Bariatric surgery (BS) is a well-established treatment for obesity that induces substantial and permanent weight loss. However, a significant portion of patients show little to no response. Weight loss might be caused by the body’s metabolic adaption to the rearranged digestive tract. Also, recently proposed changes in the central nervous system, altering eating and motivational behavior, suggest a strong link between gut and brain signaling.
While differences in gut-brain-communication following BS have been topic of recent research interest, little is known about its relationship to the high variability in patients’ weight loss. Here, we aim to identify differences between patients with good and poor therapy outcomes by connecting metabolic to cognitive and psychosocial explanatory models.
Using a post-hoc design, we test 50 participants with either high (>70%) or little (<35%) excess weight loss at least 2 years after either Roux-en-Y-gastric bypass or sleeve gastrectomy, only including adults without neurological impairment, uncontrolled diabetes (HbA1c > 7%) or substance abuse. We use cognitive tasks that are indirect markers of central dopaminergic function, specifically testing working memory, learning behavior and impulsivity. Release of gut peptides and a metabolic profile will be measured via blood samples before and after a 300-kcal standardized liquid meal. Eating behavior, personality traits and mood are assessed via standardized questionnaires. Enteric microbiota will be analyzed via shotgun sequencing.
We expect to find a significant group difference between therapeutic outcome and ingestion-related response of gut peptides, psychosocial characteristics and central dopaminergic level as measured by cognitive function.
Author
Grasser, L.1, 2, Lammert, M.1, 2, 3, Fenske, W.K.1, 3, Horstmann, A.1, 2, 3
Affiliations
1 Integrated Research and Treatment Center (IFB) AdiposityDiseases, University of Leipzig
2 Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig
3 Collaborative Research Centre 1052 “Obesity Mechanisms”
Keywords
bariatric surgery, gastric surgery, dopamin, dopamine deficiency, gut-brain-axis, gut-brain-communication, gut peptides