Remarkable Metabolic Versatility of the Commensal Bacteria Eubacterium hallii and Intestinimonas butyriciproducens: Potential Next-Generation Therapeutic Microbes

Our gastrointestinal tract is host to a wide variety of bacteria, together referred to as the microbiota. These bacteria influence our health and well-being through many different mechanisms. Most of these effects are the result of metabolites that are being produced by these bacteria or through triggering the expression of metabolites by the host. In this chapter we will highlight two bacterial species that have remarkable metabolic features that make them prime candidates for the development as next-generation probiotics. The first is Eubacterium hallii, a bacterium that is capable of producing two important short-chain fatty acids (SCFAs), propionate and butyrate. The other bacterium is Intestinimonas butyriciproducens, a bacterium that is capable of producing butyrate from not only sugars but also lysine and even glycated lysine. Both species also can produce pseudovitamin B12. We will discuss conditions that can result in the production of specific metabolites and the implications this can have on human health.