An altered microbiome in urban coyotes mediates relationships between anthropogenic diet and poor healthOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This study tested whether eating human food alters the coyote gut microbiome and harms health. It linked diet, fecal bacteria, and physical condition in wild urban and rural coyotes. Diet was measured from stomach contents and from stable isotopes in claw samples. Fecal bacteria were profiled by 16S ribosomal RNA gene sequencing of the V4 region. Body condition, spleen mass, and parasite infection were also recorded.
Who was studied?
The study used 95 coyote carcasses collected near Edmonton, Alberta, Canada. This included 30 urban coyotes from the city and 65 rural coyotes from surrounding areas. Animals were roadkill, trapper-collected, or lethally managed after conflicts. Each carcass underwent necropsy for body measurements, age by tooth cementum, diet, and fecal microbiome. This was a wildlife field study, not a controlled experiment.
What were the most important findings?
Urban coyotes consumed 2.5 times more anthropogenic food and 25 percent less prey than rural coyotes. They had half as much kidney fat, spleens 37 percent larger, and 50 percent higher prevalence of the zoonotic parasite Echinococcus multilocularis. Urban microbiomes had higher Shannon and phylogenetic diversity, with more Streptococcus and Enterococcus. Rural microbiomes were richer in Fusobacteria, Sutterella, and Anaerobiospirillum. Random forest models discriminated location with 86 percent accuracy. Erysipelotrichaceae, Lachnospiraceae, and Coriobacteriaceae correlated with larger spleens in urban coyotes.
What are the greatest implications of this study?
The findings suggest a carbohydrate-rich human diet reshapes a naturally carnivorous microbiome and worsens coyote health. Increased diversity and lactic acid bacteria appear harmful in this carnivore context, opposite to their role in omnivores. The authors propose these bacteria feed a vicious cycle of poor diet, poor condition, and disease. Because the study is observational, it identifies associations rather than proven causes. Specific taxa could still serve as non-invasive scat-based indicators of coyote health.