Fecal Microbial Communities of Overweight and Obese Client-Owned Dogs Fed Cooked Bean Powders as Assessed by 454-Pyrosequencing

Alison N Beloshapka, Genevi

Abstract

Dry beans are consumed around the world and contain a multitude of health benefits, some of which may be related to the gut microbiome. The objective of this study was to evaluate the effects of feeding a 25% cooked Navy Bean (NB) or Black Bean (BB) powder on the fecal microbiota of overweight and obese companion dogs undergoing calorically restricted weight loss, compared to dogs fed an iso-nutrient control diet using 454 pyrosequencing. A double-blinded, placebo-controlled, three-arm clinical trial was conducted. Thirty client-owned, clinically healthy, overweight or obese, adult, male and female dogs of diverse breeds were randomized to one of the three isocaloric, nutritionally complete weight loss diets containing either 0% bean powder (placebo-control); 25% cooked BB powder; or 25% cooked NB powder and calorically restricted to achieve weight loss of up to 2% body weight/wk. for 4 wks. Fresh fecal samples were collected from each dog immediately after completing the 4-wk diet intervention and weight loss phase. Fecal genomic DNA was extracted and used to create 16S rRNA gene amplicons, which were subjected to 454-pyrosequencing. Predominant bacterial phyla present in all dogs included Firmicutes, Fusobacteria, Actinobacteria, Proteobacteria, and Bacteroidetes. Predominant fecal bacterial genera included Clostridium, Blautia, Fusobacterium, and undefined Lachnospiraceae. Fecal undefined Ruminococcus were greater (P<0.05) in dogs fed BB compared to dogs fed the control diet. Client-owned dogs with various dietary and environmental exposures, ages, and breeds were evaluated for fecal microbiota changes during short-term weight loss on different diets. A high variability in fecal microbiota was observed in this free living dog population, leading to few differences among treatments. The gut microbiota may be an area for investigation during long-term weight loss in companion animals, but such studies require a higher level of dietary control and larger sample sizes.