The potential health benefit of LAB has been intensively investigated during the last century. In this direction the DEPROHEALTH project aimed at providing information regarding probiotic use in treating human intestinal disorders. In addition the project examined the mechanisms involved in the immunomodulation capacity of LAB. Probiotics are live ingredients in foods, which provide either a therapeutic and/or prophylactic benefit to consumers against disease. This is achieved through their ability to influence the human immune system, acting as immunomodulators, which reduce inflammatory conditions or beneficially regulate the immune system. The research group worked on engineering probiotic strains to prevent intestinal illnesses such a stomach ulcers or Chrohn's disease, which severely affect patients' quality of life. Experimental evidence has also demonstrated that LAB can act as host-vector for heterologous expression. A host-vector system is a compatible combination of host, i.e. bacteria, and vector, i.e. plasmid, that allows propagation of DNA. The metabolism of the host cell is used for the growth and reproduction of the plasmid or other form of foreign DNA. Expression systems are used to find out whether a particular gene produces a protein and whether the protein produced is functional or defective. The gene construct is transfected into a host cell and its expression is then measured at the protein or activity level. Research results indicated a strategy, which may be widely applicable for expressing heterologous proteins in commensal lactic acid bacteria. This can comprise a possible approach for local delivery of bioactive molecules. Industrial partners are now invited to exploit the findings of the project and develop new tools for the construction of lactic acid bacteria with increase health properties.