Supplementation of a lacto-fermented rapeseed-seaweed blend promotes gut microbial- and gut immune-modulation in weaner piglets

Abstract

The direct use of medical zinc oxide (ZnO) in feed will be abandoned after 2022 in Europe, leaving an urgent need for substitutes to prevent post-weaning disorders. This study assessed whether rapeseed meal added two brown macroalagae species (Saccharina latissima and Ascophylum nodosum) and fermented using lactic acid bacteria (FRS) could improve piglet performance and gut health. The weaned piglets were fed one of three different feeding regimens (n = 230 each): basal diet, 2.5% and 5% FRS from day 28 of life to day 85. The piglets fed with 2.5% FRS presented superior phenotype with alleviated intraepithelial and stromal lymphocytes infiltration in the gut, enhanced colon mucosa barrier as well as numerically improvements of final body weight. Colon microbiota composition was determined using amplicon sequencing of the V3 and V1 - V8 region of the 16S rRNA gene using Illumina Nextseq and Oxford Nanopore MinION sequencing, respectively. The two amplicon sequencing strategies showed high consistence between the detected bacteria. Both sequencing technologies showed that the FRS fed piglets had a distinctly different microbial composition relative to the basal diet. Compared with piglets fed the basal diet, Prevotella stercorea was verified by both technologies to be more abundant in the FRS piglets, and positively correlated with colon mucosa thickness and negatively correlated with blood levels of leucocytes and IgG. In conclusion, FRS supplementation improved gut health of weaner piglets, and altered their gut microbiota composition. Increasing the dietary inclusion of FRS from 2.5% to 5% did not cause further improvements.

Effect of fermented rapeseed meal in the mixture for growing pigs on the gastrointestinal tract, antioxidant status, and immune response

“…Based on the results of our previous research, we postulated that the fermented component (FRSMb), as a factor including the absorption of minerals, including zinc 34 , and stimulating immune processes 24 , 45 , would be effective enough that the addition of zinc to the diet of piglets could be minimized or even eliminated (group FR). This assumption was very bold, but the results enabled some interesting observations that should be further studied.…”

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].…”