**5. Conclusion**

Lactic acid fermentation is an ancestral process performed by numerous bacterial strains. Fermentation conditions, substrates, and potential additives represent challenges and constraints for yield optimization, process stabilization, and standardization. Indeed, lactic fermentation by *Lactobacillus* allows the production of many molecules of interest. When these bacteria ferment plant products, they induce biochemical conversions and the production of phenolic compounds, organic acids, and vitamins through their enzymatic activities. This review highlights the different applications related to the production of these compounds. The latter have bioactivities such as AO, AI, prebiotic, antimicrobial, and many others.

In addition, they are of growing interest to the food industry for their ability to increase nutritional value but also for their use as preservatives and modifiers of organoleptic properties. The different studies reviewed here are looking for alternatives to meet environmental and social consumer demand. In order to reduce production costs and the carbon footprint of the process, genetic engineering and the revalorization of plant by-products appear to be interesting avenues of research to improve the yield of compounds of interest. However, there is still a lack of scientific data on the control of fermentation by *Lactobacillus.* Further studies are needed to identify the biochemical reactions and metabolism of *Lactobacillus* involved in the production of bioactive compounds. In addition, studies are needed to further investigate the mechanisms involved in the bioactivities of interest.
