Impacts of Bariatric Surgery on the Microbiome and Brain Function

Summary

Emerging evidence suggests that dietary and metabolic interventions could potentially target prevention and supportive therapies as well as treatments that may slow the clinical deterioration of neurodegenerative disorders. Though certain dietary patterns can impair specific cognitive domains, e.g., declines in reasoning and global cognition, there is still no consensus on the optimal diet to maintain brain health. Studies have also shown an association between the gut microbiome and neurocognition, as the microbiota can affect neuronal function through neurotransmitters and neuroactive microbial metabolites. Furthermore, studies indicate that diet may strongly influence the gut microbiota. However, the mechanisms for these complex relationships are still poorly understood. Bariatric procedures \[i.e., weight loss surgeries\] create a unique environment, in which a fast change in gut microbiota composition and dietary patterns occurs through surgery-induced intestinal and metabolic modifications, leading to changes in gut-brain communication. Interestingly, improvements in neurocognitive domains including memory and executive function have been reported post-bariatric surgery. However, there is large variability in these outcomes, indicating that the benefits are not universal. The goal of the current study is to explore the associations between dietary patterns and gut microbiota with cognition and brain structure, using bariatric surgery as an efficient naturalistic experimental design. This project will also explore potential mediators of diet-microbiome alterations as they relate to improvements in brain function and structure. A total of 120 adult patients (\> 30y yrs.) scheduled to undergo a first bariatric surgery along with 60 age-, sex-, and BMI-matched waitlist control group will be recruited from the bariatric surgery clinic at the CIUSSS du Nord-de-l'Île-de-Montréal. These individuals will undergo assessments 3 months before surgery, as well as 6- and 12-months post-surgery, or an equivalent time for those on the waitlist. This study will also include 60 age-and sex-matched individuals who are not eligible for bariatric surgery as an additional healthy Canadian comparison group (only one assessment time point). Assessments taken during the data collection period will include: self-report information \[e.g., sociodemographic and background information, health and diet behaviours\]; information from medical records \[e.g., medications usage, peri- and post-surgical complications, etc.\]; physiological measures \[i.e., blood, urine and fecal samples collection\]; cognitive assessment \[i.e., neuropsychological tests battery\]; and brain imaging \[i.e., structural MRI\]. Collectively, this study is designed to provide critical information about potential individually targeted diet-based preventative strategies to reduce the development and progression of neurodegenerative disorders. Moreover, this project will explore potential mediators of diet-microbiome alterations as they relate to improvements in brain function and structure, and as such, it will provide essential information on key mechanisms, stimulating further research and the creation of parallel non-dietary therapeutic options.

Conditions

• Bariatric Surgery Candidate
• Weight Loss

Sponsors & Collaborators

• Concordia University, Montreal

  collaborator OTHER

• Centre de Recherche de l'Institut Universitaire de Geriatrie de Montreal

  collaborator OTHER

• University of Ottawa

  collaborator OTHER

• Centre Integre Universitaire de Sante et Services Sociaux du Nord de l'ile de Montreal

  lead OTHER

Principal Investigators

• Simon Bacon, PhD · Centre Integre Universitaire de Sante et Services Sociaux du Nord de l'ile de Montreal

Eligibility

Min Age

30 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2022-08-01

Primary Completion

2025-01-31

Completion

2025-05-31

Countries

• Canada

Study Locations