Showing papers in "Molecular Nutrition & Food Research in 2019"

Nutrimetabolomics: An Integrative Action for Metabolomic Analyses in Human Nutritional Studies

Abstract: The life sciences are currently being transformed by an unprecedented wave of developments in molecular analysis, which include important advances in instrumental analysis as well as biocomputing. In light of the central role played by metabolism in nutrition, metabolomics is rapidly being established as a key analytical tool in human nutritional studies. Consequently, an increasing number of nutritionists integrate metabolomics into their study designs. Within this dynamic landscape, the potential of nutritional metabolomics (nutrimetabolomics) to be translated into a science, which can impact on health policies, still needs to be realized. A key element to reach this goal is the ability of the research community to join, to collectively make the best use of the potential offered by nutritional metabolomics. This article, therefore, provides a methodological description of nutritional metabolomics that reflects on the state-of-the-art techniques used in the laboratories of the Food Biomarker Alliance (funded by the European Joint Programming Initiative "A Healthy Diet for a Healthy Life" (JPI HDHL)) as well as points of reflections to harmonize this field. It is not intended to be exhaustive but rather to present a pragmatic guidance on metabolomic methodologies, providing readers with useful "tips and tricks" along the analytical workflow.

An Overview of Carotenoids, Apocarotenoids, and Vitamin A in Agro-Food, Nutrition, Health, and Disease.

Abstract: Carotenoids are fascinating compounds that can be converted into many others, including retinoids that also play key roles in many processes. Although carotenoids are largely known in the context of food science, nutrition, and health as natural colorants and precursors of vitamin A (VA), evidence has accumulated that even those that cannot be converted to VA may be involved in health-promoting biological actions. It is not surprising that carotenoids (most notably lutein) are among the bioactives for which the need to establish recommended dietary intakes have been recently discussed. In this review, the importance of carotenoids (including apocarotenoids) and key derivatives (retinoids with VA activity) in agro-food with relevance to health is summarized. Furthermore, the European Network to Advance Carotenoid Research and Applications in Agro-Food and Health (EUROCAROTEN) is introduced. EUROCAROTEN originated from the Ibero-American Network for the Study of Carotenoids as Functional Food Ingredients (IBERCAROT).

Lactobacillus and Bifidobacterium Improves Physiological Function and Cognitive Ability in Aged Mice by the Regulation of Gut Microbiota.

Abstract: Scope Age-related degeneration is associated with imbalances of gut microbiota and its related immune system, thus gut microbiota dysbiosis is considered to be a key target to improve senescence. The potential roles of probiotics on physiological function and cognitive ability in aged mice are investigated in this study. Methods and results Lactobacillus casei LC122 or Bifidobacterium longum BL986, are orally administrated for 12 weeks, and the anti-aging effects, as well as the composition and function of gut microbiota, are investigated in aged mice. Probiotics supplementation ameliorates hepatic lipid accumulation, enhances muscle strength and function, attenuates oxidative stress and inflammation in peripheral tissues, and improves gut barrier function. These results are associated with improved learning and memory ability as assessed by behavioral tests and upregulation of neurodegenerative and neurotrophic factors expressions in hippocampus. Moreover, the diversity and composition of gut microbiota are altered in aged mice, and both probiotics treatment display distinguished features of gut microbiota. Comparisons of two probiotic strains reveal significant differences in the taxa at family and genus level, leading to the functional profile change of the microbial community. Conclusion L. casei LC122 and B. longum BL986 might be used as novel and promising anti-aging agents in human.

Quercetin-Induced miR-369-3p Suppresses Chronic Inflammatory Response Targeting C/EBP-β.

Abstract: Scope Dendritic cells (DCs) are the most potent antigen-presenting cells that play an important role in the crosstalk between the innate and the adaptive immune response. Quercetin exposure is identified as an effective strategy to suppress the inflammatory response induced by LPS. Methods and results In this study, using a next-generation sequencing analysis, the effect of quercetin on microRNAs (miRNAs) expression in DCs is examined. A signature of 113 miRNAs that are differentially regulated in LPS-stimulated DCs after quercetin exposure is defined. It is demonstrated that the loss of function of miR-369-3p in LPS-stimulated DCs during quercetin exposure led to an increase of CCAAT/enhancer binding protein β (C/EBP-β) mRNA and protein and its downstream targets tumor necrosis factor-α (TNF-α) and interleukin 6 (IL6). Conversely, it is shown that the ectopic induction of miR-369-3p without quercetin suppresses the inflammatory response of LPS reducing C/EBP-β, TNF-α, and IL6 production. In vivo, oral administration of quercetin in dextran-sulfate-sodium-induced colitis induces miR-369-3p expression. Conclusions These findings indicate that quercetin-induced miR-369-3p regulates the inflammatory cascade in chronic inflammatory response and present promising therapeutic implications.

Trimethylamine N‐Oxide Aggravates Liver Steatosis through Modulation of Bile Acid Metabolism and Inhibition of Farnesoid X Receptor Signaling in Nonalcoholic Fatty Liver Disease

Abstract: Scope Trimethylamine N-oxide (TMAO), the metabolite of choline generated by gut microbiota, is associated with nonalcoholic fatty liver disease (NAFLD) and could influence bile acid (BA) metabolism. However, whether TMAO aggravates liver steatosis by modulating BA metabolism and the related mechanisms has not been investigated. Methods and results A case-control study including biopsy-proven NAFLD patients (n = 34) and controls (n = 14) is conducted to determine the correlation between TMAO and BA metabolism. Serum levels of total BA and the percentage of farnesoid X receptor (FXR)-antagonistic BA species are markedly higher in NAFLD patients than in the controls. Serum levels of TMAO positively correlated with the serum levels of total BA and hepatic mRNA expression of cholesterol 7 alpha hydroxylase (CYP7A1). In a murine model, it is found that 18 weeks administration of TMAO impairs liver function and increases hepatic triglyceride accumulation and lipogenesis in mice fed with a high-fat diet. TMAO increases BA synthesis and shifted hepatic BA composition toward FXR-antagonistic activity. Knockdown of CYP7A1 via small interfering RNA or activation of FXR by GW4064 blocks the effect of TMAO-induced lipogenesis in palmitic acid-treated HepG2 cells. Conclusion TMAO aggravates liver steatosis by suppressing BA-mediated hepatic FXR signaling.

Taurine is Involved in Energy Metabolism in Muscles, Adipose Tissue, and the Liver

Abstract: Energy metabolism is a basic and general process, by which the body acquires and uses energy to maintain normal function, and taurine plays a vital role in energy metabolism. Taurine deficiency may cause a weak energy metabolism and energy metabolism dysfunction. Taurine biosynthetic ability is limited, and its supplementation in the diet can strengthen energy metabolism in muscle performance, cardiac function, liver activity, and adipose tissue. Combining taurine with other drugs may have a superior effect in energy metabolism. In many metabolic disorders, taurine, or the combination of taurine with other drugs, also functions as a repair treatment for damaged tissues, and acts as a promoter for the balance of energy metabolism. The present study discusses the potential roles of taurine in energy metabolism.

Sex Differences in the Gut Microbiota as Potential Determinants of Gender Predisposition to Disease.

Abstract: Scope Dysbiosis of gut microbiota is involved in metabolic syndrome (MetS) development, which has a different incidence between men (M) and women (W). The differences in gut microbiota in MetS patients are explored according to gender, and whether consuming two healthy diets, Mediterranean (MED) and low-fat (LF), may, over time, differentially shape the gut microbiota dysbiosis according to gender is evaluated. Materials and methods All the women from the CORDIOPREV study whose feces samples were available and a similar number of men, matched by the main metabolic variables (N = 246, 123 women and 123 men), and categorized according to the presence or not of MetS are included. Gut microbiota is analyzed at baseline and after 3 years of dietary intervention. Results Higher abundance of Collinsella, Alistipes, Anaerotruncus, and Phascolarctobacterium genera is observed in MetS-W than in MetS-M, whereas the abundance of Faecalibacterium and Prevotella genera is higher in MetS-M than in MetS-W. Moreover, higher levels of Desulfovibrio, Roseburia, and Holdemania are observed in men than in women after the consumption of the LF diet. Conclusion The results suggest the potential involvement of differences in gut microbiota in the unequal incidence of metabolic diseases between genders, and a sex-dependent effect on shaping the gut microbiota according to diet.

Taurine: a regulator of cellular redox homeostasis and skeletal muscle function.

Abstract: Taurine is a nonproteinogenic s-aminosulfonic acid. Important dietary sources of taurine are fish and seafood. Taurine interacts with ion channels, stabilizes membranes, and regulates the cell volume. These actions confirm its high concentrations in excitable tissues like retina, neurons, and muscles. Retinal degeneration, cardiomyopathy, as well as skeletal muscle malfunction are evident in taurine-deficient phenotypes. There is evidence that taurine counteracts lipid peroxidation and increases cellular antioxidant defense in response to inflammation. In activated neutrophils, taurine reacts with hypochloric acid to form taurine chloramine, which triggers the Kelch-like ECH-associated protein 1-nuclear factor E2-related factor 1 (Keap1-Nrf2) pathway. Consequently, Nrf2 target genes, such as heme oxygenase-1 and catalase, are induced. Furthermore, taurine may prevent an overload of reactive oxygen species (ROS) directly by an inhibition of ROS generation within the respiratory chain. Taurine affects mitochondrial bioenergetics and taurine-deficient mice exhibit an impaired exercise performance. Moreover, some studies demonstrate that taurine enhances the glycogen repletion in the postexercise recovery phase. In the case of taurine deficiency, many studies observed a phenotype known in muscle senescence and skeletal muscle disorders. Overall, taurine plays an important role in cellular redox homeostasis and skeletal muscle function.

Correlating Infant Faecal Microbiota Composition and Human Milk Oligosaccharide Consumption by Microbiota of One-Month Old Breastfed Infants.

Abstract: Scope Understanding biological functions of different free human milk oligosaccharides (HMOs) in shaping gastrointestinal tract microbiota during infancy is of great interest. We examined a link between HMOs in maternal milk and infant faecal microbiota composition and investigated the role of microbiota in degrading HMOs within the GI tract of healthy, breastfed, one-month old infants. Methods and results Maternal breast milk and corresponding infant faeces originated from the KOALA Birth Cohort. HMOs were quantified in milk and infant faecal samples using PGC-UPLC-MS and HPAEC-PAD. Faecal microbiota composition was characterised using Illumina HiSeq amplicon 16S rRNA sequencing. The composition associated with gender, mode of delivery, and milk HMOs: Lacto-N-fucopentaose I and 2'-Fucosyllactose. Overall, Bifidobacterium, Bacteroides, Escherichia-Shigella and Parabacteroides were predominating genera. We detected three different patterns in the infant faecal microbiota structure. Gastrointestinal degradation of HMOs was strongly associated with faecal microbiota composition, and there was a link between utilisation of specific HMOs and abundance of various phylotypes (OTUs). Conclusions HMOs in maternal milk are among important factors shaping GI tract microbiota composition in one-month old breastfed infants. Infant's ability to metabolise different HMOs strongly correlate with faecal microbiota composition, and with phylotypes within genera Bifidobacterium, Bacteroides and Lactobacillus. This article is protected by copyright. All rights reserved.

Deciphering the Human Gut Microbiome of Urolithin Metabotypes: Association with Enterotypes and Potential Cardiometabolic Health Implications.

Abstract: Scope The gut microbiota ellagitannin-metabolizing phenotypes (i.e., urolithin metabotypes [UMs]) are proposed as potential cardiovascular disease (CVD) risk biomarkers because the host blood lipid profile is reported to be associated with specific UMs. However, the link for this association remains unknown so far. Methods and results The gut microbiome of 249 healthy individuals is analyzed using 16S rDNA sequencing analysis. Individuals are also stratified by UMs (UM-A, UM-B, and UM-0) and enterotypes (Bacteroides, Prevotella, and Ruminococcus). Associations of UMs discriminating bacteria with CVD risk markers are investigated. Distribution and gut microbiota composition of UMs and enterotypes are not coincident. Almost half of the discriminating genera between UM-A and UM-B belongs to the Coriobacteriaceae family. UM-B individuals present higher blood cholesterol levels and higher alpha-diversity, including Coriobacteriaceae family, than those of UM-A. Coriobacteriaceae, whose abundance is the highest in UM-B, is positively correlated with total cholesterol, LDL cholesterol, and body mass index. Conclusions Results herein suggest that the family Coriobacteriaceae could be a link between individuals' UMs and their blood cholesterol levels. Further research is needed to explore the mechanisms of the host metabolic phenotype, including cholesterol excretion products, to modulate this bacterial family.

Abundance of Probiotics and Butyrate-Production Microbiome Manages Constipation via Short-Chain Fatty Acids Production and Hormones Secretion.

Abstract: Scope The characteristics of gut microbiota and host metabolism are hypothesized to be associated with constipation status, but the regulation mechanism is not fully understood. Thus, the current study investigates the effect of constipation symptoms on gut functionality following the modulation of gut microbiota and metabolites via dietary fiber intervention. Methods and results Constipation causes a significantly reduced short-chain fatty acids (SCFAs) production and a higher level of iso-butyrate. The feces of constipated people are characterized with inhibited Faecalibacterium, Ruminococcaceae and Roseburia abundance. Desulfovibrionaceae is identified to be an important endotoxin producer in constipated patients, and a butyrate-enriched SCFAs profile achieved by dietary fiber supplement accelerates gastrointestinal transit and increases the thickness of the mucosal layer, possibly through triggering the secretion of colonic hormones and enhancing the expression of tight junction proteins for maintaining intestinal barrier integrity. More importantly, an interacting regulatory mechanism among SCFAs, in particular butyrate and propionate, may be involved in signaling between the microbiome and host cells in the colon. Conclusion Gut microbiota, characterized with enriched butyrate-producing and depressed Desulfovibrionaceae bacteria, attenuates constipation symptoms through promoting intestinal hormones secretion and maintaining gut barrier integrity.

Honey Polyphenols Ameliorate DSS-Induced Ulcerative Colitis via Modulating Gut Microbiota in Rats.

Abstract: Scope Ulcerative colitis (UC) is a multifaceted and recurrent immune disorder that requires long-term potent pharmacological treatment. Honey, as a natural food of nourishment and pharmaceutical value, has been found to defend against colitis. Methods and results The effects of different constituents in honey are investigated on DSS-induced colitis in rats. Rats are given DSS, sugars, honey, polyphenols, or SASP for a week, with blood and colon samples collected for the biochemical parameters and inflammation-related gene analysis and colon contents for gut microbiota. The results show that pretreatments with honey polyphenols significantly improve SOD, GSH-Px, NO, and MPO levels and reduce DSS-induced colonic apoptosis, the colonic inflammatory cytokines IL-6, TNF-α, and TGF-β1 accompanied by downregulation of IL-1β, IL-6, TNF-α, and IFN-γ gene and upregulation of IκB-α gene. Furthermore, honey polyphenols and SASP show similar microbial community structure shifts and selective enrichment of key species. At the genus level, honey polyphenols significantly reduce the population of Bacteroides, Corynebacterium, and Proteus species. The correlation analysis indicates that colonic gene expression regulated by honey polyphenols is relative to the key species of gut microbiota. Conclusions Honey polyphenols improve intestinal inflammation and oxidative stress resistance via modulating gut microbiota, which is conducive to revealing the host-microbe interactions.

Green Tea Polyphenols Modify the Gut Microbiome in db/db Mice as Co-Abundance Groups Correlating with the Blood Glucose Lowering Effect.

Abstract: Scope The effects of green tea polyphenols, Polyphenon E (PPE), and black tea polyphenols, theaflavins (TFs), on gut microbiota and development of diabetes in db/db mice are investigated and compared. Methods and results Supplementation of PPE (0.1%) in the diet of female db/db mice for 7 weeks decreases fasting blood glucose levels and mesenteric fat while increasing the serum level of insulin, possibly through protection against β-cell damage. However, TFs are less or not effective. Microbiome analysis through 16S rRNA gene sequencing shows that PPE and TFs treatments significantly alter the bacterial community structure in the cecum and colon, but not in the ileum. The key bacterial phylotypes responding to the treatments are then clustered into 11 co-abundance groups (CAGs). CAGs 6 and 7, significantly increased by PPE but not by TFs, are negatively associated with blood glucose levels. The operational taxonomic units in these CAGs are from two different phyla, Firmicutes and Bacteroidetes. CAG 10, decreased by PPE and TFs, is positively associated with blood glucose levels. Conclusion Gut microbiota respond to tea polyphenol treatments as CAGs instead of taxa. Some of the CAGs associated with the blood glucose lowering effect are enriched by PPE, but not TFs.

Tea Consumption and Health Outcomes: Umbrella Review of Meta-Analyses of Observational Studies in Humans.

Abstract: Scope The aim of this article is to conduct an umbrella review to study the strength and validity of associations between tea consumption and diverse health outcomes. Methods and results Meta-analyses of observational studies examining associations between tea consumption and health outcomes in all human populations and settings are screened. The umbrella review identifies 96 meta-analyses with 40 unique health outcomes. Tea consumption shows greater benefits than harm to health in this review. Dose-response analyses of tea consumption indicates reduced risks of total mortality, cardiac death, coronary artery disease, stroke, and type 2 diabetes mellitus with increment of two to three cups per day. Beneficial associations are also found for several cancers, skeletal, cognitive, and maternal outcomes. Harmful associations are found for esophageal and gastric cancer when the temperature of intake is more than 55-60 °C. Conclusion Tea consumption, except for very hot tea, seems generally safe at usual levels of intake, with summary estimates indicating the largest reduction for diverse health outcomes at two to three cups per day. Generally, tea consumption seems more beneficial than harmful in this umbrella review. Randomized controlled trials are further needed to understand whether the observed associations are causal.

Metabolomics‐Based Dietary Biomarkers in Nutritional Epidemiology—Current Status and Future Opportunities

Abstract: The application of metabolomics in nutrition epidemiology holds great promise and there is a high expectation that it will play a leading role in deciphering the interactions between diet and health. However, while significant progress has been made in the identification of putative biomarkers, more work is needed to address the use of the biomarkers in dietary assessment. The aim of this review is to critically evaluate progress in these areas and to identify challenges that need to be addressed going forward. The notable applications of dietary biomarkers in nutritional epidemiology include 1) determination of food intake based on biomarkers levels and calibration equations from feeding studies, 2) classification of individuals into dietary patterns based on the urinary metabolic profile, and 3) application of metabolome wide-association studies. Further work is needed to address some specific challenges to enable biomarkers to reach their full potential.

Metabolic Profiling of Dietary Polyphenols and Methylxanthines in Normal and Malignant Mammary Tissues from Breast Cancer Patients

Abstract: Scope Dietary polyphenols may protect against breast cancer. However, it is unknown whether polyphenols reach human malignant breast tumors in molecular forms and(or) at concentrations likely to act against cancer. Methods and results Ninteen breast cancer patients consumed three capsules daily from biopsy-confirmed diagnosis to surgery (6 ± 2 days). The capsules contained pomegranate, orange, lemon, olive, cocoa, and grapeseed extracts plus resveratrol, providing 37 different phenolics (473.7 mg), theobromine and caffeine (19.7 mg). A total of 101 metabolites are identified in urine, 69 in plasma, 39 in normal (NT), and 33 in malignant (MT) tissues by UPLC-ESI-QTOF-MS. Eight control patients did not consume extracts. Phenolic-derived metabolites in MT and NT are mainly glucuronidated and(or) sulfated. Some representative metabolites detected in MT (median and range, pmol g-1 ) are urolithin-A-3-O-glucuronide (26.2; 3.2-66.5), 2,5-dihydroxybenzoic acid (40.2; 27.7-52.2), resveratrol-3-O-sulfate (86.4; 7.8-224.4), dihydroresveratrol-3-O-glucuronide (109.9; 10.3-229.4), and theobromine (715.0; 153.9-3,216). Metabolites, as detected in breast tissues, do not exert antiproliferative or estrogenic/antiestrogenic activities in MCF-7 breast cancer cells. Conclusion This is the first study that describes the metabolic profiling of dietary phenolics and methylxanthines in MT and NT comprehensively. Although phase-II conjugation might hamper a direct anticancer activity, long-term tumor-senescent chemoprevention cannot be discarded.

Lactobacillus sakei Alleviates High-Fat-Diet-Induced Obesity and Anxiety in Mice by Inducing AMPK Activation and SIRT1 Expression and Inhibiting Gut Microbiota-Mediated NF-κB Activation

Abstract: Scope Long-term feeding of a high-fat diet (HFD) causes gastrointestinal inflammation and gut microbiota disturbance, leading to the increased occurrence of obesity and anxiety. In the present study, the effects of heat-labile Lactobacillus sakei OK67, tyndallized OK67 (tOK67), and heat-stable Lactobacillus sakei PK16 on HFD-induced obesity and anxiety in mice are examined. Methods and results Obesity is induced in mice by feeding with HFD. Oral administration of live OK67, tOK67, or PK16 reduces HFD-induced body and liver weights and blood triglyceride, total cholesterol, corticosterone, and lipopolysaccharide levels. These treatments also suppress HFD-induced NF-κB activation and increased HFD-suppressed AMP-activated protein kinase (AMPK) activation and SIRT-1 expression in the liver. OK67 or PK16 treatment alleviates HFD-induced anxiety-like behaviors and increases BDNF expression and NF-κB activation in the hippocampus. Moreover, OK67 or PK16 treatment suppresses HFD-induced colitis and suppresses the Proteobacteria population and fecal lipopolysaccharide levels in mice. OK67 or PK16 treatment inhibits NF-κB activation and induced AMPK activation and SIRT-1 expression in lipopolysaccharide-stimulated Caco-2 cells. Overall, the antiobesity and anxiolytic effects of live OK67 are more potent than those of tOK67. Conclusion Lactobacillus sakei can alleviate HFD-induced obesity, colitis, and anxiety by regulating gut microbiota-mediated AMPK and NF-κB activation and SIRT-1 expression.

Functional Interactions between Gut Microbiota Transplantation, Quercetin, and High-Fat Diet Determine Non-Alcoholic Fatty Liver Disease Development in Germ-Free Mice.

Abstract: Scope Modulation of intestinal microbiota has emerged as a new therapeutic approach for non-alcoholic fatty liver disease (NAFLD). Herein, it is addressed whether gut microbiota modulation by quercetin and intestinal microbiota transplantation can influence NAFLD development. Methods and results Gut microbiota donor mice are selected according to their response to high-fat diet (HFD) and quercetin in terms of obesity and NAFLD-related biomarkers. Germ-free recipients displayed metabolic phenotypic differences derived from interactions between microbiota transplanted, diets, and quercetin. Based on the evaluation of hallmark characteristics of NAFLD, it is found that gut microbiota transplantation from the HFD-non-responder donor and the HFD-fed donor with the highest response to quercetin results in a protective phenotype against HFD-induced NAFLD, in a mechanism that involves gut-liver axis alteration blockage in these receivers. Gut microbiota from the HFD-responder donor predisposed transplanted germ-free mice to NAFLD. Divergent protective and deleterious metabolic phenotypes exhibited are related to definite microbial profiles in recipients, highlighting the predominant role of Akkermansia genus in the protection from obesity-associated NAFLD development. Conclusions The results provide scientific support for the prebiotic capacity of quercetin and the transfer of established metabolic profiles through gut microbiota transplantation as a protective strategy against the development of obesity-related NAFLD.

Epigallocatechin-3-Gallate Attenuates Microglial Inflammation and Neurotoxicity by Suppressing the Activation of Canonical and Noncanonical Inflammasome via TLR4/NF-κB Pathway.

Abstract: Scope In this study, it has been investigated whether the neuroprotective efficacy of epigallocatechin-3-gallate (EGCG) is mediated by inhibition of canonical and noncanonical inflammasome activation via toll-like receptor 4 (TLR4)/NF-κB pathway both in LPS+Aβ-induced microglia in vitro and in APP/PS1 mice in vivo. Methods and results In BV2 cells, EGCG inhibits the expressions of Iba-1, cleaved IL-1β, and cleaved IL-18 induced by LPS+Aβ. Then, the supernatants are used to treat SH-SY5Y cells, and EGCG treatment significantly recovers the neurotoxicity from LPS+Aβ-induced microglial conditioned media. Subsequently, it has been found that EGCG reduces the microglial expressions of caspase-1 p20, NLRP3, and caspase-11 p26. Furthermore, the expression levels of Toll-like receptor 4 (TLR4), p-IKK/IKK, and p-NF-κB/NF-κB were decreased after EGCG treatment. As expected, when a caspase-1 specific inhibitor Z-YVAD-FMK, and an IKK and caspase-11 inhibitor wedelolactone are used for blocking, Z-YVAD-FMK and wedelolactone exacerbate the inhibitory efficacy than using EGCG alone. Finally, consistent with the results obtained in BV2 cells, EGCG treatment reduces microglial inflammation and neurotoxicity by suppressing the activation of canonical NLRP3 and noncanonical caspase-11-dependent inflammasome via TLR4/NF-κB pathway in LPS+Aβ-induced rat primary microglia and hippocampus of APP/PS1 mice. Conclusion EGCG attenuates microglial inflammation and neurotoxicity by inhibition of canonical NLRP3 and noncanonical caspase-11-dependent inflammasome activation via TLR4/NF-κB pathway.

Modulation of Intestinal Epithelial Glycocalyx Development by Human Milk Oligosaccharides and Non-Digestible Carbohydrates

Abstract: Scope The epithelial glycocalyx development is of great importance for microbial colonization. Human milk oligosaccharides (hMOs) and non-digestible carbohydrates (NDCs) may modulate glycocalyx development. Methods and results The effects of hMOs and NDCs on human gut epithelial cells (Caco2) are investigated by quantifying thickness and area coverage of adsorbed albumin, heparan sulfate (HS), and hyaluronic acid (HA) in the glycocalyx. Effects of hMOs (2 '-FL and 3-FL) and NDCs [inulins with degrees of polymerization (DP) (DP3-DP10, DP10-DP60, DP30-DP60) and pectins with degrees of methylation (DM) (DM7, DM55, DM69)] are tested using immunofluorescence staining at 1 and 5 days stimulation. HMOs show a significant enhancing effect on glycocalyx development but effects are structure-dependent. 3-FL induces a stronger albumin adsorption and increases HS and HA stronger than 2 '-FL. The DP3-DP10, DP30-60 inulins also increase glycocalyx development in a structure-dependent manner as DP3-DP10 selectively increases HS, while DP30-DP60 specifically increases HA. Pectins have less effects, and only increase albumin adsorption. Conclusion Here, it is shown that 2 '-FL and 3-FL and inulins stimulate glycocalyx development in a structure-dependent fashion. This may contribute to formulation of effective hMO and NDC formulations in infant formulas to support microbial colonization and gut barrier function.

Targeting on Gut Microbial Metabolite Trimethylamine-N-Oxide and Short-Chain Fatty Acid to Prevent Maternal High-Fructose-Diet-Induced Developmental Programming of Hypertension in Adult Male Offspring.

Abstract: Scope Alterations of gut metabolites, such as SCFAs and trimethylamine (TMA), and microbial composition are associated with the development of hypertension. Whether maternal 3,3-dimethyl-1-butanol (DMB, an inhibitor for TMA formation) treatment or the predominant SCFA acetate supplementation can prevent programed hypertension induced by a high-fructose diet (HFD) exposure during pregnancy and lactation in adult male offspring is examined. Methods and results Male offspring are divided into four groups: ND, normal diet; HFD, 60% HFD; ACE, HFD plus 200 mmol L-1 magnesium acetate in drinking water; and DMB: HFD plus 1% DMB in drinking water. Maternal HFD induces programed hypertension in adult male offspring, which is prevented by maternal acetate supplementation or DMB treatment. HFD-induced hypertension is relevant to increased plasma levels of TMA and acetate, and alterations of gut microbial composition. The protective effects of acetate supplementation are associated with decreased plasma TMA level and TMA-to-trimethylamine-N-oxide (TMAO) ratio, and increased renal expression of SCFA receptors. Maternal DMB treatment reduces plasma TMA, TMAO, acetate, and propionate levels. Conclusion Early intervention targeting on gut-microbiota-derived metabolites TMAO and SCFAs to reprogram hypertension may have significant impact to reduce the burden of hypertension.

Mechanisms of Transport and Delivery of Vitamin A and Carotenoids to the Retinal Pigment Epithelium.

Abstract: Vision depends on the delivery of vitamin A (retinol) to the retina. Retinol in blood is bound to retinol-binding protein (RBP). Retinal pigment epithelia (RPE) cells express the RBP receptor, STRA6, that facilitates uptake of retinol. The retinol is then converted to retinyl esters by the enzyme lecithin:retinol acyltransferase. The esters are the substrate for RPE65, an enzyme that produces 11-cis retinol, which is converted to 11-cis retinaldehyde for transport to the photoreceptors to form rhodopsin. The dietary xanthophylls, lutein (LUT) and zeaxanthin (ZEA), accumulate in the macula of the eye, providing protection against age-related macular degeneration. To reach the macula, carotenoids cross the RPE. In blood, xanthophylls and β-carotene mostly associate with high-density lipoprotein (HDL) and low-density lipoprotein (LDL), respectively. Studies using a human RPE cell model evaluate the kinetics of cell uptake when carotenoids are delivered in LDL or HDL. For LUT and β-carotene, LDL delivery result in the highest rate of uptake. HDL is more effective in delivering ZEA (and meso-ZEA). This selective HDL-mediated uptake of ZEA, via a scavenger receptor and LDL-mediated uptake of LUT and β-carotene provides a mechanism for the selective accumulation of ZEA > LUT and xanthophylls over β-carotene in the macula.

SIRT3 Deficiency Promotes High-Fat Diet-Induced Nonalcoholic Fatty Liver Disease in Correlation with Impaired Intestinal Permeability through Gut Microbial Dysbiosis.

Abstract: Scope Sirtuin 3 (SIRT3) plays a protective role against nonalcoholic fatty liver disease (NAFLD) by improving hepatic mitochondrial dysfunction. Gut microbiota imbalance contributes to the pathogenesis of NAFLD, yet the underlying mechanism linking SIRT3 with gut microbiota in NAFLD progression remains obscure. Methods and results Wild-type 129 mice and SIRT3 knockout (SIRT3KO) mice are placed under a chow diet or high-fat diet (HFD) treatment for 18 weeks. HFD resulted in a significantly increased hepatic steatosis and inflammation, which are exacerbated in SIRT3KO mice. The gut microbiota by 16s rRNA gene sequencing and phylogenetic reconstruction of unobserved states analysis are characterized. Lack of SIRT3 facilitates gut microbial dysbiosis in mice following HFD, with increased Desulfovibrio, Oscillibacter, and decreased Alloprevotella. SIRT3 deficiency resulted in an impaired intestinal permeability and inflammation in HFD-fed mice, which can be attenuated by sodium butyrate (NaB). SIRT3KO HFD-fed mice is followed by an increased lipopolysaccharide into the circulation and dysregulated expressions of cannabinoid receptor 1 and 2 in colon and liver, which are significantly associated with the alterations of intestinal microbiota. Conclusions SIRT3 deficiency promotes NAFLD progression in correlation with impaired intestinal permeability through gut microbiota dysbiosis.

Ameliorative Effects of Probiotic Lactobacillus paracasei NL41 on Insulin Sensitivity, Oxidative Stress, and Beta-Cell Function in a Type 2 Diabetes Mellitus Rat Model.

Abstract: Scope The present study aims to assess the antidiabetic effect of Lactobacillus paracasei strain NL41 and its potential mechanisms in rats with type 2 diabetes mellitus (T2DM) induced by a high-fat diet and low-dose streptozotocin administration (HFD/STZ). Methods and results Eighteen Sprague-Dawley (SD) rats are randomly assigned to three groups: one control, one HFD/STZ model, and one HFD/STZ-Lactobacillus protection group with administration of strain NL41 for 12 weeks. Blood is collected for biochemical parameters analysis and tissue samples for histological analysis. Treatment with strain NL41 results in excellent blood glucose regulation and significantly decreases insulin resistance, and HbA1c, glucagon, and leptin levels, accompanied by remarkable improvement of dyslipidemia and oxidative stress status in the animals. Islets of Langerhans, liver, and kidney are significantly protected in the NL41-treated rats compared to the HFD/STZ-T2DM model rats. Histochemistry shows that strain NL41 inhibits beta-cell loss and alpha-cell expansion, indicating pancreatic islets as the targeted tissues for the primary ameliorative effect of the probiotic strain on HFD/STZ-T2DM rats. Crosstalk between the gut-liver and liver-pancreas endocrine axes is discussed. Conclusion Probiotic strain NL41 prevents HFD/STZ-T2DM by decreasing insulin resistance and oxidative stress status, and protecting beta-cell function.

Dietary Black Raspberries Impact the Colonic Microbiome and Phytochemical Metabolites in Mice.

Abstract: Scope Black raspberries (BRB) are a rich source of bioactive phytochemicals, including anthocyanins and ellagitannins. These phytochemicals are poorly absorbed and may be transformed by gut microbiota into various metabolites that may impact the colonic mucosa or upon absorption have systemic bioactivity. The objective of this study is to define the impact of a BRB-containing diet on the colon microbiome in mice and quantify the phytochemical metabolites in the colon contents and circulation. Methods and results Male mice were fed 10% w/w freeze-dried BRB powder for 6 weeks. The colonic microbiota was evaluated by 16S rRNA gene sequencing. Anthocyanin and ellagitannin metabolites, protocatechuic acid, and urolithins were analyzed by HPLC-MS/MS. The BRB diet impacted colon mucosal microbial composition with a more robust effect observed on the luminal microflora. BRB-derived protocatechuic acid and urolithins were quantified in the colon, luminal contents, plasma, liver, and prostate with protocatechuic acid present in higher concentrations compared to urolithins. Conclusion This study highlights the complex interactions between dietary phytochemicals, the host microbiome, and metabolism. It is demonstrated that microbially produced phytochemical metabolites are present in the colon and systemic circulation where they may exert biological activity.

Egg White–Derived Antihypertensive Peptide IRW (Ile‐Arg‐Trp) Reduces Blood Pressure in Spontaneously Hypertensive Rats via the ACE2/Ang (1‐7)/Mas Receptor Axis

Abstract: Scope It is found in the previous study that egg-white-derived antihypertensive peptide Ile-Arg-Trp (IRW) upregulated angiotensin converting enzyme 2 (ACE2) in spontaneously hypertensive rats (SHRs). The objective of this study is to evaluate the contribution of ACE2 activation by IRW to blood-pressure-lowering activity in vivo. Methods and results Adult male SHRs (13-15 week old) are assigned into four groups: 1) untreated with saline infusion; 2) IRW administration (15 mg per kg body weight) with saline infusion; 3) Mas receptor (MasR) antagonist A779 (48 µg per kg body weight per h) infusion; 4) A779 infusion and IRW. Animals are implanted with telemetry transmitter first, and then an osmotic pump filled with saline or A779 is implanted. A779/saline is infused for 7 days, continued with an additional 7 days of treatments. Results indicate that blocking MasR abolished the blood-pressure-lowering effect of IRW. Akt/eNOS signaling in aorta is upregulated by IRW treatment but deactivated by A779 infusion. Circulating levels of interleukin 6 and monocyte chemoattractant protein 1, along with cyclooxygenase 2 in aorta are reduced by IRW but restored by A779 infusion. Conclusion IRW reduces blood pressure of SHR via the ACE2/Ang (1-7)/MasR axis. Mechanisms pertaining to IRW as an ACE2 activator in vivo include enhanced endothelium-dependent vasorelaxation and reduced vascular inflammation.

Identification and Peptidomic Profiling of Exosomes in Preterm Human Milk: Insights Into Necrotizing Enterocolitis Prevention.

Abstract: Scope Human breast milk has been shown to prevent necrotizing enterocolitis (NEC). Although exosomes have been identified in breast milk, their function and components have not been fully addressed. This study is conducted to elucidate the differences in peptidomic complexities between preterm and term milk exosomes. Methods and results Breast milk samples are collected from healthy lactating mothers who have delivered term and preterm infants. Exosomes are separated and quantified. The protective effects of purified exosomes against NEC are investigated both in vitro and in vivo. The peptidomic complexities in term and preterm milk exosomes are analyzed by iTRAQ LC-MS/MS to screen differentially expressed exosomal peptides. Preterm milk exosomes administration significantly enhances proliferation and migration of intestinal epithelial cells compared with term milk exosomes. A total of 70 peptides are found to be significantly modulated in preterm milk samples compared to term milk samples. Of these, 47 peptides are upregulated, and 23 peptides are downregulated. Bioinformatics analysis suggests several potential regulatory roles of the altered peptides in intestinal epithelial cell function. Conclusion These results reveal the differences for the first time in peptidomic complexities between preterm and term milk exosomes. Milk exosome administration might be a promising prevention for NEC.

Sulforaphane Improves Lipid Metabolism by Enhancing Mitochondrial Function and Biogenesis In Vivo and In Vitro.

Abstract: Scope Sulforaphane (SFN) is reported to reduce the accumulation of lipids. However, the underling mechanism remains unclear. In this study, the potential of SFN to improve lipid metabolism is investigated through altering mitochondrial function and biogenesis-related mechanisms. Methods and results The abnormal lipid metabolism model was established both in HHL-5 cells and in rats by feeding a high-fat diet (HFD) for 10 weeks. The current findings suggest that SFN alleviates the swelling of mitochondria and stimulates mitochondrial biogenesis. The reduced expression of NRF1 and TFAM, were reversed by SFN. SFN increases the levels of antioxidant compounds via nuclear factor erythroid-2-related factor (Nrf2) activation. Furthermore, SFN improves multiple mitochondrial bioactivities, such as mitochondrial membrane potential, ATP, and the electron transfer chain based on PGC-1α pathway. SFN also activates lipolysis by transcriptionally upregulating adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL). Conclusions SFN enhances utilization of lipids via both the PGC- 1α-dependent promotion of mitochondrial biogenesis and Nrf2 dependent improvement of mitochondrial function.

Conjugated Linoleic Acid Ameliorates High Fructose-Induced Hyperuricemia and Renal Inflammation in Rats via NLRP3 Inflammasome and TLR4 Signaling Pathway.

Abstract: Scope Conjugated linoleic acid (CLA), a bioactive substance predominantly found in ruminant products, improves insulin resistance and exhibits anti-inflammatory activity. The chief objective of the study is to investigate the effects and potential mechanisms of CLA on high fructose-induced hyperuricemia and renal inflammation. Methods and results Hyperuricemia and renal inflammation are induced in rats by 10% fructose. Hyperuricemia, insulin resistance, and renal inflammation are evaluated. CLA potently ameliorates fructose-induced hyperuricemia with insulin resistance and significantly reduces the levels of inflammation factors in serum and kidney. It reverses fructose-induced upregulation of glucose transporter 9 (GLUT9) and urate transporter 1 (URAT1) in the kidney. Moreover, CLA dramatically inhibits the activation of the nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome. Additionally, CLA suppresses toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88) signaling activation to inhibit nuclear factor-kB (NF-kB) signaling in the kidney of fructose-fed rats. Conclusion CLA ameliorates hyperuricemia along with insulin resistance and renal inflammatory, which may be associated with the suppression of renal GLUT9 and URAT1 in fructose-fed rats. Its molecular mechanism may be related to the inhibition of NLRP3 inflammasome and TLR4/MyD88 signaling pathway. Therefore, CLA may be a promising candidate for preventing fructose-induced hyperuricemia and renal inflammation.

Walnut‐Derived Peptide PW5 Ameliorates Cognitive Impairments and Alters Gut Microbiota in APP/PS1 Transgenic Mice

Abstract: Scope Decreasing β-amyloid (Aβ) accumulation is of significance in finding therapeutic candidates for cognitive impairments in Alzheimer's disease (AD). The aim of this study is to investigate the potency of the active components of walnut protein in decreasing Aβ aggregation and ameliorating cognitive impairments. Methods and results Cell model of intracellular Aβ42 aggregation is used to explore the active ingredients in walnut protein hydrolysate (WPH). A bioactive peptide (Pro-Pro-Lys-Asn-Trp, PW5) with great anti-Aβ42 aggregation activity identified from the WPH is synthesized for in vitro and in vivo experiments. Using classic APP/PS1 mouse model, it is validated that PW5 exerts its effects on cognitive improvement through reducing Aβ plaques accumulation. Moreover, metabolomic analysis reveals that serum norepinephrine (NE) and isovalerate levels are significantly increased in response to PW5 intervention, with decreased serum levels of acetylcholine (AChe) and valerate, compared with the vehicle-treated APP/PS1 mice. PW5 feeding also improves gut dysbiosis in APP/PS1 transgenic mice by increasing the relative abundance of Firmicutes and decreasing Proteobacteria and Verrucomicrobia as displayed by 16s rRNA analyses. Conclusions These promising results support the utilization of peptide PW5 as an active ingredient in functional foods or potential drug candidate for the prevention and/or treatment of AD.