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Effect of PROeq™ Saccharomyces cerevisiae fermentation-based postbiotic (SCFP) on stress recovery

A simulated prolonged transport stress model was used to evaluate immune system responses in young horses supplemented with PROeq™postbiotic. This study was conducted at the University of Florida Institute of Food and Agricultural Sciences 1,2.


  • The head elevation model utilized in this study successfully created acute peripheral and local stress inflammation in young horses as evidenced by increased airway mucus, serum cortisol, and immune cell responses in serum, NPF secretions and feces.

  • Changes in both local and systemic response to stress were indicative of PROeq™ postbiotic positively balancing the immune response:

  • A lower number of lymphocytes and neutrophils with higher levels of monocytes (developing macrophages) suggest PROeq™ exerts a role in immune cell architecture. Previous studies in other species have demonstrated that yeast cell wall and yeast-derived MOS affects immune cell numbers. This response is typified by fewer numbers of cells with increased ability to respond.

  • A reduction in lymphocyte proliferation in response to concanavalin A in CON horses with no change in those fed PRO suggests PROeq™ can help maintain a level of primary immune responsiveness under conditions of stress.

  • During the process of phagocytosis, immune cells such as macrophages undergo a strong respiratory burst during which they consume oxygen and convert it to potent oxidants to neutralize and destroy pathogens. The higher phagocytosis-induced respiratory burst noted in this study indicates that PROeq™ helped enhance local immune responsiveness.

  • Immunoglobulin A (IgA) is the most abundant antibody class present at mucosal surfaces and is involved in opsonizing pathogens and inducing pro-inflammatory responses to help eliminate pathogens. Higher levels of IgA and changes in leukocytes and IgG in mucosal secretions suggest PROeq™ was involved in balancing the immune response.

Stress Study
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