Gómez-Conde M S, García J, Chamorro S, Eiras P, Rebollar P G, Pérez de Rozas A, Badiola I, de Blas C, Carabaño R
Departamento de Producción Animal, Universidad Politécnica de Madrid, E.T.S. Ingenieros Agrónomos, 28040 Madrid, Spain.
J Anim Sci. 2007 Dec;85(12):3313-21. doi: 10.2527/jas.2006-777. Epub 2007 Aug 20.
The effect of neutral detergent-soluble fiber level on gut barrier function and intestinal microbiota was examined in weaned rabbits. A control diet (AH) containing 103 g of neutral detergent-soluble fiber/ kg of DM included alfalfa hay as main source of fiber. Another diet (B-AP) was formulated by replacing half of the alfalfa hay with a mixture of beet and apple pulp resulting in 131 g of soluble fiber/kg of DM. A third diet (OH) was obtained by substituting half of the alfalfa hay with a mix of oat hulls and a soybean protein concentrate and contained 79 g of soluble fiber/kg of DM. Rabbits weaned at 25 d and slaughtered at 35 d were used to determine ileal digestibility, jejunal morphology, sucrase activity, lamina propria lymphocytes, and intestinal microbiota. Suckling 35-d-old rabbits were used to assess mucosa morphology. Mortality (from weaning to 63 d of age) was also determined. Villous height of the jejunal mucosa increased with soluble fiber (P = 0.001). Rabbits fed with the greatest level of soluble fiber (BA-P diet) showed the highest villous height/ crypt depth ratio (8.14; P = 0.001), sucrase specific activity (8,671 mumol of glucose/g of protein; P = 0.019), and the greatest ileal starch digestibility (96.8%; P = 0.002). The opposite effects were observed in rabbits fed decreased levels of soluble fiber (AH and OH diets; 4.70, 5,848 mumol of glucose/g of protein, as average, respectively). The lowest ileal starch digestibility was detected for animals fed OH diet (93.2%). Suckling rabbits of the same age showed a lower villous height/crypt depth ratio (6.70) compared with the B-AP diet group, but this ratio was higher than the AH or OH diet groups. Lower levels of soluble fiber tended (P = 0.074) to increase the cellular immune response (CD8+ lymphocytes). Diet affected IL-2 production (CD25+, P = 0.029; CD5+CD25+, P = 0.057), with no clear relationship between soluble fiber and IL-2. The intestinal microbiota biodiversity was not affected by diets (P >/= 0.38). Rabbits fed the B-AP and AH diets had a reduced cecal frequency of detection compatible with Campylobacter spp. (20.3 vs. 37.8, P = 0.074), and Clostridium perfringens (4.3 vs. 17.6%, P = 0.047), compared with the OH diet group. Moreover, the mortality rates decreased from 14.4 (OH diet) to 5.1% (B-AP diet) with the increased presence of soluble fiber in the diet. In conclusion, increased levels of dietary soluble fiber improve mucosal integrity and functionality.
在断奶仔兔中研究了中性洗涤剂可溶性纤维水平对肠道屏障功能和肠道微生物群的影响。对照日粮（AH）含有103克中性洗涤剂可溶性纤维/千克干物质，以苜蓿干草作为纤维的主要来源。另一种日粮（B-AP）是通过用甜菜和苹果渣混合物替代一半苜蓿干草配制而成，可溶性纤维含量为131克/千克干物质。第三种日粮（OH）是用燕麦壳和大豆浓缩蛋白混合物替代一半苜蓿干草获得的，可溶性纤维含量为79克/千克干物质。选用25日龄断奶、35日龄屠宰的仔兔来测定回肠消化率、空肠形态、蔗糖酶活性、固有层淋巴细胞和肠道微生物群。选用35日龄哺乳仔兔来评估黏膜形态。还测定了死亡率（从断奶至63日龄）。空肠黏膜绒毛高度随可溶性纤维增加而升高（P = 0.001）。饲喂最高水平可溶性纤维（BA-P日粮）的仔兔绒毛高度/隐窝深度比值最高（8.14；P = 0.001）、蔗糖酶比活性最高（8671微摩尔葡萄糖/克蛋白质；P = 0.019）且回肠淀粉消化率最高（96.8%；P = 0.002）。在饲喂可溶性纤维水平降低的日粮（AH和OH日粮）的仔兔中观察到相反的效果（平均分别为4.70、5848微摩尔葡萄糖/克蛋白质）。饲喂OH日粮的动物回肠淀粉消化率最低（93.2%）。同年龄的哺乳仔兔与B-AP日粮组相比绒毛高度/隐窝深度比值较低（6.70），但该比值高于AH或OH日粮组。较低水平的可溶性纤维有增加细胞免疫反应（CD8+淋巴细胞）的趋势（P = 0.074）。日粮影响白细胞介素-2的产生（CD25+，P = 0.029；CD5+CD25+，P = 0.057），可溶性纤维与白细胞介素-2之间无明确关系。日粮对肠道微生物群生物多样性无影响（P≥0.38）。与OH日粮组相比，饲喂B-AP和AH日粮的仔兔盲肠弯曲杆菌属的检出频率降低（20.3对37.8，P = 0.074），产气荚膜梭菌的检出频率降低（4.3对17.6%，P = 0.047）。此外，随着日粮中可溶性纤维含量增加，死亡率从14.4%（OH日粮）降至5.1%（B-AP日粮）。总之，日粮中可溶性纤维水平的提高可改善黏膜完整性和功能。
