Use of advanced technologies and feed additives in connecting gut microbiome maturation to broiler performance

The postbiotics could promote butyric acid producing bacteria directly or through cross-feeding mechanisms, while the essential oil compounds could control harmful bacterial, resulting in higher growth of butyric acid producing bacteria. Overall, the synergistic action of postbiotics and essential oil compounds could accelerate the development of a balanced and resilient mature microbiota in birds leading to improved performance.

Vivek Kuttappan, DVM/PhD
Poultry Technology Lead – Postbiotics
Cargill

Poultry production is forecasted to lead the global meat production by 59% in the next decade to meet consumer needs and ensure global food security (OECD/FAO, 2022). The challenge will be to meet this target in a sustainable way, making the most of limited feed resources and without being overly reliant on antibiotic or chemical compounds. As feed represents the largest cost input in poultry production, optimizing nutrient utilization and digestive efficiency are critical success factors. With 109 to 1011 bacteria/gram of intestinal digesta, the gut microbiome is a complex system with potential impact on gut health and production performance in broilers. Due to that complexity, understanding the changes in the gut microbiome and how we can influence it to adapt to challenges could be overwhelming at times. The use of advanced technologies and interventions, providing practical insights into the gut microbiome analysis of broilers to help improve animal health, performance, and preharvest food safety, can be advantageous in addressing sustainable broiler production.

THE CONCEPT OF GUT MICROBIOME MATURATION
Considering the complexity of the gut microbiome and the associated variations, it is important to establish the key attributes of a healthy gut microbiome. Extensive analysis of gut microbiome in broilers from field trials, as well as control research trials, were conducted using a non-invasive advanced microarray tool coupled with artificial intelligence – Galleon™ Microbiome Intelligence – to identify biomarkers for performance, preharvest food safety, harmful bacteria, etc. Results revealed that the broiler gut microbiome undergoes a maturation process from a simple to a more diverse microbial population (Figure 1). During the first week of age, the poultry gut microbiome primarily contains lactate producing bacteria (Lactobacillaceae, Streptococcaceae etc.). The short chain fatty acid (SCFA) producing bacteria (Lachnospiraceae, Ruminococcaceae etc.) uses lactate as a substrate, and thus there is a cross-feeding mechanism between the groups. As a result, the SCFA-producing bacteria increases in abundance later and produces SCFA such as butyric acid. Butyric acid has been reported to have several benefits by improving the gut integrity, barrier function, and reducing inflammation. Overall, the maturation of the gut microbiome results in a more resilient microbiota which can withstand challenges and support the birds in better digestion as well as utilization of nutrients.

Figure 1. Healthy gut microbiome maturation profile in broilers

In fact, birds are most vulnerable to challenges during the initial stages of this maturation process. Interestingly, a comparison of high versus low performing flocks (~300g difference in body weight) showed that high performing birds had a more mature microbiome at an earlier age. Moreover, this could have helped the high performing birds to be more resilient to various environmental challenges, and divert more nutrients towards production performance. Low performing flocks were characterized by a lower abundance of lactate-producing bacteria during the first 14 days of production, resulting in lower numbers of short chain fatty acid (SCFA) producing bacteria at 35 days of age. The low producing birds showed higher abundance of several opportunistic harmful bacteria (Proteobacteria such as E. coli, Salmonella etc.), resulting in increased bacteria and food safety risk. Based on these findings, dietary interventions can be designed and implemented with changes in raw materials, nutrient levels, and using specific feed additives to promote a more favorable microbiome maturation, while keeping harmful bacteria under control.

INFLUENCING GUT MICROBIOME MATURATION USING FEED ADDITIVES
a. Postbiotics
Learnings from these field trials, with respect to maturation of the gut microbiome, were used to evaluate the microbiome modulation benefit of a postbiotic-based feed additive. Postbiotics are defined by the International Scientific Association for Probiotics and Prebiotics (ISAPP) as preparation of inanimate microorganisms and/or their components that confer a health benefit on the host. A metanalysis of nine trials was conducted comparing birds with and without dietary inclusion of postbiotics, focusing on the changes in microbiome using microarray assay and artificial intelligence biomarker identification. The artificial intelligence model generated from the analysis revealed that nine out of ten biomarkers at 14d of age from the birds were linked to lactate producing bacteria. Interestingly, the dietary inclusion of postbiotics resulted in significantly higher abundance of lactate producers at 14d, which promoted the growth of Lachnospiraceae (short chain fatty acid producers), indicative of an early maturation of gut microbiome compared to the respective no-additive control.

b. Syngery between postbotics and essential oil compounds
In addition to that, a unique combination of postbiotics with a proprietary blend of essential oil compounds was evaluated for gut microbiome modulatory and performance benefits in broilers. Four independent trials were conducted comparing broiler birds fed on a basal diet with birds fed the blend of postbiotic and essential oil blend on top of the basal diet. The results from the four studies showed that birds fed with the new solution containing postbiotics and essential oils showed significantly higher body weight and feed conversion ratio compared to control birds. Moreover, there was a significantly higher abundance of butyrate producing bacteria, and reduction of opportunistic harmful bacteria such as Clostridium perfringens at 21 and 35d. In fact, the postbiotics could promote butyric acid producing bacteria directly or through cross-feeding mechanisms, while the essential oil compounds could control harmful bacterial, resulting in higher growth of butyric acid producing bacteria. Overall, the synergistic action of postbiotics and essential oil compounds could accelerate the development of a balanced and resilient mature microbiota in birds leading to improved performance.

CONCLUSION
The use of advanced tools and technology is imperative to understand the changing in patterns of the complex poultry gut microbiome. Connecting these gut microbiome changes with animal health, performance, and preharvest food safety can help to implement appropriate interventions strategies with changes in raw materials, nutrients levels, inclusion of additives, etc., in the diet to attain the specific production targets in a more sustainable way.

About Vivek Kuttappan
Vivek Kuttappan, Ph.D., is a Poultry Technology Lead at Cargill, Inc. that supports the animal agriculture industry through unparalleled research capabilities, innovative feed and premix products and services, and digital modeling and formulation solutions. Throughout his career, Dr. Kuttappan has provided valuable contributions to the poultry industry in two specific areas:1) broiler meat quality, reducing poultry carcass quality defects such as myopathies, and 2) poultry gut health, improving gut health in broilers, thereby reducing economic losses to poultry producers. Dr. Kuttappan holds a patent for a novel molecule to improve gut health in broilers and has participated in approximately 100 scientific publications, including 40 peer-reviewed journal articles cited by researchers worldwide. He has received several awards for his research, including the prestigious PSA Early Achievement Award for Industry. As a subject expert in solving poultry meat quality challenges, he has served as an invited speaker in the industry as well as in academia. Dr. Kuttappan continues to collaborate with academia to solve gut health threats in antibiotic-free production as a research partner in various projects investigating non-antibiotic feed additive strategies to mitigate health challenges and improve poultry production performance. He has been an active member of the Poultry Science Association since 2009 and currently serves as the Chair of the PSA Committee on Industry Relations to propose how the Poultry Science Association can support, fund, or create projects, plans, and actions to fulfill potential needs and initiatives within the sector of industry relations. He is also an editorial board member and reviewer for several scientific journals. Dr. Kuttappan received his doctorate in poultry science from the Center of Excellence for Poultry Science, University of Arkansas, and a bachelor’s degree and master’s degree in veterinary science from Kerala Agricultural University, India.