This project proposes an innovative strategy to alleviate Vitamin A (VA) deficiency in the developing world by harnessing the metabolic power of a probiotic bacterium, Lactobacillus casei. By engineering L. casei to produce provitamin A (β-carotene) during yogurt fermentation, the team can develop a safe and sustainable method of increasing dietary intake of VA. This provitamin A biofortified (i.e., enhanced) yogurt can support VA status and benefit the health of populations in India who consume yogurt as a staple. Moreover, the bacteria strain can be produced inexpensively, freeze-dried into a room-temperature-stable powder, and seamlessly integrated into existing yogurt production cycles. As L. casei is common in many different fermentations processes, this strain could be adapted for use in many other human and animal food sources. Once this strain becomes established in a fermentation system, it will self-perpetuate to ensure a sustainable source of dietary β-carotene.