Go L L, Ford H R, Watkins S C, Healey P J, Albanese C T, Donhalek A, Simmons R L, Rowe M I
Department of Surgery, University of Pittsburgh (Pa) School of Medicine.
Arch Surg. 1994 Nov;129(11):1184-90. doi: 10.1001/archsurg.1994.01420350082011.
To elucidate the mechanisms of bacterial translocation in animals fed a conventional formula by correlating transmucosal bacterial passage in vitro with the structural characteristics of the neonatal intestinal mucosa.
Newborn rabbits were randomized to receive a conventional formula or breast milk. Bacterial translocation to the mesenteric lymph nodes, liver, and spleen was quantitated after 7 days, and transmucosal passage of bacteria was measured in vitro using the Ussing chamber. The mucosal membranes were examined by light, transmission electron, and confocal laser scanning microscopy.
Bacterial passage was rarely seen in the breast milk-fed animals in contrast to the formula-fed animals. Unlike the normal-appearing membranes from breast milk-fed animals, the epithelial cells of formula-fed animals were vacuolated but healthy, with normal polarization and microvillus border by confocal laser scanning microscopy. Villi of formula-fed animals were less densely packed than those of the breast milk-fed animals. Bacterial adhesion, internalization, and transmucosal passage were seen only in membranes from formula-fed animals. Transmission electron microscopy demonstrated bacteria incorporating into the epithelial surface through an active phagocytic process, with rearrangement of the actin cytoskeleton. Once internalized, these bacteria were seen within the cytoplasmic vacuoles and subsequently in the submucosa. No bacteria passed between epithelial cells.
Morphological changes in the intestinal mucosa of formula-fed newborn rabbits may increase permeability to bacteria.
通过将体外跨黏膜细菌通过情况与新生动物肠黏膜的结构特征相关联，阐明喂食传统配方奶的动物中细菌易位的机制。
将新生兔随机分为两组，分别喂食传统配方奶或母乳。7天后对肠系膜淋巴结、肝脏和脾脏的细菌易位进行定量，并使用尤斯灌流小室体外测量细菌的跨黏膜通过情况。通过光学显微镜、透射电子显微镜和共聚焦激光扫描显微镜检查黏膜。
与喂食配方奶的动物相比，喂食母乳的动物很少出现细菌通过情况。与喂食母乳动物外观正常的黏膜不同，喂食配方奶动物的上皮细胞出现空泡化但健康，共聚焦激光扫描显微镜显示其极化和微绒毛边界正常。喂食配方奶动物的绒毛比喂食母乳动物的绒毛排列稀疏。仅在喂食配方奶动物的黏膜中观察到细菌黏附、内化和跨黏膜通过。透射电子显微镜显示细菌通过活跃的吞噬过程进入上皮表面，肌动蛋白细胞骨架发生重排。一旦内化，这些细菌出现在细胞质空泡内，随后出现在黏膜下层。未观察到细菌在上皮细胞之间通过。
喂食配方奶的新生兔肠黏膜的形态学变化可能会增加对细菌的通透性。
