Kelberman I, Cheetham B C, Rosenthal J, Levine G M
Division of Gastroenterology and Nutrition, Albert Einstein Medical Center, Philadelphia, USA.
JPEN J Parenter Enteral Nutr. 1995 Mar-Apr;19(2):100-6. doi: 10.1177/0148607195019002100.
The role of fiber in postresection adaptation is poorly understood. We examined the significance of short-chain fatty acids produced by intracolonic fiber fermentation during colonic adaptation.
Rats underwent one of three surgeries: control laparotomy, cecal resection, or cecal resection with placement of perfusion catheter. Rats of each surgical group were randomly assigned to receive treatment regimens of standard fiber diet (with or without fermentation-suppressing antibiotics), fiber-free diet, or diet plus intracolonic perfusion of short-chain fatty acids. Adaptation parameters of mucosal weight, mucosal DNA and protein content, water absorption, and butyrate absorption were measured.
Compared with controls, postresection rats that were fed fiber had 65% greater basal and 112% greater butyrate-stimulated water absorption as well as 140% greater butyrate absorption. Fiber-fed rats exhibited significantly greater colonic weight and colonic mucosal protein after cecal resection. These changes were absent in postresection rats fed a fiber-free diet. Inhibition of fermentation by neomycin and metronidazole added to a standard fiber diet also prevented postresection adaptation. All adaptive changes were restored when the cecal-resection rats that were fed the fiber diet with antibiotics received an intracolonic infusion of short-chain fatty acids. Adaptation did not occur when short-chain fatty acids were infused into colons of postresection rats that were fed a fiber-free diet.
Cecal resection leads to significant functional and structural changes in the adapting residual colon. Fermentation of dietary fiber by colonic flora to short-chain fatty acids is necessary, but it alone is not sufficient to mediate adaptation.
膳食纤维在结肠切除术后适应性变化中的作用尚不清楚。我们研究了结肠内膳食纤维发酵产生的短链脂肪酸在结肠适应性变化过程中的意义。
大鼠接受三种手术之一：对照剖腹术、盲肠切除术或盲肠切除并放置灌注导管。每个手术组的大鼠被随机分配接受以下治疗方案：标准纤维饮食（含或不含抑制发酵的抗生素）、无纤维饮食或饮食加结肠内灌注短链脂肪酸。测量黏膜重量、黏膜DNA和蛋白质含量、水吸收及丁酸盐吸收等适应性参数。
与对照组相比，术后喂食纤维的大鼠基础水吸收增加65%，丁酸盐刺激的水吸收增加112%，丁酸盐吸收增加140%。盲肠切除术后，喂食纤维的大鼠结肠重量和结肠黏膜蛋白显著增加。而喂食无纤维饮食的术后大鼠未出现这些变化。在标准纤维饮食中添加新霉素和甲硝唑抑制发酵也可阻止术后适应性变化。当喂食含抗生素纤维饮食的盲肠切除大鼠接受结肠内短链脂肪酸灌注时，所有适应性变化均得以恢复。将短链脂肪酸注入喂食无纤维饮食的术后大鼠结肠时，未发生适应性变化。
盲肠切除导致残余结肠在适应性变化过程中出现显著的功能和结构改变。结肠菌群将膳食纤维发酵为短链脂肪酸是必要的，但仅此一项不足以介导适应性变化。
