author(s)
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.