Interpretive Summary: Fecal microbiota composition changes after a BW loss diet in Beagle dogs.
By: Surely Wallace
In an article published in August 2018 in the Journal of Animal Science, researchers analyzed the fecal microbiota of obese beagles before and after they lost weight while on a low fat, high fiber diet. Their aim was to better understand how microbial changes in the guts of dogs might be related to or affected by changes in body weight.
Obese companion animals can suffer from a variety of health ailments, which is also a problem in pet dogs. Since the gut microbiota is known to potentially influence factors that can contribute to increased body weight in humans and mice, such as satiety and energy extraction from food, the authors decided to characterize the gut microbiota of dogs.
Six healthy, but obese Beagles (3 male and 3 female, age 4 to 10 years), with an average starting body weight of 16 kg were used in this study. None of the animals had recently taken antibiotics, which could alter their gut microbiota population. The dogs were fed commercial dog food, housed indoors, and had daily access to an outdoor yard.
The experimental period lasted a total of 17 weeks. Two different diets were used in this study. The initial control diet was comprised of 15% fat, 29% starch, and 2% crude fiber (3909 kcal). The control diet was fed to all dogs for 8 weeks during an adaptation period. The weight loss diet (referred to as obesity diet) was comprised of 8% fat, 19% starch, and 10% crude fiber (2870 kcal). In addition, prebiotic fructooligosaccharides (FOS) and sugar beet pulp fiber was included in the fiber component of the obesity diet. All dogs were kept on the obesity diet for 17 weeks, or until they reached their ideal body weight. Weight loss for Beagles on the obesity diet was 1-2% of total body weight per week. A DEXA scan was used to determine body composition. Stool and blood samples were also collected before and after the weight loss period.
Results from the DEXA scan indicated that dogs lost body fat, but not bone or lean muscle mass. There were several quantifiable changes in the dogs after they lost weight while on the obesity diet. Notably, total serum cholesterol was reduced from baseline. Differences in gut microbiota were also noted, as follows: Clostridium, Lactobacillus, Dorea and Fusobacteria fecal bacteria populations significantly decreased, while Allobaculum significantly increased. Biodiversity also increased. Microbes also produced less enzymes associated with breaking down proteins.
In conclusion, this small study suggests that fecal bacteria changes do occur in obese Beagles on a weight loss diet. Due to the limited number of dogs in this study, and the multiple factors that might have affected fecal bacteria, it cannot be definitely concluded what specific part of the experiment led to the observed changes. It is possible that reduced caloric intake, weight loss, or the prebiotic and fiber component of the obesity diet affected fecal bacteria, separately or combined with other factors. Therefore, much larger studies looking at the potential factors that might affect fecal bacteria separately in obese dogs would help to clarify these questions.
To view the article, “Fecal microbiota composition changes after a BW loss diet in Beagle dogs,” visit the Journal of Animal Science.