Department of Gastroenterology, Central Clinical School, Monash University, Melbourne, Victoria, Australia.
J Gastroenterol Hepatol. 2013 Dec;28 Suppl 4:25-8. doi: 10.1111/jgh.12272.
Gastrointestinal symptoms including diarrhea are common complications of enteral nutrition (EN); however, the cause is unclear. Mode of EN delivery that alters digestion and possibly absorption is suggested to contribute to the high incidence of diarrhea; however, enteral formula is frequently blamed. Most research has focused on fiber-supplemented EN, with a meta-analysis showing that fiber reduces the incidence of diarrhea in non-intensive care unit studies. Other hypotheses include formula osmolality and FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) content. FODMAPs are poorly absorbed short-chain carbohydrates that exert an osmotic effect. Dietary FODMAPs have been shown to reduce gastrointestinal symptoms, including diarrhea, in those with irritable bowel syndrome and, given a high-enough dose, will induce a laxative effect in most people. As FODMAPs are commonly added to enteral formula and EN is frequently used as the main source of nutrition, it is reasonable to hypothesize that EN provides more FODMAPs than usual dietary intake and increases risk for developing diarrhea. This hypothesis was assessed through a retrospective study showing that the standard-use enteral formula Isosource 1.5 had a protective effect of developing diarrhea. The only characteristic unique to Isosource 1.5 was the lower FODMAP content as determined through methodologies previously validated for food analysis. Methodologies for application to enteral formulas are currently undergoing formal validation. Once confirmed for application in enteral formula, future directions include FODMAP analysis of specific ingredients to increase understanding of potential problems associated with enteral formula and a randomized, controlled trial investigating the role of formula FODMAP content.
胃肠道症状包括腹泻是肠内营养（EN）的常见并发症；然而，其病因尚不清楚。改变消化和吸收的 EN 输送方式被认为是导致腹泻高发的原因；然而，肠内配方经常受到指责。大多数研究都集中在纤维补充的 EN 上，一项荟萃分析表明，纤维可降低非重症监护病房研究中腹泻的发生率。其他假说包括配方渗透压和 FODMAP（可发酵寡糖、双糖、单糖和多元醇）含量。FODMAP 是不易被吸收的短链碳水化合物，具有渗透作用。在患有肠易激综合征的患者中，膳食 FODMAP 已被证明可减轻胃肠道症状，包括腹泻，并且在足够高的剂量下，会在大多数人中引起通便作用。由于 FODMAP 通常添加到肠内配方中，并且 EN 通常用作主要的营养来源，因此可以合理地假设 EN 提供的 FODMAP 比通常的饮食摄入更多，并且增加腹泻的风险。通过一项回顾性研究评估了这一假说，该研究表明标准使用的肠内配方 Isosource 1.5 具有预防腹泻的作用。Isosource 1.5 唯一独特的特征是通过以前针对食品分析验证的方法确定的较低的 FODMAP 含量。目前正在对适用于肠内配方的方法进行正式验证。一旦确认适用于肠内配方，未来的方向包括对特定成分进行 FODMAP 分析，以增加对肠内配方相关潜在问题的理解，以及一项随机对照试验，以研究配方 FODMAP 含量的作用。
