# Changes in the Protein Profile of Saliva from People with Obesity Treated with Bariatric Surgery and Physical Exercise

## TL;DR

This study shows that salivary protein profiles change after bariatric surgery and exercise in people with obesity, suggesting saliva could be used as a non-invasive tool for monitoring health changes.

## Contribution

The study identifies specific salivary proteins that change after bariatric surgery and exercise, offering potential non-invasive biomarkers for obesity interventions.

## Key findings

- Bariatric surgery led to decreased levels of Zn-alpha-2 glycoprotein and immunoglobulin chains in saliva.
- Exercise increased levels of SPLUNC, CA-VI, and cystatins while decreasing Ig kappa chain C region.
- Amylase levels significantly decreased five months after bariatric surgery.

## Abstract

Saliva was used as non-invasive alternative to blood for diagnosing pathophysiological conditions. This study aimed to assess changes in protein profile in people with obesity after bariatric surgery and to assess the impact of exercise on these changes. The saliva proteome was determined from two-dimensional gels of twenty adults (ten people with normal weight and ten people with obesity). The effects of bariatric surgery and exercise were assessed. A decrease in body weight, body mass index, and waist-to-height ratio was observed after bariatric surgery. Low levels of carbonic anhydrase VI (CA-VI), short palate, lung, and nasal epithelium clone 2 (SPLUNC2), and haptoglobin were observed. One month after bariatric surgery, spots of haptoglobin and SPLUNC2 increased, although one CA-VI spot decreased. Zn-alpha-2 glycoprotein, immunoglobulin chains, and actin-related protein-3, which are high in people with obesity, decreased 1 month after bariatric surgery. Five months after bariatric surgery, the most significant change was the amylase decrease. The exercise-induced changes in salivary proteins increased SPLUNC, CA-VI, type S cystatins, actin cytoplasmic 1, and zinc alpha-2 glycoprotein levels and decrease Ig kappa chain C region and Rab GDP dissociation inhibitor beta. It can be concluded that the salivary proteins change between people with normal weight vs. patients with obesity, as well as after bariatric surgery and exercise programmes. Salivary proteins may be useful biomarkers in non-invasive samples for monitoring and assessing the impact of interventions on people with obesity.