Correlation between Hormone Levels and Count of Microorganisms in the Vagina of Women that Participated in a 5-Day Dry Immersion Experiment
摘要
The aim of this article is to study the relationship between hormone levels and the number of vaginal microorganisms of female volunteers participating in a 5-day dry immersion (DI) experiment. The study involved six volunteers aged 25 to 40 years. The duration of the DI was 5 days. Throughout the experiment, the volunteers used one vaginal capsule containing autologous Lactobacillus spp. in a titer of 107 CFU/mL (excipients—magnesium stearate—3 mg, lactose monohydrate—sufficient to obtain a capsule content weight of 400 mg) every night for 5 days. The volunteers also orally took a lactoferrin-based preparation in the amount of 400 mg once a day in the morning, starting from the 1st day of DI and for 30 days after its completion. To study the state of the vaginal and cervical canal microflora, samples were taken before the experiment, 5–7 days and 34–36 days after the end of immersion. Blood was taken to measure the amount of estradiol and prolactin at the same points as the vaginal biomaterial. All three points fell on days 19–22 of the menstrual cycle. Vaginal contents and cervical canal discharge were cultivated on selective and non-selective agar. Species identification of microorganisms was performed by MALDI-TOF-MS analysis using a Microflex LT time-of-flight mass spectrometer with Maldi BioTyper software (Bruker Daltoniks; Germany) version 4.0. Concentrations of estradiol and prolactin were measured by the enzyme immunoassay method using commercial kits (DBC, Canada) on a Stat Fax 2100 plate immunoassay analyzer (Awareness Technology, United States). As a result, correlation was found between the levels of prolactin and estradiol and some microorganisms of the vaginal and cervical canal microbiota. Lactobacillus spp. was found to be the most sensitive to the levels of estradiol and prolactin. In addition to Lactobacillus spp., the amount of estradiol and prolactin is also affected by Staphylococcus spp., Corymebacterium spp., B. bifidum, and C. acnes. Thus, under conditions simulating individual factors of space flight, it is necessary to pay close attention to monitoring the hormonal status of female volunteers, as well as maintaining the amount of Lactobacillus spp. within the normal range to prevent the development of dysbiotic conditions of the vagina and cervical canal.