The effect of different levels of arginine supplementation on the gut microbial homeostasis of broilers during sub-clinical necrotic enteritis challenge

Authors: FATHIMA, SHAHNA - University Of Georgia; HAKEEM, WALID,AL - University Of Georgia; Shanmugasundaram, Revathi; LOURENCO, JEFERSON - University Of Georgia; SELVARAJ, RAMESH - University Of Georgia

Submitted to: Frontiers in Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/2/2024
Publication Date: 9/17/2024
Citation: Fathima, S., Hakeem, W., Shanmugasundaram, R., Lourenco, J., Selvaraj, R. 2024. The effect of different levels of arginine supplementation on the gut microbial homeostasis of broilers during sub-clinical necrotic enteritis challenge. Frontiers in Physiology. 15, p.1463420.. https://doi.org/10.3389/fphys.2024.1463420.
DOI: https://doi.org/10.3389/fphys.2024.1463420

Interpretive Summary: Clostridium perfringens is an anaerobic, gram-positive bacterium that causes necrotizing enteritis (NE). NE causes an estimated annual loss of more than $6 billion in US dollars for the global poultry industry. Researchers have studied alternative approaches to control NE in chickens in the post-antibiotic era. Arginine is a functional amino acid that modulates gene expression, protein synthesis, and the overall health of poultry. Arginine supplementation has the potential to regulate the utilization and metabolism of amino acids by certain bacterial species. This, in turn, may have an impact on the composition and activity of other gut microbial species. Arginine has the potential to alleviate NE-induced dysbiosis in chickens because of its ability to regulate gut microbial composition and intestinal immune responses. Therefore, this study evaluated the impact of two levels of arginine supplementation, 125% and 135%, on gut microbial homeostasis in poultry during NE. In this study, 135% arginine supplementation was found to be more advantageous than that of the 125% group when it came to the restoration of gut microbial balance during NE. Arginine supplementation effectively restored the loss in gut microbial diversity caused by the necrotic enteritis challenge and maintained gut microbial homeostasis in poultry.

Technical Abstract: Necrotic enteritis (NE) is an enteric disease of poultry that alters the structure of the gut microbial community causing dysbiosis. This 28-day experiment investigated the effects of 125% and 135% supplemental arginine on the gut microbial diversity and composition of broilers during a subclinical NE challenge. One hundred and twenty one-day-old chicks were randomly allocated to 4 treatments with six replicates each- Uninfected + Basal, NE + Basal, NE + Arg 125%, and NE + Arg 135% diet groups. NE was induced by inoculating 1×104 E. maxima sporulated oocysts on day 14 and 1×108 CFU C. perfringens on days 19, 20, and 21 of age. The NE challenge significantly decreased the number of observed amplicon sequence variants (p = 0.03), the abundance of the phylum Firmicutes (p < 0.01), and the species Mediterraneibacter cottocaccae (p = 0.01) in the ceca of birds on day 21. The NE challenge significantly increased the weighted UniFrac index (p < 0.01), and the abundance of the phylum Bacteroidota (p < 0.01), family Marinifilaceae (p < 0.01), genus Odoribacter (p < 0.01), and species O. splanchnicus (p = 0.01). During NE, the 125% arginine diet restored the abundance of the phylum Bacteroidota (p = 0.03), family Marinifilaceae (p = 0.03), genus Odoribacter (p = 0.03), and species O. splanchnicus (p = 0.03) and M. cottocaccae (p < 0.01). The 135% arginine diet effectively restored the loss in alpha diversity (p = 0.01) caused by NE, the abundance of the phylum Firmicutes (p = 0.01) and Bacteroidota (p < 0.01), family Oscillospiraceae (p = 0.03) and Marinifilaceae (p < 0.01), genus Odoribacter (p < 0.01), and species O. splanchnicus (p < 0.01) and M. cottocaccae (p < 0.01) on day 21. On day 28, the treatments had a significant effect on the cecal propionate (p = 0.01), butyrate (p = 0.04), and total SCFA (p = 0.04) concentrations. In conclusion, the 125% and 135% arginine diets restored gut microbial composition during NE, but not the cecal SCFA profile. Hence, arginine in combination with other feed additives could be used in restoring gut microbial homeostasis during NE in poultry.