The normal flora of human gastrointestinal tract (GIT) bacterial have many roles in human health, most of which are beneficial or neutral for the host. The intestinal bacteria play a significant role of being traffickers in antibiotics which supports the hypothesis that intestinal bacterial not only exchange resistance genes among themselves but might also interact with bacteria that are passing through the colon, causing these bacteria to acquire and transmit antibiotic resistance genes. The human gastrointestinal tract is a massive reservoir of bacteria with a potential for both receiving and transferring antibiotic resistance genes. The increased use of fermented food products and probiotics, as food supplements and health promoting products containing massive amounts of bacteria acting as either donors and/or recipient of antibiotic resistance genes in the human gastrointestinal tract, also contributes to the emergence of antibiotic resistant strains.