Lionetti Paolo, Callegari Maria Luisa, Ferrari Susanna, Cavicchi Maria Chiara, Pozzi Elena, de Martino Maurizio, Morelli Lorenzo
Department of Pediatrics, University of Florence, Meyer Children's Hospital, Florence, Italy.
JPEN J Parenter Enteral Nutr. 2005 Jul-Aug;29(4 Suppl):S173-5; discussion S175-8, S184-8. doi: 10.1177/01486071050290S4S173.
Exclusive enteral nutrition (EN) is an established primary therapy for pediatric Crohn's disease (CD). The mechanism of action of such treatment is still conjectural. The aim of the present study was to investigate if EN-induced remission is associated with modification of the fecal microflora in CD.
Stool samples were collected from 5 healthy children and adolescents over a period of 3 months, and from 9 children and adolescents with active CD. To induce disease remission, children with CD received a course of exclusive EN for 8 weeks with a polymeric formula (Modulen IBD, Nestlè). At the end of the course of exclusive EN, children returned to a free diet but continued to take 40% of the daily caloric intake as polymeric formula. Fecal microflora was analyzed by 16S ribosomal DNA polymerase chain reaction and temperature gradient gel electrophoresis (TGGE) with direct visual comparison of band profiles of PCR products.
In 8 of 9 children, the exclusive EN alone induced disease remission. In 1 child, it was necessary to add steroids to the exclusive EN course to achieve remission. In all children with CD, analysis of gel band distribution revealed profound modification of the fecal microflora after exclusive EN. Variations of band distribution corresponding to different bacterial species were observed also in children on partial EN and required time to achieve stability of the band profile. In contrast, control healthy children showed a host-specific and stable TGGE profile over time.
These data suggest that a possible mechanism of action of EN in inducing disease remission in CD is the capacity of modification of gut microflora. Possible explanations of such capacity are both low residue and prebiotic properties of the polymeric liquid formula.
肠内营养（EN）是小儿克罗恩病（CD）既定的主要治疗方法。这种治疗的作用机制仍属推测。本研究的目的是调查EN诱导的缓解是否与CD患者粪便微生物群的改变有关。
在3个月的时间里，从5名健康儿童和青少年以及9名患有活动性CD的儿童和青少年中收集粪便样本。为诱导疾病缓解，患有CD的儿童接受了为期8周的含聚合配方奶粉（雀巢公司的Modulen IBD）的全肠内营养疗程。在全肠内营养疗程结束时，儿童恢复自由饮食，但继续摄入占每日热量摄入40%的聚合配方奶粉。通过16S核糖体DNA聚合酶链反应和温度梯度凝胶电泳（TGGE）分析粪便微生物群，并直接目视比较PCR产物的条带图谱。
9名儿童中有8名仅通过全肠内营养就诱导了疾病缓解。在1名儿童中，有必要在全肠内营养疗程中添加类固醇以实现缓解。在所有患有CD的儿童中，凝胶条带分布分析显示全肠内营养后粪便微生物群有深刻改变。在部分肠内营养的儿童中也观察到对应不同细菌种类的条带分布变化，且条带图谱达到稳定需要时间。相比之下，对照健康儿童随时间显示出宿主特异性且稳定的TGGE图谱。
这些数据表明，肠内营养在诱导CD疾病缓解中的一种可能作用机制是改变肠道微生物群的能力。这种能力的可能解释是聚合液体制剂的低残渣和益生元特性。
