The digestive system is a long tube known as gastrointestinal tract (GI). The GI is divided into several parts with special characteristics in each of them originating different organs and structures, such as mouth, esophagus, stomach, and small and large intestines. Besides, there are also accessory glands associated with this system, such as liver, pancreas, and gallbladder. The main function of GI is digestion of food in order to convert it to simpler molecules, suitable to absorption, of this mode, providing the nutrients necessary for normal functionality of the body.

Unfortunately, there are several disorders that affect the gastrointestinal tract and a lot of them have a high prevalence worldwide and have been on the rise during the last few years. A significant proportion of people that suffer from those disorders are affected by inflammatory and ulcerative processes from the stomach or intestines. The main inflammatory and ulcerative disorders associated with the GI include the following: gastritis, ulcers, colitis, Crohn's disease, and mucositis. Those pathological conditions are difficult to be treated. Current approved treatment is inefficient or is associated with side effects.

Moreover, in GI, there are a huge number of microorganisms forming the microbiota that are of great importance to the normal functionality of gut. In last years, studies have shown a strong correlation between the gut microbiota and the brain chemistry and behavior. Alterations in gut microbiota can contribute to psychiatric disorders in patients with bowel problems. This is independent of the autonomic nervous system, gastrointestinal-specific neurotransmitters, or inflammation. Thus, it is believed that there is a microbiota gut-brain axis. Also, there is a link between gut microbiota and immune system. Of this mode, the microbiota is involved in several processes in organisms and its alteration is related to appearance of several diseases, for example, diarrhea, inflammatory bowel diseases, anxiety, depression, obesity, and autoimmune diseases. Therefore, the ingestion of probiotics can bring benefits in several pathological situations, such as the treatment of psychiatric and immune disorders including the inflammatory and ulcerative disorders of GI.

For this reason, there have been many preclinic or clinic studies during the last decade looking for investigating the potential application of herbal products in the treatment of these disorders when used as either complementary or alternative treatment, as well as the influence of these products on the gut microbiota. The results of such studies have emphasized the importance of herbal preparations for the development of new drugs to treat such disorders and their role in potentiating the efficacy of ongoing approved treatment.

Based on the above, we would like to invite authors to submit original and review articles.

Potential topics include but are not limited to the following:

• Studies at both the preclinic and clinic level concerning the potential role of plant extracts used in folk medicine to treat ulcerative and inflammatory disorders from gastrointestinal tract, such as gastritis, ulcers, colitis, Crohn’s disease, and mucositis
• Investigations concerning isolated compounds from natural sources to treat gastrointestinal tract disorders
• Effects of the gut microbiota on inflammatory and ulcerative disorders of GI and its influence on the SNC and immune system
• Safety of plant extracts or isolated active compounds to the GI