Active fractions of mannoproteins derived from yeast cell wall stimulate innate and acquired immunity of adult and elderly dogs

Abstract

A B S T R A C TNutritional intervention in older dogs aims to increase lifespan and improve life quality as well as delay the development of diseases related to ageing. It is believed that active fractions of mannoproteins (AFMs) obtained through extraction and fractionation of yeast cell walls (Saccharomyces cerevisiae) may beneficially modulate the immune system. However, studies that have evaluated this component and the effects of ageing on the immune system of dogs are scarce. This study aimed to evaluate the immunological effects of AFMs in adult and elderly dogs. Three extruded iso-nutrient experimental diets were formulated: without addition of AFM (T0); with AFM at 400 mg/kg (T400); and with AFM at 800 mg/kg (T800). Thirty-six beagle dogs were used, and six experimental treatments, resulting in combinations of age (adult and elderly) and diet (T0, T400, and T800), were evaluated. On days zero, 14, and 28, blood samples were obtained for leucocyte phenotyping and phagocytosis assays. On days zero and 28, a lymphoproliferation test, quantification of reactive oxygen (H 2 O 2 ) and nitrogen (NO) intermediate production, evaluation of faecal immunoglobulin A (IgA) content, and a delayed cutaneous hypersensitivity test (DCHT) were performed. Statistical analyses were performed with SAS software. Repeated measure variance analyses were performed, and means were compared by the Tukey test. Values of P ≤ 0.05 were considered significant, and values of P ≤ 0.10 were considered tendencies. Dogs fed T400 tended to have higher neutrophilic phagocytic activity than dogs fed T800 (P = 0.073). Regarding reactive oxygen intermediates, bacterial lipopolysaccharide (LPS)-stimulated neutrophils from animals that were fed T400 had a tendency to produce more H 2 O 2 than those from animals fed the control diet (P = 0.093). Elderly dogs, when compared to adult dogs, had lower absolute T and B lymphocyte counts, lower auxiliary T lymphocyte counts, and higher cytotoxic T lymphocyte counts (P < 0.05). A significant effect of diet, age, and time with saline inoculation was noted for the DCHT. There was no effect of diet or

Duration of Prebiotic Intake Is a Key-Factor for Diet-Induced Modulation of Immunity and Fecal Fermentation Products in Dogs

“…The concentration of fecal IgA increased with the addition of prebiotics over time, which is an interesting result that shows the improvement of the local immunological capacity after a longer period of exposure to the prebiotic. Other studies have observed variations in fecal IgA concentrations in dogs over time [56,57]. The continuous production of IgA occurs due to constant stimulation of the intestinal microbiota [58].…”

C-Type Lectins in Veterinary Species: Recent Advancements and Applications

“…Such an effect was also observed in a study performed in crayfish: crayfish susceptibility to the viral White-spot disease was reduced while the expression of hemocyte-associated crayfish CTL (X2C306-1) was simultaneously upregulated following the probiotic gavage of Bacillus amyloliquefaciens [ 138 ]. Further positive effects of carbohydrate supplements were demonstrated in lentinan-rich shiitake mushrooms gavage in a rat model of human dyslipidemia [ 139 ], probiotic glucan gavage in carp [ 140 ], and mannoprotein supplementation in adult and aging dogs [ 141 ].…”

Yeast Extracts: Nutritional and Flavoring Food Ingredients

“…They are usually labeled as “yeast extract” or “natural flavor” in the ingredient list of foods. In addition, the yeast cell walls derived byproducts of yeast extracts are developed for their functional effects on growth performance, gut physiology, and immunity. ,− …”