Intestinal Pioneer Colonizers as Drivers of Ileal Microbial Composition and Diversity of Broiler Chickens

Abstract

Given that recent advances in metagenomics have highlighted the importance of intestinal microbes for poultry health, there has been a corresponding search for early manipulation strategies of intestinal microbiota in order to advance immune system development and optimize functional properties of growth. In this study, we used the in ovo technique as an experimental model to address how early bacterial intestinal colonization could affect the development and establishment of the mature ileal microbiota. Inoculations containing one of the following: 0.2 mL of 0.9% sterile saline (S), approximately 10 2 cells of Citrobacter freundii (CF), Citrobacter species (C2) or lactic acid bacteria mixture (L) were administered via in ovo into the amnion. Results showed that Enterobacteriaceae abundance was negatively correlated with aging, although its high population at day of hatch affected the microbiota composition, delaying mature microbiota establishment. L treatment increased colonization of butyrate-producing bacteria by 3 and 10 days, and segmented filamentous bacteria in the lower ileum by 10 days. On the other hand, L-probiotic decreased the population of Enterococcaceae. In addition, L and C2 microbial communities were less diverse at 10 than 3 days of age in the upper ileum. Importantly, these findings provide a valuable resource for a potential study model for interactions between microbial colonization and associated immune responses. In conclusion, our analysis demonstrates that intestinal pioneer colonizers play a critical role in driving the course of microbial community composition and diversity over time, in which early life exposure to L-based probiotic supported selection alongside greater colonization of symbiotic populations in the ileum of young broilers.

Comparative of probiotics reveals cecal microbial component associated with performance parameters in broilers

“…Thus, an immediate supplementation of probiotics post-hatch is more important in avian species than in other animals [7]. The early exposure to microbial preparations has been identified as an approach to modulate the microbiota towards beneficial bacterial growth [3,4] and pathogen colonization reduction [18]. Additionally, supplementation of probiotics has been successfully linked to GIT development by stimulating the growth of villus surface area [18,19].…”

“…Additionally, supplementation of probiotics has been successfully linked to GIT development by stimulating the growth of villus surface area [18,19]. Other probiotic action mechanisms include maturation of immune system, improvement of gut barrier function, and the presence of highly competitive microbial communities, which can lead exclusion of pathogenic bacteria through competitive exclusion [3,5–9].…”

“…Probiotics have become increasingly popular across human medicine and livestock industry due to the following benefits in the host: stimulation of beneficial microbiota, reduction, and prevention of pathogen colonization, development of immune system, improvement in digestive efficiency, and maturation of intestinal microbiota [3,5–9]. Although several bacterial species and yeasts have been described as potential probiotic for broiler chickens; Bacillus, Lactobacillus, Enterococcus, Bifidobacterium, Pediococcus , and Escherichia are the most common bacterial genera used for probiotic formulations, whereas Saccharomyces cerevisiae is the most common yeast [5,7].…”

Comparative effectiveness of probiotic-based formulations on cecal microbiota modulation in broilers

“…This prediction is supported by the notion that the host immune system may limit microbial diversity, given that not all microbes are beneficial [19]. In addition, the overabundance of high-functioning commensal bacteria may lead to a low level of diversity in the intestinal ecosystem [8]. Nevertheless, stress conditions or GIT pathogen colonization can induce a reduction of microbial diversity in poultry [20,21].…”

“…In this context, probiotics have been identified as a promising nutritional intervention to promote modulation of GIT microbiota toward commensal bacteria growth [5–8]. However, modification of the microbial population is not considered a general benefit of probiotic supplementation [9].…”