Gut microbiota in mammals Term Paper Example | Topics and Well Written Essays - 2000 words

Gut microbiota in mammals - Term Paper Example The anatomy of the gut is designed to perform efficiently both of these functions. To enable nutrient uptake, many associated digestive glands and multiple folding of the inner lining ensure thorough digestion and rapid assimilation of the nutrients. The gut associated lymphoid tissue on the other hand ensures that the internal environment of gut remains devoid of harmful foreign antigens. Besides these an important component of the gut is the gut microbiota, which together with the host form a composite body. So intimately is the existence of the two entwined, that the microbial community is collectively considered an organ of the host body; and the mammalian genome is referred to as metagenome, i.e. host genome along with the genome of its microbial community (Ley et al., 1647). The number and diversity of microbes residing indigenously in the gut environment is massive comprising of bacteria, protozoans, anaerobic phycomycetes and bacteriophages. Not only are they an integral part of the gut ecosystem, but they also contribute indispensably to the nutritional, physiological and immunological functions of the gut (Mackie, 13). Though the exact composition of the gut microbiota of different animals cannot be listed with certainty, yet the variations observed are primarily due to the differences in the diet of different animals. ... this, a study of gut microbiology would proceed in three parallel lines, for three classes of microbial consortia; one for each of these gut environments. This paper aims to discuss the functional significance of the microbial population in the gut of herbivores, omnivores and carnivores. Figure 1 Mammalian Gut Figure 2: Mammalian Gut Lining II. Role of Gut Microbiota in Herbivores: Herbivores derive their nutrition from plant components; hence it is imperative to possess the ability to digest plant cell wall. However, the cellulose component of plant cell wall makes it difficult to disintegrate. Herbivores therefore, during the course of evolution have acquired adaptations that enable them to disintegrate and assimilate this otherwise indigestible material (Karasov and Carey, 364). The herbivore mammalian foregut or hindgut is divided into chambers where fermentation of the food intake is carried out with help of microbial inhabitants of the gut. These chambers are known as rumen an d the animals as ruminants. Due to exclusively plant based diet of herbivore, the role of gut microbe in herbivore gut assumes immense significance, the gut microbiota being imperative for digestion process in herbivores. This justifies an exclusive discussion of ruminant gut microbiota. Evolution of gut microbiota: Evolution of the digestive system of mammals to enable utilization of complex plant material proceeds parallel with the evolution of their gut microbiota. The ubiquitous microbes on one hand were easily able to colonize the mammals in general, but further evolutionary pattern was dependent on the diet of the host they inhabited. Thus the microbial population of the mammalian host coevolved with the evolving host digestive system. In herbivores as the gut became longer and