~ 192 ~ Journal of Entomology and Zoology Studies 2020; 8(4): 192-197 E-ISSN: 2320-7078 P-ISSN: 2349-6800 www.entomoljournal.com JEZS 2020; 8(4): 192-197 © 2020 JEZS Received: 07-05-2020 Accepted: 11-06-2020 Harshit Verma Assistant Professor, Department of Vet. Microbiology, COVAS, SVPUAT, Meerut, Uttar Pradesh, India Gulab Chandra Assistant Professor, Department of Vet. Physiology & Biochemistry, COVAS, SVPUAT, Meerut, Uttar Pradesh, India Vikas Jaiswal Assistant Professor, Department of Vet. Pathology, COVAS, SVPUAT, Meerut, Uttar Pradesh, India PS Maurya Assistant Professor, Department of Vet. Parasitology, COVAS, SVPUAT, Meerut, Uttar Pradesh, India Shivani Sahu Assistant Professor, Department of Vet. Parasitology, COVAS, SVPUAT, Meerut, Uttar Pradesh, India Corresponding Author: Vikas Jaiswal Assistant Professor, Department of Vet. Pathology, COVAS, SVPUAT, Meerut, Uttar Pradesh, India A comprehensive report on poultry intestinal microbiota Harshit Verma, Gulab Chandra, Vikas Jaiswal, PS Maurya and Shivani Sahu Abstract Productive performance of poultry depends on a complex interaction between host factors, environmental factors and gut microbiota. Gut microbiota residing in the gastrointestinal tract of chickens plays an important role in gut homeostasis and affects the animal's health & physiology. The composition of gut microbiota depends on several factors. Alteration in the microbial community can be detrimental to host on one hand but on another hand can be utilized profitably, so it should be monitored carefully. Though it is difficult to evaluate entire microbial community but newer techniques like targeted amplicon sequencing and metagenomics make it possible up to a large extent. In future, these techniques along with other biomarkers can be used to find out the peculiar gut microbial signature concerning particular factor or diseased condition. The present review is about the structure, alteration pattern and evaluation of gut microbiota. Keywords: Gut microbiota, poultry, dysbiosis and gut health 1. Introduction The growth of the global human population is increasing day by day and estimated to be 9.7 billion by 2050 [1] . To feed such a huge population with quality food is a big challenge. Current agricultural production is already in peak and there is shrinkage/reduction of cultivable land day by day. So there is increase pressure on the livestock population to increase productivity in a profitable manner. Poultry represents one of the most efficient ways to convert food into biomass. It gains 3.48 kg body weight on the consumption of 6.37 kg of feed in just 49 days [2] . Feed consist of 70% of the total production cost of poultry [3] . The present breed has been evolved as a result of years of intensive genetic selection done by geneticists in such a way to reduce feed conversion ratio at a minimum level. So in order to increase daily weight gain, there is very high feed intake which puts pressure on the gastrointestinal tract even in the absence of pathogenic organisms [4] . The microbial population residing in the gastrointestinal tract of chickens is essential for the gut homeostasis, host metabolism and affect the animal's health & physiology. They play an important role in the digestion of food, toxin neutralization, influence organ development, endocrine activity, pathogen control, interact with the gut-associated immune system and cause immune stimulation [5, 6, 7] . The microbiota is defined as the microbial community, including commensal, symbiotic and pathogenic microorganisms, which usually colonize an area of human and animal organisms, and are around two times more plentiful than somatic and germinal cells of the host [8] . 2. Normal microbiota of poultry gastrointestinal tract Gut flora, or gut microbiota, or gastrointestinal microbiota, is the complex community of microorganisms that resides in the digestive tracts of poultry and other animals. The total number of bacteria in the gastrointestinal tract is higher than the number of eukaryotic cells of the host body [9] . As food moves from anterior to posterior part of gastrointestinal tract different group of microbial communities residing start digesting the food. Broadly chicken GIT divided into three category viz anterior part, small intestine and large intestine. The microbiota in different part of gastrointestinal tract serves different function and the community composition also vary to a large extant so it is studied as separate ecosystem [10] . Though these entire segments contain different diversified microbiota but they influence the microbial community of each other [11] . The microbial colonization and the type of microbiota present in specific segment depend on gastrointestinal microenvironment e.g. type of nutrient