# Vertical Sleeve Gastrectomy Reduces Gut Luminal Deoxycholic Acid Concentrations in Mice

## TL;DR

This study shows that vertical sleeve gastrectomy in mice reduces gut levels of a specific bile acid, deoxycholic acid, possibly due to changes in gut bacteria.

## Contribution

The study identifies a surgery-induced decrease in gut luminal deoxycholic acid independent of body weight and substrate availability.

## Key findings

- Vertical sleeve gastrectomy reduces gut luminal deoxycholic acid concentrations in mice.
- The decrease in deoxycholic acid is not due to reduced precursor availability.
- The effect may be linked to changes in gut bacterial bile acid metabolism.

## Abstract

Bariatric surgery alters bile acid metabolism, which contributes to post-operative improvements in metabolic health. However, the mechanisms by which bariatric surgery alters bile acid metabolism are incompletely defined. In particular, the role of the gut microbiome in the effects of bariatric surgery on bile acid metabolism is incompletely understood. Therefore, we sought to define the changes in gut luminal bile acid composition after vertical sleeve gastrectomy (VSG).

Bile acid profile was determined by UPLC-MS/MS in serum and gut luminal samples from VSG and sham-operated mice. Sham-operated mice were divided into two groups: one was fed ad libitum, while the other was food-restricted to match their body weight to the VSG-operated mice.

VSG decreased gut luminal secondary bile acids, which was driven by a decrease in gut luminal deoxycholic acid concentrations and abundance. However, gut luminal cholic acid (precursor for deoxycholic acid) concentration and abundance did not differ between groups. Therefore, the observed decrease in gut luminal deoxycholic acid abundance after VSG was not due to a reduction in substrate availability.

VSG decreased gut luminal deoxycholic acid abundance independently of body weight, which may be driven by a decrease in gut bacterial bile acid metabolism.

The online version contains supplementary material available at 10.1007/s11695-024-07288-0.