The Effects of Fermentation of Low or High Tannin Fava Bean-Based Diets on Glucose Response, Cardiovascular Function, and Fecal Bile Acid Excretion during a 28-Day Feeding Period in Dogs: Comparison with Commercial Diets with Normal vs. High Protein.

Tressa Morris,Lucas A Rodrigues,Lynn P Weber,Luciana G Reis,Matthew E Loewen,Chloe Quilliam

doi:10.3390/metabo11120878

Abstract

We have shown that feeding dogs fava bean (FB)-based diets for 7 days is safe and FB flour fermentation with Candida utilis has the potential to decrease FB anti-nutritional factors. In the present study, the effects of 28-day feeding of 4 different FB-based test dog foods containing moderate protein (~27% dry matter (DM)) were compared with two commercial diets with normal protein (NP, grain-containing, ~31% DM protein) or high protein (HP, grain-free, ~41% DM protein). Health parameters were investigated in beagles fed the NP or HP diets or using a randomized, crossover, 2 × 2 Latin square design of the FB diets: unfermented high-tannin (UF-HT), fermented high-tannin (FM-HT), unfermented low-tannin (UF-LT), and fermented low-tannin (FM-LT). The results showed that fermentation increased glucose tolerance, increased red blood cell numbers and increased systolic blood pressure, but decreased flow-mediated vasodilation. Taken together, the overall effect of fermentation appears to be beneficial and improved FB nutritional value. Most interesting, even though the HP diet was grain-free, the diet did contain added taurine, and no adverse effects on cardiac function were observed, while glucose tolerance was impaired compared to NP-fed dogs. In summary, this study did not find evidence of adverse cardiac effects of pulses in ‘grain-free’ diets, at least not in the relatively resistant beagle breed over a 28-day period. More importantly, fermentation with C. utilis shows promise to enhance health benefits of pulses such as FB in dog food.

Highlights

Fava bean (Vicia faba L.) is a proteinaceous ingredient with potential for partially replacing animal protein sources in human diets and has been associated with health improvements triggered by its functional properties [1]
Within fava bean–based diets, there was no effect of either FM, FB, or the interaction between FM and FB on Body weight (BW), body condition score (BCS), or meal portion (p > 0.05)
One clear finding of the present study was that beagles fed high protein commercial, or moderate protein, fava bean-based diets did not show any tendency toward developing dilated cardiomyopathy (DCM)

Summary

Introduction

Fava bean (Vicia faba L.) is a proteinaceous ingredient with potential for partially replacing animal protein sources in human diets and has been associated with health improvements triggered by its functional properties [1]. Despite the increased interest in incorporating fava beans in their diets, there are still concerns about potential toxicity from anti-nutritional factors [2], which prevent fava bean’s approval as a feed ingredient for pet food by the American Association of Feed Control Officials (AAFCO). Since grain-free and pulse-containing diets tend to be high in fiber, dogs fed these diets may have decreased protein digestibility due either to decreased bioavailability of sulfurcontaining amino acids or to higher fecal excretion of taurine via taurocholate [9,10,11,12]. Plant proteins are naturally low in taurine precursor amino acids and completely lack taurine, compounding the taurine insufficiency issue

Objectives

Methods

Results

Conclusion