Display omitted •Plant fermentation is like a metabolic labyrinth undertaken by bacteria.•Omics approaches unraveled the metabolic traits of bacteria to adapt to plants.•Most of the winding metabolic pathways involve phenolic compounds.•Fermented plant foods are enriched with high bioavailable bioactive compounds.•Fermentation of plant matrices result in low amounts of anti-nutritional factors. Even though lactic acid bacteria are only a small part of the plant autochthonous microbiota, they represent the most important microbes having the capability to promote significant changes in the health-promoting properties of plant foods. Owing to the variety of plant chemical components and the possible pathways for bioconversion, plant fermentation is like a metabolic labyrinth undertaken by bacteria. The winding metabolic pathways involve several secondary plant metabolites (e.g. phenolics). The success of these paths is connected to the adaptive growth and survival of lactic acid bacteria. A panel of various interacting omics approaches unraveled the specific traits of lactic acid bacteria to adapt to plants, which allow the optimal design of fermentation strategies for targeted raw matrices.