Integrated microbiomics and metabolomics analysis reveals the influence of gut microbiota on the growth and metabolism of sea cucumber seedlings.

AIMS: This study explores the impact of gut microbiota on body metabolites and the growth rate of sea cucumber seedlings. METHODS AND RESULTS: A comprehensive analysis using metabolomics and microbiomics was conducted to ascertain the gut microbiota and body metabolites in sea cucumber seedlings exhibiting varying growth rates. Distinct changes in the intestinal flora were observed in correlation with different growth rates of sea cucumber seedlings. The microbial communities of faster-growing seedlings exhibited greater diversity and evenness of taxa. For example, the abundance of genera Rhodococcus, Woeseia, Lysobacter, Desulfuromonadia_Sva1033, and Flavobacteriaceae_NS5_marine_group was more than 24 times higher in the fast-growing group compared to the slow-growing group. Metabolomics analysis revealed an association between high growth rates of cucumber seedlings and discrepancies in metabolites, such as amino acids, lipids, and carbohydrates. Isorenieratene, possibly synthesized by Rhodococcus, was more than 2.5 times more abundant in the fast-growing group than the slow-growing group. Slow-growing seedlings showed considerable enrichment of environmental pollutants, such as antibiotics and drugs, while their colonies were devoid of bacteria capable of degrading such pollutants. In addition, significant differences were observed between groups in the biosynthesis of amino acids, metabolism of arginine and proline, biosynthesis of unsaturated fatty acids, and metabolism of linoleic acid. Moreover, significant correlations between the microbial genera and sea cucumber metabolites were identified through correlation analysis. CONCLUSIONS: Significant differences exist in the gut microbiota and metabolite composition among seedlings with varying growth rates. Microbes residing in the gut have the potential to influence the growth of seedlings through modulation of their metabolism.

Structure and Metabolically Oriented Efficacy of Fucoidan from Brown Alga Sargassum muticum in the Model of Colony Formation of Melanoma and Breast Cancer Cells.

This work reports the detailed structure of fucoidan from Sargassum miticum (2SmF2) and its ability to potentiate the inhibitory effect of glycolysis inhibitor 2-deoxy-d-glucose (2-DG). 2SmF2 was shown to be sulfated and acetylated galactofucan containing a main chain of alternating residues of 1,3- and 1,4-linked α-l-fucopyranose, fucose fragments with monotonous 1,3- and 1,4-type linkages (DP up to 3), α-d-Gal-(1→3)-α-L-Fuc disaccharides, and 1,3,4- and 1,2,4-linked fucose branching points. The sulfate groups were found at positions 2 and 4 of fucose and galactose residues. 2SmF2 (up to 800 µg/mL) and 2-DG (up to 8 mM) were not cytotoxic against MDA-MB-231 and SK-MEL-28 as determined by MTS assay. In the soft agar-based model of cancer cell colony formation, fucoidan exhibited weak inhibitory activity at the concentration of 400 µg/mL. However, in combination with low non-cytotoxic concentrations of 2-DG (0.5 or 2 mM), 2SmF2 could effectively inhibit the colony formation of SK-MEL-28 and MDA-MB-231 cells and decreased the number of colonies by more than 50% compared to control at the concentration of 200 µg/mL. Our findings reveal the metabolically oriented effect of fucoidan in combination with a glycolysis inhibitor that may be beneficial for a therapy for aggressive cancers.

Neiella holothuriorum sp. nov., isolated from the gut of a sea cucumber Apostichopus japonicus.

A Gram-stain negative, aerobic, rod-shaped bacterium, designated 126T, was isolated from the intestinal content of a sea cucumber, Apostichopus japonicus, in China. Strain 126T was found to grow optimally at 25-28 °C and pH 7.5-8.0 in marine 2216 E medium, with tolerance of 1-7% (w/v) NaCl. Strain 126T is motile by means of one to several polar flagella. The dominant fatty acids of strain 126T were identified as C16:1 ω7c/C16:1 ω6c (29.5%), C18:1 ω7c/C18:1 ω6c (19.8%) and C16:0 (16.7%). The respiratory quinone was found to be Q-8. The polar lipid profile was found to be mainly composed of phosphatidylglycerol and phosphatidylethanolamine. The total length of the draft genome is approximately 4.2 × 106 bp, encoding 3655 genes and 3576 coding sequences. The G + C content of the genomic DNA is 48.0%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 126T belongs to the genus Neiella and is closely related to Neiella marina J221T (96.5%). Genomic comparisons of 126T to N. marina J221T revealed that they had similar genome size, G + C content and complement of clusters of orthologous groups. However, average nucleotide identity and digital DNA-DNA hybridization values between strains126T and N. marina J221T was 75.5% and 19.7%, which could distinguish the strains. On the basis of these phenotypic and genotypic data, strain 126T is concluded to represent a novel species, for which the name Neiella holothuriorum sp. nov. is proposed. The type strain is 126T (= GDMCC 1.2530T = KCTC 82829T).

Structural characterization of a P-selectin and EGFR dual-targeting fucoidan from Sargassum fusiforme.

In this study, we obtained fucoidans SFP, SHP, STP, and FVP from Sargassum fusiforme, Sargassum horneri, Sargassumthunbergii, and Fucus vesiculosus, respectively. Chitosan/fucoidan nanoparticles (Cs/F NPs) were prepared using the fucoidans mentioned above. SFP NPs and SHP NPs showed strong binding abilities to P-selectin and epithelial growth factor receptor (EGFR). Given the yields from the alga, SFP was first selected to explore the structural characteristics of the P-selectin and EGFR dual-targeting fucoidan. SFP had an estimated molecular weight of 739 kDa and was mainly composed of galactose (26.57%, mol%) and fucose (66.81%), with minor amounts of mannose (2.54%), glucosamine (0.42%), and glucose (3.66%). Galactose and fucose accounted for thevast majority. Further investigation, including methylation analysis, one- and two-dimensional nuclear magnetic resonance, and mass spectroscopy, was performed to reveal the fine structure of SFP. The results indicated that SFP mainly consisted of â†’ 3)-α-l-Fucp-(1→, →4)-α-l-Fucp-(1→, →3,4)-α-l-Fucp-(1→, →3)-ß-d-Galp-(1→, and minor â†’ 6)-ß-d-Galp-(1→, partially sulfated at the C-4 of â†’ 3)-α-l-Fucp-(1→, C-3 of â†’ 4)-α-l-Fucp-(1→, C-3 of â†’ 6)-ß-d-Galp-(1→, and C-6 of â†’ 3)-ß-d-Galp-(1 â†’ . Sulfated fuco- and galactofuco-segments formed the branches.

Hypolipidemic effect of soluble dietary fibers prepared from Asparagus officinalis and their effects on the modulation of intestinal microbiota.

The soluble dietary fiber from Asparagus officinalis (ASDF) was successively prepared using enzymolysis combined with spray-drying technology. High-performance liquid chromatography analysis showed that ASDF contained two polysaccharide fractions with the average molecular weight of 2.77 × 105 and 6.44 × 103 Da, and was composed of mannose, rhamnose, galacturonic acid, glucose, galactose, and arabinose with a molecular ratio of 19.93:1.02:1.94:32.17:1.00:1.91, respectively. ASDF showed potential in vitro antioxidant activities. The oral administration of ASDF significantly reduced the levels of total cholesterol, triglyceride, and low-density lipoprotein cholesterol in HD-induced mice serum. Furthermore, 16S rRNA gene sequencing analysis showed that ASDF significantly affected the composition of intestinal microbiota, especially reducing the Firmicutes/Bacteroidotetes ratio and the relative abundances of Desulfobacterota, Proteobacteria, Actinobacteriota and increasing that of Muribaculaceae, Bacteroides, and Alloprevotella. These results demonstrated that the intake of ASDF could regulate intestinal microbiota and serum lipid levels in hyperlipidemic conditions.

Characterization and Caco-2 Cell Transport Assay of Chito-Oligosaccharides Nano-Liposomes Based on Layer-by-Layer Coated.

Chito-oligosaccharides (COSs) were encapsulated by the film-ultrasonic method into three nano-liposomes, which were uncoated liposomes (COSs-Lip), chitosan-coated liposomes (CH-COSs-Lip), and sodium alginate (SA)/chitosan (CH)-coated liposomes (SA/CH-COSs-Lip). The physicochemical and structural properties, as well as the stability and digestive characteristics, of all three nano-liposomes were assessed in the current study. Thereafter, the characteristics of intestinal absorption and transport of nano-liposomes were investigated by the Caco-2 cell monolayer. All nano-liposomes showed a smaller-sized distribution with a higher encapsulation efficiency. The ζ-potential, Z-average diameter (Dz), and polydispersity index (PDI) demonstrated that the stability of the SA/CH-COSs-Lip had much better stability than COSs-Lip and CH-COSs-Lip. In addition, the transport of the nano-liposomes via the Caco-2 cell monolayer indicated a higher transmembrane transport capacity. In summary, the chitosan and sodium alginate could serve as potential delivery systems for COSs to fortify functional foods and medicines.

A fucoidan from Sargassum fusiforme with novel structure and its regulatory effects on intestinal microbiota in high-fat diet-fed mice.

A fucoidan SFP, having novel structure, was extracted from Sargassum fusiforme. It had a molecular weight of 703 kDa and was composed of fucose and galactose with the ratio of 73.16:26.84 (mol%). Structural analyses showed that it mainly consisted of 1,3-, 1,4-, 1,3,4-linked-α-l-Fucp and 1,3-, 1,6-linked-ß-d-Galp, with partial sulfation at C-4, C-3 of fucose units and C-6, C-3 of galactose units. The branches consisted of sulfated fucosyl and galactofucosyl oligosaccharides. The regulatory effects of SFP on the intestinal microbiota in high-fat diet-fed mice were investigated. The high-dosage SFP exhibited good hypolipidemic effects, especially in regulating the high-densitylipoproteincholesterol, non-esterified fatty acid levels and lipase activity. It also significantly decreased the ratio of phyla Firmicutes/Bacteroidetes (P < 0.05). Besides, SFP had certain effects on the richness and diversity of intestinal microbiota. Therefore, SFP exhibited novel structure and certain beneficial effects on the disorder of intestinal microbiota in high-fat diet-fed mice.

Hot water pretreatment-induced significant metabolite changes in the sea cucumber Apostichopus japonicus.

Hot water pretreatment of sea cucumbers potentially changes nutritional benefits. This study aimed to quantify hot water pretreatment-induced changes in metabolite profiles of sea cucumber body walls. ICP-OES, GC-MS, and LC-MS analyses of untreated- (UT-BW), hot water-treated body walls (HW-BW) of Apostichopus japonicus, and the hot water extract (HW-E) determined significant losses of minerals (25-50% w/w), protein (~11% w/w), carbohydrate (33% w/w), saponins (~41% w/w), and spermidine (100%), a potential antipsychotic from hot water-treated samples. Multivariate comparisons of HW-BW with UT-BW and HW-BW with HW-E showed increases in amino acids and fatty acids, suggesting hot water-induced degradation or transformation or easier extraction of protein, lipid or other components. Presence of 80 to 88.5% of compounds in the HW-E and lower DHA, EPA and glycerophospholipids levels in HW-BW suggested extraction of these metabolites. These data indicate that novel processing technologies are required to preserve the full nutritional benefits of sea cucumbers.

Three new oleanane-type triterpenoid saponins from the seeds of Celosia cristata L.

Phytochemical investigation of the 1-butanol soluble fraction of 60% ethanol extract of the seeds of Celosia cristata L. led to the identification of three new oleanane-type triterpenoid saponins. Using 1D and 2D NMR experiment methods, ESI-MS analysis and acid hydrolysis, their structures were identified as 3-O-[ß-D-xylopyranosyl-(1 â†’ 3)-ß-D-glucuronopyranosyl]-2ß-hydroxy-oleanolic acid-28-O-ß-D-glucopyranoside (1), 3-O-[ß-D-xylopyranosyl-(1 â†’ 3)-ß-D-glucuronopyranosyl]-2ß, 23-dihydroxy-oleanolic acid-28-O-ß-D-glucopyranoside (2) and 3-O-[ß-D-glucopyranosyl-(1 â†’ 4)-ß-D-glucopyranosyl]-2-hydroxyl-medicagenic acid-28-O-ß-D-glucopyranosyide (3), respectively.