How does dietary particle size affect carnivore gastrointestinal transit: A dog model

Area of Science:

• Veterinary Science
• Animal Physiology
• Digestive Physiology

Background:

• Gastrointestinal (GI) transit in carnivores is not well understood.
• Dietary particle size is a potential factor influencing GI physiology.

Purpose of the Study:

• To investigate the effect of dietary particle size on GI transit in dogs.
• To compare transit parameters using a wireless motility capsule and titanium dioxide (TiO2).

Main Methods:

• Six beagle dogs were fed two diets of differing particle sizes (fine vs. coarse) in a crossover design.
• Transit parameters were assessed using a wireless motility capsule (IntelliCap®) and TiO2.
• Gastric emptying time (GRT), small bowel transit time (SBTT), colonic transit time (CTT), and total transit time (aTTT) were measured.

Main Results:

• Dietary particle size did not significantly affect capsule transit times (GRT, SBTT, CTT, aTTT) or TiO2 mean retention time (MRT).
• The time of last TiO2 excretion (MaxRT) was significantly later for the coarse diet.
• Both MRT and MaxRT correlated positively with aTTT, and the MRT/aTTT ratio tended towards higher values for the coarse diet.

Conclusions:

• Dietary particle size may influence GI transit in dogs, but the effects are likely not physiologically significant.
• The wireless motility capsule's accuracy may be influenced by the relationship between particle size and marker size.