**Abstract**

Inflammatory bowel diseases (IBDs) represent a category of diseases characterized by intestinal inflammation and include two main entities, ulcerative colitis and Crohn's disease, one of the representative clinical characteristics of which being chronic diarrhea. The etiology of these diseases is multifactorial, combining genetic, immunological, and also environmental factors, along with gut dysbiosis. In recent years, we encountered a higher incidence of IBD cases and of severe forms of disease. Therefore, there is an urgent need to develop new and efficient treatments, including strategies to improve the microbiome. In this chapter, we will discuss the current knowledge about the impact of different therapies influencing gut microbiota, such as prebiotics, probiotics, synbiotics, and other agents in IBD prevention, and also in the induction/ maintenance of IBD remission. The manuscript will focus also on potential areas for research in the future using agents that modify intestinal microbiota and combined strategies.

**Keywords:** chronic diarrhea, inflammatory bowel diseases, microbiota, prebiotics, probiotics, synbiotics
