Manuel Zúñiga is a Tenured Scientist of the Spanish National Research Council since 2005 working at the Instituto de Agroquímica y Tecnología de Alimentos (IATA). He obtained his PhD at the University of Valencia in 1994 focusing on the genetics of Oenococcus oeni. His study first demonstrated the conjugal transfer of plasmids and transposons to this species. After his PhD, he moved to the IATA to work on the genetics of the arginine deiminase pathway of Lactobacillus sakei. From 1997 to 1999 he stayed at the Molecular Genetics Department of the University of Groningen on an Spanish Ministry of Education grant and a Marie Curie Fellowship. During his stay, he characterized the replisome organizer protein of the Lactococcus lactis bacteriophage r1t. Back at the IATA, he has been working on the physiology and genetics of Lactobacillus casei, the molecular evolution of metabolic pathways and the characterization of the intestinal microbiota of rabbits. Since 2005, his research has dealt with signal transduction two component systems of L. casei and their role in stress response. In recent years, he is also working on the regulation of phosphate metabolism and its relationship with the stress response and probiotic properties of L. casei. This study has led to a new research line focused on the toxic effects of the dietary ingestion heavy metals, including their effects on the gut microbiota, and the use of probiotics to alleviate them.