Lactulose as a prebiotic supplement which is believed to be important and beneficial to performance and health. This literature review showed lactulose administration could effectively increase diversity and create a distinct microbial community in weaned piglets and the supplement of a mixture of 1% (w/v) lactulose in the feed influenced numbers of Salmonella in the ileum and caecum of pigs. The dietary supplementation of Lactulose improved reduced ammonia gas emissions in weaned piglets but is inconclusive for hematological of piglets.