Gut microbiota, intestinal permeability, obesity-induced inflammation, and liver injury

Unraveling the Puzzle: Health Benefits of Probiotics-A Comprehensive Review

A growing number of probiotic-containing products are on the market, and their use is increasing. Probiotics are thought to support the health of the gut microbiota, which in turn might prevent or delay the onset of gastrointestinal tract disorders. Obesity, type 2 diabetes, autism, osteoporosis, and some immunological illnesses are among the conditions that have been shown to possibly benefit from probiotics. In addition to their ability to favorably affect diseases, probiotics represent a defense system enhancing intestinal, nutritional, and oral health. Depending on the type of microbial strain utilized, probiotics can have variable beneficial properties. Although many microbial species are available, the most widely employed ones are lactic acid bacteria and bifidobacteria. The usefulness of these bacteria is dependent on both their origin and their capacity to promote health. Probiotics represent a valuable clinical tool supporting gastrointestinal health, immune system function, and metabolic balance. When used appropriately, probiotics may provide benefits such as a reduced risk of gastrointestinal disorders, enhanced immunity, and improved metabolic health. Most popular probiotics, their health advantages, and their mode of action are the topic of this narrative review article, aimed to provide the reader with a comprehensive reappraisal of this topic matter.

Gut microbiota-associated taurine metabolism dysregulation in a mouse model of Parkinson's disease

IMPORTANCE

PD is recognized as a multisystem disease concerning GI dysfunction and microbiota dysbiosis but still lacks ideal therapies. Recently, aberrant microbiota-derived metabolites are emerging as important participants in PD etiology. However, the alterations of gut microbiota community and serum untargeted metabolite profile have not been fully investigated in a PD mice model. Here, we discover sharply reduced levels of Lactobacillus and taurine in MPTP-treated mice. Moreover, Lactobacillus, Adlercreutzia, and taurine-related metabolites showed the most significant correlation with pathological and GI performance of PD mice. The abundances of microbial transporter and enzymes participating in the degeneration of taurine were disturbed in PD mice. Most importantly, taurine supplement ameliorates MPTP-induced motor deficits, DA neuron loss, and microglial activation. Our data highlight the impaired taurine-based microbiome-metabolism axis during the progression of PD and reveal a novel and previously unrecognized role of genera in modulating taurine metabolism.

Role of Immunological Cells in Hepatocellular Carcinoma Disease and Associated Pathways

Hepatocellular carcinoma (HCC) remains one of the predominant causes of cancer-related mortality across the globe. It is attributed to obesity, excessive alcohol consumption, smoking, and infection by the hepatitis virus. Early diagnosis of HCC is essential, and local treatments such as surgical excision and percutaneous ablation are effective. Palliative systemic therapy, primarily with the tyrosine kinase inhibitor Sorafenib, is used in advanced cases. However, the prognosis for advanced HCC remains poor. This Review additionally describes the pathophysiological mechanisms of HCC, which include aberrant molecular signaling, genomic instability, persistent inflammation, and the paradoxical position of the immune system in promoting and suppressing HCC. The paper concludes by discussing the growing body of research on the relationship between mitochondria and HCC, suggesting that mitochondrial dysfunction may contribute to the progression of HCC. This Review focuses on immunological interactions between different mechanisms of HCC progression, including obesity, viral infection, and alcohol consumption.

Artemether Attenuates Gut Barrier Dysfunction and Intestinal Flora Imbalance in High-Fat and High-Fructose Diet-Fed Mice

Intestinal inflammation is a key determinant of intestinal and systemic health, and when our intestines are damaged, there is disruption of the intestinal barrier, which in turn induces a systemic inflammatory response. However, the etiology and pathogenesis of inflammatory diseases of the intestine are still not fully understood. Artemether (ART), one of the artemisinin derivatives, has been widely used to treat malaria. Nevertheless, the effect of ART on intestinal inflammation remains unclear. The present study intended to elucidate the potential mechanism of ART in diet-induced intestinal injury. A high-fat and high-fructose (HFHF) diet-induced mouse model of intestinal injury was constructed, and the mice were treated with ART to examine their role in intestinal injury. RT-qPCR, Western blotting, immunohistochemical staining, and 16S rRNA gene sequencing were used to investigate the anti-intestinal inflammation effect and mechanism of ART. The results indicated that ART intervention may significantly ameliorate the intestinal flora imbalance caused by the HFHF diet and alleviate intestinal barrier function disorders and inflammatory responses by raising the expression of tight junction proteins ZO-1 and occludin and decreasing the expression of pro-inflammatory factors TNF-α and IL-1β. Moreover, ART intervention restrained HFHF-induced activation of the TLR4/NF-κB p65 pathway in colon tissue, which may be concerned with the potential protective effect of ART on intestinal inflammation. ART might provide new insights into further explaining the mechanism of action of other metabolic diseases caused by intestinal disorders.

Microbiota-Dependent Upregulation of Bitter Taste Receptor Subtypes in the Mouse Large Intestine in High-Fat Diet-Induced Obesity

Bitter taste receptors (Tas2rs in mice) detect bitterness, a warning signal for toxins and poisons, and are expressed in enteroendocrine cells. We tested the hypothesis that Tas2r138 and Tas2r116 mRNAs are modulated by microbiota alterations induced by a long-term high-fat diet (HFD) and antibiotics (ABX) (ampicillin and neomycin) administered in drinking water. Cecum and colon specimens and luminal contents were collected from C57BL/6 female and male mice for qRT-PCR and microbial luminal 16S sequencing. HFD with/without ABX significantly increased body weight and fat mass at 4, 6, and 8 weeks. Tas2r138 and Tas2r116 mRNAs were significantly increased in mice fed HFD for 8 weeks vs. normal diet, and this increase was prevented by ABX. There was a distinct microbiota separation in each experimental group and significant changes in the composition and diversity of microbiome in mice fed a HFD with/without ABX. Tas2r mRNA expression in HFD was associated with several genera, particularly with Akkermansia, a Gram-negative mucus-resident bacterium. These studies indicate that luminal bacterial composition is affected by sex, diet, and ABX and support a microbial dependent upregulation of Tas2rs in HFD-induced obesity, suggesting an adaptive host response to specific diet-induced dysbiosis.

Understanding the impact of radical changes in diet and the gut microbiota on brain function and structure: rationale and design of the EMBRACE study

BACKGROUND

Bariatric surgery leads to profound changes in gut microbiota and dietary patterns, both of which may interact to impact gut-brain communication. Though cognitive function improves postsurgery, there is a large variability in outcomes. How bariatric surgery-induced modifications in the gut microbiota and dietary patterns influence the variability in cognitive function is still unclear.

OBJECTIVES

To elucidate the associations between bariatric surgery-induced changes in dietary and gut microbiota patterns with cognition and brain structure.

SETTING

University hospital.

METHODS

A total of 120 adult patients (≥30 years) scheduled to undergo a primary bariatric surgery along with 60 age-, sex-, and body mass index-matched patients on the surgery waitlist will undergo assessments 3-months presurgery and 6- and 12-month postsurgery (or an equivalent time for the waitlist group). Additionally, 60 age-and sex-matched nonbariatric surgery eligible individuals will complete the presurgical assessments only. Evaluations will include sociodemographic and health behavior questionnaires, physiological assessments (anthropometrics, blood-, urine-, and fecal-based measures), neuropsychological cognitive tests, and structural magnetic resonance imaging. Cluster analyses of the dietary and gut microbiota changes will define the various dietary patterns and microbiota profiles, then using repeated measures mixed models, their associations with global cognitive and structural brain alterations will be explored.

RESULTS

The coordinating study site (Centre intégré universitaire de santé et de services sociaux du Nord-de-l'Île-de-Montréal, QC, Canada), provided the primary ethical approval (Research Ethics Board#: MP-32-2022-2412).

CONCLUSIONS

The insights generated from this study can be used to develop individually-targeted neurodegenerative disease prevention strategies, as well as providing critical mechanistic information.

Microbial Reprogramming in Obsessive-Compulsive Disorders: A Review of Gut-Brain Communication and Emerging Evidence

Obsessive-compulsive disorder (OCD) is a debilitating mental health disorder characterized by intrusive thoughts (obsessions) and repetitive behaviors (compulsions). Dysbiosis, an imbalance in the gut microbial composition, has been associated with various health conditions, including mental health disorders, autism, and inflammatory diseases. While the exact mechanisms underlying OCD remain unclear, this review presents a growing body of evidence suggesting a potential link between dysbiosis and the multifaceted etiology of OCD, interacting with genetic, neurobiological, immunological, and environmental factors. This review highlights the emerging evidence implicating the gut microbiota in the pathophysiology of OCD and its potential as a target for novel therapeutic approaches. We propose a model that positions dysbiosis as the central unifying element in the neurochemical, immunological, genetic, and environmental factors leading to OCD. The potential and challenges of microbial reprogramming strategies, such as probiotics and fecal transplants in OCD therapeutics, are discussed. This review raises awareness of the importance of adopting a holistic approach that considers the interplay between the gut and the brain to develop interventions that account for the multifaceted nature of OCD and contribute to the advancement of more personalized approaches.

Beer-gut microbiome alliance: a discussion of beer-mediated immunomodulation via the gut microbiome

As a long-established fermented beverage, beer is rich in many essential amino acids, vitamins, trace elements, and bioactive substances that are involved in the regulation of many human physiological functions. The polyphenols in the malt and hops of beer are also important active compounds that interact in both directions with the gut microbiome. This review summarizes the mechanisms by which polyphenols, fiber, and other beneficial components of beer are fermentatively broken down by the intestinal microbiome to initiate the mucosal immune barrier and thus participate in immune regulation. Beer degradation products have anti-inflammatory, anticoagulant, antioxidant, and glucolipid metabolism-modulating potential. We have categorized and summarized reported data on changes in disease indicators and in vivo gut microbiota abundance following alcoholic and non-alcoholic beer consumption. The positive effects of bioactive substances in beer in cancer prevention, reduction of cardiovascular events, and modulation of metabolic syndrome make it one of the candidates for microecological modulators.

Lipopolysaccharide-binding protein and future Parkinson's disease risk: a European prospective cohort

INTRODUCTION

Lipopolysaccharide (LPS) is the outer membrane component of Gram-negative bacteria. LPS-binding protein (LBP) is an acute-phase reactant that mediates immune responses triggered by LPS and has been used as a blood marker for LPS. LBP has recently been indicated to be associated with Parkinson's disease (PD) in small-scale retrospective case-control studies. We aimed to investigate the association between LBP blood levels with PD risk in a nested case-control study within a large European prospective cohort.

METHODS

A total of 352 incident PD cases (55% males) were identified and one control per case was selected, matched by age at recruitment, sex and study center. LBP levels in plasma collected at recruitment, which was on average 7.8 years before diagnosis of the cases, were analyzed by enzyme linked immunosorbent assay. Odds ratios (ORs) were estimated for one unit increase of the natural log of LBP levels and PD incidence by conditional logistic regression.

RESULTS

Plasma LBP levels were higher in prospective PD cases compared to controls (median (interquartile range) 26.9 (18.1-41.0) vs. 24.7 (16.6-38.4) µg/ml). The OR for PD incidence per one unit increase of log LBP was elevated (1.46, 95% CI 0.98-2.19). This association was more pronounced among women (OR 2.68, 95% CI 1.40-5.13) and overweight/obese subjects (OR 1.54, 95% CI 1.09-2.18).

CONCLUSION

The findings suggest that higher plasma LBP levels may be associated with an increased risk of PD and may thus pinpoint to a potential role of endotoxemia in the pathogenesis of PD, particularly in women and overweight/obese individuals.

Chronotoxicity of Acrylamide in Mice Fed a High-Fat Diet: The Involvement of Liver CYP2E1 Upregulation and Gut Leakage

Acrylamide (ACR) is produced under high-temperature cooking of carbohydrate-rich foods via the Maillard reaction. It has been reported that ACR has hepatic toxicity and can induce liver circadian disorder. A high fat diet (HFD) could dysregulate liver detoxification. The current study showed that administration of ACR (100 mg/kg) reduced the survival rate in HFD-fed mice, which was more pronounced when treated during the night phase than during the day phase. Furthermore, ACR (25 mg/kg) treatment could cause chronotoxicity in mice fed a high-fat diet, manifested as more severe mitochondrial damage of liver during the night phase than during the day phase. Interestingly, HFD induced a higher CYP2E1 expressions for those treated during the night phase, leading to more severe DNA damage. Meanwhile, the expression of gut tight junction proteins also significantly decreases at night phase, leading to the leakage of LPSs and exacerbating the inflammatory response at night phase. These results indicated that a HFD could induce the chronotoxicity of ACR in mice liver, which may be associated with increases in CYP2E1 expression in the liver and gut leak during the night phase.

Signalling cognition: the gut microbiota and hypothalamic-pituitary-adrenal axis

Cognitive function in humans depends on the complex and interplay between multiple body systems, including the hypothalamic-pituitary-adrenal (HPA) axis. The gut microbiota, which vastly outnumbers human cells and has a genetic potential that exceeds that of the human genome, plays a crucial role in this interplay. The microbiota-gut-brain (MGB) axis is a bidirectional signalling pathway that operates through neural, endocrine, immune, and metabolic pathways. One of the major neuroendocrine systems responding to stress is the HPA axis which produces glucocorticoids such as cortisol in humans and corticosterone in rodents. Appropriate concentrations of cortisol are essential for normal neurodevelopment and function, as well as cognitive processes such as learning and memory, and studies have shown that microbes modulate the HPA axis throughout life. Stress can significantly impact the MGB axis via the HPA axis and other pathways. Animal research has advanced our understanding of these mechanisms and pathways, leading to a paradigm shift in conceptual thinking about the influence of the microbiota on human health and disease. Preclinical and human trials are currently underway to determine how these animal models translate to humans. In this review article, we summarize the current knowledge of the relationship between the gut microbiota, HPA axis, and cognition, and provide an overview of the main findings and conclusions in this broad field.

Potential role of gut microbiota in prostate cancer: immunity, metabolites, pathways of action?

The gut microbiota helps to reveal the relationship between diseases, but the role of gut microbiota in prostate cancer (PCa) is still unclear. Recent studies have found that the composition and abundance of specific gut microbiota are significantly different between PCa and non-PCa, and the gut microbiota may have common and unique characteristics between different diseases. Intestinal microorganisms are affected by various factors and interact with the host in a variety of ways. In the complex interaction model, the regulation of intestinal microbial metabolites and the host immune system is particularly important, and they play a key role in maintaining the ecological balance of intestinal microorganisms and metabolites. However, specific changes in the composition of intestinal microflora may promote intestinal mucosal immune imbalance, leading to the formation of tumors. Therefore, this review analyzes the immune regulation of intestinal flora and the production of metabolites, as well as their effects and mechanisms on tumors, and briefly summarizes that specific intestinal flora can play an indirect role in PCa through their metabolites, genes, immunity, and pharmacology, and directly participate in the occurrence, development, and treatment of tumors through bacterial and toxin translocation. We also discussed markers of high risk PCa for intestinal microbiota screening and the possibility of probiotic ingestion and fecal microbiota transplantation, in order to provide better treatment options for clinic patients. Finally, after summarizing a number of studies, we found that changes in immunity, metabolites.

Innate Immune System in the Pathogenesis of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a prevalent condition characterized by lipid accumulation in hepatocytes with low alcohol consumption. The development of sterile inflammation, which occurs in response to a range of cellular stressors or injuries, has been identified as a major contributor to the pathogenesis of NAFLD. Recent studies of the pathogenesis of NAFLD reported the newly developed roles of damage-associated molecular patterns (DAMPs). These molecules activate pattern recognition receptors (PRRs), which are placed in the infiltrated neutrophils, dendritic cells, monocytes, or Kupffer cells. DAMPs cause the activation of PRRs, which triggers a number of immunological responses, including the generation of cytokines that promote inflammation and the localization of immune cells to the site of the damage. This review provides a comprehensive overview of the impact of DAMPs and PRRs on the development of NAFLD.

Food, gut barrier dysfunction, and related diseases: A new target for future individualized disease prevention and management

Dysfunction of gut barrier is known as "leaky gut" or increased intestinal permeability. Numerous recent scientific evidences showed the association between gut dysfunction and multiple gastrointestinal tract (GI) and non-GI diseases. Research also demonstrated that food plays a crucial role to cause or remedy gut dysfunction related to diseases. We reviewed recent articles from electronic databases, mainly PubMed. The data were based on animal models, cell models, and human research in vivo and in vitro models. In this comprehensive review, our aim focused on the relationship between dietary factors, intestinal permeability dysfunction, and related diseases. This review synthesizes currently available literature and is discussed in three parts: (a) the mechanism of gut barrier and function, (b) food and dietary supplements that may promote gut health, and food or medication that may alter gut function, and (c) a table that organizes the synthesized information by general mechanisms for diseases related to leaky gut/intestinal permeability and associated dietary influences. With future research, dietary intervention could be a new target for individualized disease prevention and management.

Bacillus coagulans T4 and Lactobacillus paracasei TD3 Ameliorate Skeletal Muscle Oxidative Stress and Inflammation in High-Fat Diet-Fed C57BL/6J Mice

Background

This study aims to investigate the effects of Bacillus coagulans T4 and Lactobacillus paracasei TD3 probiotics on skeletal muscle inflammation and oxidative stress in C57BL/6J mice fed a high-fat diet (HFD).

Methods

Probiotics B. coagulans T4, and L. paracasei TD3 were administered to male C57BL/6J mice fed with HFD. The gene expression of macrophage infiltration markers, inflammatory cytokines, and oxidative stress indicators in the muscle tissue was investigated.

Results

Treatment with B. coagulans T4 and L. paracasei TD3 reduced macrophage infiltration, accompanied by a decrease in the expression of monocyte chemoattractant protein-1 (MCP-1) and an increase in the expression of interleukin (IL)-10. On the other hand, L. paracasei TD3 decreased malondialdehyde (MDA) while B. coagulans T4 decreased carbonyl and increased catalase activity.

Conclusions

Treatment with probiotics B. coagulans T4 and L. paracasei TD3 partially ameliorated obesity-induced skeletal muscle inflammation in HFD-fed mice.

Mucosal and hormonal adaptations after Roux-en-Y gastric bypass

The aim of this study was to perform a comprehensive literature review regarding the relevant hormonal and histologic changes observed after Roux-en-Y gastric bypass (RYGB). We aimed to describe the relevant hormonal (glucagon-like peptides 1 and 2 [GLP-1 and GLP-2], peptide YY [PYY], oxyntomodulin [OXM], bile acids [BA], cholecystokinin [CCK], ghrelin, glucagon, gastric inhibitory polypeptide [GIP], and amylin) profiles, as well as the histologic (mucosal cellular) adaptations happening after patients undergo RYGB. Our review compiles the current evidence and furthers the understanding of the rationale behind the food intake regulatory adaptations occurring after RYGB surgery. We identify gaps in the literature where the potential for future investigations and therapeutics may lie. We performed a comprehensive database search without language restrictions looking for RYGB bariatric surgery outcomes in patients with pre- and postoperative blood work hormonal profiling and/or gut mucosal biopsies. We gathered the relevant study results and describe them in this review. Where human findings were lacking, we included animal model studies. The amalgamation of physiologic, metabolic, and cellular adaptations following RYGB is yet to be fully characterized. This constitutes a fundamental aspiration for enhancing and individualizing obesity therapy.

ALDH2 deficiency increases susceptibility to binge alcohol-induced gut leakiness, endotoxemia, and acute liver injury in mice through the gut-liver axis

Mitochondrial aldehyde dehydrogenase 2 (ALDH2) is the major enzyme responsible for metabolizing toxic acetaldehyde to acetate and acts as a protective or defensive protein against various disease states associated with alcohol use disorder (AUD), including alcohol-related liver disease (ARLD). We hypothesized that Aldh2-knockout (KO) mice are more susceptible to binge alcohol-mediated liver injury than wild-type (WT) mice through increased oxidative stress, gut leakiness and endotoxemia. Therefore, this study aimed to investigate the protective role of ALDH2 in binge alcohol-induced gut permeability, endotoxemia, and acute inflammatory liver injury by exposing Aldh2-KO or WT mice to a single oral dose of binge alcohol 3.5, 4.0, or 5.0 g/kg. Our findings showed for the first time that ALDH2 deficiency in Aldh2-KO mice increases their sensitivity to binge alcohol-induced oxidative and nitrative stress, enterocyte apoptosis, and nitration of gut tight junction (TJ) and adherent junction (AJ) proteins, leading to their degradation. These resulted in gut leakiness and endotoxemia in Aldh2-KO mice after exposure to a single dose of ethanol even at 3.5 g/kg, while no changes were observed in the corresponding WT mice. The elevated serum endotoxin (lipopolysaccharide, LPS) and bacterial translocation contributed to systemic inflammation, hepatocyte apoptosis, and subsequently acute liver injury through the gut-liver axis. Treatment with Daidzin, an ALDH2 inhibitor, exacerbated ethanol-induced cell permeability and reduced TJ/AJ proteins in T84 human colon cells. These changes were reversed by Alda-1, an ALDH2 activator. Furthermore, CRISPR/Cas9-mediated knockout of ALDH2 in T84 cells increased alcohol-mediated cell damage and paracellular permeability. All these findings demonstrate the critical role of ALDH2 in alcohol-induced epithelial barrier dysfunction and suggest that ALDH2 deficiency or gene mutation in humans is a risk factor for alcohol-mediated gut and liver injury, and that ALDH2 could be an important therapeutic target against alcohol-associated tissue or organ damage.

Understanding the role of smoking and chronic excess alcohol consumption on reduced caloric intake and the development of sarcopenia

This narrative review provides mechanistic insight into the biological link between smoking and/or chronic excess alcohol consumption, and increased risk of developing sarcopenia. Although the combination of excessive alcohol consumption and smoking is often associated with ectopic adipose deposition, this review is focused on the context of a reduced caloric intake (leading to energy deficit) that also may ensue due to either lifestyle habit. Smoking is a primary cause of periodontitis and chronic obstructive pulmonary disease that both induce swallowing difficulties, inhibit taste and mastication, and are associated with increased risk of muscle atrophy and mitochondrial dysfunction. Smoking may contribute to physical inactivity, energy deficit via reduced caloric intake, and increased systemic inflammation, all of which are factors known to suppress muscle protein synthesis rates. Moreover, chronic excess alcohol consumption may result in gut microbiota dysbiosis and autophagy-induced hyperammonemia, initiating the up-regulation of muscle protein breakdown and down-regulation of muscle protein synthesis via activation of myostatin, AMPK and REDD1, and deactivation of IGF-1. Future research is warranted to explore the link between oral healthcare management and personalised nutrition counselling in light of potential detrimental consequences of chronic smoking on musculoskeletal health outcomes in older adults. Experimental studies should investigate the impact of smoking and chronic excess alcohol consumption on the gut-brain axis, and explore biomarkers of smoking-induced oral disease progression. The implementation of behavioural change interventions and health policies regarding smoking and alcohol intake habits may mitigate the clinical and financial burden of sarcopenia on the healthcare system.

Pesticide thiram exposure alters the gut microbial diversity of chickens

Thiram is a major dithiocarbamate pesticide commonly found in polluted field crops, feed, and rivers. Environmental thiram exposure has been demonstrated to cause angiogenesis and osteogenesis disorders in chickens, but information regarding thiram influences on gut microbiota, apoptosis, and autophagy in chickens has been insufficient. Here, we explored the effect of thiram exposure on gut microbiota, apoptosis, and autophagy of chickens. Results demonstrated that thiram exposure impaired the morphology and structure of intestinal and liver tissues. Moreover, thiram exposure also triggered liver apoptosis and autophagy. The gut microbiota in chickens exposed to thiram exhibited a significant decline in alpha diversity, accompanied by significant shifts in taxonomic compositions. Bacterial taxonomic analysis indicated that thiram exposure causes a significant reduction in the levels of eight genera, as well as a significant increase in the levels of two phyla and 10 genera. Among decreased bacterial genera, seven genera even cannot be observed in the thiram-induced chickens. In summary, this study demonstrated that thiram exposure not only dramatically altered the gut microbial diversity and composition but also induced liver apoptosis and autophagy in chickens. Importantly, this study also conveyed a key message that the dysbiosis of gut microbiota may be one of the major pathways for thiram to exert its toxic effects.

Role of CB1 receptors in the acute regulation of small intestinal permeability: effects of high-fat diet

The endocannabinoid system of the gastrointestinal tract is involved in the control of intestinal barrier function. Whether the cannabinoid 1 (CB1) receptor is expressed on the intestinal epithelium and acutely regulates barrier function has not been determined. Here, we tested the hypothesis that ligands of the CB1 receptor acutely modulate small intestinal permeability and that this is associated with altered distribution of tight junction proteins. We examined the acute effects of CB1 receptor ligands on small intestinal permeability both in chow-fed and 2-wk high-fat diet (HFD)-fed mice using Ussing chambers. We assessed the distribution of CB1 receptor and tight junction proteins using immunofluorescence and the expression of CB1 receptor using PCR. A low level of CB1 expression was found on the intestinal epithelium. CB1 receptor was highly expressed on enteric nerves in the lamina propria. Neither the CB1/CB2 agonist CP55,940 nor the CB1 neutral antagonist AM6545 altered the flux of 4kDa FITC dextran (FD4) across the jejunum or ileum of chow-fed mice. Remarkably, both CP55,940 and AM6545 reduced FD4 flux across the jejunum and ileum in HFD-fed mice that have elevated baseline intestinal permeability. These effects were absent in CB1 knockout mice. CP55,940 reduced the expression of claudin-2, whereas AM6545 had little effect on claudin-2 expression. Neither ligand altered the expression of ZO-1. Our data suggest that CB1 receptor on the intestinal epithelium regulates tight junction protein expression and restores barrier function when it is increased following exposure to a HFD for 2 wk.NEW & NOTEWORTHY The endocannabinoid system of the gastrointestinal tract regulates homeostasis by acting as brake on motility and secretion. Here we show that when exposed to a high fat diet, intestinal permeability is increased and activation of the CB1 receptor on the intestinal epithelium restores barrier function. This work further highlights the role of the endocannabinoid system in regulating intestinal homeostasis when it is perturbed.

The Related Metabolic Diseases and Treatments of Obesity

Obesity is a chronic disease characterized by the abnormal or excessive accumulation of body fat, affecting more than 1 billion people worldwide. Obesity is commonly associated with other metabolic disorders, such as type 2 diabetes, non-alcoholic fatty liver disease, cardiovascular diseases, chronic kidney disease, and cancers. Factors such as a sedentary lifestyle, overnutrition, socioeconomic status, and other environmental and genetic conditions can cause obesity. Many molecules and signaling pathways are involved in the pathogenesis of obesity, such as nuclear factor (NF)-κB, Toll-like receptors (TLRs), adhesion molecules, G protein-coupled receptors (GPCRs), programmed cell death 1 (PD-1)/programmed death-ligand 1 (PD-L1), and sirtuin 1 (SIRT1). Commonly used strategies of obesity management and treatment include exercise and dietary change or restriction for the early stage of obesity, bariatric surgery for server obesity, and Food and Drug Administration (FDA)-approved medicines such as semaglutide and liraglutide that can be used as monotherapy or as a synergistic treatment. In addition, psychological management, especially for patients with obesity and distress, is a good option. Gut microbiota plays an important role in obesity and its comorbidities, and gut microbial reprogramming by fecal microbiota transplantation (FMT), probiotics, prebiotics, or synbiotics shows promising potential in obesity and metabolic syndrome. Many clinical trials are ongoing to evaluate the therapeutic effects of different treatments. Currently, prevention and early treatment of obesity are the best options to prevent its progression to many comorbidities.

Nanoencapsulation of Bimi® extracts increases its bioaccessibility after in vitro digestion and evaluation of its activity in hepatocyte metabolism

Isothiocyanates (ITCs) have low stability in aqueous conditions, reducing their bioavailability when used as food ingredients. Therefore, the aim of this work was to increase the stability of the ITCs present in extracts of Bimi® edible parts by nanoencapsulation using cauliflower-derived plasma membrane vesicles. The bioactivity of these nanoencapsulates was evaluated in a HepG2 hepatocyte cell line in a model for low-grade chronic inflammation. The vesicles showed a higher capacity of retention in the in vitro gastrointestinal digestion for 3,3-diindolylmethane (DIM), indole-3-carbinol (I3C) and sulforaphane (SFN). Furthermore, Transmission Electron Microscopy (TEM) analysis of the vesicles revealed a decreased size under acidic pH and a release of their cargo after the intestinal digestion. The HepG2 experiments revealed differences in metabolism under the condition of chronic inflammation. The cauliflower-derived plasma membrane vesicles are able to enhance the stability of ITCs through the in vitro gastrointestinal digestion, improving their bioaccesibility and potential bioavailability.

Discrepancies among healthy, subclinical mastitic, and clinical mastitic cows in fecal microbiome and metabolome and serum metabolome

Mastitis is generally considered a local inflammatory disease caused by the invasion of exogenous pathogens and resulting in the dysbiosis of microbiota and metabolites in milk. However, the entero-mammary pathway theory may establish a possible link between some endogenous gut bacteria and the occurrence and development of mastitis. In the current study, we attempted to investigate differences in the gut microbiota profile and metabolite composition in gut and serum from healthy cows and those with subclinical mastitis and clinical mastitis. Compared with those of healthy cows, the microbial community diversities in the feces of cows with subclinical mastitis (SM) and clinical mastitis (CM) were lower. Lower abundance of Bifidobacterium, Romboutsia, Lachnospiraceae_NK3A20_group, Coprococcus, Prevotellaceae_UCG-003, Ruminococcus, and Alistipes, and higher abundance of the phylum Proteobacteria and the genera Escherichia-Shigella and Streptococcus were observed in CM cows. Klebsiella and Paeniclostridium were significantly enriched in the feces of SM cows. Several similarities were observed in feces and serum metabolites in mastitic cows. Higher levels of proinflammatory lipid products (20-trihydroxy-leukotriene-B4, 13,14-dihydro-15-keto-PGE₂, and 9,10-dihydroxylinoleic acids) and lower levels of metabolites involved in secondary bile acids (deoxycholic acid, 12-ketolithocholic acid), energy (citric acid and 3-hydroxyisovalerylcarnitine), and purine metabolism (uric acid and inosine) were identified in both SM and CM cows. In addition, elevated concentrations of IL-1β, IL-6, tumor necrosis factor-α and decreased concentrations of glutathione peroxidase and superoxide dismutase were detected in the serum of SM and CM cows. Higher serum concentrations of triglyceride and total cholesterol and lower concentrations of high-density lipoproteins in mastitic cows might be related to changes in the gut microbiota and metabolites. These findings suggested a significant difference in the profile of feces microbiota and metabolites in cows with different udder health status, which might increase our understanding of bovine mastitis.

Chemical Compounds of Berry-Derived Polyphenols and Their Effects on Gut Microbiota, Inflammation, and Cancer

Berry-derived polyphenols are bioactive compounds synthesized and secreted by several berry fruits. These polyphenols feature a diversity of chemical compounds, including phenolic acids and flavonoids. Here, we report the beneficial health effects of berry-derived polyphenols and their therapeutical application on gut-microbiota-related diseases, including inflammation and cancer. Pharmacokinetic investigations have confirmed the absorption, availability, and metabolism of berry-derived polyphenols. In vitro and in vivo tests, as well as clinical trials, showed that berry-derived polyphenols can positively modulate the gut microbiota, inhibiting inflammation and cancer development. Indeed, these compounds inhibit the growth of pathogenic bacteria and also promote beneficial bacteria. Moreover, berry-derived polyphenols exhibit therapeutic effects against different gut-microbiota-related disorders such as inflammation, cancer, and metabolic disorders. Moreover, these polyphenols can manage the inflammation via various mechanisms, in particular the inhibition of the transcriptional factor Nf-κB. Berry-derived polyphenols have also shown remarkable effects on different types of cancer, including colorectal, breast, esophageal, and prostate cancer. Moreover, certain metabolic disorders such as diabetes and atherosclerosis were also managed by berry-derived polyphenols through different mechanisms. These data showed that polyphenols from berries are a promising source of bioactive compounds capable of modulating the intestinal microbiota, and therefore managing cancer and associated metabolic diseases. However, further investigations should be carried out to determine the mechanisms of action of berry-derived polyphenol bioactive compounds to validate their safety and examinate their clinical uses.

Association of antibiotic-consumption patterns with the prevalence of hematological malignancies in European countries

Hematological malignancies are considered the fifth most common cancer in the world. Several risk factors and probable etiological agents have been suspected in the pathomechanism of those malignancies as infections, chemicals, irradiation, etc., and recently, the contribution of the altered gut flora, dysbiosis, was identified also as a possible additional factor to the existing ones. Host, and external factors, like antibiotics, which were identified as a major disruptor of the "normal" gut flora, influence the composition of the microbiome. Considering the several-fold differences in antibiotic consumption patterns and the incidence of hematological malignancies in European countries, the hypothesis was raised that the dominant consumption of certain antibiotic classes might influence the incidence of different hematological malignancies through the modification of gut flora. Comparisons were performed between the average antibiotic consumption databases reported yearly by ECDC (2009–2019) and the incidence rate of Hodgkin lymphoma (HL), non-Hodgkin lymphoma (NHL), multiple myeloma (MM), and leukemia (LEU) estimated for 2020 in 30 European countries. Applying Spearman calculations, significant positive correlation has been found between the incidence of HL and tetracycline (J01A) consumption (r = 0.399, p = 0.029), NHL and narrow spectrum, beta-lactamase resistant penicillin (J01CF) (r = 0.580, p = 0.001), MM and tetracycline (r = 0.492, p = 0.006), penicillin (J01C) (r = 0.366, p = 0.047), narrow spectrum, beta-lactamase resistant penicillin (J01CF) (r = 0.574, p = 0.001), while strong, significant negative correlation has been recorded between NHL and cephalosporin (r = − 0.460, p = 0.011), and quinolone (r = − 0.380, p = 0.038). The incidence of LEU did not show any positive or negative association with any antibiotic classes using Spearman calculation. Multivariate ordinal logistic regression (OR) indicated increased risk between HL and the total consumption of systemic antibiotics (J01 p: 0.038), and tetracyclin (J01A p: 0.002). Similarly, increased risk has been detected between the MM and tetracyclin (J01A p: 0.02), and narrow spectrum, beta-lactamase resistant penicillin (J01CF p: 0.042) and decreased risk between cephalosporin and MM (J01D p:0.022). LEU showed increased risk with the consumption of macrolides (p: 0.047).

Individuals with Metabolic Syndrome Show Altered Fecal Lipidomic Profiles with No Signs of Intestinal Inflammation or Increased Intestinal Permeability

BACKGROUND

Metabolic Syndrome (MetS) is a clinical diagnosis where patients exhibit three out of the five risk factors: hypertriglyceridemia, low high-density lipoprotein (HDL) cholesterol, hyperglycemia, elevated blood pressure, or increased abdominal obesity. MetS arises due to dysregulated metabolic pathways that culminate with insulin resistance and put individuals at risk to develop various comorbidities with far-reaching medical consequences such as non-alcoholic fatty liver disease (NAFLD) and cardiovascular disease. As it stands, the exact pathogenesis of MetS as well as the involvement of the gastrointestinal tract in MetS is not fully understood. Our study aimed to evaluate intestinal health in human subjects with MetS.

METHODS

We examined MetS risk factors in individuals through body measurements and clinical and biochemical blood analysis. To evaluate intestinal health, gut inflammation was measured by fecal calprotectin, intestinal permeability through the lactulose-mannitol test, and utilized fecal metabolomics to examine alterations in the host-microbiota gut metabolism.

RESULTS

No signs of intestinal inflammation or increased intestinal permeability were observed in the MetS group compared to our control group. However, we found a significant increase in 417 lipid features of the gut lipidome in our MetS cohort. An identified fecal lipid, diacyl-glycerophosphocholine, showed a strong correlation with several MetS risk factors. Although our MetS cohort showed no signs of intestinal inflammation, they presented with increased levels of serum TNFα that also correlated with increasing triglyceride and fecal diacyl-glycerophosphocholine levels and decreasing HDL cholesterol levels.

CONCLUSION

Taken together, our main results show that MetS subjects showed major alterations in fecal lipid profiles suggesting alterations in the intestinal host-microbiota metabolism that may arise before concrete signs of gut inflammation or intestinal permeability become apparent. Lastly, we posit that fecal metabolomics could serve as a non-invasive, accurate screening method for both MetS and NAFLD.

The role of bacterial translocation in sepsis: a new target for therapy

Sepsis is a leading cause of death in critically ill patients, primarily due to multiple organ failures. It is associated with a systemic inflammatory response that plays a role in the pathogenesis of the disease. Intestinal barrier dysfunction and bacterial translocation (BT) play pivotal roles in the pathogenesis of sepsis and associated organ failure. In this review, we describe recent advances in understanding the mechanisms by which the gut microbiome and BT contribute to the pathogenesis of sepsis. We also discuss several potential treatment modalities that target the microbiome as therapeutic tools for patients with sepsis.

Supplementation with sodium butyrate protects against antibiotic-induced increases in ethanol consumption behavior in mice

BACKGROUND

We have recently reported that oral treatment of adult male C57BL/6J mice with a non-absorbable antibiotic cocktail resulted in an increase in ethanol intake and in significant reductions in butyrate-producing gut microbiota populations. This work led us to hypothesize that reduction in butyrate levels within the gut is linked to antibiotic-induced increases in voluntary ethanol consumption.

OBJECTIVE

This study tested whether ad libitum sodium butyrate supplementation can prevent antibiotic-induced ethanol consumption in mice.

METHODS

Sodium butyrate was provided to adult male C57BL/6J mice in drinking water alone or in combination with antibiotic cocktail. Effects on ethanol (20%) intake were measured using drinking in the dark and modified 2-bottle choice paradigms. Body parameters, food and liquid intake, cecum, and adipose tissues were measured during and/or at the conclusion of the drinking in the dark study. Cecal 16s rRNA was analyzed for microbiota diversity and changes in specific bacterial phyla/species.

RESULTS

In drinking in the dark, sodium butyrate supplementation prevented antibiotic-induced increases in ethanol intake without altering basal ethanol consumption. Furthermore, sodium butyrate supplementation lowered ethanol preference in the 2-bottle choice study. Ethanol intake was correlated to specific bacterial phyla/species. Sodium butyrate did not affect the changes in microbiota diversity and composition induced by antibiotic cocktail.

CONCLUSIONS

The findings support a role of gut microbiota-derived butyrate in regulating alcohol-induced behaviors. Additionally, the work contributes to efforts in development of novel microbiome-based strategies as novel preventative and intervention-based therapeutics to address alcohol use disorder.

Lactobacillus plantarum strains attenuated DSS-induced colitis in mice by modulating the gut microbiota and immune response

Gut microbiota has become a new therapeutic target in the treatment of inflammatory Bowel Disease (IBD). Probiotics are known for their beneficial effects and have shown good efficacy in the clinical treatment of IBD and animal models of colitis. However, how these probiotics contribute to the amelioration of IBD is largely unknown. In the current study, the DSS-induced mouse colitis model was treated with oral administration of Lactobacillus plantarum strains to investigate their effects on colitis. The results indicated that the L. plantarum strains improved dysbiosis and enhanced the abundance of beneficial bacteria related to short-chain fatty acids (SCFAs) production. Moreover, L. plantarum strains decreased the level of pro-inflammatory cytokines, i.e., IL-17A, IL-17F, IL-6, IL-22, and TNF-α and increased the level of anti-inflammatory cytokines, i.e., TGF-β, IL-10. Our result suggests that L. plantarum strains possess probiotic effects and can ameliorate DSS colitis in mice by modulating the resident gut microbiota and immune response.

Exposed to Sulfamethoxazole induced hepatic lipid metabolism disorder and intestinal microbiota changes on zebrafish (Danio rerio)

Antibiotics are widely used around the world. Pollution of Sulfamethoxazole (SMX) in water poses a great threat to aquatic life. In this study, the toxic effects of SMX on the liver were assessed through RNA sequencing analysis and 16S rRNA sequencing analysis was conducted to determine the influence of SMX on gut microbiota of zebrafish (Danio rerio). Adult male zebrafish were exposed to 0, 5, 90 and 450 μg/L of environmentally relevant concentrations of SMX for 21 days respectively. The results showed that the liver had severe histopathological damages including pyknotic nuclei, cytoplasmic hyalinization and vacuolization and deformed hepatocytes with loose cell-to-cell contact. Transcriptomic analysis revealed that liver function was seriously affected by SMX exposure. Meanwhile, SMX exposure significantly inhibited the expression of genes associated with fatty acid synthesis, oxidation and transport. Besides, exfoliated and dissolved epithelial cells were observed in the gut after SMX treatment. Although there was no significant change on richness and species diversity of intestinal microbial community, the relative abundance of phylum and genus of SMX treatments were significantly different from that of control group. The present study implied that SMX may cause potential health risks to fish through inducing histopathological damages, genetic expression alterations, disorder of fatty acid metabolism and intestinal microbiota dysbiosis.

Gut Microbiota Dysbiosis Strengthens Kupffer Cell-mediated Hepatitis B Virus Persistence through Inducing Endotoxemia in Mice

BACKGROUND AND AIMS

Change of gut microbiota composition is associated with the outcome of hepatitis B virus (HBV) infection, yet the related mechanisms are not fully characterized. The objective of this study was to investigate the immune mechanism associated with HBV persistence induced by gut microbiota dysbiosis.

METHODS

C57BL/6 mice were sterilized for gut-microbiota by using an antibiotic (ABX) mixture protocol, and were monitored for their serum endotoxin (lipopolysaccharide [LPS]) levels. An HBV-replicating mouse model was established by performing HBV-expressing plasmid pAAV/HBV1.2 hydrodynamic injection (HDI) with or without LPS, and was monitored for serum hepatitis B surface antigen, hepatitis B e antigen, HBV DNA, and cytokine levels. Kupffer cells (KCs) were purified from antibiotic-treated mice and HBV-replicating mice and analyzed for IL-10 production and T cell suppression ability.

RESULTS

ABX treatment resulted in increased serum LPS levels in mice. The KCs separated from both ABX-treated and LPS-treated HBV-replicating mice showed significantly increased IL-10 production and enhanced ability to suppress IFN-γ production of TCR-activated T cells than the KCs separated from their counterpart controls. HDI of pAAV/HBV1.2 in combination with LPS in mice led to a delayed HBV clearance and early elevation of serum IL-10 levels compared to pAAV/HBV1.2 HDI alone. Moreover, IL-10 function blockade or KC depletion led to accelerated HBV clearance in LPS-treated HBV-replicating mice.

CONCLUSIONS

Our results suggest that dysbiosis of the gut microbiota in mice leads to endotoxemia, which induces KC IL-10 production and strengthens KC-mediated T cell suppression, and thus facilitates HBV persistence.

The role of lipopolysaccharides in diabetic retinopathy

Diabetes mellitus (DM) is a complex metabolic syndrome characterized by hyperglycemia. Diabetic retinopathy (DR) is the most common complication of DM and the leading cause of blindness in the working-age population of the Western world. Lipopolysaccharides (LPS) is an essential ingredient of the outer membrane of gram-negative bacteria, which induces systemic inflammatory responses and cellular apoptotic changes in the host. High-level serum LPS has been found in diabetic patients at the advanced stages, which is mainly due to gut leakage and dysbiosis. In this light, increasing evidence points to a strong correlation between systemic LPS challenge and the progression of DR. Although the underlying molecular mechanisms have not been fully elucidated yet, LPS-related pathobiological events in the retina may contribute to the exacerbation of vasculopathy and neurodegeneration in DR. In this review, we focus on the involvement of LPS in the progression of DR, with emphasis on the blood-retina barrier dysfunction and dysregulated glial activation. Eventually, we summarize the recent advances in the therapeutic strategies for antagonising LPS activity, which may be introduced to DR treatment with promising clinical value.

Akkermansia muciniphila: is it the Holy Grail for ameliorating metabolic diseases?

The increasing prevalence of metabolic diseases has become a severe public health problem. Gut microbiota play important roles in maintaining human health by modulating the host's metabolism. Recent evidences demonstrate that Akkermansia muciniphila is effective in improving metabolic disorders and is thus considered as a promising "next-generation beneficial microbe". In addition to the live A. muciniphila, similar or even stronger beneficial effects have been observed in pasteurized A. muciniphila and its components, including the outer membrane protein Amuc_1100, A. muciniphila-derived extracellular vesicles (AmEVs), and secreted protein P9. Hence, this paper presents a systemic review of recent progress in the effects and mechanisms of A. muciniphila and its components in the treatment of metabolic diseases, including obesity, type 2 diabetes mellitus, cardiovascular disease, and nonalcoholic fatty liver disease, as well as perspectives on its future study.

A high-fat High-fructose Diet Dysregulates the Homeostatic Crosstalk Between Gut Microbiome, Metabolome and Immunity in an Experimental Model of Obesity

SCOPE

Ample evidence supports the prominent role of gut-liver axis in perpetuating pathological networks of high-fat high-fructose (HFF) diet induced metabolic disorders, however, the molecular mechanisms are still not fully understood. Herein, we aim to present a holistic delineation and scientific explanation for the crosstalk between the gut and liver, including the potential mediators involved in orchestrating the metabolic and immune systems.

METHODS

An experimental obesity associated metaflammation rat model was induced with a HFF diet. An integrative multi-omics analysis was then performed. Following the clues illustrated by the multi-omics discoveries, putative pathways were subsequently validated by RT-qPCR and Western blotting.

RESULTS

HFF diet led to obese phenotypes in rats, as well as histopathological changes. Integrated omics analysis showed there existed a strong interdependence among gut microbiota composition, intestinal metabolites and innate immunity regulation in the liver. Some carboxylic acids might contribute to gut-liver communication. Moreover, activation of the hepatic LPS-TLR4 pathway in obesity was confirmed.

CONCLUSIONS

HFF-intake disturbs gut flora homeostasis. Crosstalk between gut microbiota and innate immune system mediated hepatic metaflammation in obese rats, associated with LPS-TLR4 signaling pathway activation. Moreover, α-hydroxyisobutyric acid and some other organic acids may play a role as messengers in the liver-gut axis. High-fat high-fructose diet (HFF) induces obesity associated chronic inflammation; HFF dysregulates the rat intestinal metabolome and gut microbiota composition; HFF impacts hepatic expression of genes involved in innate immunity; Modulation of gut microbiota composition and innate immunity are connected partly via TLR4 signalling; Small molecular carboxylic acids are potential mediators of gut-liver axis communication in chronic obesity. This article is protected by copyright. All rights reserved.

Signal-Strength and History-Dependent Innate Immune Memory Dynamics in Health and Disease

Innate immunity exhibits memory characteristics, reflected not only in selective recognition of external microbial or internal damage signals, but more importantly in history and signal-strength dependent reprogramming of innate leukocytes characterized by priming, tolerance, and exhaustion. Key innate immune cells such as monocytes and neutrophils can finely discern and attune to the duration and intensity of external signals through rewiring of internal signaling circuitries, giving rise to a vast array of discreet memory phenotypes critically relevant to managing tissue homeostasis as well as diverse repertoires of inflammatory conditions. This review will highlight recent advances in this rapidly expanding field of innate immune programming and memory, as well as its translational implication in the pathophysiology of selected inflammatory diseases.

Alcohol consumption and MRI markers of brain structure and function: Cohort study of 25,378 UK Biobank participants

Moderate alcohol consumption is widespread but its impact on brain structure and function is contentious. The relationship between alcohol intake and structural and functional neuroimaging indices, the threshold intake for associations, and whether population subgroups are at higher risk of alcohol-related brain harm remain unclear. 25,378 UK Biobank participants (mean age 54.9 ± 7.4 years, 12,254 female) underwent multi-modal MRI 9.6 ± 1.1 years after study baseline. Alcohol use was self-reported at baseline (2006-10). T1-weighted, diffusion weighted and resting state images were examined. Lower total grey matter volumes were observed in those drinking as little as 7-14 units (56-112 g) weekly. Higher alcohol consumption was associated with multiple markers of white matter microstructure, including lower fractional anisotropy, higher mean and radial diffusivity in a spatially distributed pattern across the brain. Associations between functional connectivity and alcohol intake were observed in the default mode, central executive, attention, salience and visual resting state networks. Relationships between total grey matter and alcohol were stronger than other modifiable factors, including blood pressure and smoking, and robust to unobserved confounding. Frequent binging, higher blood pressure and BMI steepened the negative association between alcohol and total grey matter volume. In this large observational cohort study, alcohol consumption was associated with multiple structural and functional MRI markers in mid- to late-life.

Type 3 resistant starch from Canna edulis modulates obesity and obesity-related low-grade systemic inflammation in mice by regulating gut microbiota composition and metabolism

Obesity is a most prevalent human health problem. Several studies showed that appropriate modulation of gut microbiota could help reshape the metabolic profile of obese individuals, thereby altering the development of obesity. A nutritional strategy for treating obesity includes prebiotics. Type 3 Resistant Starch from Canna edulis (Ce-RS3) is a dietary fiber that exerts potential effects on the intestinal microbial community; however, the metabolic landscape and anti-obesity mechanism remain unclear. In the present study, obese mice were treated with Ce-RS3, and 16S rRNA gene sequencing and metabolomics were used to measure changes in gut microbiota and fecal metabolic profiles, respectively. At the end of the treatment (13 weeks), we observed slow weight gain in the mice, and pathological damage and inflammation were substantially reduced. Ce-RS3 constructs a healthy gut microbiota structure and can enhance intestinal immunity and reduce metabolic inflammation. Ce-RS3 increased the diversity of gut microbiota with enrichment of Bifidobacterium and Roseburia. Ce-RS3 regulated the systemic metabolic dysbiosis in obese mice and adjusted 26 abnormal metabolites in amino acids and lipids metabolism, many of which are related to the microbiome. More importantly, we found that the anti-obesity effect of Ce-RS3 can be transferred by fecal transplantation. The beneficial effects of Ce-RS3 might derive from gut microbiota changes, which might improve obesity and metabolic inflammation by altering host-microbiota interactions with impacts on the metabolome. In conclusion, Ce-RS3 can be used as a prebiotic with potential value for the treatment of obesity.

Stabilin receptors clear LPS and control systemic inflammation

Lipopolysaccharides (LPSs) cause lethal endotoxemia if not rapidly cleared from blood circulation. Liver sinusoidal endothelial cells (LSEC) systemically clear LPS by unknown mechanisms. We discovered that LPS clearance through LSEC involves endocytosis and lysosomal inactivation via Stabilin-1 and 2 (Stab1 and Stab2) but does not involve TLR4. Cytokine production was inversely related to clearance/endocytosis of LPS by LSEC. When exposed to LPS, Stabilin double knockout mice (Stab DK) and Stab1 KO, but not Stab2 KO, showed significantly enhanced systemic inflammatory cytokine production and early death compared with WT mice. Stab1 KO is not significantly different from Stab DK in circulatory LPS clearance, LPS uptake and endocytosis by LSEC, and cytokine production. These data indicate that (1) Stab1 receptor primarily facilitates the proactive clearance of LPS and limits TLR4-mediated inflammation and (2) TLR4 and Stab1 are functionally opposing LPS receptors. These findings suggest that endotoxemia can be controlled by optimizing LPS clearance by Stab1.

Dysregulated Inflammation During Obesity: Driving Disease Severity in Influenza Virus and SARS-CoV-2 Infections

Acute inflammation is a critical host defense response during viral infection. When dysregulated, inflammation drives immunopathology and tissue damage. Excessive, damaging inflammation is a hallmark of both pandemic influenza A virus (IAV) infections and Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) infections. Chronic, low-grade inflammation is also a feature of obesity. In recent years, obesity has been recognized as a growing pandemic with significant mortality and associated costs. Obesity is also an independent risk factor for increased disease severity and death during both IAV and SARS-CoV-2 infection. This review focuses on the effect of obesity on the inflammatory response in the context of viral respiratory infections and how this leads to increased viral pathology. Here, we will review the fundamentals of inflammation, how it is initiated in IAV and SARS-CoV-2 infection and its link to disease severity. We will examine how obesity drives chronic inflammation and trained immunity and how these impact the immune response to IAV and SARS-CoV-2. Finally, we review both medical and non-medical interventions for obesity, how they impact on the inflammatory response and how they could be used to prevent disease severity in obese patients. As projections of global obesity numbers show no sign of slowing down, future pandemic preparedness will require us to consider the metabolic health of the population. Furthermore, if weight-loss alone is insufficient to reduce the risk of increased respiratory virus-related mortality, closer attention must be paid to a patient’s history of health, and new therapeutic options identified.

Supplementation with Lactiplantibacillus plantarum IMC 510 Modifies Microbiota Composition and Prevents Body Weight Gain Induced by Cafeteria Diet in Rats

Changes in functionality and composition of gut microbiota (GM) have been associated and may contribute to the development and maintenance of obesity and related diseases. The aim of our study was to investigate for the first time the impact of Lactiplantibacillus (L.) plantarum IMC 510 in a rat model of diet-induced obesity, specifically in the cafeteria (CAF) diet. This diet provides a strong motivation to voluntary overeat, due to the palatability and variety of selected energy-dense foods. The oral administration for 84 days of this probiotic strain, added to the CAF diet, decreased food intake and body weight gain. Accordingly, it ameliorated body mass index, liver and white adipose tissue weight, hepatic lipid accumulation, adipocyte size, serum parameters, including glycemia and low-density lipoprotein levels, in CAF fed rats, potentially through leptin control. In this scenario, L. plantarum IMC 510 showed also beneficial effects on GM, limiting the microbial imbalance established by long exposure to CAF diet and preserving the proportion of different bacterial taxa. Further research is necessary to better elucidate the relationship between GM and overweight and then the mechanism of action by which L. plantarum IMC 510 modifies weight. However, these promising results prompt a clear advantage of probiotic supplementation and identify a new potential probiotic as a novel and safe therapeutic approach in obesity prevention and management.

Effects of Acute Fructose Loading on Markers of Inflammation-A Pilot Study

Inflammation plays a role in development of diabetic complications. The postprandial state has been linked to chronic low grade inflammation. We therefore aimed to investigate the acute effects of fructose loading, with and without a pizza, on metabolic and inflammatory markers in patients with type 2 diabetes (T2D) (n = 7) and in healthy subjects (HS) (n = 6), age 47–76 years. Drinks consumed were blueberry drink (18 g fructose), Coca-Cola (17.5 g fructose), and fructose drink (35 g fructose). The levels of glucose, insulin, insulin-like growth factor binding protein-1 (IGFBP-1) and inflammatory markers: Interleukin-6 (IL-6), Monocyte chemoattractant protein-1 (MCP-1), Interleukin-18 (IL-18), Intercellular Adhesion Molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), and bacterial lipopolysaccharides (LPS) were analyzed in blood. The postprandial responses were assessed using Wilcoxon’s matched-pairs test, Friedman’s ANOVA and Mann–Whitney U test. There was no difference in baseline levels of inflammatory markers between the groups. In T2D, MCP-1 decreased following blueberry drink and Coca-Cola (p = 0.02), Coca-Cola + pizza and fructose + pizza (p = 0.03). In HS, IL-6 increased following blueberry + pizza and fructose + pizza (p = 0.03), there was a decrease in MCP-1 following blueberry drink and Coca-Cola (p = 0.03), and in ICAM-1 following blueberry + pizza (p = 0.03). These results may indicate a role for MCP-1 as a link between postprandial state and diabetes complications, however further mechanistic studies on larger population of patients with T2D are needed for confirmation of these results.

Gut microbiota as the critical correlation of polycystic ovary syndrome and type 2 diabetes mellitus

Gut microbiota forms a symbiotic relationship with the host and maintains the ecological balance of the internal and external environment of the human body. However, dysbiosis of the gut microbiota and immune deficiency, as well as environmental changes, can destroy the host-microbial balance, leading to the occurrence of a variety of diseases, such as polycystic ovary syndrome (PCOS), type 2 diabetes mellitus (T2DM), and obesity. Meanwhile, diseases can also affect gut microbiota, forming a vicious cycle. The role of the intestinal microbiota in different diseases have been proven by several studies; however, as a common target of PCOS and T2DM, there are few reports on the treatment of different diseases through the regulation of intestinal microbiota as the critical correlation. This review analyzed the common mechanisms of intestinal microbiota in PCOS and T2DM, including the dysbiosis of gut microbiota, endotoxemia, short-chain fatty acids, biotransformation of bile acids, and synthesis of amino acid in regulating insulin resistance, obesity, chronic inflammation, and mitochondrial dysfunction. The possible therapeutic effects of probiotics and/or prebiotics, fecal microbiota transplantation, bariatric surgery, dietary intervention, drug treatment, and other treatments targeted at regulating intestinal microbiota were also elucidated.

Postnatal inflammation in ApoE-/- mice is associated with immune training and atherosclerosis

BACKGROUND AND AIMS

Preterm birth is associated with increased risk of cardiovascular disease (CVD). This may reflect a legacy of inflammatory exposures such as chorioamnionitis which complicate pregnancies delivering preterm, or recurrent early-life infections, which are common in preterm infants. We previously reported that experimental chorioamnionitis followed by postnatal inflammation has additive and deleterious effects on atherosclerosis in ApoE-/- mice. Here, we aimed to investigate whether innate immune training is a contributory inflammatory mechanism in this murine model of atherosclerosis.

METHODS

Bone marrow-derived macrophages and peritoneal macrophages were isolated from 13-week-old ApoE-/- mice, previously exposed to prenatal intra-amniotic (experimental choriomanionitis) and/or repeated postnatal (peritoneal) lipopolysaccharide (LPS). Innate immune responses were assessed by cytokine responses following ex vivo stimulation with toll-like receptor (TLR) agonists (LPS, Pam3Cys) and RPMI for 24-h. Bone marrow progenitor populations were studied using flow cytometric analysis.

RESULTS

Following postnatal LPS exposure, bone marrow-derived macrophages and peritoneal macrophages produced more pro-inflammatory cytokines following TLR stimulation than those from saline-treated controls, characteristic of a trained phenotype. Cytokine production ex vivo correlated with atherosclerosis severity in vivo. Prenatal LPS did not affect cytokine production capacity. Combined prenatal and postnatal LPS exposure was associated with a reduction in populations of myeloid progenitor cells in the bone marrow.

CONCLUSIONS

Postnatal inflammation results in a trained phenotype in atherosclerosis-prone mice that is not enhanced by prenatal inflammation. If analogous mechanisms occur in humans, then there may be novel early life opportunities to reduce CVD risk in infants with early life infections.

Fiber in the ICU: Should it Be a Regular Part of Feeding?

PURPOSE OF REVIEW

To highlight the controversy of fiber use in the current critical care nutrition guidelines; review the effect of fiber on the gut microbiota in the critically ill; and examine the data on fiber and outcomes in the intensive care setting.

RECENT FINDINGS

Fiber is increasingly recognized as a necessary component of colonic health and nutrition support. In critical illness there is a shift toward gut dysbiosis and immune dysregulation. Through fermentation and the generation of short-chain fatty acids, fiber has a role in maintaining intestinal homeostasis, immune function, and supporting commensal bacteria. In contrast to fermentable fiber, recent animal models suggest that non-fermentable fiber can also favorably alter intestinal homeostasis in a mechanism distinct from short chain fatty acids. In the critically ill, RCTs and meta-analyses suggest that soluble and mixed fiber supplemented enteral nutrition can reduce diarrhea and is well tolerated. Based on limited data, there may be benefits in reducing length of hospital stay, certain infections, and glucose metabolism. Nonetheless, the role of fiber enriched nutrition in critically ill patients is controversial as evident in the conflicting guidelines. Despite shortcomings in the literature, soluble and mixed fiber supplemented enteral nutrition is safe and beneficial in most hemodynamically stable intensive care patients. More research is necessary to determine optimal fiber composition.

miR-133a-3p regulates the proliferation and apoptosis of intestinal epithelial cells by modulating the expression of TAGLN2

Sepsis is one of the most common diseases in patients in intensive care units. Intestinal barrier dysfunction serves a critical role in the pathogenesis and progression of sepsis. Therefore, preservation of the intestinal epithelial barrier function is an area of ongoing research in the treatment of sepsis. The present study investigated the effects of miR-133a-3p on the proliferation and apoptosis of intestinal epithelial cells and the possible mechanism underlying its actions. miR-133a-3p was used to upregulate the intestinal epithelial FHs 74 Int cell line and cell proliferation and apoptosis were investigated. A luciferase reporter assay was used to determine whether the 3'-UTR of TAGLN2 mRNA was a binding target of miR-133a-3p. FHs 74 Int cells were transfected with TAGLN2 shRNA and the effects of TAGLN2 on the proliferation and apoptosis of intestinal epithelial cells were investigated. It was found that miR-133a-3p inhibited the proliferation and promoted the apoptosis of intestinal epithelial cells. A luciferase reporter assay confirmed that miR-133a-3p targeted TAGLN2 directly. In addition, low expression of TAGLN2 inhibited the proliferation and promoted the apoptosis of intestinal epithelial cells. The results of the present study suggested that the miR-133a-3p inhibition of proliferation and promotion of apoptosis occurred via the inhibition of TAGLN2. These results suggested that miR-133a-3p may be a promising therapeutic target for the diagnosis and treatment of gut-origin sepsis.