title: Reduced particle size wheat bran is butyrogenic and lowers Salmonella colonization, when added to poultry feed.
abstract: Feed additives, including prebiotics, are commonly used alternatives to antimicrobial growth promoters to improve gut health and performance in broilers. Wheat bran is a highly concentrated source of (in)soluble fiber which is partly degraded by the gut microbiota. The aim of the present study was to investigate the potential of wheat bran as such to reduce colonization of the cecum and shedding of Salmonella bacteria in vivo. Also, the effect of particle size was evaluated. Bran with an average reduced particle size of 280μm decreased levels of cecal Salmonella colonization and shedding shortly after infection when compared to control groups and groups receiving bran with larger particle sizes. In vitro fermentation experiments revealed that bran with smaller particle size was fermented more efficiently, with a significantly higher production of butyric and propionic acid, compared to the control fermentation and fermentation of a larger fraction. Fermentation products derived from bran with an average particle size of 280μm downregulated the expression of hilA, an important invasion-related gene of Salmonella. This downregulation was reflected in an actual lowered invasive potential when Salmonella bacteria were pretreated with the fermentation products derived from the smaller bran fraction. These data suggest that wheat bran with reduced particle size can be a suitable feed additive to help control Salmonella infections in broilers. The mechanism of action most probably relies on a more efficient fermentation of this bran fraction and the consequent increased production of short chain fatty acids (SCFA). Among these SCFA, butyric and propionic acid are known to reduce the invasion potential of Salmonella bacteria.
authors.affiliation: Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium.
authors.forename: K
authors.initials: K
authors.lastname: Vermeulen
authors.affiliation: Laboratory of Food Chemistry and Biochemistry, Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Kasteelpark Arenberg 22 box2463, B-3001 Leuven, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Verspreet
authors.affiliation: Laboratory of Food Chemistry and Biochemistry, Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Kasteelpark Arenberg 22 box2463, B-3001 Leuven, Belgium.
authors.forename: C M
authors.initials: CM
authors.lastname: Courtin
authors.affiliation: Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium.
authors.forename: F
authors.initials: F
authors.lastname: Haesebrouck
authors.affiliation: Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium.
authors.forename: R
authors.initials: R
authors.lastname: Ducatelle
authors.affiliation: Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium. Electronic address: filip.vanimmerseel@ugent.be.
authors.forename: F
authors.initials: F
authors.lastname: Van Immerseel
mesh_terms: D000821:Animal Feed / Q000032:analysis* / Q000382:microbiology; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics; D057138:Bacterial Shedding; D002432:Cecum / Q000382:microbiology; D002645:Chickens; D004032:Diet / Q000662:veterinary; D004043:Dietary Fiber / Q000008:administration & dosage / Q000032:analysis*; D005232:Fatty Acids, Volatile / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D010316:Particle Size; D012475:Salmonella / Q000502:physiology; D012481:Salmonella Infections, Animal / Q000178:diet therapy* / Q000382:microbiology; D015534:Trans-Activators / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D004043:Dietary Fiber; D005232:Fatty Acids, Volatile; C102236:HilA protein, Salmonella; D015534:Trans-Activators
keywords: Broiler; Invasion; Salmonella; Wheat bran