Supplementing a Saccharomyces cerevisiae fermentation product modulates innate immune function and ameliorates bovine respiratory syncytial virus infection in neonatal calves

Abstract

The objectives of this study were to determine the effects of oral supplementation with Saccharomyces cerevisiae fermentation products (SCFP; SmartCare and NutriTek; Diamond V, Cedar Rapids, IA) on immune function and bovine respiratory syncytial virus (BRSV) infection in preweaned dairy calves. Twenty-four Holstein x Angus, 1-2 day old calves (38.46 ± 0.91 kg initial body weight) were assigned two treatment groups: control; or SCFP treated, milk replacer with 1 g/d SCFP (SmartCare) and calf starter top-dressed with 5 g/d SCFP (NutriTek). The study consisted of one 31 d period. On d 19-21 of the supplementation period, calves were challenged via aerosol inoculation with BRSV strain 375. Calves were monitored twice daily for clinical signs, including rectal temperature, cough, nasal and ocular discharge, respiration effort and lung auscultation. Calves were euthanized on d 10 post infection (d 29-31 of the supplementation period) to evaluate gross lung pathology and pathogen load. Supplementation with SCFP did not affect body weight (P = 0.762) or average daily gain (P = 0.750), percentages of circulating white blood cells (P < 0.05), phagocytic (P = 0.427 for neutrophils and P = 0.460 for monocytes) or respiratory burst (P = 0.119 for neutrophils and P = 0.414 for monocytes) activity by circulating leukocytes either before or following BRSV infection, or serum cortisol concentrations (P = 0.321) after BRSV infection. Calves receiving SCFP had reduced clinical disease scores compared to control calves (P = 0.030); reduced airway neutrophil recruitment (P < 0.002); reduced lung pathology (P = 0.031); and a reduced incidence of secondary bacterial infection. Calves receiving SCFP shed reduced virus compared to control calves (P = 0.049) and tended towards lower viral loads in the lungs (P = 0.051). Immune cells from the peripheral blood of SCFP treated calves produced increased (P < 0.05) quantities of IL-6 and TNFα in response to toll-like receptor stimulation; while cells from the bronchoalveolar lavage (BAL) of SCFP treated calves secreted less (P < 0.05) proinflammatory cytokines in response to the same stimuli. Treatment with SCFP had no effect on virus-specific T cell responses in the blood, but resulted in reduced (P = 0.045) virus-specific IL-17 secretion by T cells in the BAL. Supplementing with SCFP modulates both systemic and mucosal immune responses and may improve the outcome of an acute respiratory viral infection in preweaned dairy calves.

A Saccharomyces cerevisiae Fermentation Product (Olimond BB) Alters the Early Response after Influenza Vaccination in Racehorses

“…The period of six weeks in which feed was supplemented with SCFP did not result in an altered composition of circulating immune cells as at the day of vaccination both groups (PLA, OLI) did not differ significantly in any of the measured parameters ( Table 2 ). This is in line with findings in calves and lambs where the SCPF feeding had no influence on the fraction of circulating immune cells subpopulations [ 15 , 25 ]. In contrast, according to the literature, SCFP supplementation raised the numbers of circulating leukocytes and neutrophils in heat-stressed cows [ 26 ] and the fraction of monocytes and B-cells in adult dogs [ 9 ].…”

“…In adult cows, SCFP supplementation (20–90 g/animal/day for up to 60 days) altered the phenotype of circulating neutrophilic granulocytes, their phagocytosing capacity, and the gene expression of circulating leukocytes [ 13 , 14 ]. In calves, SCFP supplementation (1–5 g/day/animal) modulated both systemic and mucosal immune responses, resulting in reduced lung pathology, and a reduced incidence of secondary bacterial infection [ 15 ]. In beef calves challenged intravenously with LPS, SCFP-fed animals (12 g/day for 21 days) showed a reduced acute phase response and lower serum TNF levels [ 16 ].…”

First Metabolic Insights into Ex Vivo Cryptosporidium parvum-Infected Bovine Small Intestinal Explants Studied under Physioxic Conditions

“…The current experimental approach also intended to maintain each BSI explant and its individual microbiome under conditions reflecting physioxic oxygen conditions of 5% O 2 (Note: 1-10% O 2 is commonly found in the small intestinal lumen of mammalian hosts [29]). As an interesting finding, SEM analyses showed parasite-driven hole-like lesions in the epithelial surfaces of parasitized villi, as reported for both in vitro experiments with permanent host cells [13] and in vivo lesions in C. parvum-infected bovine small intestines [41,42].…”

FeedingSaccharomyces cerevisiaefermentation products lessens the severity of a viral–bacterial coinfection in preweaned calves

“…Saccharomyces cerevisiae fermentation products ( SCFP ) have positive effects on many aspects of immune function in cattle, swine, poultry, and humans ( Moyad et al, 2009 ; Shen et al, 2011 ; Brewer et al, 2014 ; Alugongo et al, 2017 ). In a previous study, we observed that supplementation with SCFP modulated innate immune function in preweaned calves ( Mahmoud et al, 2020 ). Immune cells isolated from the blood of SCFP-fed calves had an increased capacity for proinflammatory cytokine production, whereas immune cells isolated from the lungs produced fewer proinflammatory cytokines ( Mahmoud et al, 2020 ).…”

“…Immune cells isolated from the blood of SCFP-fed calves had an increased capacity for proinflammatory cytokine production, whereas immune cells isolated from the lungs produced fewer proinflammatory cytokines ( Mahmoud et al, 2020 ). Subsequently, calves receiving SCFP developed less clinical disease and less lung pathology following an experimental bovine respiratory syncytial viral ( BRSV ) infection ( Mahmoud et al, 2020 ).…”