RESUMEN

The use of Tasco (air-dried Ascophyllum nodosum) as a feed supplement for ruminants has been reported to affect rumen fermentation and reduce Escherichia coli O157:H7 shedding in feces, but the mode of action behind this phenomenon is unclear. In this study, the effects of four Tasco levels (0, 1, 3, and 5%) on rumen microbiota and rumen/fecal E. coli O serogroups in rams were investigated. Rumen total bacteria and archaea were linearly reduced (P < 0.001) and protozoa were linearly increased (P < 0.001) by increasing levels of Tasco. The relative abundances of seven bacterial species and one protozoal species differed among Tasco levels. With Tasco, 14 predicted metabolic pathways were enriched while only 3 were suppressed. A lower ruminal butyrate concentration is possibly associated with enrichment of the "butanoate metabolism" pathway in Tasco-fed rams. The ruminal total E. coli population was linearly reduced (P < 0.001) by Tasco. Supplementation with Tasco only completely eliminated O121 in the rumen and feces, and higher levels of Tasco (3 and 5%) reduced fecal shedding of serogroups O45, O103, and O111 even though these serogroups were present in the rumen. Our results suggest that Tasco effectively reduced pathogenic E. coli but had only minimal impacts on rumen fermentation in rams. IMPORTANCE Maintaining product safety and reducing the carbon footprint of production are two sustainability goals of the livestock industry. The objective of this study was to study the impact of Tasco, a product derived from the brown macroalga Ascophyllum nodosum, on the rumen microbiome and its function. The inclusion of Tasco altered both rumen and fecal microbiota levels without affecting rumen fermentation. Tasco reduced fecal Escherichia coli populations and specifically reduced the prevalence of Shiga toxin-producing E. coli O45, O103, O111, and O121 in feces. The findings of this study highlight the application of Tasco as a potential feed additive to reduce pathogen shedding in rams without interfering with ruminal metabolism.

RESUMEN

BACKGROUND: Gastrointestinal microbial communities are diverse and are composed of both beneficial and pathogenic groups. Prebiotics, such as digestion-resistant fibers, influence the composition of gut microbiota, and can contribute to the improvement of host health. The red seaweed Chondrus crispus is rich in dietary fiber and oligosaccharides, however its prebiotic potential has not been studied to date. METHODS: Prebiotic effects were investigated with weaning rats fed a cultivated C. crispus-supplemented diet. Comparison standards included a fructo-oligo-saccharide (FOS) diet and a basal diet. The colonic microbiome was profiled with a 16S rRNA sequencing-based Phylochip array. Concentrations of short chain fatty acids (SCFAs) in the feacal samples were determined by gas chromatography with a flame ionization detector (GC-FID) analysis. Immunoglobulin levels in the blood plasma were analyzed with an enzyme-linked immunosorbent assay (ELISA). Histo-morphological parameters of the proximal colon tissue were characterized by hematoxylin and eosin (H&E) staining. RESULTS: Phylochip array analysis indicated differing microbiome composition among the diet-supplemented and the control groups, with the C. crispus group (2.5% supplementation) showing larger separation from the control than other treatment groups. In the 2.5% C. crispus group, the population of beneficial bacteria such as Bifidobacterium breve increased (4.9-fold, p=0.001), and the abundance of pathogenic species such as Clostridium septicum and Streptococcus pneumonia decreased. Higher concentrations of short chain fatty acids (i.e., gut microbial metabolites), including acetic, propionic and butyric acids, were found in faecal samples of the C. crispus-fed rats. Furthermore, both C. crispus and FOS supplemented rats showed significant improvements in proximal colon histo-morphology. Higher faecal moisture was noted in the 2.5% C. crispus group, and elevated plasma immunoglobulin (IgA and IgG) levels were observed in the 0.5% C. crispus group, as compared to the basal feed group. CONCLUSIONS: The results suggest multiple prebiotic effects, such as influencing the composition of gut microbial communities, improvement of gut health and immune modulation in rats supplemented with cultivated C. crispus.

Asunto(s)

RESUMEN

The aim of this study was to evaluate the effect of the inclusion of red seaweed supplementation to standard poultry diets on production performance, egg quality, intestinal histology, and cecal short-chain fatty acids in Lohmann Brown Classic laying hens. A total of 160 birds were randomly assigned to 8 treatment groups. Control hens were fed a basal layer diet; positive control hens were fed a diet containing 2% inulin; and 6 treatment groups were fed a diet containing one of the following; 0.5, 1, or 2% Chondrus crispus (CC0.5, CC1, and CC2, respectively) and one of the same 3 levels of Sarcodiotheca gaudichaudii (SG0.5, SG1, and SG2, respectively). Dietary supplementation had no significant effect on the feed intake, BW, egg production, fecal moisture content, and blood serum profile of the birds. The feed conversion ratio per gram of egg was significantly more efficient (P = 0.001) for CC2 and SG2 treatments. Moreover, SG1 supplementation increased egg yolk weight (P = 0.0035) and birds with CC1 supplementation had higher egg weight (P = 0.0006). The SG2 and CC2 groups had greater (P < 0.05) villus height and villus surface area compared with the control birds. Seaweed supplementation increased the abundance of beneficial bacteria [e.g., Bifidobacterium longum (4- to 14-fold), Streptococcus salivarius (4- to 15-fold)] and importantly reduced the prevalence of Clostridium perfringens in the gut of the chicken. Additionally, the concentrations of short-chain fatty acids, including acetic acid, propionic acid, n-butyric acid, and i-butyric acid, were significantly higher (P < 0.05) in CC and SG treatments than in the control. In conclusion, dietary supplementation using red seaweed inclusions can act as a potential prebiotic to improve performance, egg quality, and overall gut health in layer hens.

Asunto(s)

RESUMEN

The extracts of the brown alga, Ascophyllum nodosum, which contains several bioactive compounds, have been shown to impart biotic and abiotic stress tolerance properties when consumed by animals. However, the physiological, biochemical and molecular mechanism underlying such effects remain elusive. We investigated the effect of A. nodosum fucose-containing polymer (FCP) on tolerance to thermally induced stress using the invertebrate animal model, Caenorhabditis elegans. FCP at a concentration of 150 µg mL(-1) significantly improved the life span and tolerance against thermally induced stress in C. elegans. The treatment increased the C. elegans survival by approximately 24%, when the animals were under severe thermally induced stress (i.e. 35 °C) and 27% under mild stress (i.e. 30 °C) conditions. The FCP induced differential expression of genes and proteins is associated with stress response pathways. Under thermal stress, FCP treatment significantly altered the expression of 65 proteins (54 up-regulated & 11 down-regulated). Putative functional analysis of FCP-induced differential proteins signified an association of altered proteins in stress-related molecular and biochemical pathways of the model worm.

Asunto(s)

RESUMEN

The effects of Tasco®, a product made from the brown seaweed (Ascophyllum nodosum) were tested for the ability to protect Caenorhabditis elegans against Pseudomonas aeruginosa infection. A water extract of Tasco® (TWE) reduced P. aeruginosa inflicted mortality in the nematode. The TWE, at a concentration of 300 µg/mL, offered the maximum protection and induced the expression of innate immune response genes viz.; zk6.7 (Lypases), lys-1 (Lysozyme), spp-1 (Saponin like protein), f28d1.3 (Thaumatin like protein), t20g5.7 (Matridin SK domain protein), abf-1 (Antibacterial protein) and f38a1.5 (Lectin family protein). Further, TWE treatment also affected a number of virulence components of the P. aeuroginosa and reduced its secreted virulence factors such as lipase, proteases and toxic metabolites; hydrogen cyanide and pyocyanin. Decreased virulence factors were associated with a significant reduction in expression of regulatory genes involved in quorum sensing, lasI, lasR, rhlI and rhlR. In conclusion, the TWE-treatment protected the C. elegans against P. aeruginosa infection by a combination of effects on the innate immunity of the worms and direct effects on the bacterial quorum sensing and virulence factors.

Asunto(s)

RESUMEN

Tasco(®), a commercial product manufactured from the brown alga Ascophyllum nodosum, has been shown to impart thermal stress tolerance in animals. We investigated the physiological, biochemical and molecular bases of this induced thermal stress tolerance using the invertebrate animal model, Caenorhabiditis elegans. Tasco(®) water extract (TWE) at 300 µg/mL significantly enhanced thermal stress tolerance as well as extended the life span of C. elegans. The mean survival rate of the model animals under thermal stress (35 °C) treated with 300 µg/mL and 600 µg/mL TWE, respectively, was 68% and 71% higher than the control animals. However, the TWE treatments did not affect the nematode body length, fertility or the cellular localization of daf-16. On the contrary, TWE under thermal stress significantly increased the pharyngeal pumping rate in treated animals compared to the control. Treatment with TWE also showed differential protein expression profiles over control following 2D gel-electrophoresis analysis. Furthermore, TWE significantly altered the expression of at least 40 proteins under thermal stress; among these proteins 34 were up-regulated while six were down-regulated. Mass spectroscopy analysis of the proteins altered by TWE treatment revealed that these proteins were related to heat stress tolerance, energy metabolism and a muscle structure related protein. Among them heat shock proteins, superoxide dismutase, glutathione peroxidase, aldehyde dehydrogenase, saposin-like proteins 20, myosin regulatory light chain 1, cytochrome c oxidase RAS-like, GTP-binding protein RHO A, OS were significantly up-regulated, while eukaryotic translation initiation factor 5A-1 OS, 60S ribosomal protein L18 OS, peroxiredoxin protein 2 were down regulated by TWE treatment. These results were further validated by gene expression and reporter gene expression analyses. Overall results indicate that the water soluble components of Tasco(®) imparted thermal stress tolerance in the C. elegans by altering stress related biochemical pathways.

Asunto(s)

Asunto(s)