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As a common used food additive, the threat of carrageenan to colon health is controversial, and is inseparable from personal eating habits. However, no detailed descriptions are available concerning the influence of different dietary patterns on the risk of carrageenan-induced colitis. In this study, we explored the risk of κ-carrageenan-induced colitis under high-sucrose or high-salt diet in mice. Intervention with carrageenan under high-sucrose diet significantly reduced colon length and induced more serious deepening of the crypts. In addition, the intake of carrageenan under high-sucrose/high-salt diet induced more serious goblet cell reduction and increased intestinal permeability. 16S rRNA sequencing and LC-MS based metabonomic approaches were conducted to explore the changes of gut microbiota and metabolites. It was found that the intake of carrageenan under high-sucrose/high-salt diet significantly reduced the abundance of anti-inflammatory bacterium and increased the abundance of harmful bacterium, which was significantly related to the decrease of anti-inflammatory metabolites in colon, such as methyl caffeate, spermine, oleanolic acid and senecionine. Overall, high-sucrose or high-salt diet increased the risk of carrageenan-induced colitis. This reminds us to maintain good eating habits, do not prefer high-sugar or high-salt foods, and try not to consume large amounts of carrageenan continuously to maintain gut health.

Emulsion-based delivery systems have been reported to improve the solubility, stability and bioavailability of astaxanthin. In this study, the ability of astaxanthin-loaded emulsions (AL) to ameliorate obesity induced by a high-fat and high-sucrose diet was explored, using astaxanthin in the oil phase (ASTA) as a comparison. After the administration of AL, ASTA (30 mg per kg body weight), or saline on normal or obese mice for 4 weeks, the body fat accumulation levels, hepatic lipid contents and hepatic fatty acid profiles were detected, and AL showed better anti-obesity properties than ASTA. In an acute feeding experiment, it was first observed that the astaxanthin concentration of AL was higher than that of ASTA in the blood and liver of obese mice. What's more, AL altered the microbial co-occurrence patterns in obese mice. Some gut microbial modules that were significantly correlated with obesity-related physiological parameters were identified. Overall, the improvement effect of AL on obesity is better than that of ASTA due to their higher oral absorbability and modulating effects on the gut microbiota, and we suggest AL as a more suitable astaxanthin product type for obese bodies.

It is unclear how docosahexaenoic acid (DHA) improves insulin resistance via modulating gut microbiome in obese individuals. We used diet-induced obesity (DIO) mice as a model to study the effects of DHA-rich fish oil (DHA-FO) on host metabolic disorders and colonic microbiome. DHA-FO reduced fat deposition, regulated lipid profiles and alleviated insulin resistance in DIO mice. Probably because DHA-FO prevented the permeation of lipopolysaccharide across intestinal epithelial barrier, and promoted peptide YY (PYY) secretion via the mediation of short chain fatty acids receptor (FFAR2) in colon. Furthermore, DHA-FO might regulate PYY expression by reversing microbial dysbiosis, including increasing the abundance of Akkermansia muciniphila and Lactobacillus, and suppressing the growth of Helicobacter. DHA-FO also altered gut microbial function (e.g. “linoleic acid metabolism”) associated with PYY expression (r > 0.80, P

CEH may effectively protect mice against diet-induced hyperglycemia and microbial dysbiosis.

Mannuronate oligosaccharide (MOS) is α-D-mannuronic acid polymer with 1,4-glycosidic linkages that possesses beneficial biological properties. The aim of this study was to investigate the hypouricemic effect of MOS in hyperuricemic mice and demonstrate the possible protective mechanisms involved. In this research, 200 mg/kg/day of MOS was orally administered to hyperuricemic mice for four weeks. The results showed that the MOS treatment significantly reduced the serum uric acid (SUA) level from 176.4 ± 7.9 μmol/L to 135.7 ± 10.9 μmol/L (p < 0.05). MOS alleviated the inflammatory response in the kidney. Moreover, MOS promoted uric acid excretion by regulating the protein levels of renal GLUT9, URAT1 and intestinal GLUT9, ABCG2. MOS modulated the gut microbiota in hyperuricemic mice and decreased the levels of Tyzzerella. In addition, research using antibiotic-induced pseudo-sterile mice demonstrated that the gut microbiota played a crucial role in reducing elevated serum uric acid of MOS in mice. In conclusion, MOS may be a potential candidate for alleviating HUA symptoms and regulating gut microbiota.

Previous study has suggested the colonic nontoxicity and obesity inhibition of food‐grade κ‐carrageenan in obese mice. Further study using transcriptome is important to provide further understanding on the gene expressions of inflammation and obesity. Here, the obese mice without any treatment (HFD) or with 5% food‐grade κ‐carrageenan diet intervention (H5%) were used to perform colonic transcriptome sequencing. The results showed that genes involved in the inflammatory pathways or tight junction protein encoding were not significantly dysregulated by 5% carrageenan. However, the expression of lipid metabolism genes meaningfully changed as evidenced by the decreased gene levels of adipocytokines, lipogenesis, lipid absorption and transport, and the increased adipolysis and oxidation. In addition, the carrageenan metabolism experiments by toluidine blue (TB) staining of colon and high‐performance size exclusion chromatography (HPSEC) of feces supernatant showed that the food‐grade κ‐carrageenan was not absorbed or significantly degraded in the digestive tract of obese mice. Hence, the fact that food‐grade κ‐carrageenan was not significantly metabolized by the organism and did not cause obvious dysregulation of colonic inflammatory genes provided evidences for its noncolonic toxicity in obese mice. An anti‐obesity potential of food‐grade κ‐carrageenan was probably mediated by the regulation of lipids metabolism‐related genes., In this study, we aimed to explore the mechanisms of carrageenan actions, and the obese mice with no treatment (HFD) or 5% food‐grade κ‐carrageenan intervention (H5%) were used to perform carrageenan metabolism experiments and colonic transcriptome sequencing. The toluidine blue (TB) staining of colon and high‐performance size exclusion chromatography (HPSEC) of feces supernatant showed that the food‐grade κ‐carrageenan was not absorbed or significantly degraded in the digestive tract of obese mice. The transcriptome sequencing showed that no genes involved in the inflammatory pathways or tight junction protein encoding were significantly dysregulated by 5% carrageenan. However, the expression of lipid metabolism genes meaningfully changed as evident by the decreased gene levels of adipocytokines, lipogenesis, along with absorption and transport, but increased adipolysis and oxidation.

BACKGROUND Oyster's lipid degradation leads to a decrease in edible and nutritional value. Curcumin-mediated photodynamic treatment (PDT) is an innovative non-thermal technology, although evaluation of the oyster's lipid degradation has been scarce. In the present study, we investigated peroxide value, thiobarbituric acid reactive substance, triacylglycerol and free fatty acids to evaluate the effect of curcumin-mediated PDT on lipid degradation of oysters during refrigerated storage. RESULTS The results showed that curcumin-mediated PDT could delay oyster's lipid degradation. Next, the activities of enzymes were detected to determine the mechanisms behind the effects of curcumin-mediated PDT. It was revealed that the activities of lipase, phospholipase A2 (PLA2 ), phospholipase C (PLC), phospholipase D (PLD) and lipoxygenase (LOX) were significantly inhibited after curcumin-mediated PDT (P

5-fluorouracil (5-FU)-induced intestinal mucositis (IM) often makes chemotherapy patients suffer from physical and psychological suffering. Kappaphycus alvarezii (KA) is known for its potent multip...

The lipid and fatty acid (FA) contents of abalone Haliotis discus hannai from Fujian, Qingdao, and Rongcheng, China were studied over four seasons. In spring, the lipid content of abalone from Rongcheng was significantly higher than Qingdao and Fujian, and there was no significant difference in other seasons. Palmitic acid was the major saturated fatty acid (SFA) in all seasons. Oleic acid was identified as the major monounsaturated fatty acid (MUFA). Arachidonic acid (ARA) was the major polyunsaturated fatty acid (PUFA), and C18:0 was the major dimethyl acetals (DMA) in all zones. Lipid composition changed significantly over the different zones according to the season. In Fujian, higher total lipid content was observed in the summer, whereas PUFA content peaked in spring. The highest fat content was observed in spring and autumn in Qingdao and Rongcheng, respectively. Abalone contains docosapentaenoic acid and trace amounts of docosahexaenoic acid (DHA), which was recorded in small quantities during the summer. In general, the DMA content was higher in spring and summer than in autumn and winter. These findings can be useful for identifying the origin of abalone and evaluating the utilization of by-products of this species in the future.

Sargassum fusiforme, a nutritious edible brown alga, has been widely suggested to play an important role in the development of functional food because of its multiple biological activities. The aim of this study was to explore the anti-obesity effect of the combination of Sargassum fusiforme with extracts of fruit and vegetable by comparing the effects of Sargassum fusiforme (S), Sargassum fusiforme together with pomegranate peel extract (SP), Sargassum fusiforme together with turmeric extract (ST) and Sargassum fusiforme together with turmeric extract and pomegranate peel extract (C) on diet-induced obese C57BL/6J mice. Long-term consumption of a high-fat diet can lead to high levels of blood lipid, increase adipocyte size, and cause lipid metabolism dysfunction and gut microbiota dysbiosis. According to the results of the experiments, SP and ST were more effective in reducing lipid levels and fat accumulation than S; and, C exhibited the strongest efficacy compared with the other three supplements. ST and C also regulated adipocytokines and had significant effects on the gene expression of lipid metabolism. We also found that C alleviated the imbalance of intestinal flora caused by a high-fat diet to a certain extent. In conclusion, SP, ST and C have anti-obesity potentials, which can be used as alternative ingredients in the formula of functional food for obese people.

Intestinal mucosal immunity is important to human body; however, obesity induced by high-fat diet may bring a series of problems, such as chronic inflammation which may damage intestinal mucosal immunity. In this study, the effects of two different enzymatic hydrolysates of porphyra on the function of intestinal mucosal were explored in obese mice. The results showed that 10 consecutive weeks of high-fat dietary intake resulted in weight gain and intestinal abnormalities in C57BL/6 mice. However, the administration of enzymatic hydrolysate of porphyra effectively protected the intestinal mucosa from these injuries while reducing levels of oxidative stress (MDA, GSH, and GSH-Px). Specifically, they were found to improve small intestine morphological structure, increase growth of goblet cells and mucous, raise expression levels of lysozyme, and stimulate SIgA secretion, especially in the group administered with the enzymatic hydrolysate containing protease and polysaccharide enzyme (EHPP). The results showed that the enzymatic hydrolysates of porphyra may provide a protective measure to maintain intestinal mucosal barriers, which is beneficial to overall health. Porphyra is widely distributed all over the world. Moreover, an increasing number of studies have described its diverse biological functions. Therefore, it is necessary to find a way to develop products related to porphyra. In this study, a new type of polysaccharide enzyme of porphyra found in our previous research was used to make a clear porphyra energy drink with a lower molecular weight polysaccharide. Our findings highlighted the repaired intestinal barriers in obese bodies after the treatment with the enzymatic hydrolysate. PRACTICAL APPLICATIONS: Porphyra is widely distributed all over the world. Moreover, an increasing number of studies have described its diverse biological functions. Therefore, it is necessary to find a way to develop products related to porphyra. In this study, a new type of polysaccharide enzyme of porphyra found in our previous research was used to make a clear porphyra energy drink with a lower molecular weight polysaccharide. Our findings highlighted the repaired intestinal barriers in obese bodies after the treatment with the enzymatic hydrolysate.

The study aims to investigate the potentially neuroprotective effects and underlying mechanisms for brown seaweed polysaccharide of polymannuronic acid (PM) against Parkinson's disease (PD) pathogenesis. PD model mice were pretreated with PM via oral gavage once per day for 4 weeks and the preventative effects of PM against neuronal loss together with its modulation on brain-gut-microbiota axis were systematically explored. The results showed PM administration improved motor functions by preventing dopaminergic neuronal loss in the substantia nigra pars compacta (SNpc) and enhanced contents of striatal homovanillic acid (HVA), serotonin (5-HT), 5-hydroxyindole acetic acid (5-HIAA) and γ-aminobutyric acid (GABA) in PD mice. PM significantly alleviated inflammation in gut, brain and systemic circulation as shown by reduced levels or expressions of pro-inflammatory cytokines concurrently and inhibited mitogen-activated protein kinases (MAPK) signaling pathway in mice colon. Meanwhile, PM greatly improved integrity of intestinal barrier and blood brain barrier (BBB) as indicated by increased expressions of tight junction associated proteins in both mice colon and SNpc. Further studies indicated PM treatment resulted in changes of gut microbial compositions, together with great alterations of digestion and metabolism of dietary proteins and fats, which led to surge increase of fecal short chain fatty acids (SCFAs) in the colon of PD mice. In conclusion, pre-administration of PM could provide neuroprotective effects against PD pathogenesis by suppressing inflammation in gut, brain and systemic circulation, and by improving integrity of intestinal barrier and BBB. PM might modulate brain-gut-microbiota axis, at least in part, via gut microbiota derived SCFAs as mediators.

Astaxanthin has been favored as a health food supplement by obese consumers. However, no detailed descriptions are available concerning the absorption of astaxanthin in obese individuals. In this study, we conducted acute and chronic feeding experiments in C57BL/6J mice to study the differences in astaxanthin absorption in normal and obese bodies. The obesity condition greatly decreased astaxanthin concentration in the blood and liver, its accumulation in tissues and organs, and the bioaccessibility. This may be related to the excessive intake of sucrose, fatty acids, and cholesterol, the increased gastrointestinal motility, and the disorder of gut microbiota in the obese body. Overall, our study showed that the obese body had a far less oral absorbability of astaxanthin than a normal body, and we suggest that the recommended or approved doses of astaxanthin can be properly increased for the obese body in the hope that astaxanthin will play a more active role in obese individuals.

In this study, the disinfection effect of curcumin-mediated photodynamic therapy on the contact surfaces of fresh fruit was investigated. Our results showed that the optimum concentration of curcumin and the energy density required were 0.5 μM and 7.2 J/cm2, respectively. Photodynamic therapy showed an excellent disinfection rate for the fresh fruits with a reduction of more than 80% in the total bacteria and coliform counts. The photodynamic therapy inhibited species that belonged to the categories of gram-negative and facultative anaerobic bacteria, except for two species of the Trichoderma fungus. Importantly, photodynamic therapy prolonged the shelf-life of grapes for two days at room temperature. Therefore, photodynamic therapy should be commercialized as a high efficiency and non-thermal sterilization technology for use in the food industry.

Increasing pressure of life may bring some disease risks and stress injuries, which may destroy the immune system and result in intestinal mucosal immune disorders. In this study, the effects of different doses of ATX (30 mg per kg b.w., 60 mg per kg b.w. and 120 mg per kg b.w.) on intestinal mucosal functions were explored in cyclophosphamide (Cy)-induced immunodeficient mice. The results showed that continuous intraperitoneal injection of 100 mg per kg b.w. Cy for three days led to a persistent decrease of body weight and a range of abnormalities in the intestine of C57BL/6 mice. However, administration of ATX at 60 and 120 mg per kg b.w. could effectively prevent intestinal mucosa from this damage, including reduced levels of oxidative stress (MDA, GSH and GSH-PX), increased intestinal morphological structural integrity, stimulative growth of goblet cells and mucous secretion, decreased development of Paneth cells and expression levels of antimicrobial peptides (AMPs) (Reg-3γ and lysozyme), increased IgA secretion, ameliorative main gut flora (especially total bacteria, Lactobacillus and Enterobacteriaceae spp. ) and its metabolites (acetic acid, propionic acid and butyric acid). These protective effects of ATX were better than those of control-β-carotene in general. Our results may provide a new protective measure to keep intestinal mucosal barriers, which is of great significance for maintaining immune function in the body.

Astaxanthin has been widely favored as a health food supplement by individuals but its absorption in the body seems not to be satisfactory. In addition, the peak time of astaxanthin derived from Haematococcus pluvialis in the plasma was much longer than other carotenoids found in our previous research. Thus, it is necessary to explore the process that affects the absorption of astaxanthin in order to potentially find a novel approach to improve the absorption in the future. In this study, we confirmed that the colon has an ability to absorb astaxanthin and conducted acute feeding experiments with the treatment of antibiotics in C57BL/6J mice and chronic feeding experiments in germ-free (GF) mice to detect the relationship between the gut microbiota and the absorption of astaxanthin. Our study showed that the decrease of gut microbiota led to a less oral absorbability, which might be related to the decreased expression of SR-BI in the small intestine and the reduction of free form and Z-astaxanthin converted by the gut microbiota found in the vitro culture. The experiments of anaerobic culture also implied that Lactobacillus might play an important role in the absorption of astaxanthin.

Bacteria-induced wound infections and multifunctional hydrogels have received widespread attention in wound repair. In this study, self-assembling peptides (SAPs) were grafted on O-carboxymethyl chitosan (O-CMCS), and compact spatial structure and good drug sustained-release effect on mel-d1, a new AMP designed based on melittin with the same antimicrobial activity but lower cytotoxicity and ciprofloxacin (CIP) were obtained. In vivo test showed that the O-CMCS/SAP hydrogel loaded with CIP and mel-d1 accelerated the wound closure speed caused by infection of Escherichia coli and skin tissue regeneration. Both of the enhanced interaction between O-CMCS/SAP and CIP/Mel-d1 because of the hydrophobic interaction and π-π stacking, and the potential tissue healing ability of SAP played important roles. This study provided a rational design method of O-CMCS by grafting SAPs to give a wider range of biological functions.

SCOPE This study aims to investigate and compare the potentially neuroprotective effects and underlying mechanisms for brown seaweed polysaccharides (PS) of Alginate (Alg) and its two components, including Polymannuronic acid (PM) and Polyguluronic acid (PG), against Parkinson's disease (PD) pathogenesis. METHODS AND RESULTS Model mice of PD were pretreated with Alg or PM or PG, separately via oral gavage once per day for four weeks. Our results found PM improved motor functions of PD mice, but Alg or PG did not. PM or PG, but not Alg, could prevent dopaminergic neuronal loss by increasing tyrosine hydroxylase expressions in midbrain of PD mice. The neuroprotective effects of PM relied on its anti-inflammation effects and its ability to improve striatal neurotransmitters (serotonin and 5-hydroxyindole acetic acid) levels in PD mice. PM inhibited inflammation, but PG or Alg induced inflammation in systemic circulation of PD mice. The neuroprotection provided by PG might be related to its ability to increase striatal neurotransmitter of 5-hydroxyindole acetic acid levels in PD mice. CONCLUSION PM played better than PG to provide neuroprotection, but Alg did not show any neuroprotection against PD. Alg and its two components acted differently in preventing dopaminergic neuronal loss in PD mice. This article is protected by copyright. All rights reserved.

5-fluorouracil (5-FU)-induced intestinal mucositis (IM) often makes chemotherapy patients suffer from physical and psychological suffering.

Here we have explored the effect of neoagarotetraose (NAT) on liver injury caused by intense exercise. Our results showed that NAT treatment obviously decreased liver weight (p < 0.01), improved the liver morphological structure, decreased ALT level (p < 0.05) and endotoxin (LPS) (p < 0.01). In addition, NAT could regulate bile acid profiles in feces and serum of mice, which indicated the potential of liver function, suggesting that NAT was effective to relieve intense exercise-induced liver injury. NAT could regulate the expression of colon genes. NAT tended to alter the microbial composition of mice under intense exercise. We uncovered the network interactions between liver traits and microbial communities in NAT treatment mice. Interestingly, our data indicated that intense exercise-induced liver injury may be related to Clostridiales. In summary, these results demonstrated that NAT relieved liver injury induced by intense exercise may be related to gut microbiota.

The objective of this study was to evaluate the bactericidal effect of curcumin (CUR)-mediated photodynamic inactivation (PDI) against Escherichia coli DH5α in vitro and in oysters, then further investigate the edible security of PDI-treated oysters based on cellular toxicological methods. First, DH5α cells were irradiated by a 470 nm LED light source with an energy density of 3.6 J/cm2. Colony forming units (CFU) were counted and the viability of DH5α cells was calculated after treatment with CUR-mediated PDI. Intracellular production of reactive oxygen species (ROS) was studied by measuring the fluorescence of 2, 7-dichlorofluorescein (DCF) using a flow cytometry. Membrane permeability was measured using confocal laser scanning microscopy (CLSM) with propidium iodide (PI) staining. After that, the bactericidal effect of CUR-mediated PDI was evaluated in oysters which were pre-contaminated with DH5α cells. Finally, cellular toxicology of PDI-treated oysters was evaluated through morphological observation, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, DNA ladder assay, and nuclear staining. Results showed that the viability of DH5α was significantly decreased in a CUR concentration-dependent manner and resulted in an approximately 3.5-log reduction at the concentration of 20 μM. After treatment with CUR-mediated PDI (20 μM, 3.6 J/cm2), the ROS level in DH5α cells and the membrane permeability markedly increased. Our data demonstrated that CUR-mediated PDI had a good decontamination effect against DH5α contaminated in oysters. After incubation with PDI-treated oysters, fibroblasts L929 cell morphology, MTT absorbance and cell apoptosis had no obvious changes. Our findings preliminarily demonstrated that CUR-mediated PDI-treated oysters had no cytotoxicity to fibroblasts.

Stress exposure can increase the appearance of intestinal dysfunction. DHA and EPA have been shown to possess significant anti-inflammatory and immuno-enhancement bioactivities. The aim of the study was to investigate whether different forms of DHA or EPA would affect intestinal barriers (including intestinal epithelium integrity and immunity responses, gut microbiota and its metabolites) in mice under chronic stress, and might therefore prevent stress induced intestinal dysfunction. Chronic stress caused a series of anomalies in the intestine, including decreased faecal water content, increased pro-inflammatory cytokines (IFN-γ, TNF-α, IL-1β and IL-6), reduced expression levels of ZO-1, occludin and E-cadherin, and aberrant microbiota composition (especially Roseburia spp., Prevotella spp., bifidobacteria and lactobacilli) and its metabolites, mainly LPS, acetic acid, propionic acid and butyric acid. Our data indicated that both DHA-PL and EPA-PL counteracted these adverse effects effectively. In conclusion, DHA-PL and EPA-PL may effectively protect mice against intestinal dysfunction under chronic stress exposure as potential ingredients for functional food.

It remains to study whether docosahexaenoic acid-rich fish oil (DHA-FO) improves hepatic lipid metabolism by leptin-independent mechanisms. We used ob/ob mice as a model to investigate the effects of DHA-FO on hepatic steatosis. DHA-FO inhibited lipid droplets (LD) formation in liver of ob/ob mice. Probably because DHA-FO consumption prevented the accumulation of oleic acid, and suppressed the synthesis of triglycerides and cholesteryl esters. These beneficial effects might be concerned with the promotion of short chain fatty acids (SCFAs) production. Furthermore, DHA-FO could reverse gut bacteria dysbiosis, including increasing the abundance of SCFAs producers (e.g. Akkermansia and unclassified_Muribaculaceae), and suppressing the proliferation of conditional pathogenic bacteria, such as unclassified_Lachnospiraceae. DHA-FO also promoted colonic microbial function ("Glycerolipid metabolism") associated with lipid metabolism. As a potential ingredient for functional food, DHA-FO reduced LD accumulation, which might be associated with modulation of obesity-linked gut microbiome in ob/ob mice.

Chronic diseases, such as obesity, cause great harm to human health. Conventional drugs have promising therapeutic effects but also cause significant side effects. Functional foods are an excellent therapeutic alternative to pharmaceuticals, as they have fewer side effects. However, screening for active ingredients in natural foods is difficult. In this study, a novel pancreatic lipase inhibitor screening strategy, guided by the drug molecule orlistat, was combined with experimental verification. Twenty compounds from natural foods were evaluated based on the characteristics of orlistat interaction with pancreatic lipase. The characteristics of 13 molecules were comparable to those of orlistat. The pancreatic lipase inhibition rates of curcumin and sinensetin were 82.42 ± 0.50% and 81.07 ± 2.05%, respectively, and their IC50 values were 0.971 mM and 0.526 mM, respectively; both the inhibition rates as well as IC50 values were similar to those of orlistat. Curcumin and sinensetin prevented weight gain in mice by 69.17% and 52.29%, respectively, compared to orlistat. Curcumin and sinensetin did not cause significant organ damage in vivo, but significantly reduced the contents of triglycerides and cholesterol in blood and lipids in the liver, protecting liver function. Furthermore, 57 328 molecules in the Chinese Natural Product Database library were screened, and 20 potentially active molecules, found to be highly efficient in our study, were selected. Thus, we successfully established an efficient and accurate strategy for screening active ingredients in natural foods under the guidance of a drug molecule, providing valuable insights for functional food development.

Most athletes continually endure mental and physical stress from intense exercise. Fructo-oligosaccharide (FOS) can reduce physical exhaustion, but the concrete mechanism behind it still needs further research. In this study, the effect of FOS on colonic mucosal barriers was investigated using an exercise-induced stress mouse model. Except for control individuals, mice were subject to cycles of 2-day exercise (at 20 rpm) interleaved by 5-day rest. The mice experienced a total of 6 days of exercise during the feeding period. FOS improved common indicators of exhaustion, such as glycogen storage in muscle. 16S rRNA data supported that changes in the gut microbiome were also closely related to stress status. Notably, Anaerotruncus was increased in mice under stress, while FOS facilitated the growth of Dorea, which is negatively associated with exhaustion. The RNA-seq analysis revealed that FOS could maintain the integrity of colonic epithelial barriers. For example, FOS significantly restored the expression of tight junctions (Occludin and Zonula occludens-1) in the colon, which was impaired under a stress state. Besides, the NOD-like receptor family pyrin domain containing 6 (NLRP6) inflammasome might contribute to the protection of the colonic mucosa by promoting the secretion of IL-18, Mucin2 (Muc2) and intestine lectin 1 (Itln1) in FOS-treated individuals. In short, FOS administration attenuated the damage of colonic mucosal barriers in exercise-induced stressed mice.

Food additives, often used to guarantee the texture, shelf-life, taste, and appearance of processed foods, have gained widespread attention due to their increased link to the growing incidence of chronic diseases. As one of the most common additives, carrageenans have been used in human diets for hundreds of years. While classified as generally recognized as safe (GRAS) for human consumption, numerous studies since the 1980s have suggested that carrageenans, particularly those with random coil conformations, may have adverse effects on gastrointestinal health, including aggravating intestinal inflammation. While these studies have provided some evidence of adverse effects, the topic is still controversial. Some have suggested that the negative consequence of the consumption of carrageenans may be structure dependent. Furthermore, pre-existing conditions may predispose individuals to varied outcomes of carrageenan intake. In this review, structure-function relationships of various carrageenans in the context of food safety are discussed. We reviewed the molecular mechanisms by which carrageenans exert their biological effects. We summarized the findings associated with carrageenan intake in animal models and clinical trials. Moreover, we examined the interactions between carrageenans and the gut microbiome in the pathogenesis of gastrointestinal disorders. This review argues for personalized guidance on carrageenan intake based on individuals' health status. Future research efforts that aim to close the knowledge gap on the effect of low-dose and chronic carrageenan intake as well as interactions among food additives should be conducive to the improved safety profile of carrageenans in processed food products.

Natural compounds have tremendous potential to regulate glucose metabolism, but conventional methods for studying their bioactivities are usually labor intensive. Here, hypoglycemic properties in 22 selected food-derived compounds were examined using molecular docking. The results indicated that curcumin is an inhibitor of both α-glucosidase and dipeptidyl-peptidase 4 (DPP-4), which are important for glycemic control. These effects of curcumin were also confirmed by enzymatic determination in vitro. Furthermore, curcumin significantly improved diet-induced hyperglycemia (e.g., fasting plasma glucose levels and glycogen storage in muscle or liver) in mice. This might be attributed to its inhibitory effects on the activities of α-glucosidase and DPP-4 in vivo. Curcumin also upregulated the expression of genes (e.g., glucagon-like peptide 1) related to DPP-4 activity in the small intestine. In conclusion, curcumin is a potential ingredient of functional foods used for diet-induced hyperglycemia management. PRACTICAL APPLICATIONS: Curcumin has been widely used as a colorant in the food industry. Moreover, a growing number of studies have described its diverse biological functions, such as anti-inflammatory, anti-oxidant, and anti-angiogenic activities. Thus, curcumin is regarded as a potential ingredient in functional foods. Our results highlighted the hyperglycemic effect of curcumin, suggesting that curcumin may be included in food products for hyperglycemic patients.

In this study, the fucoxanthin (FUC)-loaded gliadin nanoparticles (Gli NPs) stabilized by chondroitin sulfate (ChS) were fabricated. Results showed that the particle size and turbidity of Gli-ChS NPs were highly pH-dependent. Hydrogen bond, electrostatic interaction and hydrophobic interaction were involved in the formation of Gli-ChS NPs. The surface hydrophobicity of Gli NPs decreased remarkably after coating with ChS. FUC-Gli-ChS NPs increased the stability of FUC against heating and ultraviolet (UV) irradiation. Adding ChS to FUC-Gli NPs enhanced their stabilities to ionic strength and thermal treatment, especially in an acidic environment. Furthermore, FUC-loaded Gli-ChS NPs inhibited the FUC release in simulated gastric fluid (SGF), while enhanced the release of FUC in simulated intestinal fluid (SIF) and simulated colonic fluid (SCF). In summary, this work has important practical significance for the development of Gli NPs as nano-delivery systems for FUC or other hydrophobic compounds.

Background The anti-inflammatory property of ω-3 polyunsaturated fatty acids (PUFA) has been exploited in the management of inflammatory bowel disease (IBD) with promising results. However, it remains unclear if PUFA play a significant role in the resolution of inflammation and promotion of mucosal healing. Krill oil (KO) is a natural product rich in PUFA and the potent antioxidant, astaxanthin. In this study, we attempted to understand the mechanisms through which KO modulates the gut microbiome and metabolome using in vitro and in vivo colitis models and a multi-omics based approach. Results KO significantly decreased LPS-induced IL1β and TNFα expression in human macrophages in vitro in a dose-dependent manner by regulating a broad spectrum of signaling pathways, including NF-κB and NOD-like receptor signaling, and displayed a synergistic effect with COX2 and IKK2 inhibitors in attenuating inflammatory pathways. Moreover, KO was involved in the resolution of inflammation by promoting M2 polarization and enhancing macrophage-mediated intracellular bacterial killing. Parasite-dependent intestinal mucosal damage and microbial dysbiosis induced by Trichuris suis infection in pigs were partially restored by feeding KO. KO supplementation reduced the abundance of Rickettsiales and several species of Lactobacillus, which were among the important features identified by random forests analysis contributing to classification accuracy for KO supplementation. Several microbial signatures with strong predictive power for the status of both infection and supplementation were identified. The inhibitory effect of KO on histidine metabolism was identified using untargeted metabolomics. KO supplementation reduced several key metabolites related to histamine metabolism by suppressing the expression of a gene encoding l-histidine decarboxylase in the colon mucosa and reducing histamine biosynthesis of microbial origin. Moreover, the pro-resolving properties of KO were validated using a Citrobacter rodentium-induced Th1-dependent colitis murine model. Further, microbial signatures with high prediction accuracy for colitis-related pathophysiological traits were identified in mice. Conclusion The findings from this study provided a mechanistic basis for optimizing microbiome-inspired alternative therapeutics in the management of IBD. The microbial signatures identified, particularly those with strong predictive accuracy for colitis phenotypes, will facilitate the development of biomarkers associated with appropriate dietary intervention to manage intestinal inflammation.

Astaxanthin n-octanoic acid diester (AOD) is a type of astaxanthin connecting medium-chain fatty acids with a more stable structure. In this study, we examined the role of AOD in ameliorating insulin resistance (IR) induced by a high-fat and high-sucrose diet (HFD) as well as its effect on modulating gut microbiota in mice, with free astaxanthin (AST) as a comparison. Four groups of male C57BL/6J mice (6 weeks old, n = 10 per group) were fed with a normal control diet (NC), HFD orally administered with AOD, AST (50 mg/kg body weight), or vehicle for 8 weeks. AOD improved glucose tolerance, IR, systematic and intestinal inflammation, and intestinal integrity better than AST. Further, both AOD and AST modulated gut microbiota. A significantly higher abundance of Bacteroides and Coprococcus was found in AOD than in AST, and the predicted pathway of carbohydrate metabolism was significantly impacted by AOD. Overall, AOD may play a role in alleviating IR and inflammation with the modulating effect on microbiota in HFD-fed mice. Our findings could facilitate the development of AOD as a bioactive nutraceutical and more stable alternative to AST.

Additional file 1: Figure S1. A PCA plot showing that krill oil (KO), COX2 inhibitor (celecoxib) and IKK2 inhibitor (TPCA1) induced distinct transcriptome patterns in human THP1 cells differentiated using phorbol 12-myristate 13-acetate (PMA). Figure S2. MA plots (log ratio vs mean average) for the visualization of differences in global transcriptome features of THP1 cells under different treatment conditions. The percentage denotes the number of up (red) or down (green) regulated genes induced by various compounds at a false discovery rate (FDR) < 0.05. Figure S3. Heatmaps showing genes in Chemokine (A) and Nod-like receptor signaling (B) pathways significantly inhibited by krill oil and other inhibitors at FDR < 0.05. Figure S4. Krill oil acted synergistically with COX2 and IKK2 inhibitors in increasing the expression of PPARG and FABP5 in human THP1 cells differentiated using PMA. Figure S5. The expression of IL17RA was significantly inhibited by krill oil in human THP1 cells in vitro. Figure S6. The number of bacteria engulfed by human macrophage phagocytosis was marginally increased by krill oil in vitro. Figure S7. A. A heat map showing the genes displaying a significant difference in abundance in the four experimental groups in the proximal colon tissue in pigs in response to Trichuris suis infection and dietary supplements. SC: uninfected pigs fed SO. SI: infected pigs fed SO. KC: uninfected pigs fed KO. KI: infected pigs fed KO. B. Modules-trait relationships in the signed consensus network. The correlation between pathophysiological traits, worm count, gut histamine levels, and gut fatty acid (FA_22:6) measurements, and the module eigengene value was calculated based on Pearson correlation. C. A scatterplot showing gene significance (y-axis) vs. module membership (x-axis) in the purple module. D. Transcription factors significantly enriched in the purple module in the signed consensus network. Figure S8. ANOSIM analysis of beta diversity in the porcine proximal colon microbiome. Figure S9. Global microbial interaction networks inferred using a Random Matrix Theory (RMT) based algorithm in the porcine proximal colon microbial community. Figure S10. Microbial signatures or balances associated with acetate and eicosapentaenoic acid (EPA) concentrations in proximal colon contents in pigs. Figure S11. Select pathways significantly correlated with soybean (SO) and krill oil (KO) supplementation. Figure S12. Taxa significantly correlated with gut luminal concentrations of histamine, 1-methyhistamine, and/or cir-urocanate in a Citrobacter rodentium induced murine colitis model. Figure S13.Citrobacter rodentium infection in mice had a significant impact on gut microbial diversity. Table S1. Composition analysis of krill oil and soybean oil used in the study. Table S2. Top 20 genera selected by Random Forests that distinguish the infection status in a porcine model. Table S3. Serum long chain polyunsaturated fatty acid (LCFA) in pigs. KO: krill oil. SO: soybean oil. HMDB: The Human Metabolome Database. Table S4. The metabolites related to Histidine Metabolism was significantly affected by krill oil supplement (KO) in pigs infected by Trichuris suis.

Seaweeds have been studied extensively for their nutritional values but their potential nutraceutical application remained underutilized due to uncharacterized bioactive compounds. Here we demonstrated that water extracts of Kappaphycus, Halimeda, Padina and Sargassum were able to improve insulin resistance, reduced hyperglycemia and protect liver and pancreatic tissue from HFD-induced damage in mice, with both Padina and Sargasssum displayed more significant results than the other two seaweeds. A list of potential bioactive compounds was then composed by virtual screening of 276 compounds detected by LC-MS on selected Padina fractions using molecular docking by Surflex-Dock. Further analysis determined punicate as the most potent bioactive compound that inhibits both glucosidase and dipeptidyl-peptidase-4 enzymes. In conclusion, we discovered novel in vivo hypoglycemic activity in Halimeda and several potential α-glucosidase and DPP-4 inhibitors in Padina via virtual screening, demonstrating the efficacy of molecular docking to facilitate discovery of novel bioactive compounds.