Seaweed nutraceuticals and their therapeutic role in disease prevention

Seaweeds in Pig Nutrition

Seaweeds are macroalgae, with different sizes, colors and composition. They consist of brown algae, red algae and green algae, which all have a different chemical composition and bioactive molecule content. The polysaccharides, laminarin and fucoidan are commonly present in brown seaweeds, ulvans are found in green seaweeds and, red algae contain a large amount of carrageenans. These bioactive compounds may have several positive effects on health in livestock. In order to reduce the antimicrobials used in livestock, research has recently focused on finding natural and sustainable molecules that boost animal performance and health. The present study thus summarizes research on the dietary integration of seaweeds in swine. In particular the influence on growth performance, nutrients digestibility, prebiotic, antioxidant, anti-inflammatory, and immunomodulatory activities were considered. The review highlights that brown seaweeds seem to be a promising dietary intervention in pigs in order to boost the immune system, antioxidant status and gut health. Data on the use of green seaweeds as a dietary supplementation seems to be lacking at present and merit further investigation.

Quantification of Polyphenols in Seaweeds: A Case Study of Ulva intestinalis

In this case study, we explored quantitative ¹H NMR (qNMR), HPLC-DAD, and the Folin-Ciocalteu assay (TPC) as methods of quantifying the total phenolic content of a green macroalga, Ulva intestinalis, after optimized accelerated solvent extraction. Tentative qualitative data was also acquired after multiple steps of purification. The observed polyphenolic profile was complex with low individual concentrations. The qNMR method yielded 5.5% (DW) polyphenols in the crude extract, whereas HPLC-DAD and TPC assay yielded 1.1% (DW) and 0.4% (DW) respectively, using gallic acid as the reference in all methods. Based on the LC-MS observations of extracts and fractions, an average molar mass of 330 g/mol and an average of 4 aromatic hydrogens in each spin system was chosen for optimized qNMR calculations. Compared to the parallel numbers using gallic acid as the standard (170 g/mol, 2 aromatic H), the optimized parameters resulted in a similar qNMR result (5.3%, DW). The different results for the different methods highlight the difficulties with total polyphenolic quantification. All of the methods contain assumptions and uncertainties, and for complex samples with lower concentrations, this will be of special importance. Thus, further optimization of the extraction, identification, and quantification of polyphenols in marine algae must be researched.

The Effect of Increasing Inclusion Levels of a Fucoidan-Rich Extract Derived from Ascophyllum nodosum on Growth Performance and Aspects of Intestinal Health of Pigs Post-Weaning

This study examines the effects of increasing dietary inclusion levels of fucoidan, from a 44% fucoidan extract on the growth performance and intestinal health of pigs post-weaning (PW). Seventy-two newly weaned pigs (8.4 kg (SD 1.06)) were assigned to: (T1) basal diet (BD); (T2) BD + 125 ppm fucoidan; (T3) BD + 250 ppm fucoidan (8 pens/treatment). The appropriate quantity of a 44% fucoidan extract was included to achieve these inclusion levels. Faecal scores were recorded daily. On d15 PW, samples were collected from the intestinal tract from 1 pig/pen from the BD and BD + 250 ppm fucoidan groups. Pigs supplemented with 250 ppm fucoidan had improved faecal scores and increased concentrations of total volatile fatty acids and propionate in the colon (p < 0.05). The fucoidan-rich extract reduced the expression of CLDN5 (duodenum), SCL5A1/SGLT1 and SI (jejunum) and TJP1, FABP2, and SLC5A1 (ileum) (p < 0.05). The extract reduced the relative abundance of Prevotella and Lachnospiraceae (p < 0.05) and increased the abundance of Helicobacter (p < 0.01) in the caecum. However, no negative impact on growth performance or small intestinal morphology was observed. Thus, the inclusion of 250 ppm fucoidan improves faecal consistency without affecting growth performance and therefore warrants further investigation as a supplement for the prevention of PW diarrhoea under more challenging commercial conditions.