**Abstract**

Functional foods are responsible for the improvement of human health and can significantly reduce the probability of disease in the host body. Functional foods are directly or indirectly part of different food ingredients and can induce functional activities in the host biological system. Functional foods are present in fruits, vegetables, dairy, bakery, cereals and meat products. Functional foods are not additional food supplements, drugs or antibiotics, they are the main component of a normal human and animal diet. Functional foods are cost-effective and easily available in the market. Daily consumption of functional foods can prevent the gastrointestinal diseases and also provide ease against different acute and chronic diseases. Adequate administration of probiotics in a human food can convert a normal food into functional food. This chapter will highlight the effective role of functional food in an individual's daily life.

**Keywords:** functional food, GI health, probiotic, microflora
