Exploring the link between inflammation and brain function after metabolic-bariatric surgery: A year-long fMRI study

Area of Science:

• Neuroscience
• Immunology
• Bariatric Surgery

Background:

• Metabolic-bariatric surgery (MBS) improves brain function beyond weight loss.
• Mechanisms linking MBS-induced inflammation and brain changes are not fully understood.
• Investigating inflammation's role in postoperative brain function can refine patient selection and improve MBS outcomes.

Purpose of the Study:

• Identify brain regions where spontaneous neural activity and functional connectivity correlate with the changing inflammatory profile after MBS.
• Explore the relationship between the interleukin-6 to interleukin-10 (IL-6/IL-10) ratio and brain activity.
• Examine these correlations at multiple time points before and after laparoscopic sleeve gastrectomy.

Main Methods:

• Assessed the perioperative IL-6/IL-10 ratio in 36 patients undergoing laparoscopic sleeve gastrectomy.
• Measured amplitude of low-frequency fluctuation (ALFF) and functional connectivity across 375 brain regions.
• Analyzed data at three time points: pre-surgery, 3 months post-surgery, and 12 months post-surgery.

Main Results:

• The IL-6/IL-10 ratio initially rose post-MBS, then fell below pre-surgery levels by 12 months.
• ALFF in subcortical regions decreased with rising IL-6/IL-10 ratio, while 16 cortical regions showed the opposite trend.
• Functional connectivity between the left insula and medial prefrontal cortex increased with a rising IL-6/IL-10 ratio.

Conclusions:

• This study identifies specific brain regions linked to inflammation post-MBS.
• Many identified regions are implicated in obesity pathogenesis or are targets for obesity treatments.
• Findings provide crucial insights for future obesity research and therapeutic strategies.