Recently, the significance of the intestinal bacterial community known as the microbiome on the host’s health has become increasingly clear. Food digestion is mutually dependent on the host and the microbiome. During the digestive process, substances from food are metabolized by the host and the microbiome and either absorbed or excreted. Excreted substances are collectively known as the fecal metabolome. Signs of chronic gastrointestinal disease (CE) are very common in elderly cats and often caused by chronic inflammation (IBD) or cancer (LGAL). Diagnosis can be challenging and requires the collection of tissue samples under anesthesia. However, these patients are frequently not ideal anesthetic candidates. Therefore, a non-invasive diagnostic test using fecal material would be highly desirable. They hypothesize that the microbiome and metabolome in healthy cats and cats with IBD and LGAL differs and that a panel of different combined biomarkers from feces has the same or better diagnostic value as the currently used invasive tests.