Purpose of Review Cancers are a leading cause of death in humans and for many other species. Diet has often been associated with cancers, and the microbiome is an essential mediator between diet and cancers. Here, we review the work on cancer and the microbiome across species to search for broad patterns of susceptibility associated with different microbial species. Recent Findings Some microbes, such as Helicobacter bacteria, papillomaviruses, and the carnivore-associated Fusobacteria, consistently induce tumorigenesis in humans and other species. Other microbes, such as the milk-associated Lactobacillus, consistently inhibit tumorigenesis in humans and other species. Summary We systematically reviewed over a thousand published articles and identified links between diet, microbes, and cancers in several species of mammals, birds, and flies. Future work should examine a larger variety of host species to discover new model organisms for human preclinical trials, to better understand the observed variance in cancer prevalence across species, and to discover which microbes and diets are associated with cancers across species. Ultimately, this could help identify microbial and dietary interventions to diagnose, prevent, and treat cancers in humans as well as other animals.

Cancers are a leading cause of death in humans and for many other species. Diet has often been associated with cancers, and the microbiome is an essential mediator between diet and cancers. Here we review the work on cancer and the microbiome across species. We systematically reviewed over a thousand published articles and identified links between diet, microbes and cancers in several species of mammals, birds, and flies. Some microbes, specifically Fusobacteria, Bacteroides fragilis, Helicobacter bacteria, and papillomaviruses, have cancer-inducing effects in gerbils, mice, dogs, or cats. Other microbes, such as Lactobacillus species, mostly found in milk products, prevent gastrointestinal, breast, and lung cancers in mice and rats. Future work should examine a larger variety of host species to discover new model organisms for human preclinical trials, better understand the observed variance in cancer prevalence across species, and discover which microbes and diets are associated with cancers across species. Ultimately this could help identify microbial and dietary interventions to diagnose, prevent and treat cancers in humans as well as other animals.

Did you know that food, microbes, and cancer are often linked together? These links are well-studied in humans, but not as well-studied in other species. We wanted to find out whether specific foods and/or microbes are linked with cancer across non-human species. So, we searched over a thousand articles reporting links between diet, microbes, and cancer. We found that some microbes, such as Helicobacter, papillomaviruses, and Fusobacteria which are often found in carnivores, can promote tumor development in people as well as in other animals. Other microbes, such as the Lactobacillus found in milk products, can decrease tumor development in people and other animals. There is lots more to learn about these patterns across hundreds of species. Ultimately, these results have great potential to help researchers understand the variation in cancer risk across animals, and to help doctors and vets improve the early detection and treatment of cancer.