Eggerthella lenta: metabolism, pathogenesis and therapeutic implications.

Despite a tremendous body of literature on environmental Actinomycetota, their role in the human gut remains poorly understood. In this Review, we highlight the representative species Eggerthella lenta, which has emerged as a major player in the gut microbiota and is increasingly amenable to mechanistic dissection. We discuss the unique metabolic niche of this asaccharolytic obligate anaerobe, including growth on amino acids and short-chain fatty acids, versatile anaerobic respiratory capacity, and the extensive biotransformation of endogenous, diet-derived and pharmaceutical small molecules. E. lenta is associated with a wide range of chronic diseases in humans and sufficient to exacerbate disease in preclinical models, prompting a renewed consideration of the pathogenic potential of this common member of the gut microbiota. Further mechanistic dissection coupled with the development of microbiome-editing tools is essential to understand E. lenta and its multifaceted contributions to gut microbial ecology and host pathophysiology.