Exploring post-bariatric plasma metabolic changes using ATR-FTIR spectroscopy: Clinical insights and molecular...

Bariatric surgery offers effective treatment of obesity, yet the full metabolic response of the organism remains unclear. Attenuated Total Reflection Fourier Transform Infrared spectroscopy (ATR-FTIR) allows to track the most detailed biochemical alterations in biofluids on a molecular level. This study aimed to utilize ATR-FTIR spectroscopy for monitoring changes of the metabolic profile of plasma in post-bariatric surgery patients and compare this profile to healthy individuals. Twenty patients with morbid obesity underwent bariatric procedures, resulting in improvement of anthropometric parameters. Laboratory biomarkers showed favorable changes: decreased triglycerides and glucose. PCA analysis of ATR-FTIR spectroscopy data revealed evolution of the plasma metabolic parameters towards those which characterize the healthy group, while the metabolic profile in the baseline group was different - lipid-associated infrared bands primarily drove this differentiation. Semiquantitative analysis of the selected bands revealed distinct spectral profiles with increased total lipid contributions in baseline as compared to follow-up and control. In turn, protein conformation showed increased β-sheet/α-helix ratios and altered secondary protein structures in follow-up. Tyrosine-ascribed region intensity attained the lowest value in baseline. C-O moieties and polysaccharides were elevated in follow-up. Alterations in protein structures were potentially influenced by supplementation and inflammation resolution, while lower tyrosine levels in obesity suggest oxidative stress involvement. Above findings highlight FTIR's potential in revealing impact of bariatric surgery on various elements of the metabolic profile. The multifaceted insight on plasma composition provided by FTIR shows significant improvements of this metabolic profile in post-surgery patients already six months after the intervention.