Lactobacillus bacteria have a strong, but underexplored potential as sustainable bio-based solutions for many food and health-related problems. Since Nobel-laureate Eli Metchnikoff hypothesized that lactic acid bacteria can promote human health in the gut, the research on lactobacilli and probiotics has mainly focused on the human gut and fermented dairy foods. However, a major knowledge gap exists on the beneficial potential of Lactobacillus species in other human body sites (vagina, skin, upper respiratory tract), animals (e.g. chickens, honey bees), plants, crops, and even on abiotic surfaces. In addition, lactobacilli play a key role in many plant- and vegetable-based fermentations, where they promote the shelf life and nutritional value of food and feed. Yet, why and how Lactobacillus species can be beneficial in such a wide variety of niches is currently underexplored.

Therefore, the core aim of this project is a systematic and integrated analysis of the evolutionary history, ecology, and beneficial functions of Lactobacillus species. I propose an unconventional approach situated at the intersections of molecular microbiology (focusing on a single microbe), molecular ecology (focusing on microbial communities) and comparative genomics with an evolutionary perspective on niche adaptation of lactobacilli. By looking deeper into Lactobacillus biology, a paradigm shift can be made moving from a classical ad hoc base to a unique knowledge-based framework for strain selection and analysis of fitness and performance.