Correlated Responses to Selection for Intramuscular Fat on the Gut Microbiome in Rabbits.

Area of Science:

• Animal Science
• Microbiome Research
• Genetics

Background:

• Intramuscular fat (IMF) content significantly impacts meat quality and human health.
• Host genetics and gut microbiome are key factors influencing IMF variation.
• Divergent selection experiments provide insights into genetic control of complex traits.

Purpose of the Study:

• To investigate the impact of genetic selection for high (H) and low (L) IMF on rabbit gut microbiome composition.
• To identify specific microbial taxa associated with divergent IMF genotypes.
• To develop a microbial biomarker for predicting IMF predisposition.

Main Methods:

• Utilized rabbits from the 10th generation of a divergent IMF selection experiment.
• Analyzed gut microbiota composition at phylum and genus levels.
• Employed logistic regression to develop and validate a microbial biomarker.

Main Results:

• Gut microbiome composition significantly differed between H-line and L-line rabbits.
• Specific genera, including *Hungateiclostridium* and *Escherichia*, were enriched in H-line and L-line, respectively.
• A four-genus microbial biomarker accurately classified H-line and L-line rabbits with 78% accuracy.

Conclusions:

• Divergent IMF genotypes are associated with distinct gut microbiome profiles in rabbits.
• A microbial biomarker can indicate genetic predisposition to muscle lipid accumulation.
• Findings support the development of microbiome-based strategies for IMF improvement.