Introduction: Bariatric surgery is currently the most effective long-term treatment for obesity, resulting in reduced appetite and improved glycaemic control. These benefits are due to profound changes to the gut-brain axis. Despite these benefits, a small patient subset exhibits higher rates of adverse mental health outcomes post-surgery, such as depression and anxiety. Although emerging longitudinal studies explore this association, there is a paucity of research exploring how gut-brain axis alterations could mechanistically contribute to these adverse mental health outcomes post-surgery. Therefore, the aim of this study was to investigate individual differences in the effect of bariatric surgery on depressive-like and anxiety-like behaviour in a mouse model of vertical sleeve gastrectomy (VSG).
Materials and Methods: Male and female C57BL/6 (n=57) mice were fed a high-fat, high-sugar diet (45%kcal fat; 11 weeks) before undergoing VSG or sham surgery. Before and after surgery, mice were tested for depression-like and anxiety-like behaviour. RNA was extracted from tissue punches of the dorsal striatum, a brain region associated with depression, and subjected to next-generation bulk RNA-sequencing. Analysis of this data is currently ongoing.
Results: Compared to sham surgery mice, VSG resulted in significant and sustained weight loss, accompanied by reduced food intake. VSG mice also showed a trend for higher immobility times in the forced swim test and decreased preference for sucrose solution, suggestive of depressive-like behaviour. Results from analysis of RNA-sequencing of the dorsal striatum are pending
Conclusion: Outcomes from this study will provide valuable insight into the neurobiological underpinnings of adverse mental health outcomes following bariatric surgery.