Interest in the use of bacteria-containing products for the treatment or prevention of disease has increased in recent years. Bacterial preparations for human consumption are commercially available in the form of dietary supplements and typically contain strains with a history of use in food fermentation. Advances in our understanding of the role of the microbiota in health and disease are likely to lead to development of products containing more novel bacterial species, along with genetic modification of strains to provide specific functions. By law, any substance intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease in humans meets the definition of a drug, and an Investigational New Drug (IND) application for clinical investigation must be filed with the FDA. This article is meant to provide information about the IND submission process and additional considerations with regard to chemistry, manufacturing, and controls information for live biotherapeutic products.