Exploring the Possible Link between the Gut Microbiome and Fat Deposition in Pigs

Abstract

Excessive lipid accumulation and high oxidative stress have become a serious health and economic problem in the pig industry. Fatness characteristics are crucial in pig production since they are closely related to meat quality. The gut microbiome is well acknowledged as a key element in fat deposition. But the link between gut microbiota and fat accumulation in pigs remains elusive. To examine whether there is a link between pigs’ gut microbiome, lipogenic properties, and oxidative stress, we selected 5 high-fat pigs and 5 low-fat pigs from 60 250-day-old Jinhua pigs in the present study and collected the colon content, serum sample, and liver and abdominal fat segments from each pig for metagenomic analysis, the oxidative stress assay, and RT-qPCR analysis, respectively. The backfat thickness and fat content of the longissimus dorsi muscle were considerably higher in the high-fat pigs than in the low-fat pigs ( P < 0.05 ). An obvious difference in GSH-Px and MDA in the serum between the high- and low-fat pigs was observed. After RT-qPCR analysis, we found the gene expression of ACC1 and SREBP1 in the liver and FAS, PPARγ, and LPL in the abdominal fat were significantly higher in high-fat pigs than in low-fat pigs ( P < 0.05 ). Additionally, metagenomic sequencing revealed that high-fat pigs had a higher abundance of Archaeal species with methanogenesis functions, leading to more-efficient fat deposition, while low-fat pigs had higher abundances of butyrate-producing bacteria species that improved the formation of SCFAs, especially butyrate, thus alleviating fat deposition in pigs. Furthermore, a total of 17 CAZyme families were identified to give significant enrichments in different fat phenotypes of pigs. This study would provide a detailed understanding of how the gut microbiome influences fat deposition in pigs, as well as a hint for improving growth performance and fatness traits by manipulating the gut microbiome.

Low Protein Diet Improves Meat Quality and Modulates the Composition of Gut Microbiota in Finishing Pigs

“…Thus, the composition and diversity of gut microbiota in finishing pigs were affected by dietary CP level, and LP diets could modulate the microbial community and diversity, which might be associated with changes in carcass traits and meat quality. In recent years, the gut microbiota has been recognized as an important factor contributing to the regulation of skeletal muscle mass and function ( 51 ) as well the fat deposition ( 52 ). Interestingly, targeting gut microbiota facilitates the dietary protein efficacy to prevent the diminished skeletal muscle mass and strength during aging ( 53 ).…”

Gut microbiota and meat quality

“…Gut microbiome explained nearly 11% of the variation in finishing weight ( Hu et al, 2021 ). Low fat content pigs had higher abundances of butyrate-producing bacteria species that improved the formation of SCFAs, especially butyrate, thus alleviating fat deposition, while high fat-content pigs had a higher abundance of Archaeal species along with higher methanogenesis functions, leading to more efficient fat deposition ( Zhao et al, 2022 ). SCFA administration into the ileum could improve the meat quality of growing pigs by inhibiting the mRNA expressions of fatty acid synthase (FAS) and acetyl-CoA carboxylase in the longissimus dorsi ( Jiao et al, 2021 ).…”

“…Symbiotic supplementation into the diet improved the growth performance, oxidative stability, and meat quality in both chicken ( Cheng et al, 2017 ) and duck ( Chen et al, 2018 ). Furthermore, the gut microbiome is also well-acknowledged as a key element in regulating fat deposition: since they are closely related to meat quality, excessive lipid accumulation and high oxidative stress have become a serious health and economic problem in the pig industry ( Zhao et al, 2022 ).…”

Gut Microbiome Studies in Livestock: Achievements, Challenges, and Perspectives

“…In this context, weaning is a critical life stage in which the piglet diet undergoes a sharp change. Studies on the swine gut microbiome have largely benefited from the establishment of a reference gene catalogue by means of deep metagenome sequencing of fecal samples [ 102 ] and have confirmed that also in this livestock species the interplay between diet and gut physiology across different growth stages is intimately associated with animal health and production performance [ 103 ], including fat deposition [ 104 ]. Other than varying on the basis of the food provided [ 105 , 106 , 107 , 108 ], GIT location [ 109 , 110 , 111 ], behavior [ 112 ], parasite infections [ 113 ], breed affiliation, and sex [ 114 ], the microbial diversity was found to correlate positively with piglet weight [ 115 ] and age [ 116 ].…”