Probiotics are such edible preparations which contain useful active bacteria, like Lactobacillus, Acidophilus, Lactobacillus casei, Bifidobacterium bifidum, etc. There are various reasons for which probiotics are being promoted nowadays. These bacteria are beneficial for the intestine as they help in the process of metabolism. They are usually given when a person is suffering from diarrhoea or is under antibiotic treatment. Antibiotics kill both beneficial and harmful bacteria present in our body, thus affecting the metabolic process. These probiotics form the colonies of useful microbes in alimentary canal and thus aid in the digestion process.