Microflora of Digestive Tract in Poultry

The gut flora are microorganisms that normally live in digestive tract and can do a number of benefit functions for their host health and growth. The unicellular microorganisms are bacteria (predominant), fungi and protozoans. The intestine divided into three parts: the duodenum and small intestine where the number of bacteria relatively low, <108 g(-1), the caeca where the microbial fermentation occurs and the number of bacteria present is approximately 1011 g(-1) (wet weight) and the large intestine which in most bird is relatively short and is a posterior extension of the small intestine beginning at the level of the caeca and opening into the cloaca. In chicken, bacterial activities are mainly found in crop, caeca and, to lesser extent, the small intestine. The pH and transit time of different section of chicken allow establishment of specific microbial population in chicken. The composition of microorganisms in the gut is not stable over time and not homogeneous among species, individuals, and different parts of the intestine. Development of the gut microflora is dynamic, and is influenced by parents, environment and age. In poultry, the gut microbial community composition changes greatly within the first 2-3 weeks of age before stabilizing until 5-6 weeks of age, when a final change in community composition was observed. In this review, several factors affecting intestinal microflora, members of intestinal bacteria in poultry, roles of Lactobacilli in intestinal microflora were discussed.