Supplementation of a Lacto-fermented Rapeseed-seaweed Blend Promotes Gut Microbial- and Gut Immune-Modulation in Weaner Piglets

Abstract

BackgroundThe direct use of medical zinc oxide in feed will be abandoned after 2022 in Europe, leaving an urgent need for substitutes to prevent post-weaning disorders.ResultsThis study assessed whether rapeseed meal added two brown macroalgae species (Saccharina latissima and Ascophylum nodosum) and fermented using lactic acid bacteria (FRS) could improve weaner piglet performance and gut health. From day 28 of life to day 85, the weaned piglets were fed one of three different feeding regimens (n = 230 each) with inclusion of 0%, 2.5% and 5% FRS. The piglets fed with 2.5% FRS manifested superior phenotype with alleviated intraepithelial and stromal lymphocytes infiltration in the gut, enhanced colon mucosa barrier and numerical increase of final body weight. The colon microbiota composition was determined using the V3 and V1-V8 region 16S rRNA gene amplicon sequencing by Illumina Nextseq and Oxford Nanopore MinION, respectively. The two amplicon sequencing strategies showed high consistence between the detected bacteria. Both sequencing strategies indicated that inclusion of FRS reshaped the colon microbiome of weaner piglets with increased Shannon diversity. Prevotella stercorea was verified by both technologies to be more abundant in the FRS piglets, and its abundance was positively correlated with colon mucosa thickness but negatively correlated with blood concentrations of leucocytes and IgG.ConclusionsFRS supplementation improved the gut health of weaner piglets, and reshaped the gut microbiota composition. Increasing the dietary inclusion of FRS from 2.5% to 5% did not lead to further improvements.

Seaweed Components as Potential Modulators of the Gut Microbiota

“…Many species of gut bacteria produce endogenous carbohydrate-degrading enzymes, such as β-glucanase and β-glucosidase, capable of hydrolysing the glycosidic linkages of polysaccharides [ 65 , 66 , 67 , 68 ]. Several polysaccharides within seaweed that are indigestible in the upper gastrointestinal tract are thought to exert bioactive effects including glycaemic control [ 69 ] and the promotion of gut microbial- and immune-modulation by acting as prebiotics in in vitro and in vivo studies [ 70 , 71 ]. The bioactivity of polysaccharide fractions is influenced by a number of factors such as chemical structure, molecular weight (MW), solubility, extraction method, seaweed genus and seasonal variation [ 72 , 73 ].…”