Impact of Fermented Corn-Soybean Meal on Gene Expression of Immunity in the Blood, Level of Secretory Immunoglobulin A, and Mucosa-Associated Bacterial Community in the Intestine of Grower-Finisher Pigs.

Junfeng Lu,Zhaolu Wang,Xin'E Shi,Xiao Li,Mengqing Zhu,Haigang Cao,Xiaoyu Zhang,Xuan Zhang,Jianhong Hu,Gongshe Yang

doi:10.3389/fvets.2020.00246

Abstract

This study was conducted to determine the effect of a fermented corn–soybean meal [fermented feed (FF)] on the gene expression of immunity in the blood, the level of secretory immunoglobulin A (sIgA), and mucosa-associated bacterial community in the duodenum and colon of grower-finisher pigs. In this study, crossbred barrows (Duroc × Landrace × Large White) were randomly assigned to either an unfermented corn–soybean diet (Ctrl) (n = 6) or an FF diet (n = 6), and then the following were examined: the expression of immunity using real-time reverse transcription polymerase-chain reaction in the blood, sIgA using enzyme-linked immunosorbent assay (ELISA), and changes in the bacterial community using Illumina Hiseq sequencing in the mucosa of the duodenum and colon. Compared with control pigs fed with a standard diet, the results showed that FF caused upregulation of the mRNA expression of Toll-like receptor 3 (TLR3), TLR4, TLR6, and TLR8 in the blood (P < 0.05). Moreover, sequencing of 16S rRNA genes in duodenal mucosa samples indicated that the FF diet had a lower proportion of Tenericutes (P < 0.05) in the duodenal mucosa-associated microbiota, and FF significantly increased the percentage of Rikenellaceae and Christensenellaceae but decreased the abundance of Lachnospiraceae (P < 0.05) in the colonic mucosa-associated microbiota. The ELISA results showed that FF significantly increased the concentration of sIgA in the colonic mucosa (P < 0.05). More importantly, our correlation analysis indicated that the gene expression of immunity in the blood and the concentration of sIgA was associated with colonic mucosa-associated microbiota. Our data provide new knowledge into the adaptation response of the intestine to fermented feeding in monogastric animals.

Highlights

Fermentation has been used to prepare healthy human foods for a long time [1, 2]
We found no statistical difference between the two groups. These results indicate that fermented feed (FF) administration increased the mRNA expression of Toll-like receptors (TLRs) in the blood
The results showed that fermented feeding significantly increased the proportion of Rikenellaceae and Christensenellaceae, whereas the abundance of Lachnospiraceae, Streptococcaceae, Veillonellaceae, and Succinivibrionaceae decreased in the colonic mucosa samples (P < 0.05) (Table 5)

Summary

Introduction

In the livestock industry, fermented feed (FF) has generated special attention because it is associated with the improvement of nutritional quality [3], with the reduction of antinutritional factors [4]. FF provides probiotics, beneficial microbiota, and metabolites for animals [5, 6]. Using FF could improve the growth performance of nursery [9] and weaned piglets [10]. FF has been observed to improve the growth performance of their progeny and decrease diarrhea incidence [11]. Adding luster to its growing profile is the recent report that FF has beneficial effects on modulating pig gut microbiota [12, 13]

Methods

Results

Discussion

Conclusion