Acknowledgements
The authors are grateful for all of the involvement of the participants, especially children and youth with multiple sclerosis, and their parents without whom this study would not have been possible. The authors also acknowledge the important contributions of: the Tremlett team (University of British Columbia); Dr. Morag Graham (National Microbiology Laboratory, Public Health Agency of Canada) in providing guidance for the microbiome sequencing; Thomas Duggan in facilitating study set-up, coordination and data collection; Bonnie Leung for study coordination; Michael Sargent (Department of Internal Medicine, and the University of Manitoba IBD Clinical and Research Centre laboratory, Winnipeg, MB, Canada) for managing the stool biobank, and Dr. Jessica D. Forbes (University of Toronto, Toronto, Canada) for assisting with the original grant application. We are also grateful to the investigators and study teams at each site who participated in the Canadian Paediatric Demyelinating Disease Network study, including Dr. Douglas Arnold. Finally, our study would not have been possible without the support of the endMS Personnel Award from the Multiple Sclerosis Society of Canada.
Author contributions
A.I.M. designed the research question with support from H.T. A.I.M and H.T. contributed to conception and design of the study, acquisition, interpretation of data, and drafted the first version of the manuscript, tables and figures. F.Z., Y.Z., and A.D. provided input on statistical analysis. L.B. and W.H. contributed to the study design. Y.Z., J.F., G.V.D., C.Bo., M.G., J.H., E.W. and H.T. facilitated obtaining funding (PI: Tremlett, The Multiple Sclerosis Scientific and Research Foundation). J.H. facilitated training of study coordinators the collection of stool samples. C.Be. oversaw the biobanking. M.G., N.K., and G.V.D. oversaw the 16S rRNA sequencing; C.Bo., performed the stool extractions and 16S rRNA sequencing; A.I.M. conducted the bioinformatics and analyses. All authors contributed to the interpretation of the data and provided a critical review of the manuscript.
Competing interests
A.I.M. is funded through the MS Society of Canada endMS Doctoral Studentship (EGID: 3246) and The Multiple Sclerosis Scientific and Research Foundation (PI: Tremlett, EGID: 2636). F.Z. and Y.Z. were funded through research grants held by H.T., including The Multiple Sclerosis Scientific and Research Foundation (PI: H.T., EGID: 2636).
L.B. and A.D. are supported by Multiple Sclerosis Society of Western Australia (MSWA). L.B. is also supported by MS Australia.
D.L.A. is funded by the Canadian MS Society, the International Progressive MS Alliance, the Canadian Institutes of Health Research and the US Department of Defense. He has received personal compensation for serving as a Consultant for Alexion, Biogen, Celgene, Frequency Therapeutics, GENeuro, Genentech, Merck/EMD Serono, Novartis, Roche, and Sanofi. D.L.A. has an ownership interest in NeuroRx.
A.B.-O. is funded by the NIH, ITN, NMSS and MSSOC. A.B.-O. has participated as a speaker in meetings sponsored by and received consulting fees and/or grant support from: Janssen/Actelion; Atara Biotherapeutics, Biogen Idec, Celgene/Receptos, Roche/Genentech, Medimmune, Merck/EMD Serono, Novartis, Sanofi-Genzyme.
C.Be. is supported in part by the Bingham Chair in Gastroenterology. He has consulted to or served on advisory boards for Abbvie Canada, Amgen Canada, Bristol Myers Squibb Canada, JAMP Pharmaceuticals, Janssen Canada, Pfizer Canada, Sandoz Canada, Takeda, and has received unrestricted educational grants from Abbvie Canada, Janssen Canada, Pfizer Canada, Bristol Myers Squibb Canada, and Takeda Canada. He has been on the speaker’s bureau of Abbvie Canada, Janssen Canada, Pfizer Canada and Takeda Canada. He has received research grants from Abbvie Canada, Amgen Canada, Pfizer Canada, and Sandoz Canada and contract grants from Janssen.
R.A.M. receives research funding from: CIHR, Research Manitoba, Multiple Sclerosis Society of Canada, Multiple Sclerosis Scientific Foundation, Crohn’s and Colitis Canada, National Multiple Sclerosis Society, the CMSC, the Arthritis Society and US Department of Defense. She is a co-investigator on a study funded in part by Biogen Idec and Roche Canada. She is supported by the Waugh Family Chair in Multiple Sclerosis.
J.O. receives research funding from: Multiple Sclerosis Society of Canada, Multiple Sclerosis Scientific Foundation, and CMSC.
G.V.D. is the Chief Bioinformatics Scientist with the National Microbiology Laboratory – Public Health Agency of Canada and has received research support in the last three years from the National MS Society, the Canadian Institute of Health Research, and Genome Canada.
E.A.Y. has received research support in the last 3 years from the National MS Society, Canadian Institutes of Health Research, National Institutes of Health, Ontario Institute of Regenerative Medicine, Stem Cell Network, SickKids Foundation, Peterson Foundation, MS Society of Canada, and the MS Scientific Research Foundation. She has received funding for investigator-initiated research from Biogen and has served on scientific advisory boards for Biogen, Alexion and Hoffman-LaRoche.
B.B. serves as a consultant to Novartis, UCB, and Roche. B.B. provides non-remunerated advice on clinical trial design to Novartis, Biogen, Teva Neuroscience. B.B. is funded by the NMSS, NIH, and Canadian MS Society.
E.W. is funded by the NMSS, NIH, PCORI, DoD and Race to Erase MS. E.W. has received consulting honoraria from Emerald Pharmaceutical. She is a site PI for several pharmaceutical clinical trials (Biogen, Roche, Alexion).
H.T. has, in the last five years, received research support from the Canada Research Chair Program, the National Multiple Sclerosis Society, the Canadian Institutes of Health Research, the Multiple Sclerosis Society of Canada, the Multiple Sclerosis Scientific Research Foundation and the EDMUS Foundation (‘Fondation EDMUS contre la sclérose en plaques’). In addition, in the last five years, has had travel expenses or registration fees prepaid or reimbursed to present at CME conferences from the Consortium of MS Centres (2018), National MS Society (2018), ECTRIMS/ ACTRIMS (2017-2022), American Academy of Neurology (2019). Speaker honoraria are either declined or donated to an MS charity or to an unrestricted grant for use by H.T.’s research group.
C.Bo., J.H., N.K., M.G., W.H. declare no potential conflict of interest.
Materials & Correspondence
Correspondence and requests for materials should be addressed to H.T.
Data availability
The datasets generated and analyzed during the current study are available from the study team (contact the corresponding author, H.T.), upon reasonable request along with a proposed rigorous research question. The data are not publicly available due to data protection and confidentiality requirements.
Code availability
The microbiota bioinformatics were implemented in Qiime2 (v. 2019.4) are available for download at https://qiime2.org/. The statistical analyses were implemented in the R programming language (v. 4.0.4), available for download at https://www.r-project.org/. The relevant packages used for analyses were listed in the corresponding methods section in the article and supplemental file.
Ethics
Informed consent was obtained from all participants and their parent/legal guardian. The research ethics boards at each institution approved the study.