Insights into the Two Most Common Cancers of Primitive Gut-Derived Structures and Their Microbial Connections.

The gastrointestinal and respiratory systems are closely linked in different ways, including from the embryological, anatomical, cellular, and physiological angles. The highest number (and various types) of microorganisms live in the large intestine/colon, and constitute the normal microbiota in healthy people. Adverse alterations of the microbiota or dysbiosis can lead to chronic inflammation. If this detrimental condition persists, a sequence of pathological events can occur, such as inflammatory bowel disease, dysplasia or premalignant changes, and finally, cancer. One of the most commonly identified bacteria in both inflammatory bowel disease and colon cancer is . On the other hand, patients with inflammatory bowel disease are at risk of several other diseases-both intestinal (such as malnutrition and intestinal obstruction, besides cancer) and extraintestinal (such as arthritis, bronchiectasis, and cancer risk). Cancers of the lung and colon are the two most common malignancies occurring worldwide (except for female breast cancer). Like the bacterial role in colon cancer, many studies have shown a link between chronic infection and lung cancer. However, in colon cancer, genotoxic colibactin-producing belonging to the B2 phylogroup may promote tumorigenesis. Furthermore, is believed to play an important role in the dissemination of cancer cells from the primary colonic site. Currently, seven enteric pathogenic subtypes have been described. Conversely, three can cause infections in humans ( may increase the risk of cervical and ovarian cancers). Nonetheless, striking genomic plasticity and genetic modifications allow to constantly adjust to the surrounding environment. Consequently, becomes resistant to antibiotics and difficult to manage. To solve this problem, scientists are thinking of utilizing suitable lytic bacteriophages (viruses that infect and kill bacteria). Several bacteriophages of and species are being evaluated for this purpose.