This study sounds more like a study done for dry dog food companies with a high content of grain in their formulas because BARF diet has caused great loses for these companies. Below you can read some findings on other studies about dog diets: (http://www.lhasa-apso.org/health/carnivorediet.html)
NO AMYLASE IN SALIVA. Amylase in saliva is something omnivorous and herbivorous animals possess, but not carnivorous animals like dogs or cats. As amylase is not present in saliva, the burden is entirely on the pancreas to produce the amylase needed to digest carbohydrates. Feeding dogs as though they were omnivores or herbivores makes the pancreas work harder in order to digest the carbohydrate-filled foods (instead of just producing normal amounts of the enzymes needed to digest proteins and fats).
CONCLUSIONS | CATS & DOGS ARE DESIGNED FOR AN ALMOST EXCLUSIVELY MEAT-BASED DIET