Department of Internal Medicine, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA.
Department of Pharmacology & Toxicology, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA.
Nutrients. 2024 Jan 26;16(3):363. doi: 10.3390/nu16030363.
Exclusive enteral nutrition (EEN) is an established dietary treatment for Crohn's disease (CD) by alleviating inflammation and inducing remission. However, the mechanisms of action of EEN are incompletely understood. As CD is associated with gut microbiome dysbiosis, we investigated the effect of EEN on the microbiome in a rat model of CD-like colitis. The rat model of CD-like colitis was established by an intracolonic instillation of TNBS at 65 mg/kg in 250 µL of 40% ethanol. Sham control rats were instilled with saline. Rats were fed ad libitum with either regular pellet food or EEN treatment with a clear liquid diet (Ensure). Rats were euthanized at 7 days. Fecal pellets were collected from the distal colon for 16S rRNA sequencing analysis of gut microbiota. In addition, colon tissues were taken for histological and molecular analyses in all the groups of rats. EEN administration to TNBS-induced CD rats significantly improved the body weight change, inflammation scores, and disease activity index. The mRNA expression of IL-17A and interferon-γ was significantly increased in the colonic tissue in TNBS rats when fed with regular food. However, EEN treatment significantly attenuated the increase in IL-17A and interferon-γ in TNBS rats. Our 16S rRNA sequencing analysis found that gut microbiota diversity and compositions were significantly altered in TNBS rats, compared to controls. However, EEN treatment improved alpha diversity and increased certain beneficial bacteria such as and and decreased bacteria such as and in CD-like rats, compared to CD-like rats with the regular pellet diet. In conclusion, EEN treatment increases the diversity of gut microbiota and the composition of certain beneficial bacteria. These effects may contribute to the reduced inflammation by EEN in the rat model of CD-like colitis.
肠内营养（EEN）是一种已被证实的治疗克罗恩病（CD）的饮食方法，可缓解炎症并诱导缓解。然而，EEN 的作用机制尚不完全清楚。由于 CD 与肠道微生物失调有关，我们研究了 EEN 对 CD 样结肠炎大鼠模型中微生物组的影响。通过在 250µL 40%乙醇中以 65mg/kg 的浓度向结肠内注入 TNBS 建立 CD 样结肠炎大鼠模型。假手术对照大鼠给予生理盐水灌胃。自由喂养大鼠，给予常规颗粒饲料或 EEN 治疗，EEN 治疗采用全液体饮食（Ensure）。在第 7 天处死大鼠。从远端结肠收集粪便颗粒，用于 16S rRNA 测序分析肠道微生物群。此外，对所有大鼠的结肠组织进行组织学和分子分析。EEN 给药于 TNBS 诱导的 CD 大鼠显著改善了体重变化、炎症评分和疾病活动指数。在给予常规饮食的 TNBS 大鼠的结肠组织中，IL-17A 和干扰素-γ 的 mRNA 表达显著增加。然而，EEN 治疗显著减弱了 TNBS 大鼠中 IL-17A 和干扰素-γ 的增加。我们的 16S rRNA 测序分析发现，与对照组相比，TNBS 大鼠的肠道微生物多样性和组成发生了显著改变。然而，与给予常规颗粒饮食的 CD 样大鼠相比，EEN 治疗改善了 CD 样大鼠的 alpha 多样性，增加了某些有益细菌（如 和 ），减少了某些细菌（如 和 ）。总之，EEN 治疗增加了肠道微生物多样性和某些有益细菌的组成。这些作用可能有助于减少 EEN 在 CD 样结肠炎大鼠模型中的炎症。
