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ARS Home » Midwest Area » West Lafayette, Indiana » Livestock Behavior Research » Research » Publications at this Location » Publication #400476

Research Project: Optimizing Welfare for Food Producing Animals

Location: Livestock Behavior Research

Title: Research Note: Probiotic, Bacillus subtilis, prevents neuroinflammation in the hippocampus via the gut microbiota-brain axis in heat-stressed chickens

item FU, YUECHI - Purdue University
item HU, JIAYING - Purdue University
item Cheng, Heng Wei

Submitted to: Poultry Science
Publication Type: Research Notes
Publication Acceptance Date: 3/2/2023
Publication Date: N/A
Citation: N/A

Interpretive Summary: Heat stress has been recognized as a critical environmental stressor reducing performance, health and well-being of farm animals including poultry. The objective of this study was to determine the effect of dietary supplementation of probiotics on broiler health under heat stress. Results showed that the dietary probiotic supplementation prevents the negative effects of heat stress on chickens by reducing brain inflammation. This information can be used by broiler producers to develop management guidelines for improving chicken health and welfare.

Technical Abstract: High ambient temperature (heat stress, HS) is one of the critical environmental factors causing gut microbiota dysbiosis and increasing gut permeability, consequently inciting neuroinflammation in humans and various animals including chickens. The aim of this study was to examine if a probiotic, Bacillus subtilis, can reduce neuroinflammation in heat-stressed broiler chickens. Two hundred and forty 1-day-old broiler chicks were randomly assigned to 48 pens among 4 treatments in two identical, thermal-controlled rooms (n =12): Thermoneutral (TN)-regular diet (RD), TN-PD (the regular diet mixed with a probiotic at 250 ppm), HS-RD, and HS-PD. The probiotic diet was fed from day 1, and HS at 32 ºC for 10-h daily was applied from d 15 for a 43-day trial. Results showed that compared to the TN broilers, the HS broilers had higher hippocampal interleukin (IL)-6, toll-like receptor (TLR)4, and heat shock protein (HSP)70 at both mRNA and protein levels regardless of dietary treatment (P < 0.05). In addition, the HS-PD broilers had higher levels of hippocampal IL-8 (P < 0.05) than the TN-PD broilers. Within the HS groups, compared to the HS-RD broilers, the HS-PD broilers had lower levels of IL-6, IL-8, HSP70, and TLR4 (P < 0.05) in the hippocampus. Within the TN groups, the TN-PD broilers had lower IL-8 at both mRNA expressions and protein levels (P < 0.05) but higher TLR4 protein levels (P < 0.05) in the hippocampus as compared to the TN-RD broilers. These results indicate that dietary supplementation of the Bacillus subtilis-based probiotic may reduce HS-induced brain inflammatory reactions in broilers via the gut-brain-immune axis. These results indicate the potential use of probiotics as a management strategy for reducing the impact of HS on poultry production.