Moreover, because of the strong scientific evidence in literature, we focused our attention to the analysis of the part that gut microbiota takes on in gastrointestinal malignancy development/promotion. The Part of Tumoral Microenvironment The major environmental factors responsible for induction of chronic inflammatory process and cancer genesis are represented by chronic infection (such as viral hepatitis for hepatocellular carcinoma development, infection to gastric cancer and mucosa associated lymphoid tissue development, schistosoma and bacteroides infection to bladder and colon cancer), toxic exposition (e.g., tobacco, chemical products and asbestos) as well as metabolic pathologies able to alter regulatory balance of swelling , , . immune system was first hypothesized by Rudolf Ludwig DW14800 Virchow in 1863, after leucocytes presence demonstration in neoplastic cells. This concept was taken up by a large number of studies on the topic, demonstrating a definite interconnection among swelling, oxidative stress, cytokine production, chemokines and tumoral growth, invasion and metastasis . The correlation between swelling and cancer is now very clear given the numerous scientific evidence especially in gastrointestinal tract malignancy . With this context, an inflammatory microenvironment is an essential assumption for the development of most of tumors. Indeed, only a small part of cancers is definitely correlated to germline mutation, whereas the majority is definitely the result of a assistance between environmental factors and genetic somatic mutations . The increase of metabolic pathologies, such as obesity and diabetes in the last years, has caused an increase of tumor incidence in this human population. These diseases are connected to a higher risk of developing cancer due to a direct cancerogenous effect, as well as an immune dysregulation able to promote chronic swelling and oxidative stress through antioxidant system depletion . Additionally, also advanced age and cell senescence are important factor as they are able to generate a higher predisposition to tumoral onset actually through a dysregulation of inflammatory cascade. These factors also make the immune response less efficient in fighting malignancy, allowing it to grow and metastasize . Moreover, growing scientific evidence offers demonstrated a possible part of gastrointestinal bacterial community in the rules of several inflammatory/immunitary processes involved in tumor initiation or progression. Gut microbiota represents the totality of bacteria, disease and fungi that are in our gastroenteric tract. It is a complex ecological system consisting of at least 500 different bacterial varieties. Its qualitative and quantitative composition is definitely deeply different depending on the regarded as gastroenteric tract. In the belly, a small number of bacteria have been found, mainly consisting of lactobacilli, streptococci, staphylococci, enterobacteriaceae and yeasts. In the subsequent gastrointestinal tracts, there is a quantitative increase from 0 to 105 colony-forming unit/g (CFU/g) in the DW14800 duodenum to 108 CFU/g in the ileum and 1010 CFU/g in the colon. In the colon more than 99% of the microorganisms are purely anaerobic, such as bifidobacteria, spp., spp., spp., spp., and peptostreptococci . It varies from one person to another and is revised by age, diet, type of birth, breastfeeding, ileocecal valve effectiveness, use of active medicines in both heartburn and gastrointestinal mobility , , , . In order to understand the connection ARHGEF11 between gut microbiota and malignancy, we have to bear in mind that some of the functions carried out by a eubiotic gut are resistance to intestinal colonization by pathogen bacteria able to cause dysbiosis, induction in IgA production and antimicrobial secretions, rules of structural entirety of limited junctions and, above all, rules of innate and adaptive immunity , , , . However, despite the growing interest concerning this field, today, a standardized protocol to study the relationship between gut microbiota and malignancy, especially in the interpretation of study results, does not exist. The strongest medical evidence concerning this relationship is present in relation to gastrointestinal tumors. With this review, we analyze, from a particular perspective, the different ways to induce swelling and oxidative stress in order to clarify the mechanisms underlying the development of several cancers. Moreover, because of the strong medical evidence in literature, we focused our attention to the analysis of the part that gut microbiota takes on in gastrointestinal malignancy development/promotion. The Part of Tumoral Microenvironment The major environmental factors responsible for induction of chronic inflammatory process and malignancy genesis are displayed by chronic infection (such as viral hepatitis for hepatocellular carcinoma development, illness to gastric malignancy and mucosa connected lymphoid tissue development, schistosoma and bacteroides illness to bladder and colon cancer), harmful exposition (e.g., tobacco, chemical products and asbestos) as well as metabolic pathologies able to alter regulatory balance of swelling , , . An important concept underlies the interconnection between swelling and malignancy: the DW14800 enduring swelling. It would not be the intensity of the inflammatory response but the maintenance of a low-grade and chronic swelling that determines the neoplastic transformation of eukaryotic cells or the induction of genotoxic damage . However, it is important to underline that not all chronic inflammations, although systemic, are able to promote carcinogenesis. The.