We now know that the gut microbiota can affect dogs the same way it does to humans. Does that mean that domesticated dogs have similar physiological and dietary characteristics to humans? And do they share some of their pathologies?
Dogs share several similarities with humans: they are both warm-blooded mammals and both have a monogastric digestive system containing a stomach, a small intestine, and a large intestine. We see, however, many physiological and dietary differences between them. For example, dogs have a higher body temperature than humans (ranging approximately from 38 to 39˚C), a different intestinal pH, and a shorter length of the digestive tract; all of which affect the digestive system’s enzyme activity and mechanics. Another significant difference between the two species is the morphology of their mouth: dogs have larger molars, helping them adapt to their diet. Compared to humans, they can use bones and chew less, due to their digestive tract and ancestral hunting and feeding behavior. They are obliged to rapidly absorb a maximum number of calories in the face of the risk of a potential predator
Despite our differences, the co-evolution of dogs alongside humans led to the development of multiple pathologies in dogs that are typically found in humans – some of which can even be transmitted across species. Dogs can suffer from conditions such as chronic enteropathies, allergies and skin disease.
The Lesaffre Institute of Science & Technology (LIST) has developed its expertise in canine digestive tract simulators. What are the types of these simulators and why do you use them?
Many models were built to simulate the digestive system in vitro but we focus mainly on two: the functional gastrointestinal dog model or FIDO TIM-1 of InnoGI Technologies and the Simulator of the Canine Intestinal Microbial Ecosystem or SCIME of ProDigest. FIDO TIM-1 is a dynamic upper digestive tract simulator containing compartments simulating the stomach, duodenum, jejunum and ileum and their respective temperatures, pH, and secretions1. SCIME, on the other hand, is a dynamic simulator of the entire digestive system with a more simplified version of the upper digestive tract, but a higher focus on the large intestines and its components, and the possibility to introduce a dog’s gut microbiota into it2.
We use these models as a first step or alternatives to in vivo studies. This allows us to better understand the mechanisms of digestion in dogs while respecting the principles of animal welfare in scientific research – the 3Rs: Reduce, Refine and Replace. Additionally, these models allow for an easier and non-invasive study of dogs’ digestive system and help us test different nutritional products without requiring invasive or complex procedures.
What were the main challenges in validating the FIDO TIM-1 and SCIME test protocols?
Some of the challenges in using these systems are purely technical and require many optimization steps. For example, it is important to choose the correct type of food and size of kibbles to use safely without blocking the tubes and pumps of the system. We should also consider the limitations of every model as we analyze the results and draw our conclusions.
In the case of FIDO TIM-1, the main limitation is the absence of a host, thus the absence of a host-microbe interaction. When our experiments focus on the upper digestive tract, FIDO TIM-1 can satisfactory; however, when our research question evolves around the microbiota, a complementary approach like SCIME is needed to draw a more comprehensive conclusion without in vivo experimentation.
Phileo by Lesaffre offers many solutions to improve dog gut health. Have you conducted trials on these products using canine gastrointestinal simulators?
Actisaf® Sc50 PET, a yeast probiotic – named Saccharomyces cerevisiae – is an innovative solution offered by Phileo that we are currently testing on our canine gastrointestinal simulators. Actisaf® Sc50 PET is a natural and safe probiotic that has a direct role in the improvement of digestive health in dogs by modulating their gut microbiota and decreasing potential pathogens like Escherichia coli3. In our current research, we are using both FIDO TIM-1 and SCIME systems to better understand the mode of action of Actisaf® Sc50 PET and the survival capacity of the probiotics during digestion. We can happily say that our recent results confirmed a high survival of Actisaf® Sc50 PET yeasts throughout the digestive tract in the FIDO TIM1 system, and an increase in microbial activity in the SCIME system. This is an additional advantage to the already proven stability in the diet to get to the right amount of CFU from the bag to the target site i.e. in the gut to convey the expected benefits!
Can sharing the home environment and the owner’s lifestyle influence the dog’s microbiota?
Yes, it can! The microbiota composition is closely related to the behavior and environment the host lives in. For example, a person living in France has a different microbiota composition as someone living in China. It is the same for dogs: their microbiota is directly influenced by their environment, their food and even their owner’s lifestyle. While the dog’s microbiota is not identical to its owner’s, the microbial patterns and compositions can become similar over time as they share the same environment.
Sources :
- Smeets-Peeters MJE, Minekus M, Havenaar R, Schaafsma G, Verstegen MWA. Description of a Dynamic In Vitro Model of the Dog Gastrointestinal Tract and an Evaluation of Various Transit Times for Protein and Calcium. Alternatives to Laboratory Animals. 1999;27(6):935-949. doi:10.1177/026119299902700608
- Duysburgh C, Ossieur WP, De Paepe K, Van den Abbeele P, Vichez-Vargas R, Vital M, Pieper DH, Van de Wiele T, Hesta M, Possemiers S, Marzorati M. Development and validation of the Simulator of the Canine Intestinal Microbial Ecosystem (SCIME)1. J Anim Sci. 2020 Jan 1;98(1):skz357. doi: 10.1093/jas/skz357.
- Bastos TS, Souza CMM, Legendre H, Richard N, Pilla R, Suchodolski JS, de Oliveira SG, Lesaux AA, Félix AP. Effect of Yeast Saccharomyces cerevisiae as a Probiotic on Diet Digestibility, Fermentative Metabolites, and Composition and Functional Potential of the Fecal Microbiota of Dogs Submitted to an Abrupt Dietary Change. Microorganisms. 2023; 11(2):506. https://doi.org/10.3390/microorganisms11020506