The digestive system has an explicit role in decomposing nutrients into
energy and other necessary substances required by the body. The gastrointestinal tract
contains a complex set of different microorganisms. It is considered the most dynamic
and active organ in the body from a biological perspective. The environmental
condition and daily diet are principal parameters that significantly influence the
composition of gut microbiota. From birth to middle age, it undergoes significant
changes. Several factors, such as maternal microbiota, birth status (natural, cesarean
section), postpartum nutrition practices, microbial infections, overuse of antibiotics,
diet (highly processed, low fiber), chronic diarrhea, and stress in life, have a significant
effect on the gut microbiome. All of these factors lead to impaired bowel function and
health. One of the most important strategies for overcoming dysbiosis conditions and
establishing eubiosis conditions is the employment of foods containing probiotic,
prebiotic, and postbiotic ingredients. Hence, this chapter provides a review of the
concept and health-promoting issues regarding probiotics and prebiotics, with a focus
on their biological role in the establishment of health.
Keywords: Dysbiosis, Eubiosis, Functional food, Gastrointestinal tract, Gutmicrobiota, Health, Postbiotic, Prebiotic, Probiotic.