I entered graduate school at Baylor College of Medicine in August 2011 as part of the Integrative Molecular and Biomedical Sciences graduate program. After five rotations encompassing a broad range of topics from Bacillus anthracis (the causative agent of anthrax) to nociception in bacterially infected Drosophila melanogaster larvae, I finally joined a lab focused on the human microbiome. My thesis work was divided into three main categories: the human microbiome and health, the human microbiome in disease, and the human microbiome and death:
The Human Microbiome and Health-Nitrate Reducing Oral Bacteria and Cardiovascular Health
While the predominate opinion of nitrates and nitrites is negative due to animal studies with no epidemiological backing, my main thesis project emphasized the health benefits of dietary nitrate. The process is simple: you ingest nitrate, bacteria in your mouth break it down to nitrite, and the nitrite enters your blood stream where it can turn into nitric oxide when conditions are right. Nitric oxide is an incredibly important molecule for human health: it relaxes smooth muscle, dilates blood vessels, is toxic to pathogens, and is an important neurotransmitter, among many other physiological roles. Human cells can't turn nitrate into nitrite, emphasizing the role that oral microbes have in contributing nitric oxide -- with all it's benefits -- to human health.
My PhD work built upon previous studies suggesting a role for nitrate-reducing oral microbes in supporting cardiovascular health. Specifically, I sought to identify the major nitrate reducers and explore the possibility of using one as a probiotic of sorts to reduce blood pressure.
The Human Microbiome and Disease-The Pulmonary Microbiome of Children with Bronchiolitis
The stats are sobering: a large proportion of children less than two years of age that are admitted to the hospital with bronchiolitis develop wheezing -- and sometimes asthma -- later in life. Working with Jonathan Mansbach at Harvard School of Public Health, I explored whether bacteria in the lungs could be associated with the viruses that cause bronchiolitis as well as the potential to develop wheezing disorders later in life. The children in this cohort will be followed until 6 years of age, the age at which most who will develop asthma develop this condition, to get a better picture of the complex relationship between bacteria, viruses, and pulmonary disorders.
The Human Microbiome and Death-The Microbiome Associated with Human Decomposition
Through a collaboration with Drs. Aaron Lynne and Sibyl Bucheli-microbiologist and entomologist-at Sam Houston State University in Houston, TX, I was able to provide some of the very first available information about the microbial communities associated with human decomposition. Although animal models such as mice and pigs have been used for years to study mammalian decomposition, the microbial communities associated with decomposition remain a new endeavour in the field, and studies with human subjects are even rarer. Through collaboration with the Southeast Texas Applied Forensic Science Research Facility, a willed-donation center that enables researchers from various fields to study the forensics sciences, we studied how bacterial communities change across time during decomposition. Further work in collaboration with Dr. Rob Knight enabled the development of a method to predict time since death to +/- 3 day error using microbial community signatures.
As a postdoctoral researcher in Rob Knight's lab, I worked on both the environmental and human microbiomes.
The Environmental Microbiome:
When I first joint the Knight lab, I characterizde the microbial communities present in the sap (latex) of the Euphorbia plant with collaborators at Oak Crest Institute in Monrovia, CA and Huntington Gardens in Pasadena, CA. I also studied the effects of closed-space lifestyles on the microbiomes of humans and animals through three model systems: humans/pets and houses, captive Komodo dragons and their enclosures, and wild amphibians and their ponds -- discovering that closed environments limit the amount of bacterial diversity that we or an animal is exposed to -- with as yet unknown consequences.
The Human Microbiome:
I also had the privelege of continuing human decomposition studies that I had started as a graduate student at BCM, working closely with Dr. Jessican Metcalf, who previously lead the forensics microbiome work in the Knight lab. I also joined a project aiming to characterize the affects of vaginal ring drug delivery systems on the vaginal microbiome -- work crucial for testing the efficacy of a drug delivery system for HIV prevention in women.
Later, I managed the world's largest citizen science research project, the American Gut Project, working with a diverse team of bioinformaticians, wet lab personnel, graduate students, and post docs to keep the project running from day to day and to glean useful information from the swaths of data collected. The project provided amazing speaking opportunities and collaborations around the world, and also led to my selection as a Forbes 30 Under 30 in Science and Healthcare. It was through my interactions with project participants that I became inspired to join the effort to improve science communication to non-scientists, and in 2018 I became a full-time freelance science writer and scientific research and communication consultant.
For more details on these and other projects that I have been involved in, please visit my publications page.