A comparative analysis of the survival rate of the human gut microbiota after low-temperature preservation under the protection of penetrating (dimethylsulfoxide and glycerol), nonpenetrating (gelatin) and gas (helium) protectors was performed. Increased resistance of intestinal bacteria to the effect of low temperatures was revealed. A significant portion of the bacteria (50.0 ± 3.0%) remained viable after freezing in liquid nitrogen without the cryoprotector(s). The greatest survival was achieved under the protection of 5% dimethylsulfoxide (86.0 ± 4.0%), 5% glycerol (82.0 ± 5.2%), and 10% gelatin (75.0 ± 5.0%). The combination of cell-penetrating (dimethylsulfoxide and glycerol) and nonpenetrating (gelatin) protectors did not lead to a synergistic effect. The use of atmospheric helium for cryoprotection of heterogeneous human gut microbiota did not increase its survival, even in combination with such powerful protectors as dimethylsulfoxide and glycerol, which indicates the need to optimize cryoprotection media, in particular, for strict anaerobes.

中文翻译：

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液氮中人类肠道微生物群的保存效率取决于冷冻保护培养基的组成

在穿透性（二甲基亚砜和甘油）、非穿透性（明胶）和气体（氦气）保护剂的保护下，对低温保存后人类肠道微生物群的存活率进行了比较分析。肠道细菌对低温影响的抵抗力增加。在没有冷冻保护剂的液氮中冷冻后，很大一部分细菌 (50.0 ± 3.0%) 仍能存活。在 5% 二甲亚砜 (86.0 ± 4.0%)、5% 甘油 (82.0 ± 5.2%) 和 10% 明胶 (75.0 ± 5.0%) 的保护下，存活率最高。细胞穿透性（二甲基亚砜和甘油）和非穿透性（明胶）保护剂的组合不会产生协同效应。