Putra, A.M. et al. 2026. Optimal level of Bacillus spp. fermented soybean meal utilization in broiler diets under commercial conditions: effect on gut morphology and microbiota. Indonesian Journal of Agricultural Research. 9, 2 (Jul. 2026), 63–71. DOI:https://doi.org/10.32734/injar.v9i2.24736.