Small Animals Gut Microbiome and Its Relationship with Cancer

Abstract

This chapter aims to discuss recent developments in understanding the small animal gut microbiome’s relationship with cancer, focusing on animals as well as a model for studying humans. Based on multidirectional interactions between the microbiome, the environment and the epigenetically/genetically vulnerable host, it intends to address the mechanisms by which microorganisms can contribute to carcinogenesis describing the roles of the microbiome directly in the pathogenesis of the disease through complex interactions between the microbiome and the host’s metabolic and immune systems. The feasibility for developing new cancer diagnostic and prognostic methodologies plus treatments based on small animals’ microbiome profiles are reviewed.

Fecal microbiome in dogs with lymphoid and nonlymphoid tumors

“…Coprococcus and Saccharimonas are beneficial bacteria that induce anti‐inflammatory effects by producing butyric acid in humans and dogs. 23 , 24 Serum albumin and sodium concentrations also tend to reduce as they are lost to the gastrointestinal tract when there is a systemic disease including inflammation or tumor, and albumin is also a negative acute phase protein. The results that total WBC counts were significantly higher and hematocrit was lower in the aggressive tumor group are associated with PNS.…”

“…In all tumors group, Saccharimonas abundance strongly correlated with the serum albumin concentration, sodium concentration, and creatinine concentration. Coprococcus and Saccharimonas are beneficial bacteria that induce anti-inflammatory effects by producing butyric acid in humans and dogs 23,24. Serum albumin and sodium concentrations also tend to reduce as they are lost to the gastrointestinal tract when there is a systemic disease including inflammation or tumor, and albumin is also a negative acute phase protein.…”

The animal's microbiome and cancer: A translational perspective

“…Many of these mechanisms can injure the host indirectly, as microbes optimizes the environment for their subsistence may result in a last common pathway of prolonged host cell survival, increased replicative capacity and differentiation. These processes converge to hallmarks of cancer 72 …”

“…These processes converge to hallmarks of cancer. 72 The gut mucosa consists of an epithelial cell layer with intraepithelial lymphocytes that are the interface with the immune system.…”

“…Changes in microbiota produce metabolites that can result in host phenotype variations; metabolic reprogramming is a crucial feature of cancer, allowing cells to generate more energy and macromolecules for cancer cell proliferation and division. 72 Cancer cells mostly produce energy by glycolysis rather than oxidative phosphorylation through the tricarboxylic acid cycle, a process called Warburg effect, even in the presence of a sufficient oxygen source. Otto Warburg proposed that cancer cells turn for aerobic glycolysis, with an increased glycolytic flux and decreased mitochondrial oxidation that holds the proliferative ability of cancer cells.…”