Engineering Lactobacillus casei to Enable Sustainable Home Production of Vitamin A Enriched Dairy Foods by At-Risk Mothers
Vitamin A deficiency (VAD) is a major problem in the developing world that disproportionately affects pregnant women, children, and infants. Vitamin A's role in development and immunity make it critically important to natal/neonatal health. The use of supplements, crops, and grains to reduce VAD has been met with limited success due to issues such as dependency on suppliers, lack of cultural acceptance, high costs, distribution difficulties, and hypervitaminosis. A sustainable, culturally acceptable, and safe way of fighting VAD is needed, particularly in Southern Asia. Fermented dairy products, particularly yogurt, are staple foods of India. In rural communities, these products are traditionally made by women using small-scale fermentations, often on a per-household basis. In all fermentations, local strains of lactic acid bacteria (LAB) have been utilized for generations as yogurt starter cultures, continuously cultured by a process called back-slopping. We propose to engineer a LAB, Lactobacillus casei, to produce the provitamin A carotenoid, β-Carotene. This strain could then be added to local starter cultures, resulting in β-Carotene enriched dairy products without any change in production methods. Once this strain is added, it would remain part of the local starter cultures, producing β-Carotene enriched products indefinitely. Because these products would contain β-Carotene and not Vitamin A itself, there would be no risk of hypervitaminosis. This technology, combined with education and outreach, could enable at-risk mothers to provide Vitamin A supplementation for themselves, their family, and even their community in a safe and sustainable way.