Effects of β-glucan on Salmonella enterica serovar Typhimurium swine colonization and microbiota alterations

Shawn M D Bearson; Julian M Trachsel; Bradley L Bearson; Crystal L Loving; Brian J Kerr; Daniel C Shippy; Tadele G Kiros

doi:10.1186/s40813-023-00302-4

Effects of β-glucan on Salmonella enterica serovar Typhimurium swine colonization and microbiota alterations

Porcine Health Manag. 2023 Feb 14;9(1):7. doi: 10.1186/s40813-023-00302-4.

Authors

Shawn M D Bearson¹, Julian M Trachsel^{2

3}, Bradley L Bearson⁴, Crystal L Loving², Brian J Kerr⁴, Daniel C Shippy², Tadele G Kiros⁵

Affiliations

¹ Food Safety and Enteric Pathogens Research Unit, USDA, ARS, National Animal Disease Center, 1920 Dayton Ave, Room 1403, Ames, IA, 50010, USA. shawn.bearson@usda.gov.
² Food Safety and Enteric Pathogens Research Unit, USDA, ARS, National Animal Disease Center, 1920 Dayton Ave, Room 1403, Ames, IA, 50010, USA.
³ Agricultural Research Service Participation Program, Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA.
⁴ Agroecosystems Management Research Unit, USDA, ARS, National Laboratory for Agriculture and the Environment, Ames, IA, USA.
⁵ Phileo by Lesaffre, North America, Milwaukee, WI, USA.

Abstract

Background: The 2017 Veterinary Feed Directive eliminated the use of medically important antibiotics for growth promotion of food animals; thus, alternative growth promoters are highly desirable by food animal producers to enhance animal health and reduce pathogen colonization, including the human foodborne pathogen Salmonella. β(1-3)(1-6)-D-glucan (β-glucan) is a soluble fiber with prebiotic characteristics; it has been shown to modulate immune and intestinal functions that strengthen swine resistance to health challenges such as bacterial infections when supplemented in the diets of growing pigs. The current study evaluated the effects of a β-glucan product on gut microbial community structure as well as Salmonella shedding and intestinal colonization.

Results: Five-week-old pigs were fed a β-glucan amended diet at 500 g/ton (n = 13) or a non-amended control diet (n = 14) for three weeks, followed by inoculation of the 27 pigs with 1 × 10⁹ colony forming units of Salmonella enterica serovar Typhimurium strain UK1. While remaining on the respective diets, fecal samples collected at 2, 4, 7, and 16 days post-inoculation (dpi) were similar for Salmonella shedding counts between the two diets. At 16 dpi, Salmonella counts were significantly lower in the cecal contents of the β-glucan-fed pigs (P = 0.0339) and a trend towards a reduction was observed in the Peyer's patches region of the ileum (P = 0.0790) compared to the control pigs. Pigs fed β-glucan for three weeks exhibited an increase in members of the Clostridia class in their fecal microbial communities, and after inoculation with Salmonella, several potentially beneficial microorganisms were enriched in the microbiota of β-glucan-fed pigs (Lactobacillus, Ruminococcaceae, Prevotellaceae, Veillonellaceae, Bifidobacterium and Olsenella).

Conclusion: Administration of β-glucan altered the swine gut microbiome and reduced Salmonella colonization in the cecal contents.

Keywords: Antibiotic alternative; Microbiota; Salmonella; Swine; β-Glucan.