Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, North Carolina, USA
Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, North Carolina, USA.
mBio. 2021 Jan 26;12(1):e03399-20. doi: 10.1128/mBio.03399-20.
NCFM is a probiotic strain commonly used in dairy products and dietary supplements. Postgenome studies of NCFM thus far have linked potential key genotypes to its probiotic-relevant attributes, including gut survival, prebiotic utilization, host interactions, and immunomodulatory activities. To corroborate and extend beyond previous and functional studies, we employed a dual RNA sequencing (RNA-seq) transcriptomic approach to identify genes potentially driving the gut fitness and activities of NCFM , and in parallel, examine the ileal transcriptional response of its murine hosts during monocolonization. Spatial expression profiling of NCFM from the ileum through the colon revealed a set of 134 core genes that were consistently overexpressed during gut transit. These core genes are predominantly involved in the metabolism of carbohydrates, amino acids, and nucleotides, along with mucus-binding proteins and adhesion factors, confirming their functionally important roles in nutrient acquisition and gut retention. Functional characterization of the highly expressed major S-layer-encoding gene established its indispensable role as a cell shape determinant and maintenance of cell surface integrity, essential for viability and probiotic attributes. Host colonization by resulted in significant downregulation of several proinflammatory cytokines and tight junction proteins. Genes related to redox signaling, mucin glycosylation, and circadian rhythm modulation were induced, suggesting impacts on intestinal development and immune functions. Metagenomic analysis of NCFM populations postcolonization demonstrated the genomic stability of as a gut transient and further established its safety as a probiotic and biotherapeutic delivery platform. To date, our basis for comprehending the probiotic mechanisms of , one of the most widely consumed probiotic microbes, was largely limited to functional genomic studies. Using a germfree murine colonization model, -based transcriptional studies provided the first view of how survives in the mammalian gut environment, including gene expression patterns linked to survival, efficient nutrient acquisition, stress adaptation, and host interactions. Examination of the host ileal transcriptional response, the primary effector site of , has also shed light into the mechanistic roles of this probiotic microbe in promoting anti-inflammatory responses, maintaining intestinal epithelial homeostasis and modulation of the circadian-metabolic axis in its host.
NCFM 是一种常用于乳制品和膳食补充剂的益生菌菌株。迄今为止，对 NCFM 的后基因组研究将其潜在的关键基因型与益生菌相关属性联系起来，包括肠道存活、益生元利用、宿主相互作用和免疫调节活性。为了证实并扩展以前的功能研究，我们采用了双 RNA 测序（RNA-seq）转录组学方法来鉴定可能驱动 NCFM 肠道适应性和活性的基因，同时检查其在单定植期间对小鼠宿主回肠的转录反应。通过回肠到结肠的 NCFM 空间表达谱分析，揭示了一组 134 个核心基因，这些基因在肠道转运过程中始终过表达。这些核心基因主要参与碳水化合物、氨基酸和核苷酸的代谢，以及粘蛋白结合蛋白和粘附因子，证实了它们在营养物质获取和肠道保留方面的重要功能作用。对高度表达的主要 S-层编码基因的功能表征确定了其作为细胞形状决定因素和维持细胞表面完整性的不可或缺作用，这对于生存能力和益生菌属性是必需的。由 引起的宿主定植导致几种促炎细胞因子和紧密连接蛋白的显著下调。与氧化还原信号、粘蛋白糖基化和昼夜节律调节相关的基因被诱导，表明其对肠道发育和免疫功能有影响。定植后 NCFM 种群的宏基因组分析证明了其作为肠道瞬态的基因组稳定性，并进一步确立了其作为益生菌和生物治疗传递平台的安全性。迄今为止，我们对 NCFM（一种最广泛消费的益生菌微生物之一）的益生菌机制的理解基础在很大程度上仅限于功能基因组研究。使用无菌小鼠定植模型，基于 NCFM 的转录组学研究提供了第一个视角，了解 NCFM 如何在哺乳动物肠道环境中存活，包括与存活、有效营养物质获取、应激适应和宿主相互作用相关的基因表达模式。检查 NCFM 的宿主回肠转录反应，作为其主要效应部位，也揭示了这种益生菌微生物在促进抗炎反应、维持肠道上皮细胞稳态和调节宿主昼夜代谢轴方面的机制作用。
