Baker’s yeast beta glucan supplementation was associated with an improved innate immune mRNA expression response after exercise

•Supplementation with BYBG altered the expression of 47 innate immune system mRNA in response.•Supplementation with BYBG intake may improve innate immune response to both DAMP and PAMP.•Multiplex mRNA detection can be an effective to measure small expression changes associated with an orally consumed nutritional compound. Beta glucans are found in many natural sources, however, only Baker’s Yeast Beta Glucan (BYBG) has been well documented to have structure–function effects that are associated with improved innate immune response to stressors (e.g., exercise, infection, etc.). The purpose was to identify a BYBG-associated mRNA expression pattern following exercise. Participants gave IRB-approved consent and were randomized to BYBG (Wellmune®; N=9) or Placebo (maltodextrin; N=10) for 6-weeks prior to performing 90 min of whole-body exercise. Paxgene blood samples were collected prior to exercise (PRE), after exercise (POST), two hours after exercise (2H), and four hours after exercise (4H). Total RNA was isolated and analyzed for the expression of 770 innate immune response mRNA (730 mRNA targets; 40 housekeepers/controls; Nanostring nCounter). The raw data were normalized against housekeeping controls and expressed as Log2 fold change from PRE for a given condition. Significance was set at p