# Effect of Sex on Intestinal Microbial Metabolites of Hainan Special Wild Boars

## TL;DR

This study explores how sex affects intestinal microbial metabolites in Hainan wild boars, revealing significant differences between males and females.

## Contribution

The study identifies sex-specific differences in intestinal microbial metabolites and their metabolic pathways in Hainan special wild boars.

## Key findings

- Entire males and females showed the highest number of differential metabolites, which were enriched in more metabolic pathways.
- Castration reduced the sex-based differences in microbial metabolites.
- Certain bacteria were linked to the production of specific metabolites like trehalose and short-chain fatty acids.

## Abstract

Metabolites of intestinal microorganisms play an important role in the growth process of animals, and there are differences in the feeding behavior of animals of different sexes. The aim of this study was to reveal the sex differences in intestinal microbial metabolites of Hainan special wild boars. This study shows that the highest number of differential metabolites was found between entire males and females, the differential metabolites were enriched in more metabolic pathways, and castration reduced this difference. This study provides a certain metabolite database for future precision feeding of Hainan special wild boars and other pig breeds of different sexes.

The intestinal microbiota and its metabolites are essential for the health and growth development of animals. Current research indicates that sex has a certain impact on the structure and function of the intestinal microbiota, but there are few reports on sex differences in intestinal microbiota metabolites, including those of castrated male animals. This study aimed to explore the impact of sex on the intestinal microbial metabolites of Hainan special wild boars (10 entire male pigs, 10 female pigs, and 10 castrated male pigs, denoted EM, FE, and CM, respectively) by employing non-targeted metabolomics and gas chromatography. A total of 1086 metabolites were detected, with the greatest number of differential metabolites observed between EM and FE (54 differential metabolites, including 18 upregulated and 36 downregulated metabolites), the fewest between CM and FE (7 differential metabolites, including 1 upregulated and 6 downregulated metabolites), and an intermediate number between CM and EM (47 differential metabolites, including 35 upregulated and 12 downregulated metabolites). Differential metabolites were involved in more pathways between EM and FE and between CM and EM, including amino acid metabolism and digestive system pathways, whereas differential metabolites were involved in the fewest pathways between CM and FE. Correlation analysis showed Ruminococcaceae UCG-009, uncultured_bacterium_o_SAR324_cladeMarine_group_B, and Candidatus Saccharimonas contributed to the production of metabolites such as trehalose, docosatrienoic acid, D(−)-beta-hydroxy butyric acid, and acetyl-DL-leucine. The levels of acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, and isovaleric acid were significantly higher in EM than in FE, with CM falling between the two. Streptococcus, Lachnospiraceae_NK4A136_group and Rikenellaceae_RC9_gut_group showed a significant positive correlation with the production of short-chain fatty acids (SCFAs), while [Eubacterium]_coprostanoligenes_group, uncultured_bacterium_f_p–251–o5 and Ruminococcaceae_UCG–005 showed a significant negative correlation with the generation of SCFAs. This study provides foundational data and significant insights into precision feeding strategies for Hainan special wild boars of different sexes, as well as the study of sex differences in intestinal microbial metabolites in animals.