Review Article Dig Dis 2020;38:128–136 From Regular Catharsis with Castor Oil to Recognizing the Importance of the Intestinal Microbiota Carlo Romano Settanni a Gianluca Ianiro a Francesco Franceschi b Giovanni Gasbarrini a Antonio Gasbarrini a a Digestive Disease Centre, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Catholic University of Sacred Heart, Rome, Italy; b Department of Emergency, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Catholic University of the Sacred Heart, Rome, Italy Received: December 7, 2019 Accepted: December 12, 2019 Published online: January 6, 2020 Prof. Antonio Gasbarrini Digestive Disease Centre, Fondazione Policlinico Universitario Agostino Gemelli IRCCS Catholic University of Sacred Heart Largo Agostino Gemelli 8, IT–00168 Rome (Italy) E-Mail antonio.gasbarrini @unicatt.it © 2020 S. Karger AG, Basel E-Mail karger@karger.com www.karger.com/ddi DOI: 10.1159/000505395 Keywords Microbiota · Dysbiosis · Probiotic · Prebiotic · Fecal microbiota transplantation Abstract The need to shed light on the unknown aspects of patho- physiology of common disorders, such as gastrointestinal ones, has led researchers through last decades to study and define the role of microorganisms within the human intes- tine and their interactions with the host. The progress of technology has permitted the overcoming of culture-based methods to study microbes and paved the way to molecular techniques, which allow the analysis of microbial genome, microbial functions, and metabolism. These progresses opened a window on the world of microbiology and permit- ted to deepen into the key role played by gut microbiota and dysbiosis in health status and diseases, both gastrointestinal and extraintestinal. So, scientists focused their attention in developing new strategies to restore eubiosis and to manip- ulate gut microbes by modifying dietary habits, administrat- ing antibiotics, probiotics, and prebiotics and using fecal mi- crobiota transplantation as treatment of gastrointestinal, in- fectious, cardiovascular, metabolic, immune-mediated, neuro-psychiatric, and oncological disorders. The next chal- lenges will be to elaborate standard protocols with definite outcomes predictors in disease-specific settings. © 2020 S. Karger AG, Basel Introduction Gastrointestinal disorders have always had a very high prevalence in the world population and still today people frequently ask for a gastroenterological consultation be- cause of them [1, 2]. As many other common disorders, they often tend to become chronic, symptoms relapse de- spite therapies, and the patients’ quality of life and work productivity are significantly impaired [3–5]. The most usual are functional disorders, like irritable bowel syn- drome (IBS) and functional dyspepsia, though the last de- cades have seen a rise of inflammatory bowel diseases (IBD), characterized by chronic inflammation of the in- testine [5–7]. The burden of health care management re- lated to these conditions is considerable as, in most cases, treatments contemplate a multidisciplinary approach, not only due to the complexity of the therapies but also because of the need to support the patients’ global health,