# Lipidomics and Transcriptomics Analyses Reveal Dietary Complex Plant Extracts Improve Lipid Composition of Back Fat in Sheep

## TL;DR

This study shows that adding plant extracts to sheep diets improves fat composition by affecting lipid metabolism and related genes.

## Contribution

The study reveals novel molecular mechanisms by which complex plant extracts improve fatty acid composition in sheep.

## Key findings

- CPE supplementation increased carcass fat content and altered fatty acid composition in sheep.
- Lipidomic analysis showed CPE modulated lipid molecules like PC, FAs, CL, and TAG.
- CPE regulated lipid metabolism via glycerophospholipid metabolism and TNF signaling pathways.

## Abstract

Complex plant extracts (CPE) have garnered significant attention in recent research owing to their impact on fatty acid compositions. Therefore, we employed CPE intervene in lambs and demonstrated that CPE regulated the lipid metabolism of back fat mainly by regulating the glycerophospholipid metabolism, TNF signaling pathway, and cytokine–cytokine receptor interaction signaling pathway. This regulation involved a series of related lipid molecules and genes. Novel insights on the molecular level for the application of CPEs in sheep to improve fatty acid composition are further provided.

Fatty acid contributes notably to meat nutrition value. A previous study investigated how complex plant extracts (CPE) can improve the fatty acid composition of ruminants, but the molecular mechanism remains unknown. This study aimed to examine the effect of dietary CPE supplementation on sheep growth performance and fatty acid composition in back fat (BF), combining lipidomics and transcriptomics analyses to explain the underlying mechanisms. Thirty-six female sheep, weighing 29.92 ± 2.52 kg and of a similar age (~4 months old), were randomly assigned into two groups: one received a basal diet (CTRL group), and the other received the same diet supplemented with 80 mg/kg of CPE (CPE group) for 75 days. The results revealed that the values of carcass fat content (GR) in the CPE group were significantly increased (p = 0.008), and the composition of fatty acid was changed. Lipidomic analysis indicated that CPE modulated lipid metabolism by regulating the contents of lipid molecules such as phosphatidylcholine (PC), fatty acyls (FAs), cardiolipin (CL), and triglyceride (TAG). After the addition of CPE, the lipid metabolism of BF was regulated mainly by regulating the glycerophospholipid metabolism, TNF signaling pathway, and cytokine–cytokine receptor interaction signaling pathway. These results revealed that changes in fatty acids were affected by the added CPE and corresponding molecular changes, which may provide new insights on the molecular level for applying CPE in sheep to improve fatty acid composition.