BioProject

Zinc is an essential trace element for most organisms. Supplemental zinc from organic sources has been suggested to be more bioavailable than inorganic ones for dog foods. More...

Zinc is an essential trace element for most organisms. Supplemental zinc from organic sources has been suggested to be more bioavailable than inorganic ones for dog foods. However, bioavailability of zinc might be affected by dietary constituents such as phytates. The present study aimed to evaluate the effects of two zinc sources (zinc sulfate and zinc proteinate) and the addition of a multi-enzymatic complex from the solid-state fermentation of Aspergillus niger on end-products of fecal fermentation and fecal microbiota of adult Beagles fed a high phytate diet. The experimental design consisted of 3 Latin Squares 4 × 4 with a 2 × 2 factorial arrangement of treatments (n = 12 Beagles), with 4 periods and 4 diets: zinc sulfate without (IZ) or with (IZ+) enzyme addition, and zinc proteinate without (OZ) or with (OZ+) enzyme addition. Enzyme addition affected the Faith Phylogenetic diversity index (P < 0.05), whereas zinc source affected both Unweighted and Weighted UniFrac distances (P < 0.05). Linear discriminant analysis effect size detected 9 taxa as markers for organic zinc, 18 for inorganic source, and none for enzyme addition. However, using a negative binomial generalized linear model, further effects were observed. Enzyme addition promoted significantly higher counts of Lactobacillus. Organic zinc was associated with a higher abundance of Firmicutes and lower Proteobacteria and Bacteroidetes (P < 0.05), although at a genus level the response varied. DNA concentration of Clostridium cluster XIV, Campylobacter spp., and Ruminococcaceae was higher in dogs fed IZ and IZ+ diets (P < 0.05). End-products of fecal fermentation were not affected by zinc source or enzyme addition (P > 0.05). An increase or a tendency to increase in some taxa of the phylum Actinobacteria and Firmicutes was observed in feces of dogs fed organic zinc with enzyme addition but not with inorganic zinc. This study fills a gap in knowledge regarding the effect of zinc source and enzyme addition on fecal microbiota of dogs, suggesting that different bioavailability of zinc source might influence bacteria abundance. Moreover, although enzymes had a modest effect in the present study, their interaction with supplemental zinc needs further assessment. Less...