Potential of a fucoidan-rich Ascophyllum nodosum extract to reduce Salmonella shedding and improve gastrointestinal health in weaned pigs naturally infected with Salmonella

Background:Dietary supplementation with a fucoidan-rich Ascophyllum nodosum extract(ANE),possessing an in vitro anti-Salmonella Typhimurium activity could be a promising on-farm strategy to control Salmonella infection in pigs.The objectives of this study were to:1)evaluate the anti-S.Typhimurium activity of ANE(containing 46.6%fucoidan,18.6%laminarin,10.7%mannitol,4.6%alginate)in vitro,and;2)compare the effects of dietary supplementation with ANE and Zinc oxide(ZnO)on growth performance,Salmonella shedding and selected gut parameters in naturally infected pigs.This was established post-weaning(newly weaned pig experiment)and following regrouping of post-weaned pigs and experimental re-infection with S.Typhimurium(challenge experiment).Results:In the in vitro assay,increasing ANE concentrations led to a linear reduction in S.Typhimurium counts(P<0.05).In the newly weaned pig experiment(12 replicates/treatment),high ANE supplementation increased gain to feed ratio,similar to ZnO supplementation,and reduced faecal Salmonella counts on d 21 compared to the low ANE and control groups(P<0.05).The challenge experiment included thirty-six pigs from the previous experiment that remained on their original dietary treatments(control and high ANE groups with the latter being renamed to ANE group)apart from the ZnO group which transitioned onto a control diet on d 21(ZnO-residual group).These dietary treatments had no effect on performance,faecal scores,Salmonella shedding or colonic and caecal Salmonella counts(P>0.05).ANE supplementation decreased the Enterobacteriaceae counts compared to the control.Enterobacteriaceae counts were also reduced in the ZnO-residual group compared to the control(P<0.05).ANE supplementation decreased the expression of interleukin 22 and transforming growth factor beta 1 in the ileum compared to the control(P<0.05).Conclusions:ANE supplementation was associated with some beneficial changes in the composition of the colonic microbiota,Salmonella shedding,and the expression of inflammatory genes associated with persistent Salmonella infection.

Seaweed nutraceuticals and their therapeutic role in disease prevention

There is a growing interest that bioactive compounds from seaweed can play a major therapeutic role in disease prevention in humans.Seaweed bioactives including polysaccharides,pigments,fatty acids,polyphenols and peptides have been proven to possess various beneficial biological properties that could potentially contribute to functional food and nutraceutical development.These bioactive are explored for functional properties such as antioxidant,antibacterial,anticancer,antidiabetic,antitumor,antiviral,anti-inflammatory and anticoagulant properties,both in an in-vitro and in-vivo model system.This review critically examines the existing scientific knowledge on primary and secondary metabolites from seaweed and their functional properties for health-related conditions.It presents an update on the most recent evidence relating to their effect on health-related conditions and their action on cellular metabolism.Recent advancement and challenges for seaweed bioactive as a nutraceutical in relation to their biocompatibility and bioavailability to understand their therapeutic development is discussed.