# 16S rRNA Gene and Metagenomic Analysis Revealed an Association Between Cecal Microbiota and Pork Umami

## TL;DR

This study finds that specific gut microbes and their functions, not overall microbial diversity, are linked to the umami flavor in pork.

## Contribution

The study identifies specific microbial species and functional pathways associated with pork umami flavor using 16S rRNA and metagenomic analyses.

## Key findings

- The high umami group had a distinct microbial community compared to other groups.
- Uncultured species CAG-632 sp900539185 was highly abundant and correlated with umami flavor.
- Functional analysis showed enrichment of genes related to carbohydrate metabolism and short-chain fatty acid pathways in high umami groups.

## Abstract

Pork flavor is a key determinant of meat quality, with umami serving as a major contributor to consumer preference and purchase decisions. However, the reason for the connection between the pork umami and the intestinal microorganisms remains unclear at present. In this study, umami intensity of pork from commercial pigs was quantified using a taste-sensing electronic tongue system, and animals were stratified into low, medium, and high umami groups. Cecal microbiota were then profiled by 16S rRNA gene sequencing and shotgun metagenomics to compare community composition and microbiome functional profiles across groups. The results show that the change in the flavor of pork may be associated with specific microorganisms and their metabolites rather than different microbial communities. This provides associative evidence that may inform future studies on precision feeding or microbiome-targeted strategies.

Umami is a key determinant of pork flavor, but the association between the intestinal microbial community and umami differences remains unclear. Here, we used the taste-sensing electronic tongue system to divide the Duroc × Landrace × Yorkshire pigs into high, medium and low groups. We combined 16S rRNA gene and shotgun metagenomic sequencing to study the differences in the microbial community composition and functional genes. The results showed that the microorganisms in the cecum of different groups had a similar core microbial community. The Shannon diversity analysis showed that there were no significant differences among the different groups. The Bray–Curtis distance indicated that there were differences in the bacterial communities between the high umami group and the other two groups. The LEfSe analysis and Spearman correlation analysis revealed that the uncultured species CAG-632 sp900539185 maintained a high abundance in the high umami group and was significantly correlated with umami. Metagenomic functional analysis revealed distinct functional signatures among umami groups, with enrichment of genes related to carbohydrate transport and metabolism, butanoate and other short-chain fatty acid pathways, nitrogen utilisation, cell-surface structures, adhesion and RNA metabolism in high umami groups. These research findings indicate that the differences in the delicious flavor of pork are more likely to be associated with specific microbial species and the functional characteristics of the cecal microbial community, rather than the overall situation of the entire microbial community.