Significance of Intestinal Microflora in Herbivory
Significance of Intestinal Microflora in Herbivory
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肠道菌群在草食动物中的意义
DOI：
10.1146/annurev.es.02.110171.001121
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发表时间：
1971
期刊：
影响因子：
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通讯作者：
R. H. McBee
中科院分区：
文献类型：
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作者：
R. H. McBee
在几乎所有的食草动物中，消化道的一个或多个部分被扩张形成一个器官，该器官容纳在消化食物中有价值的微生物群体，而动物没有必要的酶补充。动物通常利用在那里合成的维生素和蛋白质，并可能通过将尿素分泌到器官内容物中来增强蛋白质合成。微生物发酵产物从器官中吸收并被食草动物代谢。一般来说，最成功的大型食草动物，那些体重超过5公斤，有一个瘤胃或一些类似的修改前胃，发酵发生（莫尔51）。发酵性前胃不仅存在于反刍动物中，而且也存在于袋鼠、鲸鱼、儒艮、河马、树懒和冷猴中。较小的食草动物如啮齿动物通常具有较大的盲肠，尽管它们也可能具有许多适应微生物发酵的胃结构（Vorontsov 76）。其他发酵可能发生在小肠，盲肠发酵可能继续进入大肠或结肠（McBee 48）。盲肠是一个盲囊，位于小肠和大肠的交界处，是阑尾产生的器官，如果有阑尾的话。哺乳动物通常有一个盲肠，鸡类鸟类有两个，鱼类可能有几个。在盲肠以下，肠道可能有进一步的变化，以促进持续的发酵或吸收。马的盲肠容量为25-30升，可排入容量为55-70升的更大的大结肠（Sisson & Grossman 67）。蹄兔有一个比盲肠更大的第二个类似盲肠的结构。这个巨大的双角器官是大肠的一部分（Grasse 28）。
In nearly all herbivorous animals one or more parts of the alimentary tract are expanded to form an organ which accommodates a microbial population valuable in the digestion of foods for which the animals do not have the necessary complement of enzymes. The animals usually utilize the vitamins and proteins synthesized there and may enhance the protein synthesis by secretion of urea into the organ contents. Microbial fermentation products are absorbed from the organ and metabolized by the herbivores. Generally the most successful large herbivores, those over 5 kg body weight, have a rumen or some similarly modified forestomach in which fermentation occurs (Moir 51). Fermentative forestomachs are found not only in ruminants, in which their presence is well known, but also in kangaroos, whales, dugongs, hippopotamus, sloths, and colobid monkeys. Smaller herbivores such as rodents are usually endowed with a large cecum, although they may also have a number of stomach modifications accommodating microbial fermentations (Vorontsov 76). Other fermentations may occur in the small intestine, and cecal fermentations may continue into the large intestine or colon (McBee 48). The cecum is a blind pouch occurring at the juncture of the small and large intestines and is the organ from which the appendix arises, if there is one. Mammals generally have a single cecum, gallinaceous birds two, and fish may have several. Below the cecum there may be further modifications of the intestinal tract to facilitate either continued fermentation or absorption. The horse has a cecum containing 25-30 liters which empties into an even larger great colon with a capacity of 55-70 liters (Sisson & Grossman 67). The hyrax has a second cecal-like structure larger than the cecum. This large twohorned organ is part of the large intestine (Grasse 28).