Polystyrene nanoplastics amplify the toxic effects of PFOA on the Chinese mitten crab (Eriocheir sinensis)

Nanoplastics (NPs), the final form of degraded microplastics in the environment, can adsorb PFOA (an emerging organic pollutant in recent years) in several ways. Current research on these has focused on bony fishes and mollusks, however, the combined toxicity of PFOA and NPs remains unknown in Eriocheir sinensis. Therefore, the effects of single or combined exposure to PFOA and NPs were investigated. The results showed that NPs aggravated PFOA exposure-induced oxidative stress, serum lipid disorders, immune responses, and morphological damage. DEGs altered by NPs-PFOA exposure were predominantly enriched in GO terms for cell lumen, and organelle structure, and KEGG terms for spliceosome and endocrine disorders-related diseases. Notably, the apoptotic pathway plays a central role enriched under different exposure modes. PFOA or NPs-PFOA exposure disrupted the levels of lipids molecules-related metabolites by mediating the glycerophospholipid pathway, and the NPs mediated the ferroptosis pathway to exacerbate PFOA-induced metabolic toxicity. In addition, NPs exacerbated the inflammatory response and metabolic imbalance by mediating Fusobacterium ulcerans in the intestinal. In conclusion, this study provides a valuable reference for the characterization of NPs-PFOA combined pollution and a scientific basis for the development of environmental protection policies and pollution management strategies.

Impact of the Dietary Fat Concentration and Source on the Fecal Microbiota of Healthy Adult Cats

BACKGROUND/OBJECTIVES

The dietary fat supply might interact with the intestinal microbiota via different mechanisms. Research on this topic, however, remains scarce in cats. For this reason, the present study was conducted to evaluate the impact of the fat concentration and fatty acid profile in the diet on the fecal microbiota of healthy cats.

METHODS

A low-fat basal diet was fed to ten healthy adult cats. The diet was offered without or with the daily addition of 0.5 g or 1 g of sunflower oil, fish oil or lard per kg body weight of the cats, using a randomized cross-over design. Each feeding period lasted for 21 days, and the fecal samples were collected on the last days of each period. The fecal microbiota was analyzed by 16S rDNA sequencing. Additionally, microbial metabolites (short-chain fatty acids, lactate, ammonium, biogenic amines) were measured in the fecal samples.

RESULTS

The dietary treatment had no impact on the alpha-diversity of the fecal microbiota or on the relative abundance of bacterial phyla in the samples. Only a few changes were observed in the relative abundance of bacterial genera and the concentrations of microbial metabolites in the feces, probably being of minor physiological relevance.

CONCLUSIONS

The balanced intestinal microbiota of cats seems to be relatively resistant to moderate variations in the dietary fat supply over a short feeding period. Longer-term treatments and higher dietary fat levels should be evaluated in future studies to further clarify the relevance of fat intake for the feline gut microbiome.

Intestinal overexpression of Pla2g10 alters the composition, diversity and function of gut microbiota in mice

The intestinal microbiota is important for the health of the host and recent studies have shown that some genes of the host regulated the composition of the intestinal microbiota. Group 10 phospholipase A2 (PLA2G10) is a member of the lipolytic enzyme family PLA2, which hydrolyze the ester bond at the sn-2 position of phospholipids to produce free fatty acids and lysophospholipids. PLA2G10 is secreted into the intestinal lumen, but its impact on the gut microbiota remains unclear. In this study, we generated intestine-specific Pla2g10 knock-in mice, and used 16S RNA sequencing to compare their gut microbiota with that of their wild-type (WT) littermates. Results showed that gut-specific Pla2g10 knock-in induced both PLA2G10 mRNA and protein levels in the colon. Moreover, intestinal Pla2g10 overexpression reduced the α-diversity of the gut microbiota relative to that of WT mice. The abundance of Bacteroidetes was lower in the Pla2g10 knock-in mice than that in the control mice, while the ratio of Firmicutes/Bacteroidetes was higher. Furthermore, the abundance of the genus Allobaculum was reduced, whereas the abundance of beneficial bacteria genera, including Enterorhabdus, Dubosiella, and Lactobacillus, was increased by host intestinal Pla2g10 overexpression. In summary, intestinal Pla2g10 overexpression increased the proportions of beneficial bacterial in the colonic chyme of mice, providing a potential therapeutic target for future improvement of the gut microbiota.

Leaky Gut Syndrome: An Interplay Between Nutrients and Dysbiosis

PURPOSE OF REVIEW

The gut microbiota (GM) is directly related to health and disease. In this context, disturbances resulting from excessive stress, unbalanced diet, alcohol abuse, and antibiotic use, among other factors, can contribute to microbiota imbalance, with significant impacts on host health. This review provides a comprehensive examination of the literature on the influence of diet on dysbiosis and increased intestinal permeability over the past five years.

RECENT FINDINGS

Diet can be considered one of the main modulating factors of GM, impacting its composition and functionality. Excessive consumption of simple carbohydrates, saturated fats, and processed foods appears to be directly linked to dysbiosis, which can lead to intestinal hyperpermeability and leaky gut syndrome. On the other hand, diets primarily composed of food groups such as nuts, vegetables, fruits, fish, and poultry in moderate quantities, along with limited consumption of red and processed meats, are associated with a more diverse, healthier, and beneficial GM for the host. It is worth noticing that the use of prebiotics and probiotics, omega-3 supplementation, polyunsaturated fatty acids, and vitamins A, B, C, D, and E can positively modulate the intestinal microbiota by altering its metabolic activity, microbial composition, and improve intestinal barrier function. This review points to a new perspective regarding individualized dietary intervention and the need to integrate it into several aspects of cellular biology, biochemistry, and microbiology to prescribe more effective diets and thus contribute to patients' comprehensive health.

Molecular Mechanisms Linking Omega-3 Fatty Acids and the Gut-Brain Axis

The gut-brain axis (GBA) is a complex communication network connecting the gastrointestinal tract (GIT) and the central nervous system (CNS) through neuronal, endocrine, metabolic, and immune pathways. Omega-3 (n-3) fatty acids, particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are crucial food components that may modulate the function of this axis through molecular mechanisms. Derived mainly from marine sources, these long-chain polyunsaturated fatty acids are integral to cell membrane structure, enhancing fluidity and influencing neurotransmitter function and signal transduction. Additionally, n-3 fatty acids modulate inflammation by altering eicosanoid production, reducing proinflammatory cytokines, and promoting anti-inflammatory mediators. These actions help preserve the integrity of cellular barriers like the intestinal and blood-brain barriers. In the CNS, EPA and DHA support neurogenesis, synaptic plasticity, and neurotransmission, improving cognitive functions. They also regulate the hypothalamic-pituitary-adrenal (HPA) axis by reducing excessive cortisol production, associated with stress responses and mental health disorders. Furthermore, n-3 fatty acids influence the composition and function of the gut microbiota, promoting beneficial bacterial populations abundance that contribute to gut health and improve systemic immunity. Their multifaceted roles within the GBA underscore their significance in maintaining homeostasis and supporting mental well-being.

Impact of chronic stress on intestinal mucosal immunity in colorectal cancer progression

Chronic stress is a significant risk factor that contributes to the progression of colorectal cancer (CRC) and has garnered considerable attention in recent research. It influences the distribution and function of immune cells within the intestinal mucosa through the "brain-gut" axis, altering cytokine and chemokine secretion and creating an immunosuppressive tumor microenvironment. The intestine, often called the "second brain," is particularly susceptible to the effects of chronic stress. Cytokines and chemokines in intestinal mucosal immunity（IMI） are closely linked to CRC cells' proliferation, metastasis, and drug resistance under chronic stress. Recently, antidepressants have emerged as potential therapeutic agents for CRC, possibly by modulating IMI to restore homeostasis and exert anti-tumor effects. This article reviews the role of chronic stress in promoting CRC progression via its impact on intestinal mucosal immunity, explores potential targets within the intestinal mucosa under chronic stress, and proposes new approaches for CRC treatment.

Docosahexaenoic acid supplementation and infant brain development: role of gut microbiome

Perinatal stage represents a critical period for brain development. Docosahexaenoic acid (DHA) is a ω-3 polyunsaturated fatty acid preferentially accumulated in the brain that may benefit neurodevelopment. Microbial colonization and maturation parallel with the rapid development of infant metabolic and brain function that may influence the effects of DHA on neurological development. This review aims to summarize the current literature on the mediating effects of DHA on brain and gut microbiome development and attempts to reevaluate the efficacy of DHA from a gut microbiome-mediated perspective. Specifically, the regulatory roles of DHA on hypothalamic-pituitary-adrenal axis, inflammation, and neuroactive mediators may be partly moderated through gut microbiome. Consideration of the gut microbiome and gut-brain communication, when evaluating the efficacy of DHA, may provide new insights in better understanding the mechanisms of DHA and impart advantages to future development of nutritional therapy based on the nutrient-microbiome interaction.

Gut microbiota and psoriasis: pathogenesis, targeted therapy, and future directions

Background

Psoriasis is one of the most common autoimmune skin diseases. Increasing evidence shows that alterations in the diversity and function of microbiota can participate in the pathogenesis of psoriasis through various pathways and mechanisms.

Objective

To review the connection between microbial changes and psoriasis, how microbial-targeted therapy can be used to treat psoriasis, as well as the potential of prebiotics, probiotics, synbiotics, fecal microbiota transplantation, diet, and Traditional Chinese Medicine as supplementary and adjunctive therapies.

Methods

Literature related to the relationship between psoriasis and gut microbiota was searched in PubMed and CNKI.

Results

Adjunct therapies such as dietary interventions, traditional Chinese medicine, and probiotics can enhance gut microbiota abundance and diversity in patients with psoriasis. These therapies stimulate immune mediators including IL-23, IL-17, IL-22, and modulate gamma interferon (IFN-γ) along with the NF-kB pathway, thereby suppressing the release of pro-inflammatory cytokines and ameliorating systemic inflammatory conditions.

Conclusion

This article discusses the direction of future research and clinical treatment of psoriasis from the perspective of intestinal microbiota and the mechanism of traditional Chinese medicine, so as to provide clinicians with more comprehensive diagnosis and treatment options and bring greater hope to patients with psoriasis.

Marine Bioactive Compounds with Functional Role in Immunity and Food Allergy

Food allergy, referred to as the atypical physiological overreaction of the immune system after exposure to specific food components, is considered one of the major concerns in food safety. The prevalence of this emerging worldwide problem has been increasing during the last decades, especially in industrialized countries, being estimated to affect 6-8% of young children and about 2-4% of adults. Marine organisms are an important source of bioactive substances with the potential to functionally improve the immune system, reduce food allergy sensitization and development, and even have an anti-allergic action in food allergy. The present investigation aims to be a comprehensive report of marine bioactive compounds with verified actions to improve food allergy and identified mechanisms of actions rather than be an exhaustive compilation of all investigations searching beneficial effects of marine compounds in FA. Particularly, this research highlights the capacity of bioactive components extracted from marine microbial, animal, algae, and microalgae sources, such as n-3 long-chain polyunsaturated fatty acids (LC-PUFA), polysaccharide, oligosaccharide, chondroitin, vitamin D, peptides, pigments, and polyphenols, to regulate the immune system, epigenetic regulation, inflammation, and gut dysbiosis that are essential factors in the sensitization and effector phases of food allergy. In conclusion, the marine ecosystem is an excellent source to provide foods with the capacity to improve the hypersensitivity induced against specific food allergens and also bioactive compounds with a potential pharmacological aptitude to be applied as anti-allergenic in food allergy.

The Role of Gut Microbiome in Sleep Quality and Health: Dietary Strategies for Microbiota Support

Dietary components, including dietary fiber, unsaturated fatty acids, and polyphenols, along with meal timing and spacing, significantly affect the microbiota's capacity to produce various metabolites essential for quality sleep and overall health. This review explores the role of gut microbiota in regulating sleep through various metabolites such as short-chain fatty acids, tryptophan, serotonin, melatonin, and gamma-aminobutyric acid. A balanced diet rich in plant-based foods enhances the production of these sleep-regulating metabolites, potentially benefiting overall health. This review aims to investigate how dietary habits affect gut microbiota composition, the metabolites it produces, and the subsequent impact on sleep quality and related health conditions.

Effects of cold acclimation on serum biochemical parameters and metabolite profiles in Schizothorax prenanti

BACKGROUND

Environmental temperature is critical in regulating biological functions in fish. S. prenanti is a kind of cold-water fish, but of which we have little knowledge about the metabolic adaptation and physiological responses to long-term cold acclimation.

RESULTS

In this study, we determined the physiological responses of S. prenanti serum after 30 days of exposure to 6℃. Compared with the control group, the levels of TC, TG, and LDL-C in the serum were significantly (P < 0.05) increased, and the level of glucose was significantly (P < 0.05) decreased under cold acclimation. Cold acclimation had no effect on the gene expression of pro-inflammatory factors and anti-inflammatory factors of S. prenanti. Metabolomics analysis by LC-MS showed that a total of 60 differential expressed metabolites were identified after cold acclimation, which involved in biosynthesis of amino acids, biosynthesis of unsaturated fatty acids, steroid degradation, purine metabolism, and citrate cycle pathways.

CONCLUSION

The results indicate that cold acclimation can alter serum metabolites and metabolic pathways to alter energy metabolism and provide insights for the physiological regulation of cold-water fish in response to cold acclimation.

Role of antioxidative activity in the docosahexaenoic acid's enteroprotective effect in the indomethacin-induced small intestinal injury model

Therapeutic effect of non-steroidal anti-inflammatory drugs (NSAIDs) has been related with gastrointestinal injury. Docosahexaenoic acid (DHA), an omega-3 polyunsaturated fatty acid (PUFA), can prevent gastric and small intestinal damage. Nonetheless, contribution of antioxidative action in the protective effect of DHA has not been evaluated before in the small intestine injury after indomethacin treatment. Pathogenesis of NSAID-induced small intestinal injury is multifactorial, and reactive oxidative species have been related to indomethacin's small intestinal damage. The present work aimed to evaluate antioxidative activity in the protective action of DHA in the indomethacin-induced small intestinal damage. Female Wistar rats were gavage with DHA (3 mg/kg) or omeprazole (3 mg/kg) for 10 days. Each rat received indomethacin (3 mg/kg, orally) daily to induce small intestinal damage. The total area of intestinal ulcers and histopathological analysis were performed. In DHA-treated rats, myeloperoxidase and superoxide dismutase activity, glutathione, malondialdehyde, leukotriene, and lipopolysaccharide (LPS) levels were measured. Furthermore, the relative abundance of selective bacteria was assessed. DHA administration (3 mg/kg, p.o.) caused a significant decrease in indomethacin-induced small intestinal injury in Wistar rats after 10 days of treatment. DHA's enteroprotection resulted from the prevention of an increase in myeloperoxidase activity, and lipoperoxidation, as well as an improvement in the antioxidant defenses, such as glutathione levels and superoxide dismutase activity in the small intestine. Furthermore, we showed that DHA's enteroprotective effect decreased significantly LPS levels in indomethacin-induced injury in small intestine. Our data suggest that DHA's enteroprotective might be attributed to the prevention of oxidative stress.

Sulfamethoxazole stress endangers the gut health of sea cucumber (Apostichopus japonicus) and affects host metabolism

Sulfamethoxazole (SMZ) is a frequently detected antibiotic in the environment, and there is a growing concern about its potential toxic effects on aquatic organisms. sea cucumber (Apostichopus japonicas) is a benthic invertebrate whose gut acts as a primary immune defense and serves critical protective barrier. In this study, growth performance, histology, gut microbiota, and metabolomics analyses were performed to investigate the toxic response in the intestine of sea cucumber effects caused by SMZ stress for 56 d by evaluating with different concentrations of SMZ (0, 1.2×10-3, and 1.2 mg/L). The weight gain rate of sea cucumbers under SMZ stress showed significant decrease, indicating that the growth of sea cucumbers was hindered. Analysis of the intestinal morphological features indicated that SMZ stimulation resulted in atrophy of the sea cucumber gut. In the 1.2×10-3 mg/L concentration, the thickness of muscle and mucosal layers was reduced by 12.40% and 21.39%, while in the 1.2 mg/L concentration, the reductions were 35.08% and 26.98%. The abundance and diversity of sea cucumber intestinal bacteria decreased significantly (P < 0.05) under the influence of SMZ. Notably, the intestinal bacteria of sea cucumber became homogenized with the increase in SMZ concentration, and the relative abundance of Ralstonia reached 81.64% under the stress of 1.2 mg/L concentration. The SMZ stress significantly impacted host metabolism and disrupted balance, particularly in L-threonine, L-tyrosine, neuronic acid, piperine, and docosapentaenoic acid. SMZ leads to dysregulation of metabolites, resulting in growth inhibition and potential inflammatory responses that could adversely affect the normal activities of aquatic organisms. Further metabolic pathway enrichment analyses demonstrated that impaired biosynthesis of unsaturated fatty acids and aminoacyl-tRNA biosynthesis metabolic pathway were major reasons for SMZ stress-induced intestinal bacteria dysbiosis. This research aims to provide some theoretical evidence for the ecological hazard assessment of antibiotics in water.

Role of dietary intake of specific polyunsaturated fatty acids (PUFAs) on colorectal cancer risk in Iran

High-fat diets have been associated with colorectal cancer (CRC) risk, and the role of polyunsaturated fatty acids (PUFAs) has been reported to vary based on the length of PUFAs. We explored the association between dietary omega-6 and omega-3 PUFAs intake and CRC. We analyzed 865 CRC patients and 3206 controls from a case-control study of Iran (IROPICAN study). We used multivariate logistic regression models to calculate the odds ratios (OR) and 95% confidence intervals (CI) for the association between PUFAs intake and CRC risk. Our results showed that gamma-linolenic acid (18:3 n-6, GLA), arachidonic acid (20:4n-6, ARA), a-linolenic acid (Cis-18:3n-3, ALA), eicosapentaenoic acid (20:5n-3, EPA), docosahexaenoic acid (22:6n-3, DHA) consumption was not associated with the risk of CRC. However, the OR of linoleic acid (18: 2n-6, LA) intake was 1.47 (95% CI 1.01-2.14, p = 0.04) for proximal colon and that of docosapentaenoic acid (22:5n-3, DPA) intake was 1.33 (95% CI 1.05-1.69, p = 0.01) for rectum. This study indicates a high level of LA is associated with an increased risk of proximal colon cancer, and DPA intake was positively associated with rectum cancer risk. Furthermore, our study noted a high intake of n-6 (from vegetable oils) compared to n-3 PUFAs (from fish and seafood) in this population. Public awareness and government support is needed to increase fish and seafood production and consumption in Iran.

EPA and DHA Alleviated Chronic Dextran Sulfate Sodium Exposure-Induced Depressive-like Behaviors in Mice and Potential Mechanisms Involved

Patients with ulcerative colitis (UC) have higher rates of depression. However, the mechanism of depression development remains unclear. The improvements of EPA and DHA on dextran sulfate sodium (DSS)-induced UC have been verified. Therefore, the present study mainly focused on the effects of EPA and DHA on UC-induced depression in C57BL/6 mice and the possible mechanisms involved. A forced swimming test and tail suspension experiment showed that EPA and DHA significantly improved DSS-induced depressive-like behavior. Further analysis demonstrated that EPA and DHA could significantly suppress the inflammation response of the gut and brain by regulating the NLRP3/ASC signal pathway. Moreover, intestine and brain barriers were maintained by enhancing ZO-1 and occludin expression. In addition, EPA and DHA also increased the serotonin (5-HT) concentration and synaptic proteins. Interestingly, EPA and DHA treatments increased the proportion of dominant bacteria, alpha diversity, and beta diversity. In conclusion, oral administration of EPA and DHA alleviated UC-induced depressive-like behavior in mice by modulating the inflammation, maintaining the mucosal and brain barriers, suppressing neuronal damage and reverting microbiota changes.

Effect of Low Protein Diets Supplemented with Sodium Butyrate, Medium-Chain Fatty Acids, or n-3 Polyunsaturated Fatty Acids on the Growth Performance, Immune Function, and Microbiome of Weaned Piglets

This study aimed to investigate the effects of low-protein (LP) diets supplemented with sodium butyrate (SB), medium-chain fatty acids (MCT), or n-3 polyunsaturated fatty acids (n-3 PUFA) on the growth performance, immune function, and the microbiome of weaned piglets. A total of 120 healthy weaned piglets ((Landrace × Large White × Duroc); 7.93 ± 0.7 kg initial body weight), were randomly divided into five groups. Each group consisted of six replications with four piglets per replication. Dietary treatments included control diet (CON); LP diet (LP); LP + 0.2% SB diet (LP + SB); LP + 0.2% MCT diet (LP + MCT); and LP + PUFA diet (LP + PUFA). The experimental period lasted for 4 weeks. Compared with the CON diet, LP, LP + SB, LP + MCT, and LP + PUFA diets decreased the final weight and average daily gain (ADG) of piglets (p < 0.05). There were lower (p < 0.05) concentrations of IL-8 and higher (p < 0.05) Glutathione peroxidase (GSH-Px) activity in the plasma of piglets fed with LP + SB, LP + MCT, and LP + PUFA diets than those fed with the LP diet. The piglets in the LP + SB and LP + PUFA groups had lower IKK-alpha (IKKa) mRNA expression in the colonic mucosa compared with those in the CON and LP groups (p < 0.05). The mRNA expression of TLR4 in the colonic mucosa of piglets in the LP + SB, LP + MCT, and LP + PUFA groups was decreased when compared with the CON and LP groups (p < 0.05). The LP + MCT diets increased the gene expression of nuclear factor erythroid 2-related factor 2 (Nrf2) in the colonic mucosa of piglets compared with CON, LP, and LP + SB diets (p < 0.05). The abundance of Erysipelotrichaceae in the colonic microbiome of piglets in the LP group was higher than that in the other four groups (p < 0.05). Collectively, this study showed that LP diets supplemented with SB, MCT, or n-3 PUFA reduced plasma inflammatory factor levels, increased plasma GSH-Px activity, and declined mRNA expression of TLR4 and IKKa in the colonic epithelium, whereas it reduced the abundance of Erysipelotrichaceae in the colon of piglets.

Immunomodulatory effect of marine lipids on food allergy

Seafood is highly enriched in n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFAs), particularly eicosapentaenoic acid (EPA, 20:5 n-3) and docosahexaenoic acid (DHA, 22:6 n-3), in contrast to the ultra-processed foods included in the modern Western diet that have high levels of n-6 linoleic acid (LA, 18:2 n-6), precursor for the pro-inflammatory n-6 arachidonic acid (ARA, 20:4 n-6). The capacity of marine lipids to reduce plasmatic triglycerides and blood pressure have been well-described. Moreover, recent studies have also raised evidence of a potential regulatory action of marine lipids on inflammation, the immune system, and food allergy (FA). FA is considered one of the main concerns to become life threatening in food safety. The prevalence of this emerging global problem has been increasing during the last two decades, especially in industrialized countries. About a 6-8% of young children and 2-4% of adults is estimated to be affected by FA. The main objective of the current study is to update the existing knowledge, but also the limitations, on the potential impact of marine lipids and their lipid mediators in regulating immunity, inflammation, and ultimately, food allergies. In particular, the focus is on the effect of marine lipids in modulating the key factors that control the sensitization and effector phases of FA, including gut microbiota (GM), inflammation, and immune system response. Results in animal models highlight the positive effect that consuming marine lipids, whether as a supplement or through seafood consumption, may have a relevant role in improving gut dysbiosis and inflammation, and preventing or reducing the severity of FA. However, more systematic studies in humans are needed to optimize such beneficial actions to each particular FA, age, and medical condition to reach an effective clinical application of marine lipids to improve FAs and their outcomes.

Immunonutrients and intestinal microbiota: a gap in the literature

The human intestinal microbiota is composed of a wide variety of microorganisms that play an important role in intestinal permeability, digestion, and especially, in the maturation of host's immune system. At the same time, effectiveness of immunomodulatory nutrients is known, especially in situations of stress and in strengthening body's defenses. However, the influence of the use of immunonutrients on microbiota's composition and variability is still poorly investigated. Studies indicate that the use of immunomodulators such as omega 3, glutamine, and arginine, can play a role in its modulation, through the immunological enhancement of the hosts. Therefore, this article sought to concentrate the latest evidence on the influence of the use of the main immunonutrients used in clinical practice on human gut microbiota, and their potential benefits.

Targeted Application of Functional Foods as Immune Fitness Boosters in the Defense against Viral Infection

In recent times, the emergence of viral infections, including the SARS-CoV-2 virus, the monkeypox virus, and, most recently, the Langya virus, has highlighted the devastating effects of viral infection on human life. There has been significant progress in the development of efficacious vaccines for the prevention and control of viruses; however, the high rates of viral mutation and transmission necessitate the need for novel methods of control, management, and prevention. In recent years, there has been a shift in public awareness on health and wellbeing, with consumers making significant dietary changes to improve their immunity and overall health. This rising health awareness is driving a global increase in the consumption of functional foods. This review delves into the benefits of functional foods as potential natural means to modulate the host immune system to enhance defense against viral infections. We provide an overview of the functional food market in Europe and discuss the benefits of enhancing immune fitness in high-risk groups, including the elderly, those with obesity, and people with underlying chronic conditions. We also discuss the immunomodulatory mechanisms of key functional foods, including dairy proteins and hydrolysates, plant-based functional foods, fermentates, and foods enriched with vitamin D, zinc, and selenium. Our findings reveal four key immunity boosting mechanisms by functional foods, including inhibition of viral proliferation and binding to host cells, modulation of the innate immune response in macrophages and dendritic cells, enhancement of specific immune responses in T cells and B cells, and promotion of the intestinal barrier function. Overall, this review demonstrates that diet-derived nutrients and functional foods show immense potential to boost viral immunity in high-risk individuals and can be an important approach to improving overall immune health.

The Early Impact of Diets Enriched with Saturated and Unsaturated Fatty Acids on Intestinal Inflammation and Tight Junctions

The gut has been suggested as the first organ to be affected by unbalanced diets contributing to the obesogenic process. This study aimed to test a short time-course exposition model to a known pro- or anti-inflammatory enriched fatty diet to understand the early gut alterations. Male mice were exposed to the chow diet (CT), high-fat (HF) diet, or a high-fat diet partially replaced on flaxseed oil (FS), rich in omega-3 (ω3), for 14 days. HF and FS increased the total body weight mass compared with the CT group, but FS reduced the epididymal fat depot compared to HF. The bioinformatics from mice and human databases showed the Zo1-Ocln-Cldn7 tight junctions as the main protein-triad. In the ileum, the HF diet has increased IL1β transcript and IL1β, TNFα, and CD11b proteins, but reduced the tight junctions (Zo1, Ocln, and Cld7) compared to the CT group. Despite the FS diet being partially efficient in protecting the ileum against inflammation, the tight junctions were increased, compared to the HF group. The GPR120 and GPR40 receptors were unaffected by diets, but GPR120 was co-localized on the surface of ileum macrophages. The short period of a high-fat diet was enough to start the obesogenic process, ileum inflammation, and reduce the tight junctions. Flaxseed oil did not protect efficiently against dysmetabolism. Still, it increased the tight junctions, even without alteration on inflammatory parameters, suggesting the protection against gut permeability during early obesity development.

Effects of Glutamine, Curcumin and Fish Bioactive Peptides Alone or in Combination on Intestinal Permeability in a Chronic-Restraint Stress Model

Irritable bowel syndrome (IBS), a multifactorial intestinal disorder, is often associated with a disruption in intestinal permeability as well as an increased expression of pro-inflammatory markers. The aim of this study was to first test the impact of treatment with glutamine (Gln), a food supplement containing natural curcumin extracts and polyunsaturated n-3 fatty acids (Cur); bioactive peptides from a fish protein hydrolysate (Ga); and a probiotic mixture containing Bacillus coagulans, Lactobacillus acidophilus, Lactobacillus gasseri and Lactobacillus helveticus. These compounds were tested alone on a stress-based IBS model, the chronic-restraint stress model (CRS). The combination of Gln, Cur and Ga (GCG) was also tested. Eight-week-old C57Bl/6 male mice were exposed to restraint stress for two hours every day for four days and received different compounds every day one week before and during the CRS procedure. Plasma corticosterone levels were measured as a marker of stress, and colonic permeability was evaluated ex vivo in Ussing chambers. Changes in the gene expression of tight junction proteins (occludin, claudin-1 and ZO 1) and inflammatory cytokines (IL1β, TNFα, CXCL1 and IL10) were assessed using RT-qPCR. The CRS model led to an increase in plasma corticosterone and an increase in colonic permeability compared with unstressed animals. No change in plasma corticosterone concentrations was observed in response to CRS with the different treatments (Gln, Cur, Ga or GCG). Stressed animals treated with Gln, Cur and Ga alone and in combination showed a decrease in colonic permeability when compared to the CRS group, while the probiotic mixture resulted in an opposite response. The Ga treatment induced an increase in the expression of the anti-inflammatory cytokine IL-10, and the GCG treatment was able to decrease the expression of CXCL1, suggesting the synergistic effect of the combined mixture. In conclusion, this study demonstrated that a combined administration of glutamine, a food supplement containing curcumin and polyunsaturated n-3 fatty acids, and bioactive peptides from a fish hydrolysate was able to reduce colonic hyperpermeability and reduce the inflammatory marker CXCL1 in a stress-based model of IBS and could be of interest to patients suffering from IBS.

Synergistic antidepressant-like effect of n-3 polyunsaturated fatty acids and probiotics through the brain-gut axis in rats exposed to chronic mild stress

N-3 polyunsaturated fatty acids (PUFA) and probiotics have antidepressant-like effects, but the underlying mechanisms are unclear. We hypothesized that n-3 PUFA combined with live and dead probiotics synergistically improves depression by modulating the hypothalamic-pituitary-adrenal (HPA) axis and serotonergic pathways through the brain-gut axis. Rats were randomly divided into seven groups (n = 8/group): non-chronic mild stress (CMS) with n-6 PUFA, CMS with n-3 PUFA, n-6 PUFA, live probiotics, dead probiotics, n-3 PUFA and live probiotics, and n-3 PUFA and dead probiotics. Diets of n-6 and n-3 PUFA and oral supplementation of live and dead probiotics were provided for 12 weeks, and CMS was performed for the last 5 weeks. N-3 PUFA and probiotics improved depressive behaviors and modulated the brain and gut HPA axis by synergistically increasing glucocorticoid receptor expression and decreasing corticotropin-releasing factor expression and blood levels of adrenocorticotropic hormone and corticosterone. N-3 PUFA and probiotics upregulated the brain serotonergic pathway through serotonin levels and expression of brain-derived neurotrophic factor, phosphorylated cAMP response binding protein, and 5-hydroxytryptamine 1A receptor while downregulating the gut serotonergic pathway. Furthermore, n-3 PUFA and probiotics increased the abundance of Ruminococcaceae, brain and gut short chain fatty acid levels, and occludin expression while decreasing the expression of tumor necrosis factor-α, interleukin-1β, and prostaglandin E₂ and blood lipopolysaccharides levels. There was no significant difference between the live and dead probiotics. In conclusion, n-3 PUFA and probiotics had synergistic antidepressant-like effects on the HPA axis and serotonergic pathways of the brain and gut through the brain-gut axis.

Impact of cafeteria diet and n3 supplementation on the intestinal microbiota, fatty acids levels, neuroinflammatory markers and social memory in male rats

OBJECTIVE

To assess the effects of omega-3 (n3) supplementation on intestinal microbiota, fatty acids profile, neuroinflammation, and social memory of cafeteria diet (CAF)-fed rats.

METHODS

Male Wistar rats were fed with CAF for 20 weeks. Omega-3 (500 mg/kg/day) was supplemented between the 16th and 20th week. Colon morphology, intestinal microbiota composition, short-chain fatty acids (SCFA) and lipopolysaccharide (LPS) in the plasma, fatty acids profile, TLR-4 and claudin-5 expressions in the brain, and social memory were investigated.

RESULTS

CAF reduced colon length, crypts' depth, and microbiota diversity, while n3 increased the Firmicutes/Bacteroidetes ratio. CAF increased SCFA plasma levels, but n3 reduced butyrate and isobutyrate in obese rats. LPS was increased in CAF-fed rats, and n3 decreased its levels. In the cerebral cortex, n3 increased caprylic, palmitic, stearic, tricosanoic, lignoceric, myristoleic, and linoleic acids. CAF increased palmitic acid and TLR-4 expression in the cerebral cortex while decreasing claudin-5 in the hippocampus. In the social memory test, CAF-fed animals showed greater social interaction with no effect of n3.

CONCLUSIONS

The lack of n3 effect in some of the evaluated parameters may be due to the severity of the obesity caused by CAF. However, n3 reduced LPS levels, suggesting its ability to reverse endotoxemia.

Immune regulation of poly unsaturated fatty acids and free fatty acid receptor 4

Fatty acid metabolism contributes to energy supply and plays an important role in regulating immunity. Free fatty acids (FFAs) bind to free fatty acid receptors (FFARs) on the cell surface and mediate effects through the intra-cellular FFAR signaling pathways. FFAR4, also known as G-protein coupled receptor 120 (GPR120), has been identified as the primary receptor of omega-3 polyunsaturated fatty acids (ω-3 PUFAs). FFAR4 is a promising target for treating metabolic and inflammatory disorders due to its immune regulatory functions and the discovery of highly selective and efficient agonists. This review summarizes the reported immune regulatory functions of ω-3 PUFAs and FFAR4 in immune cells and immune-related diseases. We also speculate possible involvements of ω-3 PUFAs and FFAR4 in other types of inflammatory disorders.

Ameliorative Effect of Mannuronate Oligosaccharides on Hyperuricemic Mice via Promoting Uric Acid Excretion and Modulating Gut Microbiota

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.

Alginate Oligosaccharides Prevent Dextran-Sulfate-Sodium-Induced Ulcerative Colitis via Enhancing Intestinal Barrier Function and Modulating Gut Microbiota

Alginate oligosaccharides are degradation products of alginate and have attracted increasing attention due to their versatile biological functions. In the present study, C57BL/6 mice were used to assess the ameliorative effects and mechanisms of guluronate oligosaccharides (GAOS), mannuronic oligosaccharides (MAOS), and heterozygous alginate oligosaccharides (HAOS), which are the three alginate oligosaccharides of dextran sulfate sodium (DSS)-induced ulcerative colitis. The study showed that alginate oligosaccharides alleviated pathological histological damage by slowing down weight loss, inhibiting colonic length shortening, and reducing disease activity index (DAI) and histopathological scores. Alginate oligosaccharides modulated the colonic inflammatory response by reducing colonic MPO levels and downregulating the expression of IL-6 and IL-1β. Alginate oligosaccharides reduced intestinal permeability and reversed intestinal barrier damage by increasing the number of goblet cells, decreasing LPS levels, downregulating Bax protein levels, upregulating Bcl-2 protein levels, and enhancing the expression of the E-cadherin. Furthermore, alginate oligosaccharides modulated the composition of the gut microbiota and restored the production of short-chain fatty acids (SCFAs), especially acetate and butyrate. In conclusion, our study provides a scientific basis for the role of alginate oligosaccharides in relieving ulcerative colitis.

N-3 Polyunsaturated Fatty Acids and Gut Microbiota

For several decades, studies have reported that n-3 polyunsaturated fatty acids (PUFAs) play a beneficial role in cardiovascular, immune, cognitive, visual, mental and metabolic health. The mammalian intestine is colonized by microbiota, including bacteria, archaea, viruses, protozoans, and fungi. The composition of the gut microbiota is influenced by long-term dietary habits, disease-associated dysbiosis, and the use of antibiotics. Accumulating evidence suggests a relationship between n-3 PUFAs and the gut microbiota. N-3 PUFAs can alter the diversity and abundance of the gut microbiome, and gut microbiota can also affect the metabolism and absorption of n-3 PUFAs. Changes in the populations of certain gut microbiota can lead to negative effects on inflammation, obesity, and metabolic diseases. An imbalanced consumption of n-3/n-6 PUFAs may lead to gut microbial dysbiosis, in particular, a significant increase in the ratio of Firmicutes to Bacteroidetes, which eventually results in being overweight and obesity. N-3 PUFA deficiency disrupts the microbiota community in metabolic disorders. In addition, accumulating evidence indicates that the interplay between n-3 PUFAs, gut microbiota, and immune reactions helps to maintain the integrity of the intestinal wall and interacts with host immune cells. Supplementation with n-3 PUFAs may be an effective therapeutic measure to restore gut microbiota homeostasis and correct metabolic disturbances associated with modern chronic diseases. In particular, marine extracts from seaweed contain a considerable dry weight of lipids, including n-3 PUFAs such as eicosapentaenoic acid (EPA, C20: 5) and docosahexaenoic acid (DHA, C22: 6). This review describes how gut microbiota function in intestinal health, how n-3 PUFAs interact with the gut microbiota, and the potential of n-3 PUFAs to influence the gut-brain axis, acting through gut microbiota composition.

Development of a thiostrepton-free system for stable production of PLD in Streptomyces lividans SBT5

BACKGROUND

Phospholipase D (PLD) is highly valuable in the food and medicine industries, where it is used to convert low-cost phosphatidylcholine into high-value phospholipids (PLs). Despite being overexpressed in Streptomyces, PLD production requires expensive thiostrepton feeding during fermentation, limiting its industrialization. To address this issue, we propose a new thiostrepton-free system.

RESULTS

We developed a system using a combinatorial strategy containing the constitutive promoter kasOp* and PLD G215S mutation fused to a signal peptide sigcin of Streptoverticillium cinnamoneum pld. To find a candidate vector, we first expressed PLD using the integrative vector pSET152 and then built three autonomously replicating vectors by substituting Streptomyces replicons to increase PLD expression. According to our findings, replicon 3 with stability gene (sta) inserted had an ideal result. The retention rate of the plasmid pOJ260-rep3-pld* was 99% after five passages under non-resistance conditions. In addition, the strain SK-3 harboring plasmid pOJ260-rep3-pld* produced 62 U/mL (3.48 mg/g) of PLD, which further improved to 86.8 U/mL (7.51 mg/g) at 32 °C in the optimized medium, which is the highest activity achieved in the PLD secretory expression to date.

CONCLUSIONS

This is the first time that a thiostrepton-free PLD production system has been reported in Streptomyces. The new system produced stable PLD secretion and lays the groundwork for the production of PLs from fermentation stock. Meanwhile, in the Streptomyces expression system, we present a highly promising solution for producing other complex proteins.

Central and peripheral regulations mediated by short-chain fatty acids on energy homeostasis

The human gut microbiota influences obesity, insulin resistance, and the subsequent development of type 2 diabetes (T2D). The gut microbiota digests and ferments nutrients resulting in the production of short-chain fatty acids (SCFAs), which generate various beneficial metabolic effects on energy and glucose homeostasis. However, their roles in the central nervous system (CNS)-mediated outputs on the metabolism have only been minimally studied. Here, we explore what is known and future directions that may be worth exploring in this emerging area. Specifically, we searched studies or data in English by using PubMed, Google Scholar, and the Human Metabolome Database. Studies were filtered by time from 1978 to March 2022. As a result, 195 studies, 53 reviews, 1 website, and 1 book were included. One hundred and sixty-five of 195 studies describe the production and metabolism of SCFAs or the effects of SCFAs on energy homeostasis, glucose balance, and mental diseases through the gut-brain axis or directly by a central pathway. Thirty of 195 studies show that inappropriate metabolism and excessive of SCFAs are metabolically detrimental. Most studies suggest that SCFAs exert beneficial metabolic effects by acting as the energy substrate in the TCA cycle, regulating the hormones related to satiety regulation and insulin secretion, and modulating immune cells and microglia. These functions have been linked with AMPK signaling, GPCRs-dependent pathways, and inhibition of histone deacetylases (HDACs). However, the studies focusing on the central effects of SCFAs are still limited. The mechanisms by which central SCFAs regulate appetite, energy expenditure, and blood glucose during different physiological conditions warrant further investigation.

Food and Gut Microbiota-Derived Metabolites in Nonalcoholic Fatty Liver Disease

Diet and lifestyle are crucial factors that influence the susceptibility of humans to nonalcoholic fatty liver disease (NAFLD). Personalized diet patterns chronically affect the composition and activity of microbiota in the human gut; consequently, nutrition-related dysbiosis exacerbates NAFLD via the gut–liver axis. Recent advances in diagnostic technology for gut microbes and microbiota-derived metabolites have led to advances in the diagnosis, treatment, and prognosis of NAFLD. Microbiota-derived metabolites, including tryptophan, short-chain fatty acid, fat, fructose, or bile acid, regulate the pathophysiology of NAFLD. The microbiota metabolize nutrients, and metabolites are closely related to the development of NAFLD. In this review, we discuss the influence of nutrients, gut microbes, their corresponding metabolites, and metabolism in the pathogenesis of NAFLD.

Docosahexaenoic acid-rich fish oil alleviates hepatic steatosis in association with regulation of gut microbiome in ob/ob mice

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.

An insight to the therapeutic potential of algae-derived sulfated polysaccharides and polyunsaturated fatty acids: Focusing on the COVID-19

Covid-19 pandemic severely affected human health worldwide. The rapidly increasing COVID-19 cases and successive mutations of the virus have made it a major challenge for scientists to find the best and efficient drug/vaccine/strategy to counteract the virus pathogenesis. As a result of research in scientific databases, regulating the immune system and its responses with nutrients and nutritional interventions is the most critical solution to prevent and combat this infection. Also, modulating other organs such as the intestine with these compounds can lead to the vaccines' effectiveness. Marine resources, mainly algae, are rich sources of nutrients and bioactive compounds with known immunomodulatory properties and the gut microbiome regulations. According to the purpose of the review, algae-derived bioactive compounds with immunomodulatory activities, sulfated polysaccharides, and polyunsaturated fatty acids have a good effect on the immune system. In addition, they have probiotic/prebiotic properties in the intestine and modulate the gut microbiomes; therefore, they can increase the effectiveness of vaccines produced. Thus, they with respectable safety, immune regulation, and modulation of microbiota have potential therapeutic against infections, especially COVID-19. They can also be employed as promising candidates for the prevention and treatment of viral infections, such as COVID-19.

Enzymatic hydrolysate of porphyra enhances the intestinal mucosal functions in obese mice

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.

Excess DHA Induces Liver Injury via Lipid Peroxidation and Gut Microbiota-Derived Lipopolysaccharide in Zebrafish

Being highly unsaturated, n-3 long-chain polyunsaturated fatty acids (LC-PUFAs) are prone to lipid peroxidation. In this study, zebrafish were fed with low-fat diet (LFD), high-fat diet (HFD), or 2% DHA-supplemented HFD (HFDHA2.0). To study the possible negative effects of the high level of dietary DHA, growth rates, blood chemistry, liver histology, hepatic oxidative stress, apoptosis, and inflammatory processes were assessed. The cell studies were used to quantify the effects of DHA and antioxidant on cellular lipid peroxidation and viability. The possible interaction between gut microbiota and zebrafish host was evaluated in vitro. HFDHA2.0 had no effect on hepatic lipid level but induced liver injury, oxidative stress, and hepatocellular apoptosis, including intrinsic and death receptor-induced apoptosis. Besides, the inclusion of 2% DHA in HFD increased the abundance of Proteobacteria in gut microbiota and serum endotoxin level. In the zebrafish liver cell model, DHA activated intrinsic apoptosis while the antioxidant 4-hydroxy-Tempo (tempo) inhibited the pro-apoptotic negative effects of DHA. The apoptosis induced by lipopolysaccharide (LPS) was unaffected by the addition of tempo. In conclusion, the excess DHA supplementation generates hepatocellular apoptosis-related injury to the liver. The processes might propagate along at least two routes, involving lipid peroxidation and gut microbiota-generated LPS.

EPA and DHA differentially coordinate the crosstalk between host and gut microbiota and block DSS-induced colitis in mice by a reinforced colonic mucus barrier

Background: Ulcerative colitis (UC) is a chronic inflammatory disorder of the colon with a continuously remitting and relapsing course. Its etiology is closely related to abnormal interactions between host and gut microbiota. The mucus barrier lining the gastrointestinal tract is necessary to coordinate host and gut microbiota interaction by nourishing and modulating the microbiota. Differential effects of the anti-inflammatory fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on UC progression in mice were firstly addressed by our previous work; here, the mechanism for their respective effects were further uncovered from host-microbiome crosstalk based on mucus barrier modulation to pave the way for UC therapy. Methods: Assessment of the disease activity index and histopathology score was conducted in mice with dextran sodium sulfate (DSS)-induced colitis pre-treated with different doses of EPA and DHA. Mucin generation, glycosylation and secretion were evaluated by a combination of electron microscopy, specific mucous staining, and qPCR. Western blotting was used to analyze the underlying molecular events. Fecal short chain fatty acids were detected using gas chromatography, and the gut microbial composition was analyzed using 16S rRNA sequencing. Results: Compared with DHA, the more potent inhibitory effect of high dose EPA on DSS-induced colitis was reconfirmed, which was underlain by a reinforced mucus layer as indicated by increased mucin granule release, mucus layer stratification and markedly upregulated expression of the key modulators involved in goblet cell differentiation. In turn a remarkably enhanced mucus barrier in the EPA group functioned to modulate the gut microbiome, as demonstrated by the enriched abundance of the phylum Bacteroidetes and mucin-degrading bacterium Akkermansia muciniphila producing acetic and propionic acids. Conclusions: EPA and DHA differentially coordinate the interaction between the host and the gut microbiota and relieve mucus barrier disruption in DSS-induced colitis. EPA may develop into a promising adjunctive therapy for UC.

Chlorogenic Acid Alleviates Chronic Stress-Induced Duodenal Ferroptosis via the Inhibition of the IL-6/JAK2/STAT3 Signaling Pathway in Rats

Chronic stress causes duodenal damage, in which iron death is likely to play an important role. Chlorogenic acid (CGA), one of the most widely consumed dietary polyphenols, has been shown to protect the intestine. However, it is unclear whether CGA exerts a duodenoprotective effect in chronic stress by inhibiting ferroptosis. In this work, rats were daily exposed to restraint stress for 6 h over 21 consecutive days, with/without CGA (100 mg/kg, gavage). CGA reduced blood hepcidin, iron, reactive oxygen species (ROS), and ferroportin 1 (FPN1) levels and upregulated the levels of ferroptosis-related biomarkers (GPX4, GSH, NADPH, etc.). These results confirmed that CGA inhibited ferroptosis in the duodenum. Furthermore, the use of S3I-201 (STAT3 inhibitor) helped to further clarify the mechanism of action of CGA. Overall, CGA could reduce hepcidin production by inhibiting the IL-6/JAK2/STAT3 pathway in the liver to increase the expression of FPN1 in the duodenum, which restored iron homeostasis and inhibited ferroptosis, alleviating chronic stress-induced duodenal injury.

Role of omega-3 polyunsaturated fatty acids, citrus pectin, and milk-derived exosomes on intestinal barrier integrity and immunity in animals

The gastrointestinal tract of livestock and poultry is prone to challenge by feedborne antigens, pathogens, and other stress factors in the farm environment. Excessive physiological inflammation and oxidative stress that arises firstly disrupts the intestinal epithelial barrier followed by other components of the gastrointestinal tract. In the present review, the interrelationship between intestinal barrier inflammation and oxidative stress that contributes to the pathogenesis of inflammatory bowel disease was described. Further, the role of naturally existing immunomodulatory nutrients such as the omega-3 polyunsaturated fatty acids, citrus pectin, and milk-derived exosomes in preventing intestinal barrier inflammation was discussed. Based on the existing evidence, the possible molecular mechanism of these bioactive nutrients in the intestinal barrier was outlined for application in animal diets.

DHA-Enriched Phospholipids and EPA-Enriched Phospholipids Alleviate Lipopolysaccharide-Induced Intestinal Barrier Injury in Mice via a Sirtuin 1-Dependent Mechanism

Intestinal barrier dysfunction has emerged as a potential contributor to the development of several severe diseases. Herein, the effect and underlying mechanism of DHA-enriched phospholipids (DHA-PL) and EPA-enriched phospholipids (EPA-PL) on protecting against lipopolysaccharide (LPS)-induced intestinal barrier injury were elucidated. C57BL/6J male mice were fed an AIN-93G diet containing 1% DHA-PL or EPA-PL for 4 weeks and then were intraperitoneally injected with LPS (10 mg/kg) to cause intestinal barrier injury. The results manifested that DHA-PL and EPA-PL pretreatment balanced apoptosis and autophagy in intestinal epithelial cells and maintained intestinal tight junction integrity. Our findings also demonstrated that cotreatment with EX-527, a sirtuin 1 specific inhibitor, hindered the role of DHA-PL and EPA-PL against LPS-evoked intestinal barrier injury through reversing the inhibitory action of them on NF-κB and MAPKs activation as well as their potentiating actions on Nrf2 nuclear translocation. Overall, DHA-PL and EPA-PL alleviated LPS-mediated intestinal barrier injury via inactivation of the NF-κB and MAPKs pathways as well as activating the Nrf2 antioxidant pathway via up-regulating sirtuin 1.

EPA-Enriched Phospholipids Alleviate Renal Interstitial Fibrosis in Spontaneously Hypertensive Rats by Regulating TGF-β Signaling Pathways

Hypertensive nephropathy is a chronic kidney disease caused by hypertension. Eicosapentaenoic acid (EPA) has been reported to possess an antihypertensive effect, and our previous study suggested that EPA-enriched phospholipid (EPA-PL) had more significant bioactivities compared with traditional EPA. However, the effect of dietary EPA-PL on hypertensive nephropathy has not been studied. The current study was designed to examine the protection of EPA-PL against kidney damage in spontaneously hypertensive rats (SHRs). Treatment with EPA-PL for three weeks significantly reduced blood pressure through regulating the renin–angiotensin system in SHRs. Moreover, dietary EPA-PL distinctly alleviated kidney dysfunction in SHRs, evidenced by reduced plasma creatinine, blood urea nitrogen, and 24 h proteinuria. Histology results revealed that treatment of SHRs with EPA-PL alleviated renal injury and reduced tubulointerstitial fibrosis. Further mechanistic studies indicated that dietary EPA-PL remarkably inhibited the activation of TGF-β and Smad 3, elevated the phosphorylation level of PI3K/AKT, suppressed the activation of NF-κB, reduced the expression of pro-inflammatory cytokines, including IL-1β and IL-6, and repressed the oxidative stress and the mitochondria-mediated apoptotic signaling pathway in the kidney. These results indicate that EPA-PL has potential value in the prevention and alleviation of hypertensive nephropathy.

Dietary Supplementation with Vitamin D, Fish Oil or Resveratrol Modulates the Gut Microbiome in Inflammatory Bowel Disease

Gastrointestinal health is influenced by the functional genes and metabolites generated by the human microbiome. As the volume of current biomedical and translational research indicates, the importance and impact of this ecosystem of microorganisms, especially those comprising the gut microbiome on human health, has become increasingly apparent. Changes to the gut microbiome are associated with inflammatory bowel disease (IBD), which is characterized by persistent intestinal inflammation. Furthermore, the lifetime dietary choices of their host may positively or negatively affect both the gut microbiome and its impact on IBD. As such, "anti-inflammatory" dietary supplements, their impact, and mechanisms in restoring gut microbiota homeostasis during IBD is an area of intensive research. Dietary supplementation may represent an important adjuvant treatment avenue for limiting intestinal inflammation in IBD. Overall, this review addresses the development of the gut microbiome, the significance of the gut microbiome in IBD, and the use of dietary supplements such as vitamin D, fish oil, and resveratrol in the mitigation of IBD-associated gut dysbiosis and intestinal inflammation.

Evaluating the reparative effects and the mechanism of action of docosahexaenoic acid on azithromycin-induced lipid metabolism dysfunction

To explore the reparative effects of DHA on the gut microbiome disturbance and dysfunctional lipid metabolism caused by long-term antibiotic therapy, it was tested on an azithromycin (AZI) mouse antibiotic model. Thirty specific-pathogen-free BALB/c mice (SPF grade, half male and half female) were randomly separated into three groups (n = 10, 5 male and 5 female): control group (CK), azithromycin natural recovery group (AZI) and DHA group (DHA). High-throughput sequencing and bioinformatics methods were used to analyze the gut microbiome. ELASE kits were used to measure blood lipid, lipids in the liver, and bile salt hydrolase (BSH) levels in feces. Gas chromatography and UPLC-MS/MS were employed to detect DHA and bile acids contents in liver, respectively. Real-time polymerase chain reaction (RT-PCR) was used to measure the expression of key enzymes involved in lipid metabolism. Long-term AZI treatment led to dyslipidemia, gut microbiome disturbance and anxious behaviors in the mouse model. DHA was found to significantly improve the dyslipidemia and anxiety-like behaviors induced by AZI. DHA had no effect on the structure of gut microbiome and bile acids contents but increased the content of the metabolic enzyme BSH in gut microbiota and normalized the expression of enzymes involved in lipid metabolism.

Intestinal Microbiota as a Contributor to Chronic Inflammation and Its Potential Modifications

The gut microbiota is a crucial factor in maintaining homeostasis. The presence of commensal microorganisms leads to the stimulation of the immune system and its maturation. In turn, dysbiosis with an impaired intestinal barrier leads to accelerated contact of microbiota with the host’s immune cells. Microbial structural parts, i.e., pathogen-associated molecular patterns (PAMPs), such as flagellin (FLG), peptidoglycan (PGN), lipoteichoic acid (LTA), and lipopolysaccharide (LPS), induce inflammation via activation of pattern recognition receptors. Microbial metabolites can also develop chronic low-grade inflammation, which is the cause of many metabolic diseases. This article aims to systematize information on the influence of microbiota on chronic inflammation and the benefits of microbiota modification through dietary changes, prebiotics, and probiotic intake. Scientific research indicates that the modification of the microbiota in various disease states can reduce inflammation and improve the metabolic profile. However, since there is no pattern for a healthy microbiota, there is no optimal way to modify it. The methods of influencing microbiota should be adapted to the type of dysbiosis. Although there are studies on the microbiota and its effects on inflammation, this subject is still relatively unknown, and more research is needed in this area.

Effect of Antarctic krill phospholipid (KOPL) on high fat diet-induced obesity in mice

Phospholipids are the main lipid components in Antarctic krill oil, and the combination of n-3 polyunsaturated fatty acids (n-3 PUFAs) shows multiple nutritional advantages. At present, the research about Antarctic krill phospholipid (KOPL) mainly focuses on the purification, and there are few reports on the anti-obesity effect. Thus, this study aimed at evaluating the effect of KOPL on the high-fat diet (HFD)-induced obesity mice. All the mice were divided into five groups, which were fed chow diet, HFD, and different doses of KOPL + HFD, respectively. The results showed that KOPL treatment could reduce the weight gain, fat accumulation, and liver tissue damage in HFD-induced mice. KOPL treatment could reduce the levels of serum lipid (TC, TG, L-LDL) and fasting blood glucose in HFD-induced mice, and the inflammatory cytokines (IL-1β and TNF-α) in serum. Further analysis showed that KOPL could promote the normal expression of lipid-synthesis-related genes and proteins, including sterol regulatory element-binding protein-1c (SREBP-1c), fatty acid synthetase (FAS), and peroxisome proliferator-activated receptor alpha (PPAR-α) in liver tissue. Besides, it inhibited the overexpression of inflammatory cytokine genes (IL-1β and TNF-α), but increased the expression of tight junction genes (ZO-1 and Occludin) in the colon tissue. Additionally, KOPL improved the decrease of diversity and imbalance of intestinal microbiota, which could contribute to its beneficial effects. In summary, the KOPL treatment improves the effects of HFD-induced obese mice by maintaining normal lipid levels, protecting the liver tissue, reducing inflammation response and intestinal damage, and regulating intestinal microbiota abnormalities. It refer to KOPL could be a promising dietary strategy for treating obesity and improving its related metabolic diseases.

Dietary EPA-Enriched Phospholipids Alleviate Chronic Stress and LPS-Induced Depression- and Anxiety-Like Behavior by Regulating Immunity and Neuroinflammation

SCOPE

A growing number of studies have reported the effects of eicosapentaenoic acid (EPA) and terrestrial phospholipids on ameliorating mood disorders. Marine-derived EPA-enriched phospholipids (EPA-PL) exhibit the structural characteristics of EPA and phospholipids. However, the effect of dietary EPA-PL, and the differences between amphiphilic EPA-PL and lyophobic EPA on mood disorders had not been studied.

METHODS AND RESULTS

A comparative investigation to determine the effects of dietary EPA-enriched ethyl ester (EPA-EE) and EPA-PL on improving depression- and anxiety-like behavior in a mouse model is performed, induced by 4 week chronic unpredictable mild stress (CUMS) coupled with lipopolysaccharide (LPS) challenge. It is found that dietary 4 week 0.6% (w/w) EPA-PL rescued depression- and anxiety-like behavior to a greater extent than did EPA-EE. Moreover, dietary EPA-PL significantly reduced the immobility time by 56.6%, close to the normal level, in forced swimming test, which revealed a reversal of depression-like behavior. Further studies revealed that dietary EPA-PL regulated immunity, monoamine systems, and the hypothalamic-pituitary-adrenal (HPA) axis by multi-target interactions, including inhibition of neuroinflammation and apoptosis.

CONCLUSION

EPA-PL exerted superior effects to EPA-EE in alleviating depression- and anxiety-like behavior. The data suggest potential novel candidate or targeted dietary patterns to prevent and treat mood disorder.

Tilapia head glycolipids protect mice against dextran sulfate sodium-induced colitis by ameliorating the gut barrier and suppressing NF-kappa B signaling pathway

The purpose of this study was to evaluate the relieving effect of tilapia head glycolipids (TH-GLs) on dextran sulfate sodium (DSS)-induced colitis in mice and to further explore its mechanism. Mice were orally administered 3% (w/v) DSS to establish a model of ulcerative colitis (UC), and subsequently treated with TH-GLs or sulfasalazine. In addition, the expression of key targets in the intestinal mucosal barrier and the inflammatory signal pathway were studied by combining immunochemical analysis techniques. The results showed that varying doses of TH-GLs can significantly improve colon lesions caused by DSS, reduce histological scores, increase mucus secretion, extend colon length, increase weight, and inhibit the occurrence of inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), Interleukin-1β (IL-1β), and Interleukin- 6 (IL-6). Further, studies have shown that TH-GLs increase the secretion of MUC2 and up-regulate the expression of tight junction related proteins, such as ZO-1 and Occludin. In addition, TH-GLs significantly down-regulated the protein expression levels of TNF-α, IKK-β, and nuclear factor-κB (NF-κB). Here, we have elucidated the potential mechanism of TH-GLs in protecting mice with colitis. In general, this study shows that TH-GLs could improve the symptoms of UC by improving the gut barrier and inhibiting inflammatory signals, which provides a scientific basis for future clinical applications.

Egg yolk oils exert anti-inflammatory effect via regulating Nrf2/NF-κB pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Egg yolk oils (EYO) is a traditional Chinese medicine obtained from Gallus gallus domesticus Brisson, which has been used to treat inflammatory related diseases such as cheilitis, ulceration and acute anal fissure. However, the detailed anti-inflammatory mechanism of EYO is still unknown.

AIM OF THE STUDY

The anti-inflammatory activity and mechanism of EYO were investigated in tumor necrosis factor (TNF)-α induced Caco-2 cells.

MATERIALS AND METHODS

EYO was obtained by direct-heat extraction (HE), ethanol extraction (EE) and petroleum ether extraction (PE), respectively. Fatty acid compositions of three EYO were measured by gas chromatography (GC). Cell viability, enzyme-linked immunosorbent assay (ELISA), transcriptome, RT-PCR and Western blotting were also performed.

RESULTS

Fatty acid compositions of three EYO were different with varied extraction methods. EYO significantly reduced interleukin (IL)-8 secretion. EYO exerted anti-inflammatory effect via coordinating regulation of Nrf2/NF-κB pathways based on the results of transcriptome, Q-PCR and Western blotting. In detail, PE and HE inhibited the NF-κB pathway, whereas EE exerted anti-inflammatory activity via the Nrf2/NF-κB pathways.

CONCLUSIONS

The aforementioned results showed the anti-inflammatory mechanism of EYO. These findings might be beneficial to clinical applications of EYO.

N-3 PUFA improved post-menopausal depression induced by maternal separation and chronic mild stress through serotonergic pathway in rats-effect associated with lipid mediators

Early life maternal separation (MS) increases the vulnerability to depression in rats with chronic mild stress (CMS). N-3 polyunsaturated fatty acids (PUFA) improved depressive behaviors in rats with acute stress; however, their effects on rats with MS+CMS were not apparent. The purpose of the present study was to investigate the hypothesis that lifetime n-3 PUFA supplementation improves post-menopausal depression through the serotonergic and glutamatergic pathways while modulating n-3 PUFA-derived metabolites. Female rats were fed diets of either 0% n-3 PUFA during lifetime or 1% energy n-3 PUFA during pre-weaning, post-weaning, or lifetime periods. Rats were allocated to non-MS or MS groups and underwent CMS after ovariectomy. N-3 PUFA increased brain n-3 PUFA-derived endocannabinoid/oxylipin levels, and reversed depressive behaviors. N-3 PUFA decreased blood levels of adrenocorticotropic hormone and corticosterone, and brain expressions of corticotropin-releasing factor and miRNA-218, which increased the expression of the glucocorticoid receptor. N-3 PUFA decreased the expression of tumor necrosis factor-α, interleukin (IL)-6, IL-1β, and prostaglandin E2, while increased the expression of miRNA-155. N-3 PUFA also increased brainstem serotonin levels and hippocampal expression of the serotonin-1A receptor, cAMP response element-binding protein (CREB), phospho-CREB, and brain-derived neurotrophic factor. However, n-3 PUFA did not affect brain expression of α-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptor subtype 1, N-methyl-D-aspartate receptor subtype 2B, or miRNA-132. Moreover, n-3 PUFA exposure during lifetime caused greater effects than pre- and post-weaning periods. The present study suggested that n-3 PUFA improved depressive behaviors through serotonergic pathway while modulating the metabolites of n-3 PUFA in post-menopausal depressed rats with chronic stress.