Bach Knudsen K E, Jensen B B, Andersen J O, Hansen I
Department of Animal Physiology and Biochemistry, National Institute of Animal Science, Tjele, Denmark.
Br J Nutr. 1991 Mar;65(2):233-48. doi: 10.1079/bjn19910083.
The present work was undertaken to study the microbial activity in various segments of the gastrointestinal (GI) tract of pigs as influenced by the source and level of wheat and oat dietary fibre (DF). Eight experimental diets were prepared from wheat and oat fractions and studied in a series of two experiments using wheat flour as the DF-depleted control. The diets in Expt 1 were based on wheat flour and three iso-DF enriched diets comprising fractions rich in wheat aleurone, pericarp/testa or bran. In Expt 2, oat bran was added to wheat flour to achieve the same DF intake level as in Expt 1. This series included further diets based on rolled oats and rolled oats plus oat bran. The eight diets were given to thirty-two ileal-cannulated pigs, with sixteen pigs in each experiment. After a total period of 34 d (Expt 1) and 42 d (Expt 2), the pigs were slaughtered 4 h post-feeding and samples taken for adenine nucleotides (adenosine 5'-triphosphate (ATP); adenylate energy charge (AEC)), organic acids (lactic acid (LA); short chain fatty acids (SCFA)) and pH at twelve sites of the GI tract. The microbial activity as measured by the ATP concentration was low in the stomach and the cranial two-thirds of the small intestine, but tended to increase in the distal third. In the caecum a sharp rise in microbial activity was observed; the highest level was found for the diet providing most fermentable substrates. In all the diets but the rolled oats + oat bran diets, microbial activity showed a descending pattern as the digesta moved through the colon. In the large intestine source and level of residues had a marked influence on microbial activity. LA was the chief organic acid in the stomach and small intestine (10-40 mmol/l) while LA relative to SCFA was a minor component in the caecum and colon (10-20 mmol/l). The contribution of SCFA to total organic acids was reciprocal to LA, i.e. low in the stomach and small intestine (less than 20 mmol/l) and high in the caecum and colon. In the large intestine the concentration of SCFA decreased from 100-140 mmol/l in the caecum and proximal colon to 40-80 mmol/l in the distal colon. The acetic: propionic acid ratio increased from the caecum to the distal colon. With the diets based on oat alone (rolled oats; rolled oats + oat bran) the increase was less significant.(ABSTRACT TRUNCATED AT 400 WORDS)
本研究旨在探讨小麦和燕麦膳食纤维（DF）的来源及水平对猪胃肠道（GI）不同部位微生物活性的影响。用小麦和燕麦组分制备了8种实验日粮，并以小麦粉作为低DF对照，分两个系列实验进行研究。实验1的日粮以小麦粉为基础，另外三种等DF强化日粮分别包含富含小麦糊粉层、果皮/种皮或麸皮的组分。实验2中，向小麦粉中添加燕麦麸以达到与实验1相同的DF摄入量水平。该系列还包括以燕麦片以及燕麦片加燕麦麸为基础的日粮。将这8种日粮饲喂给32头回肠造瘘猪，每个实验16头。在实验1共34天、实验2共42天的饲养期结束后，猪在采食后4小时屠宰，并在胃肠道的12个部位采集样本，用于分析腺嘌呤核苷酸（腺苷5'-三磷酸（ATP）；腺苷酸能量电荷（AEC））、有机酸（乳酸（LA）；短链脂肪酸（SCFA））和pH值。以ATP浓度衡量的微生物活性在胃和小肠前三分之二部位较低，但在小肠后三分之一部位有升高趋势。在盲肠中观察到微生物活性急剧上升；提供最多可发酵底物的日粮微生物活性最高。除燕麦片+燕麦麸日粮外，在所有日粮中，随着食糜在结肠中移动，微生物活性呈下降趋势。在大肠中，残留物的来源和水平对微生物活性有显著影响。LA是胃和小肠中的主要有机酸（10 - 40 mmol/L），而相对于SCFA，LA在盲肠和结肠中是次要成分（10 - 20 mmol/L）。SCFA对总有机酸的贡献与LA相反，即在胃和小肠中较低（低于20 mmol/L），在盲肠和结肠中较高。在大肠中，SCFA浓度从盲肠和近端结肠的100 - 140 mmol/L降至远端结肠的40 - 80 mmol/L。乙酸:丙酸比值从盲肠到远端结肠升高。对于仅以燕麦为基础的日粮（燕麦片；燕麦片+燕麦麸）来说，这种升高不太显著。（摘要截选至400字）
