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Understanding human health and disease has driven research in the Dewhirst lab for the past 40 years. Systemic human health is directly linked to the health of tissues in the oral cavity. The mouth is the gateway to the gastrointestinal tract, and oral sites are easily examined and sampled to address basic biological questions. The diverse basic research in the Dewhirst laboratory all connects directly or indirectly to the mouths of human subjects.

A premise of the Human Microbiome Project is that to understand human health and disease, one must understand the composition and function of the human microbiome. The Dewhirst lab has played a major role in identifying the bacteria of the oral cavity and has created the Human Oral Microbiome Database ( to provide taxonomic and genomic information to the research community. To understand the function and genetic capabilities of the oral bacteria, the lab has obtained genome sequences for more than 300 bacterial species. In recent years, the lab has sought to determine why 30 percent of the bacteria living in the oral microbiome are uncultivable using standard microbial methods. The major reason appears to be auxotroph for factors made by the bacterial community and not present in commercial media. Using novel coculture approaches, the lab has successfully cultured dozens of previously uncultured bacteria including those from the phylum Saccharibacteria (TM7s).  

Floyd Dewhirst, DDS, PhD

Emeritus Member of Staff

Professor, Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine

Floyd Dewhirst was deciphering the oral microbiome before the term microbiome was created. Dewhirst’s long-term research focus has been to define the diversity, genetic capability and pathogenic potential of organisms […]

Demetrius DiMucci, PhD

Postdoctoral Research Fellow

Demetrius is a Postdoctoral fellow with a background in molecular biology, community ecology, and machine learning. He earned his PhD in Bioinformatics from Boston University in 2019 where he worked […]

Fabiola Miranda-Sanchez

Postdoctoral Research Fellow

Fabiola joined the Dewhirst lab as a Postdoctoral Fellow in December 2019 to investigate the assembly and development of the bacterial community from supragingival plaque on a porous material. She […]

Susan Connolly Yost

Research Associate

Susan has been working at the Forsyth Institute since November 2011. She left a teaching position in the Chemistry Department at St. Anselm College in Manchester, NH in May 2011 […]

Matthew Ouellette, PhD

Postdoctoral Research Fellow

Matt Ouellette joined the Dewhirst lab in September of 2019 as a Postdoctoral Fellow to study the interactions of Saccharibacteria (TM7) with their host organisms. He is currently working on […]

Stephane Nija Viala

Laboratory Technician

Stephane Nija Viala was introduced to the world of oral medicine through her clinical practices as a Dental Assistant. Recently, she graduated with a degree in Biology at Suffolk University in December 2020. Driven by her curiosity for molecular genetics, she […]

Lab Alumni:

Andrew Collins
Palavi Murugkar
Andrew Bejian
Ana Paula Colombo