2024/11/21 by Pauline D. Scanlan, Fernando Baquero, Bruce R. Levin · 1 voice
Biochemistry, Genetics and Molecular Biology · Medicine · #Clostridium difficile and Clostridium perfringens research #Escherichia coli research studies #Gut microbiota and health
paper · doi:10.1073/pnas.2409905121
openalex publication_date 2024/11/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Why microbes harm their hosts is a fundamental question in evolutionary biology with broad relevance to our understanding of infectious diseases. Several hypotheses have been proposed to explain this "evolution of virulence." In this perspective, we reexamine one of these hypotheses in the specific context of the human gut microbiome, namely short-sighted evolution. According to the short-sighted evolution hypothesis, virulence is a product of niche expansion within a colonized host, whereby variants of commensal microbes establish populations in tissues and sites where the infection causes morbidity or mortality. This evolution is short-sighted in that the evolved variants that infect those tissues and sites are not transmitted to other hosts. The specific hypothesis that we propose is that some bacteria responsible for invasive infections and disease are the products of the short-sighted evolution of commensal bacteria residing in the gut microbiota. We present observations in support of this hypothesis and discuss the challenges inherent in assessing its general application to infections and diseases associated with specific members of the gut microbiota. We then describe how this hypothesis can be tested using genomic data and animal model experiments and outline how such studies will serve to provide fundamental information about both the evolution and genetic basis of virulence, and the bacteria of intensively studied yet poorly understood habitats including the gut microbiomes of humans and other mammals.