The study used Seed’s VS-01 vaginal synbiotic that launched commercially in May 2024. The product is built on the research of renowned vaginal microbiome scientist Dr. Jacques Ravel and is formulated with L. crispatus LUCA103, LUCA011 and LUCA009, which were identified from over 600 candidate probiotic strains for their superior efficacy in maintaining regulated pH and promoting stability in vaginal health.
Data published in npj Biofilms Microbiomes indicated that a slow-release vaginal tablet of the synbiotic led to an optimal vaginal microbiome dominated by L. crispatus called Community State Type, or CST I. The synbiotic was also associated with a decrease in the abundance of Candida, the most common source of vaginal yeast infections.
“We demonstrated conversion to CST I and colonization of product strains without antibiotic pretreatment, suggesting that administering the synbiotic immediately post-menses may improve the colonization of L. crispatus,” wrote the researchers, led by Dr. Ravel.
Vaginal microbiome
Compared to the gut microbiome where diversity is highly desirable, the optimal vaginal microbiome is dominated by L. crispatus (Community State Type, CST I). Vaginal dysbiosis is associated with increased inflammation and the several gynecological and obstetric conditions, including infections and complications during pregnancy.
The new study studied multiple different interventions, including VS-01 as a slow-release vaginal tablet or a fast release vaginal capsule, an oral supplement with the same three strains, a commercial oral supplement containing L. crispatus, Lacticaseibacillus rhamnosus, Lactobacillus gasseri and Lactobacillus jensenii, or placebo.
The slow-release tablet led to “superior colonization of L. crispatus and conversion to an optimal CST I microbiome” compared to the fast-release capsule or placebo, wrote Dr. Ravel and his co-workers.
Specifically, VS-01 established an optimal vaginal microbiome dominated by L. crispatus in 90% of participants with a non-optimal vaginal microbiome, compared to only 11% in the placebo group.
VS-01 was also associated with reductions in Gardnerella vaginalis and Candida spp., the researchers reported.
“Notably, the synbiotic vaginal tablet showed superior efficacy in the conversion of the vaginal microbiome to a L. crispatus-dominated state compared to oral administration of the same synbiotic formulation and a commercially available oral supplement product,” they added.
Formulation matters
Commenting independently on the study’s findings, Professor Remco Kort from the Amsterdam Institute for Life and Environment at the Vrije Universiteit Amsterdam, told NutraIngredients that the study shows that formulation matters, with the slow release capsule co-formulated with maltose, calcium lactate, glutamine, magnesium citrate and cystine outperforming a fast-release capsule with leaner support (maltose, calcium lactate).
He also noted that while the comparison of an oral and vaginal product “cannot be fair … because the oral formulation’s strain/species composition differs,” the three-strain containing L. crispatus vaginal slow-release tablet did convert the vaginal microbiota to protective community state type-I without the use of antibiotics, compared to placebo.
“To make synbiotic substrates truly rational, future studies should measure what is missing in the vaginal ecosystem (baseline → longitudinal) and feed that back into formulation design,” Professor Kort said.
Seed
Widely known for its consumer health brand Seed, the company currently has two consumer products: DS-01 Daily Synbiotic for adults and PDS-08, a pediatric synbiotic.
DS-01, a broad-spectrum probiotic with 24 genetically distinct microorganisms across 12 species, was developed with Dr. Gregor Reid, Seed Health’s scientific advisor, past-president of the International Scientific Association of Probiotics and Prebiotics (ISAPP) and former chair of the United Nations World Health Organization Expert Panel that authored the global scientific definition of probiotics. The product won the NutraIngredients-USA Award for probiotic product of the year in 2022.
A paper published in Nutrients this month with DS-01 showed that the multi-species synbiotic “significantly increases diversity and abundance of key beneficial bacteria, enhances UroA production and butyrate levels, and is associated with lowered systemic inflammation,” wrote scientists from Seed Health, Harvard Medical School, Yale University School of Medicine, PACT Gastroenterology Center, Metro Infectious Disease Consultants, Increnovo LLC, and the Lawson Health Research Institute/Western University. “This is the first synbiotic to increase both UroA and butyrate.”
NutraIngredients first reported on these results following their presentation earlier this year during Digestive Disease Week.
PDS-08 launched in 2022 and is a multi-strain synbiotic formulated with L. salivarius LS01, Bifidobacterium breve B632, B. breve BR03, B. lactis BPL1, B. longum ES1, L. casei BPL4, L. rhamnosus GG, L. acidophilus NCFM and B. animalis subsp. lactis Bi-07.
Beyond the consumer products, Seed also has a biotech platform for microbiome science.
Source: npj Biofilms Microbiomes, 2025, 11, 158. doi: 10.1038/s41522-025-00788-6. “Impact of a multi-strain L. crispatus-based vaginal synbiotic on the vaginal microbiome: a randomized placebo-controlled trial”. Authors: J. Ravel, et al.
