本试验旨在探讨发酵麸皮多糖对大鼠组织细胞因子含量及盲肠菌群结构的影响.选取75只健康断奶SD大鼠,随机分为3组,每组5重复,每个重复5只.对照组、低剂量组和高剂量组分别灌胃0、100、200 mg/kg BW发酵麸皮多糖.试验期为21 d.试验结束后,每个重复随机选取1只大鼠进行屠宰,采集空肠、肝脏和脾脏组织及盲肠食糜,通过酶联免疫吸附试验法测定组织中细胞因子白细胞介素-1β( IL?1β) 、白细胞介素-2( IL?2) 、白细胞介素-6( IL?6)及肿瘤坏死因子-α( TNF?α)的含量,利用Illumina?HiSeq高通量测序技术分析盲肠菌群结构.结果表明:1)低剂量组大鼠各组织中IL?1β、IL?2、IL?6和TNF?α的含量均较对照组有所升高,其中脾脏组织中TNF?α含量与对照组的差异达到显著水平( P<0.05) ;高剂量组大鼠肝脏组织中IL?2和脾脏组织中IL?6的含量均较对照组显著降低( P<0.05) ;低剂量组大鼠空肠组织中TNF?α、肝脏组织中IL?2及脾脏组织中IL?6的含量显著高于高剂量组( P<0.05) . 2)与对照组相比,灌胃100、200 mg/kg BW发酵麸皮多糖后大鼠盲肠菌群Shannon、Chao1、ACE指数有提高趋势,但差异未达显著水平( P>0.05) .在门水平上,与对照组相比,灌胃100和200 mg/kg BW发酵麸皮多糖均显著提高了大鼠盲肠食糜中厚壁菌门( Firmicutes)的相对丰度( P<0.05) ,并显著降低了拟杆菌门( Bacteroidetes)的相对丰度( P<0.05) .在属水平上,低剂量组和高剂量组大鼠盲肠食糜中普氏菌属9( Prevotella_9)的相对丰度较对照组显著降低( P<0.05) ;低剂量组中短链脂肪酸产生菌瘤胃球菌属1( Ruminococcus_1)以及高剂量组中短链脂肪酸产生菌粪球菌属1 ( Copro?coccus_1)的相对丰度均较对照组显著增加( P<0.05) .综上所述,在本试验条件下,灌胃低剂量(100 mg/kg BW)发酵麸皮多糖可增加大鼠组织中细胞因子含量,调控其盲肠菌群结构,进而提高其免疫力.
This experiment was conducted to investigate the effects of fermented wheat bran polysaccharides ( FWBPs) on tissue cytokine contents and caecal microflora structure of rats. Seventy?five healthy weaned SD rats were randomly assigned to 3 groups with 5 replicates per group and 5 rats per replicate. Rats in the 3 groups were lavaged daily with FWBPs solution at doses of 0 ( control group) , 100 ( low FWBPs group) and 200 mg/kg BW ( high FWBPs group). The experiment was carried out for 21 days. At the end of the experi?ment, one rat was selected from each replicate and slaughtered. The jejunum, liver and spleen tissues were col?lected to measure the cytokines such as interleukin ( IL)?1β, IL?2, IL?6 and tumor necrosis factor?α ( TNF?α) contents by enzyme linked immunosorbent assay ( ELISA) method, and the structure of caecal microflora was analyzed by Illumina HiSeq high through sequencing technology. The results showed as follows: 1) lavage of FWBPs at 100 mg/kg BW improved IL?1β, IL?2, IL?6 and TNF?α content in tissues of rats, and the TNF?α content in spleen tissue of rats was significantly improved compared with control group ( P<0.05) ; compared with control group, the contents of IL?2 in liver tissue and IL?6 in spleen tissue were significantly decreased in high FWBPs group ( P<0.05) ; the contents of TNF?α in jejunum tissue, IL?2 in liver tissue and IL?6 in spleen tissue of rats in low FWBPs group were significantly higher than those in high FWBPs group ( P<0.05). 2) Lavage of FWBPs at 100 and 200 mg/kg BW both enhanced Shannon, Chao1 and ACE indices compared with control group ( P>0.05). At the phylum level, lavage of FWBPs at 100 and 200 mg/kg BW both significantly improved the relative abundance of Firmicutes and significantly decreased the relative abundance of Bacte?roidetes in caecal chyme compared with control group ( P<0.05). At the genus level, compared with control group, the relative abundance of Prevotella_9 in caecal chyme in low and high FWBPs groups was significantly decreased (P<0.05), while the relative abundances of short?chain fatty acid producing bacteria Ruminococcus_1 in low FWBPs group and Coprococcus_1 in high FWBPs group were significantly increased ( P<0.05). In con?clusion, lavage of low dose (100 mg/kg BW) FWBPs can increase the contents of cytokine in tissues and reg?ulate the structure of caecal microflora, which may further enhance the immunity of rats.[ Chinese Journal of Animal Nutrition, 2019, 31(6) :2865?2874]