Optimizing Gastrointestinal Integrity in Poultry: The Role of Nutrients and Feed Additives

Abstract

Immunomodulation of the immune system by stimulating or suppressing one or both arms, is an emerging concept driven by the understanding of the host defense system. In particular, the gastrointestinal tract (GIT) functions not only as a site for digestion and absorption of nutrients but also acts as a metabolic and immunological organ. This serves as a barrier against abnormal presentation of luminal constituents, caused by dysfunctional intestinal epithelial barrier, to the mucosal immune system. Invasion by pathogens in the case of disease or stress or a massive influx of commensal bacteria overcomes the defensive mechanisms, resulting in the full activation of local dendritic cells and the expression of co-stimulatory molecules and pro-inflammatory cytokines. A growing body of literature demonstrates the immune benefits of increasing the intake of specific nutrients. This strategy involves formulating diets that encompass the bioavailability and utilization of nutrients from various food sources and understanding the dynamics of the macro and micronutrients to support all physiological functions as well as maintaining the function of the immune cells. The nature and type of feed ingredients may also play some roles on the integrity of the GIT of birds. Because dietary intake or nutritional status as well as nutrient requirements may be altered as a result of disease or stress, this may eventually alter the gut microflora and intestinal mucosal integrity, resulting in a compromised barrier of the intestinal epithelium. The weakening of the intestinal integrity could result in an increase in bacterial adherence to the mucosa, bacterial translocation, susceptibility to opportunistic bacterial infection, and mis-appropriation of nutrients. In this chapter, we will discuss the role of dietary energy and nutrients as substrates that have the potential to influence GIT's health and integrity and their roles, directly or indirectly, in modulating bird's ability to be resilient or resist infection.

Effects of Dietary Quebracho Tannin on Performance Traits and Parasite Load in an Italian Slow-Growing Chicken (White Livorno Breed)

“…[1,4,5]. The pathways involved in the effect of most phytobiotics are still not fully understood; they may intervene by activation of feed intake and secretion of digestive enzymes [4]; by causing disruption of cellular membrane in pathogen microbes [1]; by decreasing the virulence of microbes through the increase of hydrophobicity of microbial species throughout their cell surface properties [1]; by stimulating growth of favorable bacteria in the gut [1,2,4,6,7]; by acting as immunostimulatory substances [1]; by protecting intestinal tissue from microbial attack [1,2,6]; and by acting as antioxidants [8,9].…”

A microencapsulated feed additive containing organic acids, thymol, and vanillin increases in vitro functional activity of peripheral blood leukocytes from broiler chicks

“…A complex interplay exits between early dietary interventions and the development of immune competence; however, 2 recent reviews highlight that much of the research is directed toward the impact of dietary interventions on lymphoid tissue ( Taha-Abdelaziz et al., 2018 ) or gastrointestinal integrity ( Adedokun and Olojede, 2018 ). The vast majority of studies evaluating feed additives in poultry focus on performance and growth parameters with little regard for determining the mode of action and impact on immune function outside the gut.…”

Influence of Particle Size and Xylanase in Corn-Soybean Pelleted Diets on Performance, Nutrient Utilization, Microbiota and Short-Chain Fatty Acid Production in Young Broilers

“…On the contrary, the current study did not show differences in SCFA when xylanase was added, which might be related with the extremely fast turnover rate of SCFA from the intestine into the blood [ 54 ], and/or the preference for this VFA over others in the intestinal epithelial cells and the liver [ 55 ]. Thus, the GIT is not only a site for digestion and absorption of nutrients but also experiences enormous interactions with the microbiota, and functions as a metabolic and immunological organ [ 56 ]. Thus, xylanase supplementation could have a role in reducing the immunological stress in the gut, probably through microbiota modulation and subsequent reduction in the metabolic yield of an innate immune system, which increases the availability of nutrients for growth rather than maintenance.…”