Solid-state (substrate) fermentation is the cultivation of microorganisms on moist solid supports (inert carrier or insoluble substrate). The supporting material serves as a carbon and energy source (HÖLKER et al., 2004). The fermentation conditions are adapted to the natural environment of the microorganism considering the absence or near absence of free water (PANDEY et al., 2000). The functional components produced during fermentation affect the barrier function of the gastrointestinal tract by increasing tight junction gene expression, cell proliferation, and reducing pathogen adhesion. In addition, the microbiota composition and activity are modulated. Feeding SSF products results in greater nutrient degradation and lower nutrient excretion, thus greater animal performance and lower emissions.