Probiotic capsules based on autologous Lactobacillus spp strains as countermeasures against vaginal dysbiosis of female volunteers in the annual isolation experiment "SIRIUS-23"

Abstract

It is known that prolonged isolation leads to a significant reduction in the body's immune system. The issue of altering the microbiota of female genital organs and developing innovative methods for preventing and correcting emerging disorders is particularly relevant, as recent studies have convincingly demonstrated a deterioration in the condition of the vaginal and cervical microbiota under conditions of prolonged isolation.

The aim: to investigated the effect of probiotic preparations based on autologous Lactobacillus spp strains on the vaginal microflora in women under long-term isolation. Lactobacillus spp strains were isolated from the biomaterial samples. The preparations in the form of capsules were used twice: in the first 30 days of isolation and 30 days before its end with a break for menstruation (5-6 days).

Methods. During the experiment (on days 36, 64, 102, 123, 186, 256 and 339) as well as before and after isolation, the qualitative and quantitative composition of the vaginal microbiota of the volunteers was assessed. Microorganisms were identified using MALDI-TOF-MS analysis.

The results showed that the autoprobiotic preparation stabilized the vaginal microbiota. The effect of the preparation lasted for at least 64 days. On the 102nd day of isolation, an increase in the amount of opportunistic flora was observed with a simultaneous decrease in the amount of Lactobacillus spp, which is probably due to the emergency situation on the 95th-114th day of isolation, during which the crew experienced a shortage of food and water, as well as psychoemotional stress associated with the upcoming extraterrestrial activity planned for the 125th-129th day of isolation. By the end of isolation (day 339), the number of opportunistic microorganisms decreased and a reliable increase in the amount of L. vaginalis was noted. 10 days after ending ofisolation, a decrease in all opportunistic microorganisms and an increase in L. crispatus, which formed the basis of the autoprobiotic preparation in all volunteers, were recorded. The preparation retained its effectiveness even after long-term storage at a temperature of +4°C for a year.

Conclusion: autoprobiotic capsules based on vaginal lactobacilli demonstrated the ability to maintain healthy vaginal microbiota and prevent the development of dysbiotic conditions, which could be used in long-term space missions or on a lunar base.