Lactobacilli, like bifidobacteria, are also known as probiotics. These are microorganisms/bacteria that produce lactic acid and are part of the intestinal flora of a human being. They are some of the first colonizers of a baby's intestine and then become one of the most dominant bacterial species in the gut. Lactobacilli can also be found in breast milk, e.g. Lactobacillus fermentum. Lactic acid-producing bacteria in breast milk help build a healthy intestinal flora and support babies' immune systems. Some infant formulas such as HiPP Organic Combiotic have lactobacillus added, following nature's example.