van Meer Hester, Boehm Gunther, Stellaard Frans, Vriesema Aldwin, Knol Jan, Havinga Rick, Sauer Pieter J, Verkade Henkjan J
Pediatric Gastroenterology, Department of Pediatrics, University Medical Center Groningen, Groningen, The Netherlands.
Am J Physiol Gastrointest Liver Physiol. 2008 Feb;294(2):G540-7. doi: 10.1152/ajpgi.00396.2007. Epub 2007 Dec 13.
Human milk contains prebiotic oligosaccharides, which stimulate the growth of intestinal bifidobacteria and lactobacilli. It is unclear whether the prebiotic capacity of human milk contributes to the larger bile salt pool size and the more efficient fat absorption in infants fed human milk compared with formula. We determined the effect of prebiotic oligosaccharides on bile salt metabolism in rats. Rats were fed a control diet or an isocaloric diet containing a mixture of galactooligosaccharides (GOS), long-chain fructooligosaccharides (lcFOS), and acidified oligosaccharides (AOS) for 3 wk. We determined synthesis rate, pool size, and fractional turnover rate (FTR) of the primary bile salt cholate by using stable isotope dilution methodology. We quantified bile flow and biliary bile salt secretion rates through bile cannulation. Prebiotic intervention resulted in significant changes in fecal and colonic flora: the proportion of lactobacilli increased 344% (P < 0.01) in colon content and 139% (P < 0.01) in feces compared with the control group. The number of bifidobacteria also increased 366% (P < 0.01) in colon content and 282% in feces after the prebiotic treatment. Furthermore, pH in both colon and feces decreased significantly with 1.0 and 0.5 pH point, respectively. However, despite this alteration of intestinal bacterial flora, no significant effect on relevant parameters of bile salt metabolism and cholate kinetics was found. The present data in rats do not support the hypothesis that prebiotics naturally present in human milk contribute to a larger bile salt pool size or altered bile salt pool kinetics.
人乳中含有益生元低聚糖，可刺激肠道双歧杆菌和乳酸杆菌的生长。与配方奶喂养的婴儿相比，人乳的益生元能力是否有助于婴儿拥有更大的胆盐池容量以及更高效的脂肪吸收尚不清楚。我们测定了益生元低聚糖对大鼠胆盐代谢的影响。大鼠被喂食对照饮食或含低聚半乳糖（GOS）、长链低聚果糖（lcFOS）和酸化低聚糖（AOS）混合物的等热量饮食，持续3周。我们使用稳定同位素稀释法测定了初级胆盐胆酸的合成速率、池容量和分数周转率（FTR）。我们通过胆管插管对胆汁流量和胆汁胆盐分泌率进行了定量。益生元干预导致粪便和结肠菌群发生显著变化：与对照组相比，结肠内容物中乳酸杆菌比例增加了344%（P<0.01），粪便中增加了139%（P<0.01）。益生元处理后，结肠内容物中双歧杆菌数量也增加了366%（P<0.01），粪便中增加了282%。此外，结肠和粪便的pH值分别显著下降了1.0和0.5个pH单位。然而，尽管肠道菌群发生了这种变化，但未发现对胆盐代谢和胆酸动力学的相关参数有显著影响。大鼠的现有数据不支持人乳中天然存在的益生元有助于形成更大的胆盐池容量或改变胆盐池动力学这一假设。
