# Evaluation of l-cell activity in the small intestine according to the extension of the biliopancreatic loop in patients undergoing Roux-en-Y gastric by-pass

## TL;DR

This study found that the length of the biliopancreatic loop in gastric bypass surgery does not affect L-cell activity in the small intestine.

## Contribution

The study shows that L-cell activity increases after surgery regardless of the biliopancreatic loop length.

## Key findings

- L-cell activity increased in the terminal ileum six months after surgery.
- No significant difference in L-cell activity was found between the two biliopancreatic loop lengths.
- Both loop lengths led to increased L-cell activity, but not due to loop extension.

## Abstract

•Question – Extension of the biliopancreatic loop increases l-cell activity after surgery bariatric?•Findings – l-cell activity increased independent of extension of the biliopancreatic limb.•Meaning – The additional beneficial effects of long BPL may be due to more rapid delivery of food and bile salts to more distal portions of the intestine.

Question – Extension of the biliopancreatic loop increases l-cell activity after surgery bariatric?

Findings – l-cell activity increased independent of extension of the biliopancreatic limb.

Meaning – The additional beneficial effects of long BPL may be due to more rapid delivery of food and bile salts to more distal portions of the intestine.

Individuals with severe obesity and type 2 diabetes mellitus have reduced secretion of incretins by L cells. Studies suggest an increase in L cell activity according to the length of the Biliopancreatic Loop (BPL).

Compare the effect of biliopancreatic loop extension on the number and expression of L cells in patients undergoing RYGB

Subjects (n = 13) undergoing RYGB with a BPL of 100 cm (G1) or 200 cm (G2). Intestinal biopsies were done before (T1) and 6 months after (T2) RYGB in 3 segments: gastro-enteric anastomosis (A), entero-enteric anastomosis (B) and terminal ileum (C). Analyzes of intestinal biopsies by immunohistochemistry and qRT-PCR.

There was an increase (p < 0.0001) in L cells marked by PYY and GLP1 between T1 (17 ± 10.5) and T2 (23.5 ± 10.7) only at point C. There was no difference in L cells expression between groups G1 and G2 at points A (A1: 17.3 ± 2.9; A2: 19.9 ± 1.9; p = 0.09), B (B1: 13.7 ± 6.6; B2: 14.1 ± 4.9; p = 0.89) and C (C1: 13.2 ± 2.2; C2: 11.4 ± 3.4; p = 0.32) in PYY and GLP1 gene expression (A1: 20.8 ± 4, 1; A2: 23.7 ± 3.6; p = 0.2), B (B1:14.3 ± 7.9; B2: 22.7 ± 11.8; p = 0.1), (C1: 17±4.1; C2: 21.1 ± 4.8; p = 0.2).

Both techniques lead to an increase in the number of active L cells.