Lab Members


Principal Investigator
Gillian Barlow, PhD
Project Scientist

Gillian Barlow, PhD, is a project scientist for the Medically Associated Science and Technology (MAST) Program at Cedars-Sinai. She obtained her bachelor of science from Dublin City University in Ireland, where she majored in genetics and immunology, and subsequently earned her doctorate in molecular biology from University College Dublin. Her fields of expertise include molecular biology and molecular genetics, and she is highly experienced in cell culture and the generation and analysis of knockout and transgenic mouse models. Barlow’s research interests include the roles of the gut microbiome in metabolism and weight gain, and in gastrointestinal conditions such as irritable bowel syndrome. Prior to joining the GI Motility Program, she was a research scientist in the Division of Molecular Neurogenetics (Department of Pediatrics) at Cedars-Sinai. There she worked on the molecular genetics of Down syndrome, and later worked in the Division of Reproductive Endocrinology and Infertility (Department of Obstetrics and Gynecology), where she worked on female infertility and premature ovarian failure. Barlow has held grants from the American Heart Association and has been a co-investigator on grants from the Eunice Kennedy Shriver National Institute of Child Health and Human Development. To date, she has co-authored more than 30 peer-reviewed papers and five book chapters.

Stacy Weitsman, MS
Laboratory Director

Stacy Weitsman earned her bachelor of science from Indiana University and her master of science from the University of California, Riverside. She has more than 30 years of experience in research with 20 years in laboratory management. Weitsman has co-authored more than 80 peer-reviewed journal articles and abstracts. She currently works on the rifaximin study for the Valeant grant and the polycystic ovary syndrome androgens study. Her responsibilities include overseeing basic science operations and interfacing with the research and administrative teams.

Walter Morales
Laboratory Supervisor

Walter Morales has amassed more than 10 years of clinical and translational research experience and has published in peer-reviewed journals spanning fields of cardiology, endocrinology and gastroenterology. Morales' research interests revolve around understanding the complex molecular integration of host systems and their interaction with the microbial world in both health and the pathophysiology of disease. He also has a passion to create an innovative, team-oriented culture in the pursuit of new knowledge. Morales has gained expertise in molecular biology techniques and animal models in the assessment of gastrointestinal diseases and has been project lead for numerous translational discoveries including the first diagnostic test for irritable bowel syndrome, IBSChek™. He earned his undergraduate degree in microbiology, immunology and molecular genetics as well as the study of religion from UCLA. Since then, he has expanded his studies earning a certificate in healthcare leadership and management from UCLA and is currently completing a certificate in data science from the University of California, Irvine. Morales is a recipient of the 2019 President’s Award, the most prestigious award of recognition at Cedars-Sinai.

Gabriela Leite, PhD
Project Scientist

Gabriela Leite, PhD, has more than eight years of experience as a researcher in the field of molecular biology. Her research interests include the interrelationship between the gut microbiome and gastrointestinal conditions, including irritable bowel syndrome, small intestinal bacterial overgrowth and the interdependence of the gut microbiome and metabolism. Leite has authored papers evaluating the metabolic response of human cells against microbial infection through deep sequencing of the RNA population (messenger RNA and microRNAs). She obtained her bachelor of science in pharmacy and clinical analysis followed by her master’s degree in health sciences from State University of Maringá in Brazil. Leite earned her doctorate in science from the University of São Paulo in Brazil. Before joining the MAST program, she was a postdoctoral researcher in the University of São Paulo’s Department of Clinical Analysis.

Rashin Sedighi, PhD, MS, RN
Clinical Research Coordinator II

Rashin Sedighi, PhD, MS, RN, has a wide background in nursing and nutritional science. She earned her bachelor's degree in nursing from Shahid Beheshti University School of Nursing, Tehran, Iran, followed by a master of science in maternal and child nutrition from University of California, Davis. Sedighi received her doctorate in nutritional and food science from North Carolina Agriculture and Technology State University in Greensboro. Her main clinical focuses are on the small intestine microbial study (REIMAGINE) and the Rifaximin and hypersensitivity study. Her long-term interests involve development of research to understand obesity and diabetes and their complications. Sedighi has been awarded many fellowships, including the Roy Teranishi Graduate Fellowship in Food Chemistry, in 2012, for $1,000; and U.S.D.A. Transdisciplinary Graduate Training Program Fellowship in Functional Foods, Bioactive Food Components & Human Health, in 2012–2013 for $33,300. She was the first-place poster winner of a $1,000 prize at Nutraceuticals and Functional Foods Division of the Institute of Food Technologists annual meeting, in 2013. Additionally, Sedighi provides oversight for clinical trials, interfaces with research subjects, obtains samples, analyzes data and maintains regulatory compliance.

Christine Chang, RN
Research Nurse

Christine Chang has more than 10 years of experience in the field. She earned her nursing degree from Mount Saint Mary’s University in Los Angeles. She joined the MAST program in November 2016 and was responsible for initiating one of MAST’s biggest studies to date. Chang provides oversight for clinical studies, including interfacing with the research subjects, obtaining samples, analyzing data and maintaining regulatory compliance. Her main focuses are the Syn-10 and the colonic inertia clinical trials. 

Chandrima Chatterjee, MPH
Research Administrative Coordinator I

Chandrima Chatterjee joined MAST in 2017 and is their communications manager. She balances her scientific and marketing skills in her role with the MAST program. Chatterjee provides support with philanthropy outreach, curates media/branding and presentations and streamlines social and digital media assets, along with providing laboratory support for the Small Intestine Microbiome Sampling Project (REIMAGINE). Chatterjee's experiences range from sports media to nonprofit support and management to freelance journalism and photography. She worked at the University of Pennsylvania and Emory University as a research specialist for a decade, at the University of Southern California Keck School of Medicine as a part-time editor and is always on the lookout for a good story. Chatterjee has a master’s degree in public health education and a bachelor of science in biology.

Gonzalo Parodi
Research Associate II

Gonzalo Parodi’s research focus is on the lab's polycystic ovary syndrome (PCOS) androgens study, in addition to assisting with other projects in the lab. His skills in molecular biology techniques, spectroscopy and animal handling facilitate his research of microbiome, PCOS and genomics/metabolomics. Parodi earned his bachelor of science in both biochemistry and biotechnology from California State University, Northridge.

Shreya Celly
Research Associate I

Shreya Celly joined the MAST team in June 2017 after earning her bachelor of science in biochemistry from the University of Southern California (USC). As an undergraduate student, she conducted research in behavioral studies and genetics. Celly studied muscleblind proteins at the Institute for Genetic Medicine at the USC Keck School of Medicine and her research culminated in a thesis centered around determining the experimental conditions required to deplete two murine cardiac proteins, and testing if this depletion results in the mis-splicing of target RNAs. Her primary research interest is to understand the impact of the microbiome on overall human health. Currently, Celly is working on a multitude of ongoing projects in the lab involving protein analysis, animal work and microbiology. The majority of her work is on the large-scale REIMAGINE project aimed at profiling the gut microbiome. In addition to actively volunteering in the community, Celly is a master’s degree candidate in health delivery sciences at Cedars Sinai.

Anasheh Enjily
Senior Administrative Assistant

Anasheh Enjily works closely with the MAST program executives and provides administrative support for the group. She has 12 years of health administration and customer service experience. Before joining MAST in 2017, Enjily worked at Cedars Sinai as the patient service representative II for the GI Motility Clinic and assisted Ali Rezaie, MD, the GI Motility medical director, along with other physicians. She previously worked in the emergency department of Glendale Memorial Hospital as an access care coordinator. Enjily obtained her bachelor’s degree in journalism and public relations from California State University, Northridge.

Maritza Sanchez
Research Lab Assistant II

Maritza Sanchez joined the MAST team in August 2018. She earned her bachelor of science in biochemistry from Mount St. Mary’s University in Los Angeles. Sanchez has enjoyed expanding her research knowledge and has a primary interest in autoimmune disorders. Prior to joining MAST, Sanchez focused on using analytical techniques, such as mass spectroscopy and high performance liquid chromatography, to determine the oxidative damage of glutathione on DNA-protein crosslinking in the laboratory of Eric Stemp, PhD, at Mount St. Mary’s. As part of the MAST team, Sanchez provides experimental support toward all major projects as well as assistance in managing daily operations.

Maria Jesus Villanueva Millan, PhD, MS
Postdoctoral Scientist

Maria Jesus Villanueva Millan joined the MAST team in August. She obtained her bachelor of science in biology from the University of Vigo, Spain. Millan earned a master of forensic sciences from the University of the Basque Country in Leioa, Spain. She holds a doctorate from the University of La Rioja and Zaragoza working in the Infectious Diseases, Microbiota and Metabolism Unit at the Center of Biomedical Research of La Rioja. She worked to elucidate the role of gut microbiota in pathologies, such as obesity, and was awarded an EMBO Short-Term Fellowship to perform the virome analysis in hepatitis C (HCV) infected patients in the Laboratory of Viral Metagenomics at the Katholieke Universiteit Leuven in Belgium. Her thesis project focused on the impact of different antiretrovirals, HIV/HCV coinfection and the presence of metabolic syndrome on the gut microbiota composition of HIV-infected patients. 

Millan’s work has spanned the connection between genetics and neurodegenerative disorders as well as the exploration of the microbiota in infectious diseases and its association to inflammatory states. She has additional experience identifying and characterizing the genetic determinants in patients with spinocerebellar ataxia working with the neurogenetics division of the Galician Public Foundation of Genomic Medicine at the University Hospital of Santiago de Compostela. As part of the MAST team, Millan’s role is to further investigate specific bacteria in different gastrointestinal and metabolic diseases and develop new microbial-based technologies and treatments. Currently, her focus is the hydrogen sulfide in diarrhea study.

Contact the Pimentel Lab

8700 Beverly Blvd.
Davis Building, Room 5009
Los Angeles, CA 90048

Twitter: @mastprogram and @MarkPimentelMD
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