Faculty Candidate Seminar

Presenter: Abigail Lind, PhD

Gladstone Institutes, UCSF, San Francisco, CA

Talk Title: From pathogens to commensals: human-associated microbial eukaryotes through the lens of genomics and evolution

Humans coexist with myriad microbes that live within and on us, impacting our health in beneficial and detrimental ways. These microbes come from all domains of life and include bacteria, archaea, and eukaryotes. Eukaryotic microbes, including protists and fungi, are emerging as key members of the microbiome that influence other microbiota and host health in multifaceted ways. The factors that differentiate negative and positive interactions with a human host, and mechanistically how eukaryotic microbes accomplish these impacts, are unknown.

I have developed methods to routinely and accurately identify eukaryotic microbes in microbiomes, and discovered that multiple commensal protists are common members of a healthy gut. I have found that Blastocystis, a diverse species complex of stramenopile protists, are the most prevalent commensal gut eukaryotes worldwide and can be found in the guts of animals from insects to humans. Interestingly, Blastocystis is closely associated with gut health, correlating with decreased inflammation and high bacterial diversity. However, we understand very little about the biology of this common organism, which in the past has even been viewed as a parasite. Using comparative and functional genomics approaches in combination with mechanistic experiments on defined anaerobic cultures I investigate the function of Blastocystis and other commensal gut protists in the microbiome. These approaches have identified key biological principles of Blastocystis and in the future will determine how these common commensal gut protists interact with bacterial gut microbiota and the human host to impact health.