Gastroenterology Department, Rambam Health Care Campus, Haifa, Israel.
Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel.
JPEN J Parenter Enteral Nutr. 2024 May;48(4):502-511. doi: 10.1002/jpen.2624. Epub 2024 Mar 24.
The microbiome has a pivotal role in intestinal health, and nutrition has a major role shaping its structure. Enteral deprivation, in which no oral/enteral nutrition is administered, is common in hospitalized/gastrointestinal patients. The dynamics that enteral deprivation exerts on the microbial community, specifically in the small intestine, are not well understood.
Enteral deprivation was modeled with exclusive parenteral nutrition (EPN) mice. Mice were allocated to receive either EPN or saline and chow (control) and euthanized after 0, 2, 4, or 6 days. DNA was extracted from jejunum, ileum, and colon content. 16S sequencing was used to compare changes in microbial communities between groups. Functional pathways were predicted using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States.
EPN-treated mice showed community changes throughout the intestine. Beta diversity in colon showed clear separation between the groups (Bray-Curtis, P < 0.001). Time-dependent dynamics were seen in ileal but not jejunal samples. Alpha diversity was lower in the colon of EPN mice compared with control/baseline mice (Chao1, P < 0.01) but not in ileum/jejunum. Progressive loss of single-taxon domination was seen, most notably in the small intestine. This was accompanied by increases/decreases in specific taxa. A clear separation was seen in the functional capacity of the community between fed and enterally deprived mice at the ileum and colon, which was observed early on.
Enteral deprivation disturbs the microbial community in a spatial and dynamic manner. There should be further focus on studying the effect of these changes on the host.
微生物组在肠道健康中起着关键作用，而营养在塑造其结构方面起着重要作用。肠内剥夺，即不给予口服/肠内营养，在住院/胃肠道患者中很常见。肠内剥夺对微生物群落，特别是小肠中的微生物群落施加的动态影响尚未得到很好的理解。
通过给予完全肠外营养（EPN）的小鼠来模拟肠内剥夺。将小鼠分为接受 EPN 或生理盐水和膳食（对照）的组，并在 0、2、4 或 6 天后安乐死。从空肠、回肠和结肠内容物中提取 DNA。使用 16S 测序比较组间微生物群落的变化。使用未观测状态重建的群落系统发育分析来预测功能途径。
EPN 处理的小鼠整个肠道的群落均发生了变化。结肠的 Beta 多样性在组间明显分离（Bray-Curtis，P < 0.001）。在回肠而不是空肠样本中观察到时间依赖性动态。EPN 小鼠的结肠 alpha 多样性低于对照/基线小鼠（Chao1，P < 0.01），但空肠和回肠没有。观察到单一种群主导地位的逐渐丧失，尤其是在小肠中。这伴随着特定类群的增加/减少。在回肠和结肠，给予食物和肠内剥夺的小鼠之间的群落功能能力明显分离，这在早期就观察到了。
肠内剥夺以空间和动态的方式扰乱微生物群落。应该进一步关注研究这些变化对宿主的影响。
