‘Probiotics’ as a live microbial feed supplementation which beneficially affects the host animal by improving its microbial balance and it is known to as a substitute for antibiotics in livestock feed industry. Lactic acid bacteria as a Lactobacillus sp. is formed acid and decrease pH in gastro󰠏intestine that is result in suppress harmful microorganism. Lactobacillus sp. also produces vitamin and a variety amino acids. Yeast as a saccharomyces sp. secretes digestive enzymes, decreases ammonia emission and increases feed palatability by alcohol and glutamic acid. The effects of dietary probiotics in monogastric animals that improve weight gain and feed efficiency ratio and decrease diarrhea occurrence frequency in pigs. Also, probiotics increase egg production ratio and beneficial microorganisms in laying hens. In broiler, they have more gain weight and lower blood cholesterol concentrations by probiotics. However, the other study reported probiotics supplementation in animal diets has no effect on ADG, G/F or performance. Thus, future study in these area will allow for more efficient use of the probiotics, selection of more superior microorganism and development of more efficient environment󰠏friendly probiotics like a photosynthetic bacteria.