Long-Term Transcriptomic Effects of Prebiotics and Synbiotics Delivered In Ovo in Broiler Chickens.

Anna Slawinska,Maria Siwek,Marcin Jaroszewski,Marek Bednarczyk,Arkadiusz Plowiec,Brenda A Wilson

doi:10.1371/journal.pone.0168899

Abstract

In ovo delivery of prebiotics and synbiotics in chickens allows for the development of intestinal microflora prior to hatching, which boosts their robustness. The goal of this study was to determine the transcriptomic profile of the spleen (S), cecal tonsils (CT), and large intestine (LI) of adult chickens injected with prebiotics and synbiotics in ovo. On day 12 of embryo development, incubating eggs were injected with prebiotics: inulin alone (P1) or in combination with Lactococcus lactis subsp. lactis IBB2955 (S1), galactooligosaccharides (GOS) alone (P2) or in combination with Lactococcus lactis subsp. cremoris IBB477 (S2); control group (C) was mock injected with physiological saline. Gene expression analysis was conducted using an Affymetrix Chicken Gene 1.1 ST Array Strip. Most of the differentially expressed genes (DEG) were detected in the cecal tonsils of P2 (378 DEG), and were assigned to gene ontology categories: lymphocyte proliferation, activation and differentiation, and cytokine production. Ingenuity pathway analysis of the DEG (CT of P2) indicated the inhibition of humoral and cellular immune responses, e.g., role of NFAT in regulation of immune responses, phagocytosis, production of nitric oxide, NF-κB, IL-8, and CXCR4 signaling. The DEG with the highest up-regulation from S1 and P2 were involved in gene expression (PAPOLA, RPL27A, RPLP1, and RPS29) from P1 and P2 in transport (BEST4, SLC9A3, and SLC13A2), metabolism (OGT, ALPP, CA4, and CA7), signaling (FGG, G3BP2, UBB, G3BP2, CACNA1G, and ATP6V0A4), and immune responses (MSMB, LGALS3, CABIN1, CXCR5, PAX5, and TNFRSF14). Two DEG influencing the complement system (SERPING1 and MIR1674) were down-regulated in P2 and S1. In conclusion, GOS injected in ovo provided the most potent stimulation of the host transcriptome. This is likely due to its strong bifidogenic effect, which triggers proliferation of indigenous embryonic microflora in ovo, and indirectly influences gene expression regulation in host tissues, especially cecal tonsils.

Highlights

Prebiotics and probiotics contribute to the development of healthy intestinal microflora
We have analyzed long-term transcriptomic responses in immune and gut tissues of chickens that were injected in ovo with prebiotics and synbiotics
Of four bioactive compounds delivered in ovo, GOS proved to be the most potent one in the stimulation of the host– microbiome interactions

Summary

Introduction

Prebiotics and probiotics contribute to the development of healthy intestinal microflora. Prebiotics are composed of natural, fermentable oligosaccharides that are not digested by the host On the contrary, they provide a source of metabolizable energy to some genera of the gut bacteria, which indirectly helps to modulate the biodiversity of microflora [1, 2]. Probiotics are defined as microorganisms (typically bacteria) that, once ingested, confer beneficial properties to the host. They control commensal bacteria in the gut, that are recognized by the immune system as “self” [3]. Probiotics contribute to the colonization of intestinal microflora through direct and indirect mechanisms. They produce substrates that stimulate growth of commensals, and antimicrobials to inhibit gut colonization by pathogens, to name a few. They can be combined into one synergistic compound, called a synbiotic [5]

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