INVESTIGATION OF THE PROBIOTIC ACTIVITY OF LACTOBACILLACEAE AUTO- STRAINS REGENERATED FOLLOWING A PROLONGED CRYOPRESERVATION IN A STUDY WITH ISOLATION

A comprehensive investigation of auto-probiotic prophylaxis of dysbiosis symptoms included, testing the methods of prolonged preservation of human microbial associations, and their potential use as probiotic substances during long-term isolation. The investigation was performed in a 14-d isolation study with participation of 6 human subjects. Over 7 days starting from the day of egress, 4 subjects consumed a priobiotic beverage, i.e. kefir supplemented for each one with own isolated Lactobacillaceae strains. Two subjects did not receive probiotic beverages. In the group of subjects who had consumed kefirs the number of lactobacilli stabilized. An increased number of Bacillus spp. and Bifidobacterium spp. and a decreased number of enterococci imply the benefits from the autoprobiotic beverage. After the egress, the upper airway (UA) microflora decreased abruptly; however, rise of the dyspnea index by the end of kefir consumption suggested UA microflora stabilization. Feces analysis after 6-month cryopreservation at –80 ºС showed that opportunistic microorganisms decreased considerably in samples of all subjects. Noteworthy is that numbers of Lactobacillaceae before and after cryopreservation did not differ much and reductions in Bifidobacterium spp. and E. coli were within the physiological norm margins. Our cryopreservation findings attest to potential applicability of the technology in extended space missions for preserving the intestinal bacteria consortium to be used for mixing autoprobiotic substances.