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Padmaja Subbarao

Title: Associate Chief, Clinical Research
Designations: MD, M.Sc., FRCP (C)
Pronouns: she/her
Alternate Contact Name: Olivia Tetreault
Alternate Phone: 416-813-7654 ext. 302196
Alternate Email:
U of T Positions: Professor, Department of Paediatrics and Dalla Lana School of Public Health
Chair Positions: Canada Research Chair in Pediatric Asthma and Lung Health - Tier 1

Hospital Positions

Co-Lead, Precision Child Health

Staff Respirologist, Division of Respiratory Medicine

Research Positions

Senior Scientist, Translational Medicine, Subbarao Lab

Director, CHILD Cohort study


Dr. Padmaja Subbarao is a Clinician-Scientist in Paediatric Respiratory Medicine, specializing clinically in severe asthma. Trained in both Epidemiology and infant and preschool lung function, she holds appointments at the University of Toronto in the Departments of Paediatrics, Physiology and in the Dalla Lana School of Public Health.


Dr. Subbarao’s research program focuses on disentangling preschool wheeze heterogeneity to precisely predict who will develop each type of asthma, monitor its progression and discover the risk factors, exposures and underlying biology associated with each asthma subtype. She is the Director of the CHILD cohort study, one of the largest, most intensively characterized asthma birth cohorts in the world. This world-leading study enabled the discovery of the importance of the gut microbiome for the protection against asthma (cited more than 500 times).

She also established the first infant lung function laboratory in Canada and her early work on the novel multiple breath washout (MBW) lung test helped pave the way for its acceptance by the Federal Drug Agency as an objective outcome measure for clinical trials in Cystic Fibrosis (CF). Her research in early life lung function and risk factors in asthma have enabled the earlier, precise prediction of asthma and monitoring of its progression, thus advancing the diagnosis and treatment of children with asthma.

Education and experience

  • 1988–1990: B.Sc., Biology, University of Ottawa, Ottawa, Ontario, Canada
  • 1990–1994: MD, Doctor of Medicine, University of Toronto, Toronto, Ontario, Canada.
  • 2000–2002: M.Sc. Epid., Masters of Science in Clinical Health Sciences, Health Research Methodology, McMaster University, Hamilton, Ontario, Canada
  • 1994–1997: Paediatric Residency, Faculty of Medicine, CHEO, University of Ottawa, Ottawa, Ontario, Canada.
  • 1997–1999: Respiratory Medicine Fellow, Faculty of Medicine, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
  • 1998–1999: Associate Chief Respiratory Medicine Fellow, Faculty of Medicine, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
  • 2000–2003: Canadian Lung Association Research Fellowship, Asthma Research Fellowship, McMaster University, Hamilton, Ontario, Canada.
  • 2002–2004: Canadian Institutes of Health Research Fellowship, Infant Pulmonary Function Training Fellowship, Institutes of Child Health, Great Ormond Street Hospital, London, England, UK.


  • 2013: Breathe New Life Award, Ontario Thoracic Society, Toronto, Ontario, Canada.
    Award for highest ranking in National Grant Review competition.
  • 2018: Paul Mann Lectureship, University of Alberta, Faculty of Medicine, Edmonton, Alberta, Canada.


  1. Lu Z, Foong RE, Kowalik K, Moraes TJ, Boyce A, Dubeau A, Balkovec S, Gustafsson PM, Becker AB, Mandhane PJ, Turvey SE, Lou W, Ratjen F, Sears M, Subbarao P. Ventilation inhomogeneity in infants with recurrent wheezing. Thorax. 2018 Jun 15. 
  2. Kowalik K, Dai R, Safavi S, Reyna ME, Lou W, Lepine C, McDonald E, Schaap MJ, Brydges MG, Dubeau A, Boutis K, Narang I, Eiwegger T, Moraes TJ, Ratjen F, Subbarao P.  Persistent ventilation inhomogeneity after an acute exacerbation in preschool children with recurrent wheezing.  Ped All Immunol 2020 (in press). 
  3. Subbarao P, Stanojevic S, Brown M, Jensen R, Rosenfeld M, Davis S, Brumback L, Gustafsson P, Ratjen F.  Lung clearance index as an outcome measure for clinical trials in young children with CF: A pilot study using inhaled hypertonic saline. Am J Respir Crit Care Med. 2013: 188(4): 456-60.
  4. Subbarao P, Anand SS, Becker AB, Befus AD, Brauer M, Brook JR, Denburg JA, HayGlass KT, Kobor MS, et al, Sears MR and the CHILD Study investigators. The Canadian Healthy Infant Longitudinal Development (CHILD) Study: examining the developmental origins of asthma and allergy. Thorax. 2015 Oct;70(10):998-1000.
  5. Boutin RCT, Sbihi H, Dsouza M, Malhotra R, Petersen C, Dai D, Sears MR, Moraes TJ, Becker AB, Azad MB, Mandhane PJ, Subbarao P*, Finlay BB*, Turvey SE*. Mining the infant gut microbiota for therapeutic targets against atopic disease. Allergy. 2020 Feb 22. In Press.

See a full list of Padmaja Subbarao's publications

  • 2020–2024: Principal Investigator. Causational Roles of the Gut Microbiome in Childhood Asthma: Leveraging the CHILD Cohort Study. CIHR Team Grant: Canadian Microbiome Initiative 2: Research Teams. Principal Investigators: Subbarao, Padmaja; Azad, Meghan; Duan, Qingling; Hirota, Jeremy A; Kozyrskyj, Anita L; Lou, Wen-Yi W; Mcnagny, Kelly M; Surette, Michael G; Turvey, Stuart E. $2,000,000 CAD.
  • 2019–2022: Co-Investigator. CHILDhood Asthma and Puberty: Understanding the Sex Shift in Asthma to Female Predominance. CIHR Project Grant. Principal Investigators: Becker, Allan B; Azad, Meghan. $1,220,940 CAD.
  • 2019–2019: Co-Investigator. FActors of Mothers and Infants in Longitudinal Years (FAMILY) - A maternal and child birth cohort with babies identified from three Ontario existing pediatric cohorts and linked with health administrative data to create a birth cohort of infants and their siblings and mothers to study prenatal, postnatal and early childhood factors associated with maternal and child health and developmental outcomes. Op Grant: Data Analysis - Reproductive, Maternal, Child and Youth Health. Principal Investigators: To, Teresa; Borkhoff, Cornelia M. $75,000 CAD.
  • 2018–2022: Co-Principal Investigator. Precision health for life: The Canadian Healthy Infant Longitudinal Development (CHILD) study. Genome Canada. Large-Scale Applied Research Project (LSARP) competition: Genomics & Precision Health. Nominated Principal Investigator: Stuart Turvey. $10,000,000 CAD.
  • 2018–2022: Co-Investigator. A genome-wide association study of dysanapsis. CIHR Project grant. Principal Investigators: Smith, Benjamin M; Duan, Qingling. $240,000 CAD.
  • 2018–2019: Principal Investigator. Enabling integrative analyses and discovery using CHILD Study data. AllerGen Networks of Centres of Excellence (NCE) Inc. $300,000 CAD.
  • 2018–2019: Co-Principal Investigator. CHILD Study: Governance and Policy. AllerGen Networks of Centres of Excellence (NCE) Inc. $50,000 CAD.
  • 2017–2019: Nominated Principal Applicant. Canadian Birth Cohort: Indoor Air and the Development of Asthma and Allergy (CHILD Study). AllerGen Networks of Centres of Excellence (NCE) Inc. Principal 63Investigators: Malcolm Sears, Allan Becker, Piush Mandhane, Stuart Turvery. $2,000,000 CAD.
  • 2017–2018: Co-Principal Investigator. Clinical predication rule and population monitoring rule for respiratory morbidity in young children. CIHR. CIHR Operating Grant: Analyses of Existing Canadian Cohorts & Databases – Reproductive, Maternal and Child Health. Principal Investigators: Teresa To, Kawsari Abdullah, Andrea Gershon, Wendy Lou. $75,000 CAD.
  • 2016–2021: Co-Principal Investigator. CANadian Urban Environmental (CANUE). CIHR. Health Research Consortium. Principal Investigators: Jeffrey Brook, Phillip Awadalla, Kimberlyn McGrail, Michael Brauer, Howard Hu, David Stieb. $4,165,000 CAD.
  • 2016–2021: Nominated Principal Applicant. Genes by environment interactions in the development of non-communicable chronic respiratory diseases, asthma and COPD. CIHR. Programmatic Grants in Environments, Genes and Chronic Disease. Principal Investigators: Jeffrey R. Brook, Russell J. De Souza, Qingling Duan, Anita Kozyrkskyj, Wen-Yi Lou, Michael Surette. $1,953,002 CAD.
  • 2016–2021: Co-Principal Investigator. Deciphering the metabolic signatures of the metabolic syndrome (MetS) in young children. DoHAD Team Grant. CIHR – Implications for Men, Women Boys and Girls – Full Application. Principal Investigators: Sonia Anand, Joseph Beyene, Philip Britz-Mckibbin, Russell J. De Souza, Guillaume Paré. $1,498,268 CAD.
  • 2016–2021: Co-Investigator. Programmatic research to understand how modifiable environmental factors interact with the genome in the development of asthma. CIHR. Programmatic Grants in Environments, Genes and Chronic Disease – Full Application. Principal Investigators: Stuart Turvey, Jeffrey Brook, Michael S. Kobor. $1,675,435 CAD.
  • 2016–2021: Co-Investigator. Research Advancement through Cohort Cataloguing and Hamonization (ReACH). CIHR – Operating Grant: DOHaD Cohort Registry. Principal Investigators: Stephanie Atkinson, Alan Bocking, Vincent Ferretti, Isabel Fortier and William Fraser. $780,000 CAD.
  • 2015–2020: Co-Investigator. Programmatic research to understand how modifiable environmental factors interact with the genome in the development of asthma. CIHR – Environments, Genes and Chronic Disease. Principal Investigators: Jeff Brook, Michael Kobor and Stuart Turvey. $1,169,519 CAD.
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