# Diet-Induced Modulation of Gut Microbiota Affects Meat Quality in Grass Carp (Ctenopharyngodon idellus)

## TL;DR

This study shows how diet affects gut bacteria and meat quality in grass carp, offering insights for better aquaculture practices.

## Contribution

The study reveals diet-induced differences in gut microbiota and meat quality traits in two grass carp types.

## Key findings

- Crisped grass carp had higher free amino acids, fatty acids, and collagen compared to grass carp.
- Gut microbiota diversity was higher in crisped grass carp, dominated by Proteobacteria, Fusobacteriota, and Firmicutes.
- Microbial abundance correlated with meat quality traits like fatty acids and collagen.

## Abstract

Understanding meat quality and gut microbiota hold great potential for promoting healthy and sustainable fish production, while also contributing to fisheries management and conservation. However, differences in meat quality and the diversity, structure, and function of gut microbiota among fish across different feeding regimes remain poorly understood. This study compared meat quality and gut microbiota between grass carp (gc) and crisped grass carp (cgc) to support sustainable aquaculture and provide more tasted fish meat. Cgc exhibited higher levels of free amino acids, fatty acids, and collagen, whereas gc had greater concentrations of hydrolyzed amino acids, nucleotides, and antioxidant indices. Fatty acid composition differed significantly between the two. Gut microbiota diversity was higher in cgc, with Proteobacteria, Fusobacteriota, and Firmicutes being dominant, while gc was dominated by Proteobacteria, Bacteroidota, and Firmicutes. The microbial community structures differed significantly. Functional predictions showed 1612 COG and 2032 KEGG pathways varied between groups. Significant correlations were found between microbial abundance and meat quality traits, including fatty acids, hydrolyzed amino acids, and collagen. These findings offered valuable insights for enhancing fish nutrition, optimizing feed formulations, and improving aquaculture practices.