaginal clindamycin cream for bacterial vaginosis: a randomized controlled study. The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians	Randomized Controlled Trial	2021	30879366
Phase 1 dose-ranging safety trial of Lactobacillus crispatus CTV-05 for the prevention of bacterial vaginosis. Sexually transmitted diseases	Randomized Controlled Trial	2009	19543144
A double-blind treatment study of bacterial vaginosis with normal vaginal lactobacilli after an open treatment with vaginal clindamycin ovules. Acta dermato-venereologica	Randomized Controlled Trial	2005	15848990
Testing the regulatory framework in South Africa - a single-blind randomized pilot trial of commercial probiotic supplementation to standard therapy in women with bacterial vaginosis. BMC infectious diseases	Randomized Controlled Trial	2020	32650729
Clinical study comparing probiotic Lactobacillus GR-1 and RC-14 with metronidazole vaginal gel to treat symptomatic bacterial vaginosis. Microbes and infection	Randomized Controlled Trial	2006	17045832
Vaginal & gut microbiota diversity in pregnant women with bacterial vaginosis & effect of oral probiotics: An exploratory study. The Indian journal of medical research	Research Study	2021	34380796
Oral Intake of Lactobacilli Can Be Helpful in Symptomatic Bacterial Vaginosis: A Randomized Clinical Study. Journal of lower genital tract disease	Randomized Controlled Trial	2020	32091443
Augmentation of antimicrobial metronidazole therapy of bacterial vaginosis with oral probiotic Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14: randomized, double-blind, placebo controlled trial. Microbes and infection	Randomized Controlled Trial	2006	16697231
Effectiveness of Lactobacillus-containing vaginal tablets in the treatment of symptomatic bacterial vaginosis. Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases	Randomized Controlled Trial	2009	19046169
Probiotics for the treatment of bacterial vaginosis. The Cochrane database of systematic reviews	Systematic Review	2009	19821358
CECT 30648 shows probiotic characteristics and colonizes the vagina of healthy women after oral administration. Microbiology spectrum	Randomized Controlled Trial	2025	40772934
[Efficacy of Lactobacillus Rhamnosus GR-1 and of Lactobacillus Reuteri RC-14 in the treatment and prevention of vaginoses and bacterial vaginitis relapses]. Minerva ginecologica	Randomized Controlled Trial	2008	18854803
The effects of antimicrobial therapy on bacterial vaginosis in non-pregnant women. The Cochrane database of systematic reviews	Meta-analysis	2009	19588379
Lactic acid bacteria colonization and clinical outcome after probiotic supplementation in conventionally treated bacterial vaginosis and vulvovaginal candidiasis. Microbes and infection	Randomized Controlled Trial	2010	20472091
The restoration of the vaginal microbiota after treatment for bacterial vaginosis with metronidazole or probiotics. Microbial ecology	Randomized Controlled Trial	2013	23250116
Effectiveness of vaginal administration of Lactobacillus rhamnosus following conventional metronidazole therapy: how to lower the rate of bacterial vaginosis recurrences. The new microbiologica	Randomized Controlled Trial	2008	18843900