Breed-dependent differences in gut microbiota linked to indole and skatole levels in Hezuo and DLY pigs

Indole and skatole are major odorous compounds generated in pig farms and their emissions affect the sustainable development of pig industry seriously. At present, microbial interventions represent an efficient and environmentally sustainable strategy for reducing odor emissions. Research on functional microorganisms specifically targeting indole and skatole emission reduction in pigs remains limited. To compare the concentrations of indole and skatole in Hezuo and DLY pigs, and analysis differences in microbial community characteristics between the two pig breeds, aimed to screen the potential functional gut microbiota in reducing indole and skatole production.

Indole and skatole concentrations in the cecum, colon and rectum of Hezuo pigs were reduced compared with DLY pigs (p < 0.05 or p < 0.01). The relative abundances of Treponema_D, Lactobacillus, Coprococcus_A, Anaeroplasma, and Faecalibacillus were higher in Hezuo pigs (p < 0.05). The relative abundances of Escherichia, Streptococcus, Corynebacterium, and Enterococcus_B were higher in DLY pigs (p < 0.05). Correlation analysis indicated that Lactobacillus ultunensis, Lactobacillus amylovorus, Anaeroplasma, Faecalimonas, and Faecalibacillus were negatively associated with indole and skatole concentrations (p < 0.05 or p < 0.01), whereas Streptococcus hyointestinalis, Catenibacterium, Corynebacterium, and Enterococcus_B showed positive associations (p < 0.05 or p < 0.01).

Specific gut microbiota, including Lactobacillus ultunensis, Lactobacillus amylovorus, Anaeroplasma, Faecalimonas and Faecalibacillus are associated with reduced indole and skatole level, indicating their potential as probiotics for mitigating odor emissions in pig production.