Roland N, Nugon-Baudon L, Andrieux C, Szylit O
Institut National de la Recherche Agronomique, Unité d'Ecologie et Physiologie du Système Digestif, Jouy-en-Josas, France.
Br J Nutr. 1995 Aug;74(2):239-49. doi: 10.1079/bjn19950127.
It is known that the physico-chemical characteristics of fibre modify their fermentation characteristics in the colon. Previously we showed the varying effects of inulin and different types of fibre on the hepatic and intestinal xenobiotic-metabolizing enzymes (XME) in initially germ-free rats inoculated with a human, methanogenic, whole-faecal flora (Roland et al. 1994). The aim of the present work was to assess whether or not these effects could be related to differences in production of fermentation metabolites (gases excreted in vivo and caecal metabolites) due to the different compositions of fibre. The different types of fibres were analysed with regard to their solubility and their composition of neutral monomers and uronic acids. Inulin was totally soluble, carrot (Daucus carota), cocoa (Theobroma cacao) and wheat bran were partially soluble; pea (Pisum sativum) and oat were nearly totally insoluble. Uronic acids were found mostly in carrot and cocoa fibre. Glucose was present as the main neutral monomer in each fibre type. Xylose was found also in wheat bran, pea and oat fibres, and arabinose was found in wheat bran. Inulin consumption led to high levels of H2 production but no CH4 production, to a 4-fold greater caecal concentration of butyrate than with the other fibres and to a decrease in caecal pH. Conversely, rats fed on carrot or cocoa fibre produced a large amount of CH4 but no H2 and generated a different profile of short-chain fatty acids (SCFA). The lowest amounts of gases and SCFA were found in rats fed on wheat bran, pea and oat fibre. We observed a relationship between the caecal concentration of SCFA and the activity of hepatic glutathione-S-transferase (EC 2.5.1.18) but no direct link was shown between the other XME and the fermentation profile.
众所周知，纤维的物理化学特性会改变其在结肠中的发酵特性。此前我们曾表明，菊粉和不同类型的纤维对最初无菌、接种了人类产甲烷全粪便菌群的大鼠肝脏和肠道的外源性物质代谢酶（XME）有不同影响（罗兰等人，1994年）。本研究的目的是评估这些影响是否可能与由于纤维组成不同而导致的发酵代谢产物（体内排出的气体和盲肠代谢产物）产生差异有关。对不同类型的纤维进行了溶解性分析以及中性单体和糖醛酸组成分析。菊粉完全可溶，胡萝卜（胡萝卜属）、可可（可可属）和麦麸部分可溶；豌豆（豌豆属）和燕麦几乎完全不溶。糖醛酸主要存在于胡萝卜和可可纤维中。葡萄糖是每种纤维类型中的主要中性单体。食用菊粉会导致大量氢气产生但无甲烷产生，盲肠中丁酸盐浓度比其他纤维高4倍，且盲肠pH值降低。相反，以胡萝卜或可可纤维为食的大鼠产生大量甲烷但无氢气，并产生不同的短链脂肪酸（SCFA）谱。以麦麸、豌豆和燕麦纤维为食的大鼠产生的气体和SCFA量最低。我们观察到盲肠中SCFA浓度与肝脏谷胱甘肽-S-转移酶（EC 2.5.1.18）活性之间存在关联，但未发现其他XME与发酵谱之间有直接联系。
