Effects of a 10-Strain Oral Probiotic on Parameters of Vaginal Health and Microbial Community: A Pilot Clinical Study

The human vaginal microbiota: from clinical medicine to models to mechanisms

The composition of the vaginal microbiota is linked to numerous reproductive health problems, including increased susceptibility to infection, pregnancy complications, and impaired vaginal tissue repair; however, the mechanisms contributing to these adverse outcomes are not yet fully defined. In this review, we highlight recent clinical advancements associating vaginal microbiome composition and function with health outcomes. Subsequently, we provide a summary of emerging models employed to identify microbe-microbe interactions contributing to vaginal health, including metagenomic sequencing, multi-omics approaches, and advances in vaginal microbiota cultivation. Last, we review new in vitro, ex vivo, and in vivo models, such as organoids and humanized microbiota murine models, used to define and mechanistically explore host-microbe interactions at the vaginal mucosa.

The impact of live dietary microbes on health: A scoping review

A systematic approach to collect, peruse, and summarize the available information relating to the potential benefits of consuming dietary microbes was pursued in this scoping review. This review focused on the research endpoints, experimental designs, and microbial exposure in experimental as well as observational research work. Using a structured- set of keywords, scientific databases were systematically searched to retrieve publications reporting outcomes pertaining to the use of dietary microbes in healthy, nonpatient populations. Searches were further tailored to focus on eight different health categories, namely, "antibiotic associated diarrhoea" (AAD), "gastrointestinal health" (GIH), "immunological health" (ImH), "cardiovascular health and metabolic syndrome" (CvHMS), "cancer prevention" (CanPr), "respiratory health" (ReH), "weight management" (WtMgt), and "urogenital health" (UrGH). Quality of evidence available in each publication was assessed using the Jadad scoring system. The search yielded 228 relevant publications describing 282 experimental cases comprising 62 research endpoints overall. A microbial dose of≥ 2 × 10 9 $\ge 2\times 10^9$ CFU.day-1 was associated with non-negative reported outcomes. Older population groups with a median age of 39 years were associated with positive outcomes. More high-quality research is required investigating the role of dietary microbes in maintaining general health, particularly in the health categories of UrGH, WtMgt, and CanPr.

Orally administrated Lactobacillus gasseri TM13 and Lactobacillus crispatus LG55 can restore the vaginal health of patients recovering from bacterial vaginosis

Bacterial vaginosis (BV) is a common infection of the lower genital tract with a vaginal microbiome dysbiosis caused by decreasing of lactobacilli. Previous studies suggested that supplementation with live Lactobacillus may benefit the recovery of BV, however, the outcomes vary in people from different regions. Herein, we aim to evaluate the effectiveness of oral Chinese-origin Lactobacillus with adjuvant metronidazole (MET) on treating Chinese BV patients. In total, 67 Chinese women with BV were enrolled in this parallel controlled trial and randomly assigned to two study groups: a control group treated with MET vaginal suppositories for 7 days and a probiotic group treated with oral Lactobacillus gasseri TM13 and Lactobacillus crispatus LG55 as an adjuvant to MET for 30 days. By comparing the participants with Nugent Scores ≥ 7 and < 7 on days 14, 30, and 90, we found that oral administration of probiotics did not improve BV cure rates (72.73% and 84.00% at day 14, 57.14% and 60.00% at day 30, 32.14% and 48.39% at day 90 for probiotic and control group respectively). However, the probiotics were effective in restoring vaginal health after cure by showing higher proportion of participants with Nugent Scores < 4 in the probiotic group compared to the control group (87.50% and 71.43% on day 14, 93.75% and 88.89% on day 30, and 77.78% and 66.67% on day 90). The relative abundance of the probiotic strains was significantly increased in the intestinal microbiome of the probiotic group compared to the control group at day 14, but no significance was detected after 30 and 90 days. Also, the probiotics were not detected in vaginal microbiome, suggesting that L. gasseri TM13 and L. crispatus LG55 mainly acted through the intestine. A higher abundance of Prevotella timonensis at baseline was significantly associated with long-term cure failure of BV and greatly contributed to the enrichment of the lipid IVA synthesis pathway, which could aggravate inflammation response. To sum up, L. gasseri TM13 and L. crispatus LG55 can restore the vaginal health of patients recovering from BV, and individualized intervention mode should be developed to restore the vaginal health of patients recovering from BV.

Clinical trial registration

https://classic.clinicaltrials.gov/ct2/show/, identifier NCT04771728.

Lactobacillus Probiotics Improve Vaginal Dysbiosis in Asymptomatic Women

Vaginal dysbiosis can lead to serious infections in asymptomatic women. Lactobacillus probiotics (LBPs) are being investigated as a promising therapy for reversing vaginal microbiota dysbiosis. This study aimed to investigate whether administering LBPs could improve vaginal dysbiosis and facilitate the colonization of Lactobacillus species in asymptomatic women. 36 asymptomatic women were classified based on the Nugent score as Low-NS (n = 26) and High-NS (n = 10) groups. A combination of Lactobacillus acidophilus CBT LA1, Lactobacillus rhamnosus CBT LR5, and Lactobacillus reuteri CBT LU4 was administered orally for 6 weeks. The study found that among women with a High-NS, 60% showed improved vaginal dysbiosis with a Low-NS after LBP intake, while four retained a High-NS. Among women with a Low-NS, 11.5 % switched to a High-NS. Genera associated with vaginal dysbiosis were positively correlated with the alpha diversity or NS, while a negative correlation was observed between Lactobacillus and the alpha diversity and with the NS. Vaginal dysbiosis in asymptomatic women with an HNS improved after 6 weeks of LBP intake, and qRT-PCR revealed the colonization of Lactobacillus spp. in the vagina. These results suggested that oral administration of this LBP could improve vaginal health in asymptomatic women with an HNS.

The Importance of the Microbiota in Shaping Women’s Health—The Current State of Knowledge

According to current knowledge, a properly colonized human microbiota contributes to the proper functioning of the body. The composition of the natural flora changes depending on age, health, living conditions, and the use of antimicrobial agents: antibiotics, disinfectants, and some cosmetics. The human body is diversely populated with microorganisms and undergoes constant changes under the influence of various factors, and its proper composition is extremely important for the proper functioning of the body. Given the above, it was decided that we would review current scientific research that explains the cause–effect relationship between the composition of microorganisms populating the human body and health, focusing on women’s health. As a result, an overview paper was prepared based on 109 scientific sources from 2009–2022. Special attention was paid to the most recent scientific studies of the last five years, which account for more than 75% of the cited sources.

Can probiotics enhance fertility outcome? Capacity of probiotics as a single intervention to improve the feminine genital tract microbiota in non-symptomatic reproductive-aged women

Modifications in vaginal and endometrial microbiome and microbiota have been associated with fewer implantation rates and poorest pregnancy outcomes. Therefore, its study has emerged as a new biomarker in reproductive medicine. Despite the numerous papers published on probiotic use for vaginal dysbiosis and their actual wide empiric use especially for infertile patients, there is still no clear answer to justify their recommendation. The impact of probiotics on the vaginal or endometrial microbiota has often been investigated under a symptomatic altered vaginal microbial ecosystem, such as bacterial vaginosis. However 50% of women with bacterial vaginosis are asymptomatic. Actual clinical practice guidelines clearly recommend the use of specific antimicrobial agents for the management of symptomatic vaginal infections. Assuming this should be the management as well for an infertile population, what should be the treatment for the 50% non-symptomatic women presenting unfavorable vaginal/endometrial microbiota? The aim of this review is to assess the capacity of probiotics as a single intervention to alter the feminine genital tract microbiota in non-symptomatic reproductive-aged women.