The effects of increasing concentrations of dietary fiber through the addition of dried distiller’s grains with solubles (DDGS) and wheat bran to a corn-soy bean meal were evaluated for commercial broiler and layer chicks separated into 4 groups during a 21 d trial. Diets were formulated to be isocaloric and meet or exceed nutrient recommendations. Birds had unlimited access to feed and water. The increased dietary fiber had opposite effects on the production of short chain fatty acids for broilers and layers due to differences of the microbial community in the ceca. The change also included signs of decreased cecal health of the chicks, suggesting that it is not a good idea to increase dietary fiber past nutrient recommendations in chicken feed.