Microbiome and metagenomic studies have given rise to a new understanding of microbial colonization of various human tissues and their ability to impact our health. One human microbiome growing in notoriety, the vaginal microbiome, stands out given its importance for women’s health, and is peculiar in terms of its relative bacterial composition, including its simplicity and typical domination by a small number of Lactobacillus species. The loss of Lactobacillus dominance is associated with disorders such as bacterial vaginosis, and efforts are now underway to understand the ability of Lactobacillus species to colonize the vaginal tract and adapt to this dynamic and acidic environment. Here, we investigate how various Lactobacillus species often isolated from the vaginal and intestinal cavities genomically and transcriptionally respond to iterative growth in simulated vaginal fluid. We determined the genomes and transcriptomes of L. acidophilus, L. crispatus, L. fermentum, L. gasseri, and L. jensenii and compared profiles after 50, 100, 500, and 1000 generations of iterative passages in synthetic vaginal fluid. In general, we identified relatively few genetic changes consisting of single nucleotide polymorphisms, with higher counts occurring more frequently in non-vaginal isolated species. Transcriptional profiles were more impacted over time and tended to be more extensive for species that typically do not dominate the vaginal tract, reflecting a more extensive need to adapt to a less familiar environment. This study provides insights into how vaginal and non-vaginal Lactobacillus species respond and adapt to a simulated vaginal environment. Overall, trends indicate high genomic stability for all species involved, with more variability in the transcriptome especially for non-dominant species of the vaginal tract.

中文翻译：

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对模拟阴道液中五种乳酸杆菌迭代传代的适应性反应

微生物组和宏基因组研究使人们对各种人体组织的微生物定植及其影响我们健康的能力有了新的认识。一种日益臭名昭著的人类微生物组，阴道微生物组，因其对女性健康的重要性而脱颖而出，并且在其相对细菌组成方面是独特的，包括其简单性和典型的由少数乳杆菌属物种支配。乳杆菌优势的丧失与细菌性阴道病等疾病有关，目前正在努力了解乳杆菌属物种定殖阴道并适应这种动态和酸性环境的能力。这里，我们研究了通常从阴道和肠腔中分离出的各种乳酸菌物种如何在基因组和转录上对模拟阴道液中的迭代生长做出反应。我们确定了嗜酸乳杆菌、卷曲乳杆菌、发酵乳杆菌、加氏乳杆菌和詹氏乳杆菌的基因组和转录组，并比较了合成阴道液中 50、100、500 和 1000 代迭代传代后的概况。一般来说，我们确定了相对较少的由单核苷酸多态性组成的遗传变化，在非阴道分离物种中发生的频率更高。随着时间的推移，转录谱受到的影响更大，并且对于通常不支配阴道的物种来说往往更广泛，这反映了更广泛的需要适应不太熟悉的环境。这项研究提供了有关阴道和非阴道乳杆菌物种如何响应和适应模拟阴道环境的见解。总体而言，趋势表明所有相关物种的基因组稳定性都很高，转录组的变异性更大，尤其是阴道的非优势物种。