# Effects of an Isoquinoline Alkaloids Blend on the Expression of Genes Relevant for Antioxidant Capacity, Barrier Integrity and Inflammation Along the Broiler Gut

## TL;DR

This study shows that adding isoquinoline alkaloids to broiler diets improves gut health by boosting antioxidant and anti-inflammatory gene activity, especially in the duodenum.

## Contribution

The study reveals the specific gene-level effects of isoquinoline alkaloids on gut antioxidant, barrier, and inflammatory responses in broilers.

## Key findings

- IQs increased expression of antioxidant and barrier genes in the duodenum.
- IQs reduced TLR signaling and inflammation in the cecum.
- No growth performance differences were observed between treatments.

## Abstract

Intensive broiler production may lead to perturbations of gut function and health. The maintenance of intestinal homeostasis in broilers through the use of dietary phytogenic components such as isoquinoline alkaloids (IQs) is an emerging topic of scientific investigations. In this respect, IQs effects on the underlying mechanisms involved in gut antioxidant capacity, barrier integrity and inflammatory response still remain unclear. This study aimed to investigate the effect of dietary administration of an IQs blend on the expression of genes relevant for gut antioxidant response, barrier function, and inflammatory status, along the intestine of 35‐days‐old broilers. One hundred eighty‐two one‐day‐old Ross 308 broilers were randomly distributed into 2 experimental treatments with 7 replicates of 13 broilers each for 35 d, namely: control treatment (NC) with no IQ addition in the diet and treatment (M) with dietary supplementation at 200 mg/kg diet of an IQs standardized blend. Broiler performance responses did not differ (p > 0.05) among the two treatments. The results showed that M birds had significantly higher (p < 0.05) expression levels for antioxidant capacity, barrier integrity and inflammation‐related genes, at the duodenum compared to NC. Furthermore, at the cecal level, treatment M showed significant (p < 0.05) downregulation of TLR (Toll‐like receptors) signaling and the subsequent inflammation components, compared to NC. Overall, under the optimal conditions of the trial, there were no significant growth performance benefits of IQs blend dietary addition in broilers diets. Nevertheless, IQs blend promoted gut homeostasis in 35‐days‐old broilers via the beneficial modulation of antioxidant and inflammatory responses, primarily at the duodenal level. The latter, under stress challenge conditions, may prove beneficial also for performance that needs to be specifically studied.