Therapeutic effects of an orally administered edible seaweed-derived polysaccharide preparation, ascophyllan HS, on a Streptococcus pneumoniae infection mouse model

Ascophyllan HS is a commercially available preparation of the edible brown alga Ascophyllum nodosum containing ascophyllan, a sulfated polysaccharide with diverse beneficial biological activities. In this study, the effects of ascophyllan HS were evaluated in a severe intranasal Streptococcus pneumoniae infection mouse model. The control untreated mice started to die on day 7 and 80% had died by day 14 post-infection. Continuous oral administration of ascophyllan HS before and after bacterial infection resulted in a remarkable increase in survival rate, with 90% of the low (167 mg/kg body weight/day) and 100% of the high (500 mg/kg body weight/day) dose ascophyllan HS-treated mice surviving at day 14 post-infection. Histopathological observation of the lungs of the infected mice revealed the induction of typical pneumonia features in the alveolar spaces of the untreated control mice, such as extensive infiltration of inflammatory cells, edema, and fibrin deposition. In contrast, notable levels of lung injuries or alterations were not observed in the ascophyllan HS-treated mice, and only a minor lesion was observed in one mouse. Furthermore, bacterial burdens in the lungs were significantly reduced in the ascophyllan HS-treated mice as compared to the control mice at day 4 post-infection. Significantly higher levels of IL-12 were detected in the serum of ascophyllan HS-treated mice than that of control mice measured at the end of the infection experiment (day 14). These results suggest that orally administered ascophyllan HS exerts a therapeutic effect on S. pneumoniae infection by activating the host defense systems. This is the first report of the therapeutic effect of an orally administered seaweed polysaccharide preparation on S. pneumoniae infection. Our findings suggest that ascophyllan HS has the potential to be developed as nutraceuticals and pharmaceuticals applicable for humans as well as a safe and promising therapeutic agent against S. pneumoniae infection.

Fucoidan isolated from Ascophyllum nodosum alleviates gut microbiota dysbiosis and colonic inflammation in antibiotic-treated mice

Antibiotic treatment, as an important therapeutic intervention, can cause damage to the host microbiome and the intestinal mucosal barrier. In order to find a way to alleviate the side effects of antibiotics, the present study investigated the effects of fucoidan (ANP) isolated from Ascophyllum nodosum on gut microbiota dysbiosis and colonic inflammation induced by ciprofloxacin-metronidazole (CiMe) in C57BL/6J mice. Our results showed that dietary ANP prevented colon shortening, alleviated the colonic tissue damages, and partially reversed the alteration of gut microbiota by increasing the abundance of potentially beneficial bacteria, e.g., Ruminococcaceae_UCG_014 and Akkermansia and decreasing the abundance of harmful bacteria, e.g., Proteus and Enterococcus. ANP also suppressed the overproduction of TNF-α, IL-1β, and IL-6 and promoted the expression of IL-10. In addition, ANP reversed the decreased production of short-chain fatty acids in CiMe-treated mice. Furthermore, correlation analysis indicated the presence of critical gut microbiota, which played important roles in reducing the inflammation-related indices. Thus, the present study suggests that fucoidan isolated from Ascophyllum nodosum is effective in providing protection against the negative effects of antibiotics on gut microbiota and colonic health.

Codium fragile Ameliorates High-Fat Diet-Induced Metabolism by Modulating the Gut Microbiota in Mice

Codium fragile (CF) is a functional seaweed food that has been used for its health effects, including immunostimulatory, anti-inflammatory, anti-obesity and anti-cancer activities, but the effect of CF extracts on obesity via regulation of intestinal microflora is still unknown. This study investigated anti-obesity effects of CF extracts on gut microbiota of diet-induced obese mice. C57BL/6 mice fed a high-fat (HF) diet were given CF extracts intragastrically for 12 weeks. CF extracts significantly decreased animal body weight and the size of adipocytes, while reducing serum levels of cholesterol and glucose. In addition, CF extracts significantly shifted the gut microbiota of mice by increasing the abundance of Bacteroidetes and decreasing the abundance of Verrucomicrobia species, in which the portion of beneficial bacteria (i.e., Ruminococcaceae, Lachnospiraceae and Acetatifactor) were increased. This resulted in shifting predicted intestinal metabolic pathways involved in regulating adipocytes (i.e., mevalonate metabolism), energy harvest (i.e., pyruvate fermentation and glycolysis), appetite (i.e., chorismate biosynthesis) and metabolic disorders (i.e., isoprene biosynthesis, urea metabolism, and peptidoglycan biosynthesis). In conclusion, our study showed that CF extracts ameliorate intestinal metabolism in HF-induced obese mice by modulating the gut microbiota.

Dendrobium officinale Kimura et Migo and American ginseng mixture: A Chinese herbal formulation for gut microbiota modulation

Dendrobium officinale Kimura et Migo (D. officinale) is a famous traditional Chinese medicine (TCM). A mixture of D. officinale and American ginseng has been shown to enhance cell-mediated immunity, humoral immunity, and monocyte/macrophage functions in mice. Here, the effects of a D. officinale and American ginseng mixture on the structure of gut microbial community in dogs were examined using high-throughput 16S rRNA gene amplicon sequencing. The data revealed that while the mixture did not change the diversity of gut microbial community significantly, differences among individuals were significantly reduced. Furthermore, the mixture-responsive operational taxonomic units (OTUs) exhibited a phase-dependent expression pattern. Fifty-five OTUs were found to exhibit a mixture-induced expression pattern, among which one third were short-chain fatty acid (SCFA)-producing genera and the others were probiotic genera included Lactobacillus spp., Sutterella, Alistipes, Anaerovorax, Bilophila, Coprococcus, Gordonibacter, Oscillibacter, among others. By contrast, 36% of the OTUs exhibiting a mixture-repressed expression pattern were disease-associated microorganisms, and six genera, namely Actinomyces, Escherichia/Shigella, Fusobacterium, Slackia, Streptococcus and Solobacterium, were associated with cancer. In addition, five genera were closely associated with diabetes, namely Collinsella, Rothia, Howardella, Slackia and Intestinibacter. Our results indicate that this D. officinale and American ginseng mixture may be used as a prebiotic agent to enhance SCFA-producing genera and prevent gut dysbiosis.

Differences of the microbial community structures and predicted metabolic potentials in the lake, river, and wetland sediments in Dongping Lake Basin

In freshwater ecosystems, wetlands are generally distinguished from deep-water ecosystems by 2-m water level as boundary. However, the difference of sediment microbial communities between wetlands and deep-water ecosystems is still unclear. We combined 16S rRNA gene sequencing and community metabolic prediction to compare sediment microbial communities and predicted metabolic genes of wetlands (natural and constructed wetlands) and deep-water ecosystems (river and lake) along with environmental factors in summer and autumn in Dongping Lake Basin. Results showed that the deep-water ecosystems had significantly higher community richness than the wetlands in autumn in the freshwater basin, which was mostly related to the pH of sediments. However, no significant difference in community richness was found in summer. Besides, the composition of both predicted metabolic genes and microbial communities was significantly affected by dissolved organic carbon (DOC) and dissolved oxygen (DO). The wetlands exhibited high predicted gene abundances related to xenobiotic biodegradation possibly due to the high DOC or DO level. Compared with the wetlands, most of the deep-water ecosystems exhibited high predicted gene abundances related to element (carbon, nitrogen, and sulfur) metabolism possibly due to the low DOC and DO levels in the freshwater basin. This study can expand the knowledge of ecological function distribution and detoxification mechanism of microbial communities in freshwater ecosystems.

Extracts and Marine Algae Polysaccharides in Therapy and Prevention of Inflammatory Diseases of the Intestine

Inflammatory bowel disease (IBD) is a serious public health problem worldwide. Current therapeutic strategies that use anti-inflammatory drugs, immunosuppressants, and biological treatments are often ineffective and have adverse health effects. In this regard, the use of natural compounds aimed at key pathogenic therapeutic targets in IBD attracts universal attention. Seaweed is a valuable source of structurally diverse biologically active compounds. The materials presented in the review indicate that seaweed extracts and polysaccharides are effective candidates for the development of drugs, biological food additives, and functional nutrition products for the treatment and prevention of IBD. The structural features of algal polysaccharides provide the possibility of exposure to therapeutic targets of IBD, including proinflammatory cytokines, chemokines, adhesion molecules, nuclear factor NF-kB, intestinal epithelial cells, reactive oxygen and nitrogen. Further study of the relationship between the effect of polysaccharides from different types of algae, with different structure and molecular weights on immune and epithelial cells, intestinal microorganisms will contribute to a deeper understanding of their mechanisms and will help in the development of drugs, dietary supplements, functional foods for the treatment of patients with IBD.

Caenorhabditis elegans as an in vivo model to assess fucoidan bioactivity preventing Helicobacter pylori infection

Currently, Helicobacter pylori is the unique biological carcinogenic agent. The search for antimicrobial alternatives to antibiotics against this pathogen has been categorized as a priority due to the drastic failure associated with current applied antibiotic therapy. The present study assessed the bioactive antimicrobial capability of fucoidan ("Generally Recognized as Safe" approval - European Commission December 2017) from different species of Phaeophyceae algae (Fucus vesiculosus, Undaria pinnatifida, Macrocystis pyrifera) against H. pylori. All the studied fucoidans showed bacteriostatic and bactericidal effects at the studied concentrations [5-100] μg ml-1 and exposure times [0-7 days]. The most effective anti-H. pylori fucoidan was validated in Caenorhabditis elegans as an in vivo model. C. elegans feed was supplemented with Undaria pinnatifida [0-100] μg ml-1 fucoidan, resulting in a significant improvement in lifespan, lowered H. pylori concentration in the digestive tract, and increased egg-laying pattern. New research lines proposing this compound as an active agent in nutraceutical and preventive novel therapies should be opened.

Pigs' Feed Fermentation Model with Antimicrobial Lactic Acid Bacteria Strains Combination by Changing Extruded Soya to Biomodified Local Feed Stock

Simple Summary

The world population is growing, and for this reason, it is very important to ensure increased agricultural production in a sustainable and eco-friendly manner. The aim of this study was to apply a combination of newly isolated antimicrobial characteristic possessing lactic acid bacteria (LAB) strains for local stock (rapeseed meal) fermentation and to evaluate the influence of changing an extruded soya to biomodified rapeseed meal in a feed recipe on piglet feces microbiota, health parameters, growth performance, and ammonia emission. The 36-day experiment was conducted using 25-day-old Large White/Norwegian Landrace (LW/NL) piglets, which were randomly distributed into two groups: a control group fed with a basal diet and a treated group fed with a fermented diet (500 g/kg of total feed). Changing from an extruded soya to fermented rapeseed meal led to desirable changes in piglets’ fecal microbiota (there was more than a four-fold higher Lactobacillus count compared to the control group). There was also a 20.6% reduction in ammonia emission in the treated group section. Finally, by changing from extruded soya to less expensive rapeseed meal and applying a fermentation model with selected LAB combination, piglets were fed without any undesirable changes in health and growth performance, as well as in a more sustainable manner.

Abstract

The aim of this study was to apply newly isolated antimicrobial characteristic possessing lactic acid bacteria (LAB) starters (Lactobacillus plantarum LUHS122, Lactobacillus casei LUHS210, Lactobacillus farraginis LUHS206, Pediococcus acidilactici LUHS29, L. plantarum LUHS135, and Lactobacillus uvarum LUHS245) for local stock (rapeseed meal) fermentation and to evaluate the influence of changing from an extruded soya to biomodified local stock in a feed recipe on piglets’ fecal microbiota, health parameters, growth performance, and ammonia emission. In addition, biomodified rapeseed meal characteristics (acidity and microbiological) were analyzed. The 36-day experiment was conducted using 25-day-old Large White/Norwegian Landrace (LW/NL) piglets, which were randomly distributed into two groups: a control group fed with basal diet and a treated group fed with fermented feed (500 g/kg of total feed). The study showed that the selected LAB starter combination can be recommended for rapeseed meal fermentation (viable LAB count in fermented feed 8.5 ± 0.1 log₁₀ CFU/g and pH 3.94 ± 0.04). At the beginning of the in vivo experiment, the microbial profiles in both piglet groups were very similar: The highest prevalence was Prevotella (34.6–38.2%) and Lactobacillus (24.3–29.7%). However, changing from an extruded soya to fermented rapeseed meal in the feed recipe led to desirable changes in piglets’ fecal microbiota. There was a more than four-fold higher Lactobacillus count compared to the control group. Furthermore, there was significantly lower ammonia emission (20.6% reduction) in the treated group section. Finally, by changing from an extruded soya to cheaper rapeseed meal and applying the fermentation model with the selected LAB combination, it is possible to feed piglets without any undesirable changes in health and growth performance, as well as in a more sustainable manner.

Depolymerized RG-I-enriched pectin from citrus segment membranes modulates gut microbiota, increases SCFA production, and promotes the growth of Bifidobacterium spp., Lactobacillus spp. and Faecalibaculum spp

Rhamnogalacturonan-I (RG-I)-enriched pectin (WRP) was recovered from citrus processing water by sequential acid and alkaline treatments in a previous study. RG-I-enriched pectin was proposed as a potential supplement for functional food and pharmaceutical development. However, previous studies illustrated that favorable modulations of gut microbiota by RG-I-enriched pectin were based on in vitro changes in the overall microbial structure and the question of whether there is a structure-dependent modulation of gut microbiota remains largely enigmatic. In the present study, modulations of gut microbiota by commercial pectin (CP), WRP and its depolymerized fraction (DWRP) with different RG-I contents and Mw were compared in vivo. It was revealed by 16s rRNA high-throughput sequencing that WRP and DWRP mainly composed of RG-I modulated the gut microbiota in a positive way. DWRP significantly increased the abundance of prebiotic such as Bifidobacterium spp., Lactobacillus spp., while WRP increased SCFAs producers including species in Ruminococcaceae family. By maintaining a more balanced gut microbiota composition and enriching some SCFA producers, dietary WRP and DWRP also elevated the SCFA content in the colon. Collectively, our findings offer new insights into the structure-activity correlation of citrus pectin and provide impetus towards the development of RG-I-enriched pectin with small molecular weight for specific use in health-promoting prebiotic ingredients and therapeutic products.

High-level expression of an acidic thermostable xylanase in Pichia pastoris and its application in weaned piglets

An acidic thermostable xylanase (AT-xynA) which was stable at low pH and high temperature was considered to have great potential in animal feed. For large-scale production, AT-xynA activity was enhanced about 1-fold in Pichia pastoris by constructing a double-copy expression strain in this study. Furthermore, impacts of different AT-xynA levels on growth performance, nutrient digestibility, short-chain fatty acids, and bacterial community in weaned piglets were determined. Compared with the control group, ADFI and ADG were higher for the pigs fed 4,000 or 6,000 U/kg AT-xynA (P < 0.05). AT-xynA supplementation also significantly increased the digestibility of OM, GE, and DM (P < 0.05). AT-xynA supplementation increased the concentrations of acetate in ileal (P < 0.01) and cecal digesta (P < 0.05). Isobutyrate (P < 0.05) and valerate (P < 0.05) concentrations in colonic digesta also significantly increased compared with the control group. AT-xynA supplementation increased the abundance of Lactobacillus in the ileal, cecal, and colonic digesta of weaned piglets (P < 0.05). AT-xynA alleviated anti-nutritional effects of nonstarch polysaccharides (NSP) by preventing the growth of Pateurella and Leptotrichia in the ileum (P < 0.05). AT-xynA increased the abundance of NSP-degrading bacteria, such as Ruminococcaceae, Prevotella in the cecum and colon (P < 0.05). In summary, AT-xynA addition could improve the growth performance of weaned piglets by altering gut microbiota.

Effects of fucoidan on gut flora and tumor prevention in 1,2-dimethylhydrazine-induced colorectal carcinogenesis

Colorectal cancer (CRC) is one of the major malignancies in humans. This study was designed to evaluate the effects of fucoidan on gut flora and tumor prevention in 1,2-dimethylhydrazine-induced colorectal carcinogenesis in rats. We found that dietary fucoidan treatment decreased the tumor incidence and mean tumor weight and increased cell apoptosis. Fucoidan treatment decreased the expression of β-catenin C-Myc, CyclinD1 and Survivin, while the Hippo pathway was activated with increased phosphorylation levels of mammalian sterile 20-like kinase 1 and 2, large tumor suppressor 1 and 2, and Yes-associated protein. Compared with the model group, the levels of interleukin (IL)-17 and IL-23 were decreased, but the levels of interferon-γ, IL-4 and IL-10 were increased, in the fucoidan group. Fucoidan treatment increased natural killer cells in peripheral blood and the proportion of CD4+ T cells. Immunofluorescence detection of colorectal tumor tissues showed decreased expression of Foxp3 and up-regulated expression of CD68 in the fucoidan group. Moreover, fucoidan treatment decreased the levels of diamine oxidase and lipopolysaccharides and up-regulated the levels of tight junction proteins. 16S rDNA high-throughput sequencing revealed that fucoidan treatment decreased the abundance of Prevotella and increased the abundance of Alloprevotella. Fucoidan increased the levels of butyric acid and valeric acid compared to the model group. This study provides experimental evidence that dietary fucoidan may prevent colorectal tumorigenesis by regulating gut microecology and body immunity. Meanwhile, fucoidan activated the Hippo pathway and down-regulated the β-catenin pathway to induce tumor cell apoptosis and suppress tumor growth.

Chinese Propolis Prevents Obesity and Metabolism Syndromes Induced by a High Fat Diet and Accompanied by an Altered Gut Microbiota Structure in Mice

The increasing incidence of obesity poses a great threat to public health worldwide. Recent reports also indicate the relevance of obesity in metabolic diseases. Chinese propolis (CP), as a well-studied natural nutraceutical, has shown a beneficial effect on alleviating diabetes mellitus. However, few studies have investigated the effect of CP on weight management and energy balance. We examined the beneficial effects of dietary CP on weight in high-fat diet-fed female and male mice and determined whether CP alters gut microbiota. In this study, dietary CP supplementation reduces body weight and improves insulin resistance in high-fat diet (HFD)-fed mice in a dose-dependent manner. CP treatment also reverses liver weight loss and triglyceride accumulation in association with hepatic steatosis. The 16S rRNA analysis of gut microbiota demonstrated that CP treatment modulates the composition in HFD-fed mice. Our study also suggests that male mice were more sensitive to CP treatment than female mice. Taken together, CP supplementation reduces weight gain and reverses gut microbiome dysbiosis induced by HFD. Further, the effects of CP treatment on metabolic biomarkers and microbiome structure differ by gender.

Effect of a Laminarin Rich Macroalgal Extract on the Caecal and Colonic Microbiota in the Post-Weaned Pig

Dietary supplementation with 300 ppm of a laminarin rich macroalgal extract reduces post-weaning intestinal dysfunction in pigs. A comprehensive analysis of the impact of laminarin on the intestinal microbiome during this period is essential to inform on the mode of action of this bioactivity. The objective of this study was to evaluate the effects of supplementing the diet of newly weaned pigs with 300 ppm of a laminarin rich extract, on animal performance, volatile fatty acids, and the intestinal microbiota using 16S rRNA gene sequencing. Pigs fed the laminarin-supplemented diet had higher average daily feed intake, growth rate, and body weight compared to pigs fed the control diet (p < 0.05). Pigs fed the laminarin-supplemented diet had reduced abundance of OTUs assigned to Enterobacteriaceae and increased abundance of OTUs assigned to the genus Prevotella (p < 0.05) compared to pigs fed the control diet. Enterobacteriaceae had negative relationships (p < 0.05) with average daily feed intake (ADFI), average daily gain (ADG), and butyric acid concentrations. In contrast, Prevotellaceae were positively correlated (p < 0.05) with ADFI, ADG, total VFA, acetic, propionic, butyric acids, and negatively correlated with isovaleric acid. Hence supplementation with a laminarin enriched extract potentially improves performance during the post-weaning period by promoting the proliferation of bacterial taxa such as Prevotella that favourably enhance nutrient digestion while reducing the load of potentially pathogenic bacterial taxa including Enterobacteriaceae.

Improvement of Psoriasis by Alteration of the Gut Environment by Oral Administration of Fucoidan from Cladosiphon Okamuranus

Psoriasis is a chronic autoimmune inflammatory disease for which there is no cure; it results in skin lesions and has a strong negative impact on patients' quality of life. Fucoidan from Cladosiphon okamuranus is a dietary seaweed fiber with immunostimulatory effects. The present study reports that the administration of fucoidan provided symptomatic relief of facial itching and altered the gut environment in the TNF receptor-associated factor 3-interacting protein 2 (Traf3ip2) mutant mice (m-Traf3ip2 mice); the Traf3ip2 mutation was responsible for psoriasis in the mouse model used in this study. A fucoidan diet ameliorated symptoms of psoriasis and decreased facial scratching. In fecal microbiota analysis, the fucoidan diet drastically altered the presence of major intestinal opportunistic microbiota. At the same time, the fucoidan diet increased mucin volume in ileum and feces, and IgA contents in cecum. These results suggest that dietary fucoidan may play a significant role in the prevention of dysfunctional immune diseases by improving the intestinal environment and increasing the production of substances that protect the immune system.

Potential Use of Marine Seaweeds as Prebiotics: A Review

Human gut microbiota plays an important role in several metabolic processes and human diseases. Various dietary factors, including complex carbohydrates, such as polysaccharides, provide abundant nutrients and substrates for microbial metabolism in the gut, affecting the members and their functionality. Nowadays, the main sources of complex carbohydrates destined for human consumption are terrestrial plants. However, fresh water is an increasingly scarce commodity and world agricultural productivity is in a persistent decline, thus demanding the exploration of other sources of complex carbohydrates. As an interesting option, marine seaweeds show rapid growth and do not require arable land, fresh water or fertilizers. The present review offers an objective perspective of the current knowledge surrounding the impacts of seaweeds and their derived polysaccharides on the human microbiome and the profound need for more in-depth investigations into this topic. Animal experiments and in vitro colonic-simulating trials investigating the effects of seaweed ingestion on human gut microbiota are discussed.

Long-Term Blackcurrant Supplementation Modified Gut Microbiome Profiles in Mice in an Age-Dependent Manner: An Exploratory Study

Recent studies have suggested that blackcurrant (BC) anthocyanins have promising health benefits, possibly through regulating gut microbiome. Three- and eighteen-month old female mice were fed standard mouse diets for 4 months, each with or without BC (1% w/w) supplementation (n = 3 in each treatment group, 12 in total). We then assessed gut microbiome profiles using 16S sequencing of their feces. Old mice had a less diverse microbiome community compared to young mice and there was a remarkable age-related difference in microbiome composition in the beta diversity analysis. BC supplementation did not significantly affect alpha or beta diversity. The relative abundance of several phyla, including Firmicutes, Bacteroidetes, Proteobacteria and Tenericutes, was lower in old mice. BC downregulated Firmicutes abundance in young mice and upregulated Bacteroidetes in both age groups, leading to a decreased Firmicutes/Bacteroidetes ratio. There were age-specific differences in the effect of BC supplementation on the microbiome. Twenty-four operational taxonomic units showed a significant interaction between age and BC supplementation (p < 0.01), which suggests that the ecosystem and the host health status affect the functions and efficiency of BC intake. These results indicate that BC supplementation favorably modulates gut microbiome, but there are distinct age-specific differences. Studies with human hosts are needed to better understand BC’s regulatory effects on the gut microbiome.

Anti-Inflammatory Effects of Huangqin Decoction on Dextran Sulfate Sodium-Induced Ulcerative Colitis in Mice Through Regulation of the Gut Microbiota and Suppression of the Ras-PI3K-Akt-HIF-1α and NF-κB Pathways

Objective

Huangqin decoction (HQD), a classical traditional Chinese medicinal formula, has been commonly used to treat gastrointestinal diseases for thousands of years. We investigated the anti-inflammatory effects and underlying mechanisms of HQD on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC).

Methods

Experimental mice were given 3% DSS, and HQD (2.275, 4.55, and 9.1 g/kg), or mesalazine (ME, 200 mg/kg) orally for 7 days. Body weight loss, disease activity index (DAI), colon length, histology, and levels of inflammatory cytokines were measured to evaluate the effects of HQD on colitis. The effects of HQD on the Ras-phosphoinositide-3-kinase (PI3K)-Akt-hypoxia inducible factor 1 alpha (HIF-1α) and nuclear factor-kappa B (NF-κB) pathways were evaluated by Western blot analysis. In addition, the gut microbiota was characterized using high-throughput Illumina MiSeq sequencing.

Results

The results showed that HQD significantly reduced the body weight loss, ameliorated DAI, restored colon length, and improved the intestinal epithelial cell barrier in mice with DSS-induced colitis. The messenger RNA (mRNA) expression levels of inflammatory mediators were decreased following HQD treatment. Furthermore, the Ras-PI3K-Akt-HIF-1α and NF-κB pathways were significantly inhibited by HQD. Finally, treatment with HQD resulted in recovery of gut microbiota diversity.

Conclusions

HQD ameliorates DSS-induced colitis through regulation of the gut microbiota, and suppression of Ras-PI3K-Akt-HIF-1α and NF-κB pathways. Our results suggested that HQD may be a potential candidate for treatment of UC.

Chemical Profile, Antioxidative, and Gut Microbiota Modulatory Properties of Ganpu Tea: A Derivative of Pu-erh Tea

Ganpu tea is an emerging tea drink produced from Pu-erh tea and the pericarp of Citrus reticulate Chachi (GCP). Recently, it has been increasingly favored by consumers due to the potential health effects and special taste. However, information concerning its chemical profile and biological activities is scarce. In this work, a total of 92 constituents were identified in hot-water extracts of Ganpu tea with ultra-high performance liquid chromatography/quadrupole-time-of-flight tandem mass spectrometry (UHPLC-Q-TOF-MS/MS). Moreover, the antioxidative and gut microbiota modulatory properties of Ganpu tea were investigated in rats after long-term dietary consumption. Ganpu tea and GCP could significantly enhance the activities of superoxide dismutase (SOD) by 13.4% (p < 0.05) and 15.1% (p < 0.01), as well as the activities of glutathione peroxidase (GSH-Px) by 16.3% (p < 0.01) and 20.5% (p < 0.01), respectively. Both showed better antioxidant capacities than Pu-erh tea. Ganpu tea increased the abundance of Bifidobacterium, Lactobacillus, and Lactococcus, suggesting the potential of Ganpu tea in modulating the gut microbiota to benefit human health. The obtained results provide essential information for further investigation of Ganpu tea.

Early-Life Intervention Using Fecal Microbiota Combined with Probiotics Promotes Gut Microbiota Maturation, Regulates Immune System Development, and Alleviates Weaning Stress in Piglets

Previous studies have suggested that immune system development and weaning stress are closely related to the maturation of gut microbiota. The early-life period is a “window of opportunity” for microbial colonization, which potentially has a critical impact on the development of the immune system. Fecal microbiota transplantation (FMT) and probiotics are often used to regulate gut microbial colonization. This study aims to test whether early intervention with FMT using fecal microbiota from gestation sows combined with Clostridium butyricum and Saccharomyces boulardii (FMT-CS) administration could promote the maturation of gut microbiota and development of immune system in piglets. Piglets were assigned to control (n = 84) and FMT-CS treatment (n = 106), which were treated with placebo and bacterial suspension during the first three days after birth, respectively. By 16S rRNA gene sequencing, we found that FMT-CS increased the α-diversity and reduced the unweighted UniFrac distances of the OTU community. Besides, FMT-CS increased the relative abundance of beneficial bacteria, while decreasing that of opportunistic pathogens. FMT-CS also enhanced the relative abundance of genes related to cofactors and vitamin, energy, and amino acid metabolisms during the early-life period. ELISA analysis revealed that FMT-CS gave rise to the plasma concentrations of IL-23, IL-17, and IL-22, as well as the plasma levels of anti-M.hyo and anti-PCV2 antibodies. Furthermore, the FMT-CS-treated piglets showed decreases in inflammation levels and oxidative stress injury, and improvement of intestinal barrier function after weaning as well. Taken together, our results suggest that early-life intervention with FMT-CS could promote the development of innate and adaptive immune system and vaccine efficacy, and subsequently alleviate weaning stress through promoting the maturation of gut microbiota in piglets.

Ruminal Microbiota and Fermentation in Response to Dietary Protein and Energy Levels in Weaned Lambs

Simple Summary

Ruminants, such as sheep, are economically important because they contribute to digesting and converting plant materials into edible meat and milk for humans to consume. An adequate plane of nutrients, such as energy and protein, is essential for rumen development and growth. However, sheep production is mostly affected by inadequate nutrition in rural areas of China. As one of the most prolific and perennial estrus breeds in China, Hu sheep has huge potential for catering to the growing meat demands of the market and consumers. In this study, the effects of dietary energy and protein levels on growth performance, microbial diversity, and physiological properties of the rumen in weaned lambs were evaluated. The results showed that a low dietary energy level restrained growth performance and changed the microbiota and associated ruminal fermentation phenotypes of lambs. However, protein had a minor effect. The findings are of great significance for promoting rumen development and establishing the optimal nutrient supply strategy for lambs.

Abstract

Supplying sufficient nutrients, such as dietary energy and protein, has a great effect on the growth and rumen development of ruminants. This study was conducted to evaluate the effects of dietary energy and protein levels on growth performance, microbial diversity, and structural and physiological properties of the rumen in weaned lambs. A total of 64 two-month-old Hu lambs were randomly allotted to 2 × 2 factorial arrangements with four replicates and with four lambs (half male and half female) in each replicate. The first factor was two levels of dietary metabolizable energy (ME) density (ME = 10.9 MJ/Kg or 8.6 MJ/Kg), and the second factor was two levels of dietary crude protein (CP) content (CP = 15.7% or 11.8%). The trial lasted for 60 days. A low dietary energy level restrained the growth performance of lambs (p < 0.05). The ruminal concentration of acetate and the ratio of acetate to propionate increased but the propionate concentration decreased significantly with the low energy diet. However, the rumen morphology was not affected by the diet energy and protein levels. Moreover, a low energy diet increased ruminal bacterial diversity but reduced the abundance of the phylum Proteobacteria (p < 0.05) and genus Succinivibrionaceae_uncultured (p < 0.05), which was associated with the change in ruminal fermentation phenotypes. By indicator species analysis, we found three indicator OTUs in the high energy group (Succinivibrionaceae_uncultured, Veillonellaceae_unclassified and Veillonellaceae_uncultured (p < 0.01)) and two indicator OTUs in the low energy group (Bacteroidales_norank and Lachnospiraceae_uncultured (p < 0.01)). In conclusion, these findings added new dimensions to our understanding of the diet effect on rumen microbial community and fermentation response, and are of great significance for establishing the optimal nutrient supply strategy for lambs.

Fucoidan prevent murine autoimmune diabetes via suppression TLR4-signaling pathways, regulation DC/Treg induced immune tolerance and improving gut microecology

Background

This study was to investigate the effect and its possible mechanism of fucoidan on the development of spontaneous autoimmune diabetes in non-obese diabetic (NOD) mice.

Methods

7-week-old NOD mice were randomly divided into three groups: control group, low-dose (300 mg/kg) and high-dose (600 mg/kg) fucoidan-treatment groups. After 5 weeks of treatment, 10 mice per group were randomly selected to be sacrificed after feces collection. The remaining 12 mice per group were fed until 26 weeks of age to assess the incidence of diabetes.

Results

Treatment with fucoidan increased serum insulin level, delayed the onset and decreased the development of diabetes in NOD mice. Fucoidan reduced the levels of strong Th1 proinflammatory cytokines, but induced Th2-bias ed. cytokine response. And dentridic cells (DCs) in fucoidan treatment group were characterized as low expression of MHC class II and CD86 molecules. TLR4 expressions and the downstream molecules in pancreas were down-regulated in fucoidan-treated groups. There were significant differences in the composition of gut flora between NOD control group and fucoidan group. Lactobacillus and Akkermansia were significantly enriched in fucoidan group.

Conclusions

Fucoidan could prevent the development of autoimmune diabetes in NOD mice via regulating DC/Treg induced immune tolerance, improving gut microecology, down-regulating TLR4 signaling pathway, and maintaining pancreatic internal environment.

Effect of fibre sources on performance, serum parameters, intestinal morphology, digestive enzyme activities and microbiota in weaned pigs

This study was conducted to evaluate the effects of wheat bran (WB) as insoluble fibre source, and sugar beet pulp (SBP) as soluble fibre source, on performance, serum parameters and intestinal health in weaned pigs. A total of 90 weaned pigs (BW: 7.33 ± 1.24 kg) were randomly assigned to three dietary treatments: (1) a control diet (CON) based on corn and soybean meal; (2) CON + 6% WB; (3) CON + 6% SBP. Each treatment had five replicate pens with six pigs per pen. The experimental period was divided into two phases (d 0 to 14 and d 14 to 28). Pigs in group WB tended to have greater avarage daily gain than those in group SBP. Compared with CON, SBP reduced (p < 0.05) the apparent total tract digestibility (ATTD) of dry matter, organic matter (OM), gross energy and neutral detergent fibre on d 14 and 28, while WB decreased (p < 0.05) the ATTD of OM on d 28. Pigs in group SBP had higher (p < 0.05) glucagon-like peptide 1 concentration than the other groups on d 14 and 28. The villus height to crypt depth (V:C) ratio of duodenum and jejunum in pigs fed diet WB were greater (p < 0.05) than in group SBP. The WB increased (p < 0.05) the V:C ratio of ileum compared with CON or SBP. Compared with SBP, WB increased (p < 0.05) the sucrase activity in the duodenum. Moreover, pigs in WB had higher (p < 0.05) activities of maltase and sucrase in the jejunum compared with CON or SBP. The abundances of Ruminococcaceae and Prevotellaceae were increased (p < 0.05) in WB, while the Lachnospiraceae abundance was increased (p < 0.05) in SBP. WB increased (p < 0.05) concentrations of acetate, butyrate and total short-chain fatty acids (SCFA), while SBP increased (p < 0.05) concentrations of acetate and total SCFA when compared with CON. In conclusion, WB was beneficial to performance in weaned pigs by improving morphology, enzyme activities and microbiota when compared with SBP, highlighting that effects of fibre depends on the fibre sources.

Seaweed and seaweed-derived metabolites as prebiotics

Seaweeds and their bioactive compounds, particularly polysaccharides and phenolics can be regarded as great dietary supplements with gut health benefits and prebiotics. These components are resistant to digestion by enzymes present in the human gastrointestinal tract, also selectively stimulate the growth of beneficial gut bacteria and the production of fermentation products such as short chain fatty acids. Commonly, the health benefits of seaweed components are assessed by including them in an in vitro anaerobic fermentation system containing human fecal inocula that mimics the environment of the human large bowel. Regarding to the complex interactions between dietary components, gastrointestinal physiological processes, and gut microbiota are difficult to model in vitro. Consequently it is important to follow up the promising in vitro results with in vivo animal or human testing. The aim of this chapter is to have a comprehensive review on the application of seaweeds and seaweed-derived metabolites as prebiotics, and understand the trends, gaps and future directions of both scientific and industrial developments. This work contributes to develop and expand new platform of seaweed utilization for higher-value products, particularly to functional food and nutraceutical industries in order to serve the social demand for health awareness and support economic development.

Toxicity, Pharmacokinetics, and Gut Microbiome of Oral Administration of Sesterterpene MHO7 Derived from a Marine Fungus

Sesterterpene MHO7 derived from mangrove fungus is a novel estrogen receptor degrader for the treatment of breast cancer. To explore its safety and pharmacokinetics in vivo, Log P/D values, stability in simulated gastric/intestinal (SGF/SIF), toxicity, and pharmacokinetics studies were carried mainly by liquid chromatography technique coupled with tandem mass spectrometry (LC–MS/MS) method in mice, and the effect of MHO7 on mice gut microbiota at different time points was revealed by 16S rRNA sequencing. Log P/D values ranged 0.93–2.48, and the compound in SGF and SIF is stable under the concentration of 5 mM·L⁻¹. The maximum tolerance dose (MTD) of oral administration in mice was 2400 mg·kg⁻¹. The main pharmacokinetics parameters were as following: C_max of 1.38 μg·mL⁻¹, T_max of 8 h, a half-life (t_1/2) of 6.97 h, an apparent volume of mean residual time (MRT) of 8.76 h, and an area under the curve (AUC) of 10.50 h·μg·mL⁻¹. MHO7 displayed a wide tissue distribution in mice, with most of the compound in liver (3.01 ± 1.53 μg·g⁻¹) at 1 h, then in fat (5.20 ± 3.47 μg·g⁻¹) at 4 h, and followed by reproductive organs with the concentrations of 23.90 ± 11.33 μg·g⁻¹,13.69 ± 10.29 μg·g⁻¹, 1.46 ± 1.23 μg·g⁻¹, and 0.36 ± 0.46 μg·g⁻¹ at 8, 12, 20 and 30 h, respectively. The most influenced genera of gut microbiome belonged to phylum Firmicutes (21 of 28), among which 18 genera originated from the order Clostridiales, class Clostridia, and families of Ruminococcaceae (11 of 18) and Lachnospiraceae (4 of 18). These results provide that MHO7 is suitable for oral administration in the treatment of breast cancer with the target organs of reproductive organs and regulation on Ruminococcaceae and Lachnospiraceae.

Supplementation of Sesamin Alleviates Stress-Induced Behavioral and Psychological Disorders via Reshaping the Gut Microbiota Structure

Sesamin, a lignan from sesame seed, has been reported to attenuate chronic mild stress-induced depressive-like behaviors. Gut microbiota play pivotal roles in mediating psychological behaviors by regulating gut barrier integrity and systemic inflammatory responses. Here, we found that oral sesamin administration (50 mg/kg·bodyweight/day) significantly attenuated depressive, aversive, repetitive, and anxiety-like behaviors in a long-term multiple nonsocial stress-treated mice model. Sesamin inhibited stress-induced gut barrier integrity damage, reduced circulating lipopolysaccharide (LPS) levels, and suppressed neuroinflammatory responses. Moreover, sesamin treatment also restructured the gut microbiome by enhancing the relative abundances of Bacteroidales and S24-7. The correlation analysis indicated that the microbiota composition changes were strongly correlated with behavioral disorders, serotonin, norepinephrine, and LPS levels. In conclusion, sesamin has preventive effects on stress-induced behavioral and psychological disorders, which might be highly related to the reshaped microbiota composition. This study provides a clue for understanding the systemic mechanism of anti-depression effects of sesamin.

Positive effects of dietary supplementation of three probiotics on milk yield, milk composition and intestinal flora in Sannan dairy goats varied in kind of probiotics

In this study, we investigated the effects of Saccharomyces cerevisiae (SC), Bacillus subtilis (BS) and Enterococcus faecalis (EF), singly and in combination, on the dry matter intake (DMI), milk production and composition, and faecal microflora of Saanen dairy goats. Fifty goats were randomly divided into five groups: (a) basal diet (control); (b) basal diet + SC; (c) basal diet + BS; (d) basal diet + EF; and (e) basal diet + mixed probiotics. Each treated animal received 5 g/d of probiotics for a total administration of 5 × 1,011 CFU/goat per day. The inclusion of B. subtilis and E. faecalis in the diet of lactating Saanen goats increased DMI (p < .05). Enhanced milk yield was observed with BS and EF. Milk fat percentage was significantly increased by feeding mixed probiotics compared with the control (p < .05); supplying SC, BS and mixed probiotics enhanced the protein percentage (p < .05). The milk lactose percentage in the SC and BS groups was higher than in the control (p < .05). The amount of milk total solids was higher after feeding EF or mixed probiotics than in the control group (p < .05). Non-fat solids showed no notable differences among groups (p > .05). There was no significant influence on gut bacterial abundance and diversity from adding these three probiotics, singly or in combination. Bacteroidales, Escherichia-Shigella and Christensenellaceae abundances were decreased by supplying these probiotics but Succinivibrionaceae increased. In conclusion, there were positive influences of probiotic feed supplementation on intake, milk performance and intestinal microecology.

Therapies from Fucoidan: New Developments

Since our last review in 2015, the study and use of fucoidan has extended in several research areas. Clinical use of fucoidan for the treatment of renal disease has become available and human safety studies have been undertaken on radiolabeled fucoidan for the purpose of imaging thrombi. Fucoidan has been incorporated into an increasing number of commercially available supplements and topical treatments. In addition, new measuring techniques are now available to assess the biologically relevant uptake of fucoidans and to assist in production. Microbiome modulation and anti-pathogenic effects are increasingly promising applications for fucoidans, due to the need for alternative approaches to antibiotic use in the food chain. This review outlines promising new developments in fucoidan research, including potential future therapeutic use.

Anti-Metabolic Syndrome Effects of Fucoidan from Fucus vesiculosus via Reactive Oxygen Species-Mediated Regulation of JNK, Akt, and AMPK Signaling

Recent studies have reported that dietary fiber improved metabolic syndrome (MetS). However, the effects of fucoidans on MetS were still not clear. In this study, we evaluated the activity of fucoidan from Fucus vesiculosus (FvF) on attenuating MetS and first elucidated the underlying mechanism. In vitro, FvF treatment remarkably lowered the level of reactive oxygen species (ROS) compared with the sodium palmitate (PA)-induced insulin resistance (IR) group. The phosphorylation level of c-Jun N-terminal kinase (JNK) was significantly decreased, while phosphorylation of protein kinase B (pAkt) level increased, compared with that of the HepG2 cells treated with PA. Thus, FvF increased glucose consumption and relieved IR via ROS-mediated JNK and Akt signaling pathways. In addition, these changes were accompanied by the activation of adenosine 5'-monophosphate-ativated protein kinase (AMPK) and its downstream targets (e.g., HMG-CoA reductase (HMGCR), acetyl-CoA carboxylase (ACC), and sterol-regulatory element-binding protein-1c (SREBP-1C)), which improved lipid metabolism in IR HepG2 cells. In vivo, FvF improved hyperglycemia and decreased serum insulin level in mice with MetS. Furthermore, we evaluated the inhibition of glucose transport by in vitro (Caco-2 monolayer model), semi-in vivo (everted gut sac model) and oral glucose tolerance test (OGTT), which indicated that FvF could significantly reduce the absorption of glucose into the blood stream, thus it could improve blood-glucose levels and IR in mice with MetS. Moreover, FvF decreased serum triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) levels and liver lipid accumulation, while increased the serum high density lipoprotein cholesterol (HDL-C) level in mice with MetS. Therefore, FvF could be considered as a potential candidate for the treatment of MetS by alleviating IR, inhibiting glucose transportation, and regulating lipid metabolism.

Diet Consisting of Balanced Yogurt, Fruit, and Vegetables Modifies the Gut Microbiota and Protects Mice against Nonalcoholic Fatty Liver Disease

BACKGROUND

Calorie restriction (CR) is a therapeutically effective method for nonalcoholic fatty liver disease. However, the compliance of the CR method is relatively poor. New CR methods are needed.

METHODS AND RESULTS

Each week, mice are given a 5-day high-fat diet (HFD) ad libitum plus 2 days of an intermittent calorie restriction (ICR) diet (50% calorie restriction) consisting of yogurt, fruit, and vegetables, for 16 weeks. The effect of the ICR diet model on the fatty liver of mice is examined. Compared with continuous HFD-fed mice, the mice feeding HFD+ICR have lower body weight and hepatic steatosis, reduced serum lipid and transaminase levels, increased fatty acid oxidation gene of Cpt1a, and decreased hepatic lipid synthesis gene of Pparγ and Srebf-1c, as well as improved insulin resistance and lower level of inflammation. Moreover, ICR reverses the dysbacteriosis in HFD group, including the lower Shannon diversity indexes and lower abundance of Lactobacillus.

CONCLUSION

An ICR diet consisting of yogurt, fruit, and vegetables attenuates the development of HFD-induced hepatic steatosis in mice. Furthermore, HFD+ICR diet is associated with a different fecal microbiota that tends to be more similar to normal diet controls.

Sargassum fusiforme Fucoidan SP2 Extends the Lifespan of Drosophila melanogaster by Upregulating the Nrf2-Mediated Antioxidant Signaling Pathway

Damage accumulated in the genome and macromolecules is largely attributed to increased oxidative damage and a lack of damage repair in a cell, and this can eventually trigger the process of aging. Alleviating the extent of oxidative damage is therefore considered as a potential way to promote longevity. SFPS, a heteropolysaccharide extracted from the brown alga Sargassum fusiforme, has previously been shown to alleviate oxidative damage during the aging process in mice, but whether SFPS could extend the lifespan of an organism was not demonstrated. Furthermore, the precise component within SFPS that is responsible for the antioxidant activity and the underlying mechanism of such activity was also not resolved. In this study, SP2, a fucoidan derived from SFPS, was shown to exhibit strong antioxidant activity as measured by in vitro radical-scavenging assays. SP2 also improved the survival rate of D. melanogaster subjected to oxidative stress. The flies that were fed with a diet containing SP2 from the time of eclosion displayed significant enhancement in lifespan and reduced accumulation of triglyceride at the old-age stage. In addition, SP2 markedly improved the activities of the antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) and reduced the contents of the malondialdehyde (MDA) and oxidized glutathione (GSSG) in old flies. Furthermore, SP2 also upregulated the expression levels of the nuclear factor-erythroid-2-like 2 (nfe2l2 or nrf2) and its downstream target genes, accompanied by a dramatic reduction in the expression of kelch-like ECH-associated protein 1 (keap1, a canonical inhibitor of the Nrf2) in old flies. Additional support linking the crucial role of the Nrf2/ARE pathway to the antioxidant effect of SP2 was the relatively high survival rate under heat stress for D. melanogaster individuals receiving SP2 supplement, an effect that was abolished by the inclusion of inhibitors specific for the Nrf2/ARE pathway. Collectively, the results indicated that SP2, a S. fusiforme fucoidan, could promote longevity in D. melanogaster by enhancing the Nrf2-mediated antioxidant signaling pathway during the aging process.

The fucoidan A3 from the seaweed Ascophyllum nodosum enhances RCT-related genes expression in hyperlipidemic C57BL/6J mice

Reverse cholesterol transport (RCT) has been demonstrated to reduce hyperlipidemia, and fucoidans are found to possess hypolipidemic effect. This study was designed to investigate the lipid-lowering effect of the fucoidan from the brown seaweed A. nodosum and whether it improves RCT-related genes expression in C57 BL/6J mice. Our results indicated that fucoidan A3 (100 mg/kg/day) intervention significantly reduced plasma total cholesterol (~23.2%), triglyceride (~48.7%) and fat pad index. This fucoidan significantly increased the mRNA expression of low-density lipoprotein receptor (LDLR), scavenger receptor B type 1 (SR-B1), cholesterol 7 alpha-hydroxylase A1 (CYP7A1), liver X receptor (LXR) β, ATP-binding cassette transporter (ABC) A1 and sterol regulatory element-binding protein (SREBP) 1c, and decreased the expression of peroxisome proliferator-activated receptor (PPAR) γ, however, it had no effect on the expression of proprotein convertase subtilisin/kexin type 9, PPARα, LXRα, SREBP-2, ABCG1, ABCG8 and Niemann-Pick C1-like 1. These results demonstrated that this fucoidan improved lipid transfer from plasma to the liver by activating SR-B1 and LDLR, and up-regulated lipid metabolism by activating LXRβ, ABCA1 and CYP7A1. In conclusion, this fucoidan lowers lipid by enhancing RCT-related genes expression, and it can be explored as a potential candidate for prevention or treatment of lipid disorders.

The specific use of alginate from Laminaria japonica by Bacteroides species determined its modulation of the Bacteroides community

Accumulating studies showed that the beneficial actions of polysaccharides were closely associated with an improvement of the gut microbiota, but mechanisms that link polysaccharides and gut microbiota alterations are ill defined. Alginate from Laminaria japonica (LJP-A) can avoid being digested by the upper digestive tract and reach the colon where it can improve the gut microbiota community. LJP-A increased the relative abundance of some Bacteroidaceae members, e.g. Bacteroides species. The distribution of Bacteroides species in the gut is specific to the individual, and the specific use of LJP-A by Bacteroides species can determine LJP-A-induced alterations of the intestinal Bacteroides community, in which carbon source-based syntrophic interactions occur in Bacteroides species of the human gut microbial ecosystem. Compared to other species, Bacteroides finegoldii responded more positively to LJP-A intervention, and its properties may have a close connection with the bioactivities of LJP-A. This study provides a rationale for personalized treatment with dietary polysaccharides that were optimally fermented within a particular individual.

Possible Metabolic Pathway of a Novel Bioactive Polysaccharide Extracted from Dendrobium aphyllum: An In Vivo Study

Our previous study characterized the structure-associated immunomodulatory effects of an edible Dendrobium aphyllum polysaccharide (DAP), and the in vitro gastrointestinal digestions highlighted DAP could be digested by the GI tract in some extent. Therefore, the present study further explored the digestive properties in vivo to infer the metabolic pathway with health mice model. Results revealed that DAP-treated group showed slightly lower blood glucose levels and significantly higher (P < 0.05) enzyme activities, namely G6Pase and GDH with an increment of about 0.4 to 0.9 and 45 to 91 U/mL, respectively. Meanwhile, DAP up-regulated the expression of glucose transporters, GLUT1 and GLUT2 in the increment rates of 56.34% to 68.28% and 76.63% to 83.03%, in colon. Furthermore, the beneficial effects of DAP on colon were confirmed by the increment of four types short chain fatty acids and the health-promoting microbiota diversity. The above results successfully identify the metabolic pathways after the oral administration of bioactive DAP. PRACTICAL APPLICATION: The metabolic pathways of Dendrobium aphyllum polysaccharide, after artificially stimulated oral administration, were characterized. The most of the unabsorbed portion of DAP were utilized by the colon microbiota, resulting in the significantly increasing production of four health-promoting SCFAs. The unabsorbed portion of DAP upregulated the diversity of various beneficial microbiota genus, and meanwhile downregulated kinds of harmful microbiota genus.

Dissecting the role of the gut microbiota and diet on visceral fat mass accumulation

Both gut microbiota and diet have been shown to impact visceral fat mass (VFM), a major risk factor for cardiometabolic disease, but their relative contribution has not been well characterised. We aimed to estimate and separate the effect of gut microbiota composition from that of nutrient intake on VFM in 1760 older female twins. Through pairwise association analyses, we identified 93 operational taxonomic units (OTUs) and 10 nutrients independently linked to VFM (FDR < 5%). Conditional analyses revealed that the majority (87%) of the 93 VFM-associated OTUs remained significantly associated with VFM irrespective of nutrient intake correction. In contrast, we observed that the effect of fibre, magnesium, biotin and vitamin E on VFM was partially mediated by OTUs. Moreover, we estimated that OTUs were more accurate predictors of VFM than nutrients and accounted for a larger percentage of its variance. Our results suggest that while the role of certain nutrients on VFM appears to depend on gut microbiota composition, specific gut microbes may affect host adiposity regardless of dietary intake. The findings imply that the gut microbiota may have a greater contribution towards shaping host VFM than diet alone. Thus, microbial-based therapy should be prioritised for VFM reduction in overweight and obese subjects.

High-Throughput Sequencing Reveals the Gut Microbiome of the Bactrian Camel in Different Ages

The complex gut microbiota plays a key role in host metabolism and health. However, the core microbial communities in the different aged Bactrian camels remain totally unclear. We used high-throughput 16S rRNA gene sequencing to examine the temporal variability of the fecal microbiota in Bactrian camels. At 2 months of age, the fecal microbiota was composed of Firmicutes, Proteobacteria, and Actinobacteria. At 1 and 3 years of age, the fecal microbiota was dominated by Firmicutes, Bacteroidetes, and Verrucomicrobia. At the genus level, Blautia, Fusobacterium, and Bifidobacterium were more abundant at 2 months of age, as well as Escherichia-Shigella. Ruminococcaceae_UCG-005, Akkermansia, and Christensenellaceae_R-7_group were the most abundant at 1 and 3 years of age. Diversity and stability of the gut microbiota increased with age. There was enrichment for genes associated with immune system diseases at 2 months of age. This study is the first to investigate the distribution of the gut microbiota in Bactrian camels with different ages and provide a baseline for future camel microbiology research.

The combination of wheat peptides and fucoidan protects against chronic superficial gastritis and alters gut microbiota: a double-blinded, placebo-controlled study

PURPOSE

Chronic gastritis is observed in almost half world population. Traditional medications against chronic gastritis might produce adverse effects, so alternative nutritional strategies are needed to prevent the aggravation of gastric mucosal damage. The aim of this study is to evaluate the protective effect of the combination of wheat peptides and fucoidan (WPF) on adults diagnosed with chronic superficial gastritis in a randomized, double-blind, placebo-controlled clinical trial.

METHODS

Participants were randomized to receive WPF (N = 53) or placebo (N = 53) once daily for 45 days. Pathological grading of gastric mucosal damage was scored using gastroscopy. Fecal samples were collected for the determination of calprotectin, short chain fatty acids (SCFA) levels and metagenomics analysis. Questionnaires for self-reported gastrointestinal discomforts, life quality and food frequency were collected throughout the study.

RESULTS

WPF intervention reduced gastric mucosal damage in 70% subjects (P < 0.001). Significantly less stomach pain (P < 0.001), belching (P = 0.028), bloating (P < 0.001), acid reflux (P < 0.001), loss of appetite (P = 0.021), increased food intake (P = 0.020), and promoted life quality (P = 0.014) were reported in the WPF group. WPF intervention significantly decreased fecal calprotectin level (P = 0.003) while slightly increased fecal SCFAs level (P = 0.092). In addition, we found altered microbiota composition post-intervention with increased Bifidobacterium pseudocatenulatum (P = 0.032), Eubacterium siraeum (P = 0.036), Bacteroides intestinalis (P = 0.024) and decreased Prevotella copri (P = 0.055).

CONCLUSIONS

WPF intervention could be utilized as a nutritional alternative to mitigate the progression of chronic gastritis. Furthermore, WPF played an important role in altering gut microbial profile and SCFA production, which might benefit the lower gastrointestinal tract.

Sargassum fusiforme fucoidan modifies the gut microbiota during alleviation of streptozotocin-induced hyperglycemia in mice

Diabetes is a complicated endocrine and metabolic disorder, which has become an epidemic health issue worldwide. Fucoidan is extensively distributed in the brown algae and several marine invertebrates exhibiting diverse biological activities. In the present study, the physicochemical property of Sargassum fusiforme fucoidan (SFF) and its effects on streptozotocin (STZ)-induced diabetic mice and gut microbiota were investigated. Diabetes mice not only showed abnormal blood glucose, but also accompanied by multiple symptoms, such as gradual emaciation, decreased body weight, increased food and water intake. Compared with diabetic mice after 6-week treatment, administration of SFF significantly decreased the fasting blood glucose, diet and water intake. Furthermore, SFF attenuated the pathological change in the heart and liver, improved the liver function, and suppressed oxidative stress in STZ-induced diabetic mice. Simultaneously, SFF significantly altered the gut microbiota in the faeces of diabetic mice, decreased the relative abundances of the diabetes-related intestinal bacteria, which is a potential mechanism for relieving the symptoms of diabetes. Therefore, SFF might be considered as one of the promising complementary and alternative medicines for the management of diabetes mellitus in future.

Effect of heat-killed Streptococcus thermophilus on type 2 diabetes rats

BACKGROUND AND AIMS

The link between gut microbiota and type 2 diabetes (T2D) has been addressed by numerous studies. Streptococcus thermophilus from fermented milk products, has been used as a probiotic in previous research. However, whether heat-killed S. thermophilus can improve the glycemic parameters of diabetic rats remains unanswered. In this study, we evaluated the effect of heat-killed S. thermophilus on T2D model rats and the potential mechanisms of the effect.

METHODS

Zucker diabetic fatty (ZDF) rats were used to generate a diabetic rat model induced by feeding a high-fat diet. Heat-killed S. thermophilus were orally administered to normal and diabetic rats for 12 weeks. Intestinal microbiota analysis, histology analysis, oral glucose tolerance test and measurement of inflammatory factors were performed.

RESULTS

We found that heat-killed S. thermophilus treatment reduced fasting blood glucose levels and alleviated glucose intolerance and total cholesterol in diabetic ZDF rats. Additionally, heat-killed S. thermophilus increased the interleukin 10 while reducing the levels of lipopolysaccharide, interleukin 6, and tumor necrosis factor-α in diabetic ZDF rats. The heat-killed S. thermophilus treatment can normalize the structure of the intestinal and colon mucosal layer of diabetic rats. The characteristics of the gut microbiota in heat-killed S. thermophilus-treated and control rats were similar. At the genus level, the abundances of beneficial bacteria, including Ruminococcaceae, Veillonella, Coprococcus, and Bamesiella, were all significantly elevated by heat-killed S. thermophilus treatment in ZDF diabetic rats.

CONCLUSION

Our study supports the hypothesis that treatment with heat-killed S. thermophilus could effectively improve glycemic parameters in T2D model rats. In addition, the potential mechanisms underlying the protection maybe include changing the composition of gut microbiota, reinforcing the intestinal epithelial barrier and the immunity of the intestinal mucosa, decreasing the level of inflammation, and then reducing the insulin resistance.

Prebiotics from Seaweeds: An Ocean of Opportunity?

Seaweeds are an underexploited and potentially sustainable crop which offer a rich source of bioactive compounds, including novel complex polysaccharides, polyphenols, fatty acids, and carotenoids. The purported efficacies of these phytochemicals have led to potential functional food and nutraceutical applications which aim to protect against cardiometabolic and inflammatory risk factors associated with non-communicable diseases, such as obesity, type 2 diabetes, metabolic syndrome, cardiovascular disease, inflammatory bowel disease, and some cancers. Concurrent understanding that perturbations of gut microbial composition and metabolic function manifest throughout health and disease has led to dietary strategies, such as prebiotics, which exploit the diet-host-microbe paradigm to modulate the gut microbiota, such that host health is maintained or improved. The prebiotic definition was recently updated to "a substrate that is selectively utilised by host microorganisms conferring a health benefit", which, given that previous discussion regarding seaweed prebiotics has focused upon saccharolytic fermentation, an opportunity is presented to explore how non-complex polysaccharide components from seaweeds may be metabolised by host microbial populations to benefit host health. Thus, this review provides an innovative approach to consider how the gut microbiota may utilise seaweed phytochemicals, such as polyphenols, polyunsaturated fatty acids, and carotenoids, and provides an updated discussion regarding the catabolism of seaweed-derived complex polysaccharides with potential prebiotic activity. Additional in vitro screening studies and in vivo animal studies are needed to identify potential prebiotics from seaweeds, alongside untargeted metabolomics to decipher microbial-derived metabolites from seaweeds. Furthermore, controlled human intervention studies with health-related end points to elucidate prebiotic efficacy are required.

Potential for enriching next-generation health-promoting gut bacteria through prebiotics and other dietary components

The human intestinal commensal microbiota and associated metabolic products have long been regarded as contributors to host health. As the identity and activities of the various members of this community have become clearer, newly identified health-associated bacteria, such as Faecalibacterium prausnitzii, Akkermansia muciniphila, Ruminococcus bromii and Roseburia species, have emerged. Notably, the abundance of many of these bacteria is inversely correlated to several disease states. While technological and regulatory hurdles may limit the use of strains from these taxa as probiotics, it should be possible to utilize prebiotics and other dietary components to selectively enhance their growth in situ. Dietary components of potential relevance include well-established prebiotics, such as galacto-oligosaccharides, fructo-oligosaccharides and inulin, while other putative prebiotics, such as other oligosaccharides, polyphenols, resistant starch, algae and seaweed as well as host gut metabolites such as lactate and acetate, may also be applied with the aim of selectively and/or differentially affecting the beneficial bacterial community within the gastrointestinal environment. The present review provides an overview of the dietary components that could be applied in this manner.