A human-origin probiotic cocktail ameliorates aging-related leaky gut and inflammation via modulating the microbiota/taurine/tight junction axis

Calycosin regulates gut microbiota-bile acid-FXR axis to protect rats from cerebral ischemia-reperfusion injury

Recent reports have shown that metabolites derived from gut microbiota play a vital role in intestinal diseases, immune regulation, and neuroinflammation. Nowadays, calycosin has been revealed the protective mechanism from different perspectives on cerebral ischemia-reperfusion injury (CIRI), while the effect of gut microbiota-bile acid-farnesoid X receptor (FXR) axis on the inflammatory protection of CIRI has not been explored. To this end, we established a middle cerebral artery occlusion (MCAO) model firstly to assess the protection of calycosin in CIRI through neurological deficit scoring, TTC staining, and HE staining. Secondly, 16s RNA sequencing, ELISA, real-time qPCR, Western blot, and total bile acid (TBA) detection kit were utilized to detect the pharmacology of calycosin on MCAO rats. Our data indicated that calycosin could significantly improve nerve function scores, reduce cerebral infarction volume, lower serum levels of IL-10, IL-17 inflammatory factors, and TBA, increase mRNA and protein levels of ZO-1 and Occludin in brain, as well as FXR, ZO-1 and Occludin levels in colon. In summary, calycosin can exert a neuroinflammatory protective effect on CIRI in rats via regulating the gut microbiota to improve bile acid metabolism.

Lifelong partners: Gut microbiota-immune cell interactions from infancy to old age

Our immune system and gut microbiota are intricately coupled from birth, both going through maturation during early life and senescence during aging almost in a synchronized fashion. The symbiotic relationship between the human host and microbiota is critically dependent on a healthy immune system to keep our microbiota in check, while the microbiota provides essential functions to promote the development and fitness of our immune system. The partnership between our immune system and microbiota is particularly important during early life, when microbial ligands and metabolites shape the development of the immune cells and immune tolerance; during aging, having sufficient beneficial gut bacteria is critical for the maintenance of intact mucosal barriers, immune metabolic fitness, and strong immunity against pathogens. The immune system during childhood is programmed, with the support of the microbiota, to develop robust immune tolerance, and limit autoimmunity and metabolic dysregulation, which are prevalent during aging. This review comprehensively explores the mechanistic underpinnings of gut microbiota-immune cell interactions during infancy and old age, with the goal to gain a better understanding of potential strategies to leverage the gut microbiota to combat age-related immune decline.

Delayed Impact of Ionizing Radiation Depends on Sex: Integrative Metagenomics and Metabolomics Analysis of Rodent Colon Content

There is an escalating need to comprehend the long-term impacts of nuclear radiation exposure since the permeation of ionizing radiation has been frequent in our current societal framework. A system evaluation of the microbes that reside inside a host's colon could meet this knowledge gap since the microbes play major roles in a host's response to stress. Indeed, our past study suggested that these microbes might break their symbiotic association with moribund hosts to form a pro-survival condition exclusive to themselves. In this study, we undertook metagenomics and metabolomics assays regarding the descending colon content (DCC) of adult mice. DCCs were collected 1 month and 6 months after 7 Gy or 7.5 Gy total body irradiation (TBI). The assessment of the metagenomic diversity profile in DCC found a significant sex bias caused by TBI. Six months after 7.5 Gy TBI, decreased Bacteroidetes were replaced by increased Firmicutes in males, and these alterations were reflected in the functional analysis. For instance, a larger number of networks linked to small chain fatty acid (SCFA) synthesis and metabolism were inhibited in males than in females. Additionally, bioenergy networks showed regression dynamics in females at 6 months post-TBI. Increased accumulation of glucose and pyruvate, which are typical precursors of beneficial SCFAs coupled with the activated networks linked to the production of reactive oxygen species, suggest a cross-sex energy-deprived state. Overall, there was a major chronic adverse implication in male mice that supported the previous literature in suggesting females are more radioresistant than males. The sex-biased chronic effects of TBI should be taken into consideration in designing the pertinent therapeutics.

Global research trends in inflammaging from 2005 to 2024: a bibliometric analysis

Background

Inflammaging, defined as chronic low-grade inflammation associated with aging, is considered a key factor in many age-related diseases. Despite growing research, comprehensive assessments of trends and focuses on this field over the past 2 decades remain lacking.

Objective

To comprehensively analyze literature development trends, scientific priorities, and their evolution in the field of inflammaging from 2005 to 2024 using bibliometric analysis.

Methods

Academic literature on inflammaging was retrieved from the Web of Science Core Collection. CiteSpace software was used as the bibliometric tool to analyze annual publication trends, contributing countries/regions, leading research institutions, primary journals, and keyword co-occurrence, including clustering and burst analysis in this field.

Results

The study included 1,800 eligible articles, demonstrating a consistent growth in research publications over the past 20 years. The United States and Italy were the principal contributors. The University of Bologna had the highest publication. Professor Claudio Franceschi has been a leading figure in this field. Journal analysis shows that research themes predominantly focus on molecular biology/immunology and medicine/clinical fields. Keyword analysis identifies major research hotspots as "inflammaging," "Crohn's disease," "periodontitis," "immunosenescence," "skeletal muscle," "gut microbiota," and "Parkinson's disease." Emerging term analysis indicates a shift from specific inflammatory diseases to broader aging and immune modulation studies.

Conclusion

This first systematic assessment of literature trends in the field of inflammaging from 2005 to 2024 reveals sustained academic growth and an increasingly deep research focus.

A Cascade of Microbiota-Leaky Gut-Inflammation- Is it a Key Player in Metabolic Disorders?

PURPOSE OF REVIEW

This review addresses critical gaps in knowledge and provides a literature overview of the molecular pathways connecting gut microbiota dysbiosis to increased intestinal permeability (commonly referred to as "leaky gut") and its contribution to metabolic disorders. Restoring a healthy gut microbiota holds significant potential for enhancing intestinal barrier function and metabolic health. These interventions offer promising therapeutic avenues for addressing leaky gut and its associated pathologies in metabolic syndrome.

RECENT FINDINGS

In metabolic disorders such as obesity and type 2 diabetes (T2D), beneficial microbes such as those producing short-chain fatty acids (SCFAs) and other key metabolites like taurine, spermidine, glutamine, and indole derivatives are reduced. Concurrently, microbes that degrade toxic metabolites such as ethanolamine also decline, while proinflammatory, lipopolysaccharide (LPS)-enriched microbes increase. These microbial shifts place a higher burden on intestinal epithelial cells, which are in closest proximity to the gut lumen, inducing detrimental changes that compromise the structural and functional integrity of the intestinal barrier. Such changes include exacerbation of tight junction protein (TJP)s dysfunction, particularly through mechanisms such as destabilization of zona occludens (Zo)-1 mRNA or post-translational modifications. Emerging therapeutic strategies including ketogenic and Mediterranean diets, as well as probiotics, prebiotics, synbiotics, and postbiotics have demonstrated efficacy in restoring beneficial microbial populations, enhancing TJP expression and function, supporting gut barrier integrity, reducing leaky gut and inflammation, and ultimately improving metabolic disorders. This review summarizes the mechanisms by which gut microbiota contribute to the development of leaky gut and inflammation associated with metabolic syndrome. It also explores strategies for restoring gut microbiota balance and functionality by promoting beneficial microbes, increasing the production of beneficial metabolites, clearing toxic metabolites, and reducing the proportion of proinflammatory microbes. These approaches can alleviate the burden on intestinal epithelial cells, reduce leaky gut and inflammation, and improve metabolic health.

Nootropic foods in neurodegenerative diseases: mechanisms, challenges, and future

Neurodegenerative diseases (NDDs) such as Alzheimer's and Parkinson's disease are increasing globally and represent a significant cause of age-related death in the population. Recent studies emphasize the strong association between environmental stressors, particularly dietary factors, and brain health and neurodegeneration unsatisfactory outcomes. Despite ongoing efforts, the efficiency of current treatments for NDDs remains wanting. Considering this, nootropic foods with neuroprotective effects are of high interest as part of a possible long-term therapeutic strategy to improve brain health and alleviate NDDs. However, since it is a new and emerging area in food and neuroscience, there is limited information on mechanisms and challenges to consider for this to be a successful intervention. Here, we seek to address these gaps by presenting a comprehensive review of possible pathways or mechanisms including mutual interactions governing nootropic food metabolism, linkages of the pathways with NDDs, intake, and neuroprotective properties of nootropic foods. We also discuss in-depth intervention with nootropic compounds and dietary patterns in NDDs, providing a detailed exploration of their mechanisms of action. Additionally, we analyze the demand, challenges, and future directions for successful development of nootropic foods targeting NDDs.

ALKBH5 Improves the Epithelial Cell Tight Junctions to Inhibit Escherichia coli-Induced Mastitis

Mastitis poses a severe threat to the global cattle industry, causing huge economic losses. Environmental mastitis is mainly induced by Escherichia coli (E. coli), and the current treatment is still using antibiotics, with problems such as drug resistance and food safety. ALKBH5 is an RNA m6A demethylase that plays an important role in various biological processes, while p65 is a key regulator of inflammatory responses. Therefore, studying the interaction between ALKBH5 and p65 in protecting the mammary epithelial barrier provides new insights into the pathogenesis of mastitis. This study revealed that E. coli-induced acute inflammation activated the NF-κB/p65 signaling pathway and disrupted mammary epithelial cell tight junctions. Knockdown of ALKBH5 promoted p65 phosphorylation and inhibited the expressions of the tight junction proteins TJP1, CDH1, and OCLN. Furthermore, motif analysis, CHIP-PCR, and dual luciferase assay confirmed that phosphorylated p65 inhibited TJP1 promoter activity, thereby inhibiting TJP1 expression. In addition, the mouse experiment further demonstrated that knockdown of ALKBH5 aggravated E. coli-induced acute mastitis and epithelial cell tight junction disruption, and promoted E. coli invasion and proliferation. Significantly, this study is the first to demonstrate the details of the interaction between p65 and TJP1 and to declare the molecular mechanism of ALKBH5 in improving the cell tight junction, which lays a potential target and theoretical foundation for the treatment of mastitis and other infectious diseases.

Role of Gut Microbiota in the Development of Some Autoimmune Diseases

The gut microbiota is crucial for maintaining the homeostasis and function of the immune system. It interacts with the host's immune system through various mechanisms, including promoting immune tolerance, affecting the differentiation and function of immune cells, and participating in the metabolism of immune regulatory substances. The disruption of the gut microbiome may lead to impaired mucosal barrier function, allowing bacteria and their metabolites to invade into the host, activate or interfere with the immune system, and potentially trigger or exacerbate autoimmune responses. Understanding the relationship between the microbiome and autoimmune diseases may help develop new treatment strategies. This article reviewed the recent progresses of microbiome involved in the occurrence and development of some autoimmune diseases and the treatment methods based on regulation of the microbiome, highlighted the key role of microbiome in autoimmune diseases.

The gut microbiota-immune-brain axis: Therapeutic implications

The microbiota-gut-brain axis has major implications for human health including gastrointestinal physiology, brain function, and behavior. The immune system represents a key pathway of communication along this axis with the microbiome implicated in neuroinflammation in health and disease. In this review, we discuss the mechanisms as to how the gut microbiota interacts with the brain, focusing on innate and adaptive immunity that are often disrupted in gut-brain axis disorders. We also consider the implications of these observations and how they can be advanced by interdisciplinary research. Leveraging an increased understanding of how these interactions regulate immunity has the potential to usher in a new era of precision neuropsychiatric clinical interventions for psychiatric, neurodevelopmental, and neurological disorders.

Caco2/HT-29 In Vitro Cell Co-Culture: Barrier Integrity, Permeability, and Tight Junctions' Composition During Progressive Passages of Parental Cells

Epithelial linings are crucial for the maintenance of physiological barriers. The intestinal epithelial barrier (IEB) consists of enterocytes through tight junctions and mucus-secreting cells and can undergo physiological modifications throughout life. To reproduce as closely as possible the IEB main features over time, in vitro co-cultures of Caco2/HT-29 70/30 formed by parental Caco2 and HT-29 cells sub-cultivated for more than 40 passages were set up. The measurements of the transepithelial electrical resistance (TEER) identified two populations: physiological TEER co-cultures (PC) with values > 50 Ωcm2 formed by parental cells with fewer than 40 passages, and leaky TEER co-cultures (LC) with values < 50 Ωcm2 formed by parental cells with more than 40 passages. In LC, paracellular permeability increased in parallel. By immunofluorescence and Western blot analysis, an increase in claudin 2 was observed in LC vs. PC, with no differences in occludin expression. MUC-2 immunoreactivity was stronger in PC than in LC. LC also showed an enhanced vulnerability to TNFα+IFN-γ. These results reproduce the main morpho-functional modifications reported in the human leaky/aged gut and support the usefulness of our in vitro cell model for studying the molecular processes underlying these modifications and testing drug/nutraceutical treatments to ameliorate leaky gut aging.

Enabling Targeted Drug Delivery for Treatment of Ulcerative Colitis with Mucosal-Adhesive Photoreactive Hydrogel

Ulcerative colitis (UC) is a chronic inflammatory bowel disease. UC treatments are limited by significant adverse effects associated with non-specific drug delivery, such as systematic inhibition of the host immune system. Endoscopic delivery of a synthetic hydrogel material with biocompatible gelation that can efficiently cover irregular tissue surfaces provides an effective approach for targeted drug delivery at the gastrointestinal (GI) tract. An ideal integration of synthetic material with intestinal epithelium entails an integrated and preferable chemically bonded interface between the hydrogel and mucosal surface. In this study, a photo-triggered coupling reaction is leveraged as the crosslinking platform to develop a mucosal-adhesive hydrogel, which is compatible with endoscope-directed drug delivery for UC treatment. The results demonstrated superior spatiotemporal specificity and drug pharmacokinetics with this delivery system in vivo. Delivery of different drugs with the hydrogel leads to greatly enhanced therapeutic efficacy and significantly reduced systemic drug exposure with rat colitis models. The study presents a strategy for targeted and persistent drug delivery for UC treatment.

The relationship between a high-fat diet, gut microbiome, and systemic chronic inflammation: insights from integrated multiomics analysis

BACKGROUND

The detrimental effects of a high-fat diet (HFD) extend beyond metabolic consequences and include systemic chronic inflammation (SCI), immune dysregulation, and gut health disruption.

OBJECTIVES

In this study, we used Mendelian randomization (MR) to investigate the relationship between HFD, gut microbiota, and SCI.

METHODS

Genetic variants associated with dietary fat were utilized to explore causal relationships. Genome-wide association study data for the analyses of the gut microbiota, inflammatory cytokines, immune cell characteristics, and serum metabolites were obtained from European individuals. Mediation analysis was used to reveal potential mediating factors. The GMrepo database was used to analyze the bacterial composition in different groups. Transcriptomic and single-cell sequencing analyses explored inflammation and barrier function in colonic tissue.

RESULTS

HFD consumption was linked to changes in the abundance of 3 bacterial families and 11 bacterial genera. Combined with the GMrepo database, the increased abundance of the genus Lachnospiraceae_FCS020group and the decreased abundance of genus Bacteroides and genus Barnesiella are consistent with the MR results. Transcriptomic and single-cell sequencing analyses revealed intestinal inflammation and mucosal barrier dysfunction in HFD-fed mice. MR revealed a link between HFD consumption and increased levels of interleukin (IL)-18 [odds ratio (OR): 3.64, 95%CI: 1.24, 10.69, P = 0.02], MIG (OR = 3.14, 95%CI: 1.17, 8.47, P = 0.02), IL-13 [OR = 3.21, 95% confidence interval (CI): 1.08, -9.52, P = 0.04], and IL-2RA (OR = 2.93, 95%CI: 1.01, 8.53, P = 0.049). Twenty-nine immune cell signatures, including altered monocyte and T-cell subsets, were affected by HFD consumption. Twenty-six serum metabolites that are linked to HFD consumption, particularly lipid and amino acid metabolites, were identified. The positive gut microbiota exhibit extensive associations with inflammatory cytokines. In particular, Lachnospiraceae_FCS020 group (OR: 1.93, 95% CI: 1.11, 3.37, P = 0.02) may play a mediating role in HFD-induced increases in IL-2RA concentrations.

CONCLUSIONS

Microbial dysbiosis appears to be an important mechanism for HFD-induced SCI. The Lachnospiraceae_FCS020 group may act as a key genus in HFD-mediated elevation of IL-2RA.

Non-invasive treatment of Clostridioides difficile infection with a human-origin probiotic cocktail through gut microbiome-gut metabolome modulations

Clostridioides difficile (C. difficile) is a leading cause of hospital-associated diarrhea, primarily due to gut dysbiosis following antibiotic use. Probiotics have been found to provide several benefits to hosts via modulation of the gut microbiota and their metabolites. However, till now, no conventional probiotics have been clearly proven to be an effective prophylactic option for CDI prevention. Therefore, more studies on developing specific probiotic candidates targeting CDI and improving diversity of probiotics administrated are needed. In this study, a human-origin highly diverse and highly targeted probiotic cocktail (Pro11) containing 11 various probiotic species was developed against C. difficile. Pro11 protected mice against CDI with lower clinical scores and higher survival rates, and inhibited C. difficile in vivo with less C. difficile burden and toxins production determined in colon. Histological analysis demonstrated that Pro11 strengthened gut barrier, reducing gut permeability (less secreted sCD14 in serum) and gut inflammation. In addition, gut microbiome analysis demonstrated that Pro11 increased gut microbiome diversity and beneficial species. Along with gut microbiome modulation, gut metabolites including butyrate, were significantly increased in the probiotics-fed group. Results from this study highlighted probiotics as a promising CDI therapy as gut microbiota modulators, which will lay the foundation for translating probiotics in mitigating CDI and other intestinal pathogens for clinical use.

Fecal microbiota transplant from long-living Ames dwarf mice alters the microbial composition and biomarkers of liver health in normal mice

Aging is associated with intestinal dysbiosis, a condition characterized by diminished microbial biodiversity and inflammation. This leads to increased vulnerability to extraintestinal manifestations such as autoimmune, metabolic, and neurodegenerative conditions thereby accelerating mortality. As such, modulation of the gut microbiome is a promising way to extend healthspan. In this study, we explore the effects of fecal microbiota transplant (FMT) from long-living Ames dwarf donors to their normal littermates, and vice versa, on the recipient gut microbiota and liver transcriptome. Importantly, our previous studies highlight differences between the microbiome of Ames dwarf mice relative to their normal siblings, potentially contributing to their extended lifespan and remarkable healthspan. Our findings demonstrate that FMT from Ames dwarf mice to normal mice significantly alters the recipient's gut microbiota, potentially reprogramming bacterial functions related to healthy aging, and changes the liver transcriptome, indicating improved metabolic health. Particularly, the microbiome of Ames dwarf mice, characterized by a higher abundance of beneficial bacterial families such as Peptococcaceae, Oscillospiraceae, and Lachnospiraceae, appears to play a crucial role in modulating these effects. Alongside, our mRNA sequencing and RT-PCR validation reveals that FMT may contribute to the significant downregulation of p21, Elovl3, and Insig2, genes involved with cellular senescence and liver metabolic pathways. Our data suggest a regulatory axis exists between the gut and liver, highlighting the potential of microbiome-targeted therapies in promoting healthy aging. Future research should focus on functional validation of altered microbial communities and explore the underlying biomolecular pathways that confer geroprotection.

Retinol metabolism signaling participates in microbiota-regulated fat deposition in obese mice

Obesity is a global pandemic threatening public health, excess fat accumulation and overweight are its characteristics. In this study, the interplay between gut microbiota and retinol metabolism in modulating fat accumulation was verified. We observed gut microbiota depletion reduced the body weight and the ratios of white adipose tissues (WATs) to body weight in high-fat diet (HFD) fed-mice. The kyoto encyclopedia of genes and genomes (KEGG) analysis and protein-protein interaction (PPI) network of RNA-seq results indicated that retinol metabolism signaling may be involved in the microbiota-regulated fat deposition. Furthermore, activated retinol metabolism signaling by all-trans retinoic acid (atRA) supplementation reduced body weight and WAT accumulation in obese mice. 16S rRNA gene sequencing of the ileal microbiota suggested that atRA supplementation increased the microbial diversity and induced the growth of beneficial bacteria including Parabacteroides, Bacteroides, Clostridium_XVIII, Bifidobacterium, Enterococcus, Bacillus, Leuconostoc, and Lactobacillus in obese mice. Spearman correlation showed that the microbiota altered by atRA were associated with body and WAT weights. Together, this study reveals the interaction between the gut microbiota and retinol metabolism signaling in regulating adipose accumulation and obesity. It is expected of this finding to provide new insights to prevent and develop therapeutic measures of obesity-related metabolic syndrome.

Beyond the Hayflick limit: How microbes influence cellular aging

Cellular senescence, a complex biological process resulting in permanent cell-cycle arrest, is central to aging and age-related diseases. A key concept in understanding cellular senescence is the Hayflick Limit, which refers to the limited capacity of normal human cells to divide, after which they become senescent. Senescent cells (SC) accumulate with age, releasing pro-inflammatory and tissue-remodeling factors collectively known as the senescence-associated secretory phenotype (SASP). The causes of senescence are multifaceted, including telomere attrition, oxidative stress, and genotoxic damage, and they extend to influences from microbial sources. Research increasingly emphasizes the role of the microbiome, especially gut microbiota (GM), in modulating host senescence processes. Beneficial microbial metabolites, such as short-chain fatty acids (SCFAs), support host health by maintaining antioxidant defenses and reducing inflammation, potentially mitigating senescence onset. Conversely, pathogenic bacteria like Pseudomonas aeruginosa and Helicobacter pylori introduce factors that damage host DNA or increase ROS, accelerating senescence via pathways such as NF-κB and p53-p21. This review explores the impact of bacterial factors on cellular senescence, highlighting the role of specific bacterial toxins in promoting senescence. Additionally, it discusses how dysbiosis and the loss of beneficial microbial species further contribute to age-related cellular deterioration. Modulating the gut microbiome to delay cellular senescence opens a path toward targeted anti-aging strategies. This work underscores the need for deeper investigation into microbial influence on aging, supporting innovative interventions to manage and potentially reverse cellular senescence.

Leaky Gut Syndrome: An Interplay Between Nutrients and Dysbiosis

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Protection of Alzheimer's disease progression by a human-origin probiotics cocktail

Microbiome abnormalities (dysbiosis) significantly contribute to the progression of Alzheimer's disease (AD). However, the therapeutic efficacy of microbiome modulators in protecting against these ailments remains poorly studied. Herein, we tested a cocktail of unique probiotics, including 5 Lactobacillus and 5 Enterococcus strains isolated from infant gut with proven microbiome modulating capabilities. We aimed to determine the probiotics cocktail's efficacy in ameliorating AD pathology in a humanized AD mouse model of APP/PS1 strains. Remarkably, feeding mice with 1 × 1011 CFU per day in drinking water for 16 weeks significantly reduced cognitive decline (measured by the Morris Water Maze test) and AD pathology markers, such as Aβ aggregation, microglia activation, neuroinflammation, and preserved blood-brain barrier (BBB) tight junctions. The beneficial effects were linked to a reduced inflammatory microbiome, leading to decreased gut permeability and inflammation in both systemic circulation and the brain. Although both male and female mice showed overall improvements in cognition and biological markers, females did not exhibit improvements in specific markers related to inflammation and barrier permeability, suggesting that the underlying mechanisms may differ depending on sex. In conclusion, our results suggest that this unique probiotics cocktail could serve as a prophylactic agent to reduce the progression of cognitive decline and AD pathology. This is achieved by beneficially modulating the microbiome, improving intestinal tight junction proteins, reducing permeability in both gut and BBB, and decreasing inflammation in the gut, blood circulation, and brain, ultimately mitigating AD pathology and cognitive decline.

Exercise ameliorates osteopenia in mice via intestinal microbial-mediated bile acid metabolism pathway

Rationale: Physical exercise is essential for skeletal integrity and bone health. The gut microbiome, as a pivotal modulator of overall physiologic states, is closely associated with skeletal homeostasis and bone metabolism. However, the potential role of intestinal microbiota in the exercise-mediated bone gain remains unclear. Methods: We conducted microbiota depletion and fecal microbiota transplantation (FMT) in ovariectomy (OVX) mice and aged mice to investigate whether the transfer of gut ecological traits could confer the exercise-induced bone protective effects. The study analyzed the gut microbiota and metabolic profiles via 16S rRNA gene sequencing and LC-MS untargeted metabolomics to identify key microbial communities and metabolites responsible for bone protection. Transcriptome sequencing and RNA interference were employed to explore the molecular mechanisms. Results: We found that gut microbiota depletion hindered the osteogenic benefits of exercise, and FMT from exercised osteoporotic mice effectively mitigated osteopenia. Comprehensive profiling of the microbiome and metabolome revealed that the exercise-matched FMT reshaped intestinal microecology and metabolic landscape. Notably, alterations in bile acid metabolism, specifically the enrichment of taurine and ursodeoxycholic acid, mediated the protective effects on bone mass. Mechanistically, FMT from exercised mice activated the apelin signaling pathway and restored the bone-fat balance in recipient MSCs. Conclusion: Our study underscored the important role of the microbiota-metabolic axis in the exercise-mediated bone gain, heralding a potential breakthrough in the treatment of osteoporosis.

Probiotic Lactobacillus plantarum 299v supplementation in patients with major depression in a double-blind, randomized, placebo-controlled trial: A metabolomics study

BACKGROUND

Understanding the multifactorial nature of major depressive disorder (MDD) is crucial for tailoring treatments. However, the complex interplay of various factors underlying the development and progression of MDD poses significant challenges. Our previous study demonstrated improvements in cognitive functions in MDD patients undergoing treatment with selective serotonin reuptake inhibitors (SSRIs) supplemented with Lactobacillus plantarum 299v (LP299v).

METHODS

To elucidate the biochemical mechanisms underlying cognitive functions improvements, we explored underlying metabolic changes. We employed multi-platform metabolomics, including LC-QTOF-MS and CE-TOF-MS profiling, alongside chiral LC-QqQ-MS analysis for amino acids.

RESULTS

Supplementation of SSRI treatment with LP299v intensified the reduction of long-chain acylcarnitines, potentially indicating improved mitochondrial function. LP299v supplementation reduced N-acyl taurines more than four times compared to the placebo, suggesting a substantial impact on restoring biochemical balance. The LP299v-supplemented group showed increased levels of oxidized glycerophosphocholine (oxPC). Additionally, LP299v supplementation led to higher levels of sphingomyelins, L-histidine, D-valine, and p-cresol.

LIMITATIONS

This exploratory study suggests potential metabolic pathways influenced by LP299v supplementation. However, the need for further research hinders the ability to draw definitive conclusions.

CONCLUSIONS

Observed metabolic changes were linked to mitochondrial dysfunction, inflammation, oxidative stress, and gut microbiota disruption. Despite the subtle nature of this alterations, our research successfully detected these differences and connected them to the metabolic disruptions associated with MDD. Our findings emphasise the intricate relationship between metabolism, gut microbiota, and mental health prompting further research into the mechanisms of action of probiotics in MDD treatment.

Cefazolin shifts the kidney microbiota to promote a lithogenic environment

Clinical studies of the urinary tract microbiome, termed urobiome, suggest a direct, antibiotic-dependent, impact of the urobiome on kidney physiology. However, evidence for kidney bacteria comes from indirect sources or infected tissue. Further, it is unclear how antibiotics impact kidney bacteria. Here we show direct evidence for the presence of bacteria in the kidneys, with microniches in nephrons. In murine kidneys, administration of cefazolin, a commonly used perioperative antibiotic, led to a loss of uroprotective Lactobacillus spp. and proliferation of Enterobacteriaceae (which includes many known uropathogens). This effect was dependent on treatment duration, with recovery post treatment. Uroprotective L. crispatus and a strain of stone-associated E. coli differentially influenced calcium oxalate (CaOx) crystallization through the incorporation of CaOx inhibitors or promoters, respectively. In humans, microbial signatures were identified in the kidney, with unique niches between the glomeruli and tubules, established through RNA sequencing analysis and direct imaging of two independent populations. Collectively, findings support the hypothesis that the kidneys harbor a stable and antibiotic-responsive microbiota that can influence CaOx lithogenesis. The presence of unique, age-dependent microbial signatures in the glomeruli and tubuli carry implications for non-infectious kidney diseases.

Targeted and untargeted lipidomics with integration of liver dynamics and microbiome after dietary reversal of obesogenic diet targeting inflammation-resolution signaling in aging mice

Obesity, a global epidemic linked to around 4 million deaths yearly, arises from lifestyle imbalances impacting inflammation-related conditions like non-alcoholic fatty liver disease and gut dysbiosis. But the long-term effects of inflammation caused by lifestyle-related dietary changes remain unexplained. In this study, we used young male C57Bl/6 mice which were fed either an obesogenic diet (OBD) or a control diet (CON) for six months. Later, a group of mice from the OBD group were intervened to the CON diet (OBD-R) for four months, while another OBD group remained on the OBD diet. The OBD induced distinct changes in gut microbial, notably elevating Firmicutes and Actinobacteria, while reducing Bacteroidetes and Tenericutes. OBD-R restored microbial abundance like CON. Analyzing liver, plasma, and fecal samples revealed OBD-induced alterations in various structural and bioactive lipids, which were normalized to CON in the OBD-R, showcasing lipid metabolism flexibility and adaptability to dietary shifts. OBD increased omega 6 fatty acid, Arachidonic Acid (AA) and decreased omega 3-derived lipid mediators in the OBD mimicking non-alcoholic fatty liver disease thus impacting inflammation-resolution pathways. OBD also induced hepatic inflammation via increasing alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels and proinflammatory markers CCR2, TNF-α, and IL-1β in liver. Transitioning from OBD to CON mitigated inflammatory gene expression and restored lipid and cholesterol networks. This study underscores the intricate interplay between lifestyle-driven dietary changes, gut microbiota, lipid metabolism, and liver health. Notably, it suggests that shift from an OBD (omega-6 enriched) to CON partially alleviates signs of chronic inflammation during aging. Understanding these microbial, lipidomic, and hepatic inflammatory dynamics reveals potential therapeutic avenues for metabolic disorders induced by diet, emphasizing the pivotal role of diet in sustaining metabolic health.

Probiotics as a targeted intervention in anti-ageing: a review

CONTEXT

The age-induced disruption of gut flora, termed gut dysbiosis, is intimately tied to compromised immune function, augmented oxidative stress and a spectrum of age-linked disorders.

OBJECTIVE

This review examines the fundamental mechanisms employed by probiotic strains to modulate gut microbiota composition and metabolic profiles, mitigate cognitive decline via the gut-brain axis (GBA), modulate gene transcription and alleviate inflammatory responses and oxidative stress.

CONCLUSION

We elucidate the capacity of probiotics as a precision intervention to restore gut microbiome homeostasis and alleviate age-related conditions, thereby offering a theoretical framework for probiotics to decelerate ageing, manage age-related diseases, and elevate quality of life.

The development of machine learning approaches in two-dimensional NMR data interpretation for metabolomics applications

Metabolomics has been widely applied in human diseases and environmental science to study the systematic changes of metabolites over diverse types of stimuli. NMR-based metabolomics has been widely used, but the peak overlap problems in the one-dimensional (1D) NMR spectrum could limit the accuracy of quantitative analysis for metabolomics applications. Two-dimensional (2D) NMR has been applied to solve the 1D NMR overlap problem, but the data processing is still challenging. In this study, we built an automatic approach to process the 2D NMR data for quantitative applications using machine learning approaches. Partial least square discriminant analysis (PLS-DA), artificial neural network classification (ANN-DA), gradient boosted trees classification (XGBoost-DA), and artificial deep learning neural network classification (ANNDL-DA) were applied in combination with an automatic peak selection approach. Standard mixtures, sea anemone extracts, and mouse fecal samples were tested to demonstrate the approach. Our results showed that ANN-DA and ANNDL-DA have high accuracy in selecting 2D NMR peaks (around 90 %), which have a high potential application in 2D NMR-based metabolomics quantitively study, while PLS-DA and XGBoost-DA showed limitations in either data variation or overfitting. Our study built an automatic approach to applying 2D NMR data to routine quantitative analysis in metabolomics.

Epithelial NSD2 maintains FMO-mediated taurine biosynthesis to prevent intestinal barrier disruption

BACKGROUND

Inflammatory bowel disease (IBD) presents a significant challenge due to its intricate pathogenesis. NSD2, a histone methyltransferase responsible for dimethylating histone 3 at lysine 36, is associated with transcriptional activation. NSD2 expression is decreased in both the intestinal epithelial cells (IECs) of IBD patients and the IBD mouse model. However, the precise role of NSD2 in IBD remains unexplored.

METHODS

Colon tissues from IBD mice, SW620 cells and MC38 cells, were used as research subjects. Clinical databases of IBD patients were analysed to investigate whether NSD2 expression is reduced in the occurrence of IBD. NSD2-knockout mice were generated to further investigate the role of NSD2 in IBD. The IECs were isolated for RNA sequencing and chromatin immunoprecipitation sequencing to identify molecular signalling pathways and key molecules leading to IBD in mice. Molecular and cellular experiments were conducted to analyse and validate the role of NSD2 in the development of IBD. Finally, rescue experiments were performed to confirm the molecular mechanism of NSD2 in the development of IBD.

RESULTS

Deficiency of NSD2 in mouse IECs aggravated epithelial barrier disruption and inflammatory response in IBD. Mechanistically, NSD2 loss led to downregulation of H3K36me2 and flavin-containing monooxygenase (FMO) (taurine-synthesis enzyme) mRNA, resulting in decreased taurine biosynthesis in IECs. Significantly, supplementation with taurine markedly alleviated the symptoms of NSD2 deficiency-induced IBD.

CONCLUSIONS

These data demonstrate that NSD2 plays a pivotal role in maintaining FMO-mediated taurine biosynthesis to prevent intestinal inflammation. Our findings also underscore the importance of NSD2-H3K36me2-mediated taurine biosynthesis in maintaining intestinal mucosal barrier homeostasis.

KEY POINTS

In this study, we investigated the role of the histone methyltransferase NSD2 in preventing intestinal barrier disruption by sustaining taurine biosynthesis. NSD2 levels were reduced in both human specimens and mouse models of IBD. We demonstrate that NSD2 loss hinders the process of taurine synthesis in intestinal cells, leading to increased intestinal inflammation. Supplementation with taurine significantly relieved the symptoms caused by NSD2 deficiency. These data suggest that maintenance of NSD2-mediated taurine biosynthesis is vital for preserving the intestinal barrier and attenuating inflammation.

Tenebrio molitor (Mealworm) protein as a sustainable dietary strategy to improve health span in D-galactose-induced aged mice

Aging is an irreversible and continuous biological process involving intricate and interconnected mechanisms. The present work is focused on unravelling the anti-aging mechanisms of mealworm protein and protein-enriched fruit bar and vegetable soup in D-galactose-induced aged mice. Mealworm protein and enriched products significantly enhanced body weight, organ indices, and gut health. Behavioral assessments reflected enhanced neuroprotective effects. Mealworm protein and its enriched products demonstrated protective effects through anti-inflammatory activity with the highest reduction of TNFα (17.1 %), IL-6 (55.5 %), and IL-1β (75.1 %) levels and upregulated the anti-inflammatory marker (IL-4). Gene expression studies confirmed the induction of anti-aging effects by promoting metabolism, reducing cellular senescence, and enhancing anti-oxidant enzyme activity. The treatments extended telomere lengths by 3-4 times, further affirming the potential anti-aging efficacy of mealworm protein and its enriched products. Mealworm protein demonstrated positive effects on weight gain, anti-inflammatory responses, and telomere length; while fruit and vegetable products enhanced antioxidant activity, and positively influenced gut health. Further, a synergistic effect was observed by combining them, which resulted in improved overall anti-aging effect. The present work provides valuable insights into the multifaceted anti-aging mechanisms associated with mealworm protein and enriched products, highlighting their potential as functional foods with significant health-promoting effects.

Faecal intestinal permeability and intestinal inflammatory markers in older adults with age-related disorders: A systematic review and meta-analysis

This systematic review and meta-analysis appraised previous findings to uncover potential faecal intestinal permeability and intestinal inflammatory markers in older adults. A comprehensive literature search led to the identification of ten eligible studies with findings of potential faecal intestinal permeability (zonulin and alpha-1-antitrypsin) and intestinal inflammatory markers [calprotectin, lactoferrin and neutrophil gelatinase-associated lipocalin (NGAL)]. Most of the cases (n > 2) [Parkinson's disease (PD) and Alzheimer's disease (AD)] exhibited higher faecal alpha-1-antitrypsin, zonulin and calprotectin levels. The present meta-analysis confirmed significantly higher faecal alpha-1-antitrypsin in older persons with PD compared to non-PD [MD = 22.92 mg/dL; 95 % CI = 14.02-31.81, p < 0.00001; I2 = 0 % (p = 0.73)]. There was, however, no significant difference in faecal zonulin between PD and non-PD individuals [MD = 26.88 ng/mL; 95 % CI = -29.26-83.01, p = 0.35; I2 = 94 % (p < 0.0001)]. Meanwhile, faecal calprotectin was higher in older adults with GI symptoms, multiple system atrophy (MSA) or PD than the healthy controls [MD = 9.51 μg/g; 95 % CI = 0.07-18.95, p = 0.05; I2 = 84 % (p < 0.00001)]. Altogether, faecal calprotectin appears to be a potential intestinal inflammatory marker whereas previous findings on faecal alpha-1-antitrypsin as an intestinal permeability marker remain limited and require further validation.

Low-molecular-weight heparin ameliorates intestinal barrier dysfunction in aged male rats via protection of tight junction proteins

The intestinal barrier weakens and chronic gut inflammation occurs in old age, causing age-related illnesses. Recent research shows that low-molecular-weight heparin (LMWH), besides anticoagulation, also has anti-inflammatory and anti-apoptotic effects, protecting the intestinal barrier. This study aims to analyze the effect of LMWH on the intestinal barrier of old male rodents. This study assigned Sprague-Dawley male rats to four groups: young (3 months), young + LMWH, old (20 months), and old + LMWH. The LMWH groups received 1 mg/kg LMWH via subcutaneous injection for 7 days. Optical and transmission electron microscopy (TEM) were used to examine morphological changes in intestinal mucosa due to aging. Intestinal permeability was measured using fluorescein isothiocyanate (FITC)-dextran. ELISA kits were used to measure serum levels of IL-6 and IL-1β, while Quantitative RT-PCR detected their mRNA levels in intestinal tissues. Western blotting and immunohistochemistry (IHC) evaluated the tight junction (TJ) protein levels such as occludin, zonula occludens-1 (ZO-1), and claudin-2. Western blotting assessed the expression of the apoptosis marker cleaved caspase 3, while IHC was used to detect LGR5+ intestinal stem cells. The intestinal permeability of aged rats was significantly higher than that of young rats, indicating significant differences. With age, the protein levels of occludin and ZO-1 decreased significantly, while the level of claudin-2 increased significantly. Meanwhile, our study found that the levels of IL-1β and IL-6 increased significantly with age. LMWH intervention effectively alleviated age-related intestinal barrier dysfunction. In aged rats treated with LMWH, the expression of occludin and ZO-1 proteins in the intestine increased, while the expression of claudin-2 decreased. Furthermore, LMWH administration in aged rats resulted in a decrease in IL-1β and IL-6 levels. LMWH also reduced age-related cleaved caspase3 expression, but IHC showed no difference in LGR5+ intestinal stem cells between groups. Research suggests that LMWH could potentially be a favorable therapeutic choice for age-related diseases associated with intestinal barrier dysfunction, by protecting TJ proteins, reducing inflammation, and apoptosis.

Gut dysbiosis impairs intestinal renewal and lipid absorption in Scarb2 deficiency-associated neurodegeneration

Scavenger receptor class B, member 2 (SCARB2) is linked to Gaucher disease and Parkinson's disease. Deficiency in the SCARB2 gene causes progressive myoclonus epilepsy (PME), a rare group of inherited neurodegenerative diseases characterized by myoclonus. We found that Scarb2 deficiency in mice leads to age-dependent dietary lipid malabsorption, accompanied with vitamin E deficiency. Our investigation revealed that Scarb2 deficiency is associated with gut dysbiosis and an altered bile acid pool, leading to hyperactivation of FXR in intestine. Hyperactivation of FXR impairs epithelium renewal and lipid absorption. Patients with SCARB2 mutations have a severe reduction in their vitamin E levels and cannot absorb dietary vitamin E. Finally, inhibiting FXR or supplementing vitamin E ameliorates the neuromotor impairment and neuropathy in Scarb2 knockout mice. These data indicate that gastrointestinal dysfunction is associated with SCARB2 deficiency-related neurodegeneration, and SCARB2-associated neurodegeneration can be improved by addressing the nutrition deficits and gastrointestinal issues.

Targeted discovery of gut microbiome-remodeling compounds for the treatment of systemic inflammatory response syndrome

Systemic inflammatory response syndrome (SIRS) is a severe inflammatory response that can lead to organ dysfunction and death. Modulating the gut microbiome is a promising therapeutic approach for managing SIRS. This study assesses the therapeutic potential of the Xuanfei Baidu (XFBD) formula in treating SIRS. The results showed that XFBD administration effectively reduced mortality rates and inflammation in SIRS mice. Using 16S rRNA sequencing and fecal microbiota transplantation (FMT), we substantiated that the therapeutic effects of XFBD are partly attributed to gut microbiota modulation. We conducted in vitro experiments to accurately assess the gut microbiome remodeling effects of 51 compounds isolated from XFBD. These compounds exhibited varying abilities to induce a microbial structure that closely resembles that of the healthy control group. By quantifying their impact on microbial structure and clustering their regulatory patterns, we devised multiple gut microbiome remodeling compound (GMRC) cocktails. GMRC cocktail C, comprising aucubin, gentiopicroside, syringic acid, gallic acid, p-hydroxybenzaldehyde, para-hydroxybenzoic acid, and isoimperatorin, demonstrated superior efficacy in treating SIRS compared to a single compound or to other cocktails. Finally, in vitro experiments showcased that GMRC cocktail C effectively rebalanced bacteria composition in SIRS patients. This study underscores XFBD's therapeutic potential in SIRS and highlights the importance of innovative treatment approaches for this disease by targeting the gut microbiota.IMPORTANCEDeveloping effective treatment strategies for systemic inflammatory response syndrome (SIRS) is crucial due to its severe and often life-threatening nature. While traditional treatments like dexamethasone have shown efficacy, they also come with significant side effects and limitations. This study makes significant strides by demonstrating that the Xuanfei Baidu (XFBD) formula can substantially reduce mortality rates and inflammation in SIRS mice through effective modulation of the gut microbiota. By quantitatively assessing the impact of 51 compounds derived from XFBD on the gut microbiome, we developed a potent gut microbiome remodeling compound cocktail. This cocktail outperformed individual compounds and other mixtures in efficacy against SIRS. These findings highlight the potential of XFBD as a therapeutic solution for SIRS and underscore the critical role of innovative strategies targeting the gut microbiota in addressing this severe inflammatory condition.

Aged Gut Microbiome Induces Metabolic Impairment and Hallmarks of Vascular and Intestinal Aging in Young Mice

Aging, an independent risk factor for cardiometabolic diseases, refers to a progressive deterioration in physiological function, characterized by 12 established hallmarks. Vascular aging is driven by endothelial dysfunction, telomere dysfunction, oxidative stress, and vascular inflammation. This study investigated whether aged gut microbiome promotes vascular aging and metabolic impairment. Fecal microbiome transfer (FMT) was conducted from aged (>75 weeks old) to young C57BL/6 mice (8 weeks old) for 6 weeks. Wire myography was used to evaluate endothelial function in aortas and mesenteric arteries. ROS levels were measured by dihydroethidium (DHE) staining and lucigenin-enhanced chemiluminescence. Vascular and intestinal telomere function, in terms of relative telomere length, telomerase reverse transcriptase expression and telomerase activity, were measured. Systemic inflammation, endotoxemia and intestinal integrity of mice were assessed. Gut microbiome profiles were studied by 16S rRNA sequencing. Some middle-aged mice (40-42 weeks old) were subjected to chronic metformin treatment and exercise training for 4 weeks to evaluate their anti-aging benefits. Six-week FMT impaired glucose homeostasis and caused vascular dysfunction in aortas and mesenteric arteries in young mice. FMT triggered vascular inflammation and oxidative stress, along with declined telomerase activity and shorter telomere length in aortas. Additionally, FMT impaired intestinal integrity, and triggered AMPK inactivation and telomere dysfunction in intestines, potentially attributed to the altered gut microbial profiles. Metformin treatment and moderate exercise improved integrity, AMPK activation and telomere function in mouse intestines. Our data highlight aged microbiome as a mechanism that accelerates intestinal and vascular aging, suggesting the gut-vascular connection as a potential intervention target against cardiovascular aging and complications.

Surface layer proteins from Lactobacillus helveticus ATCC® 15009™ affect the gut barrier morphology and function

Paraprobiotics and postbiotics represent a valid alternative to probiotic strains for ameliorating and preserving a healthy intestinal epithelial barrier (IEB). The present study investigated the effects of surface layer proteins (S-layer) of the dairy strain Lactobacillus helveticus ATCC® 15009™ (Lb ATCC® 15009™), as paraprobiotic, on the morpho-functional modulation of IEB in comparison to live or heat-inactivated Lb ATCC® 15009™ in an in vitro co-culture of Caco-2/HT-29 70/30 cells. Live or heat-inactivated Lb ATCC® 15009™ negatively affected transepithelial electrical resistance (TEER) and paracellular permeability, and impaired the distribution of Claudin-1, a tight junction (TJ) transmembrane protein, as detected by immunofluorescence (IF). Conversely, the addition of the S-layer improved TEER and decreased permeability in physiological conditions in co-cultures with basal TEER lower than 50 ohmcm2, indicative of a more permeable physiological IEB known as leaky gut. Transmission electron microscopy (TEM) and IF analyses suggested that the S-layer induces a structural TJ rearrangement and desmosomes' formation. S-layer also restored TEER and permeability in the presence of LPS, but not of a mixture of pro-inflammatory cytokines (TNF-α plus IFN-γ). IF analyses showed an increase in Claudin-1 staining when LPS and S-layer were co-administered with respect to LPS alone; in addition, the S-layer counteracted the reduction of alkaline phosphatase detoxification activity and the enhancement of pro-inflammatory interleukin-8 release both induced by LPS. Altogether, these data corroborate a paraprobiotic role of S-layer from Lb ATCC® 15009™ as a possible candidate for therapeutic and prophylactic uses in conditions related to gastrointestinal health and correlated with extra-intestinal disorders.

Utilizing pigs as a model for studying intestinal barrier function

Intestinal permeability has been extensively studied, particularly in gastrointestinal diseases such as inflammatory bowel disease, food allergy, visceral disease, celiac disease, and Crohn’s disease. These studies have established that changes in intestinal permeability contribute to the pathogenesis of many gastrointestinal and systemic diseases. While numerous works in the 20th century focused on this topic, it remains relevant for several reasons. Despite the development of new research techniques, it is still unclear whether changes in intestinal permeability are the primary mechanism initiating the disease process or if they occur secondary to an ongoing chronic inflammatory process. Investigating the possibility of stabilizing the intestinal barrier, thereby reducing its permeability preemptively to prevent damage and after the damage has occurred, may offer new therapeutic approaches. Increased intestinal permeability is believed to lead to reduced nutrient absorption, resulting in decreased immunity and production of digestive enzymes.

Gut microbiota and immunosenescence in cancer

Cancer is generally defined as a disease of aging. With aging, the composition, diversity and functional characteristics of the gut microbiota occur changes, with a decline of beneficial commensal microbes triggered by intrinsic and extrinsic factors (e.g., diet, drugs and chronic health conditions). Nowadays, dysbiosis of the gut microbiota is recognized as a hallmark of cancer. At the same time, aging is accompanied by changes in innate and adaptive immunity, known as immunosenescence, as well as chronic low-grade inflammation, known as inflammaging. The elevated cancer incidence and mortality in the elderly are linked with aging-associated alterations in the gut microbiota that elicit systemic metabolic alterations, leading to immune dysregulation with potentially tumorigenic effects. The gut microbiota and immunosenescence might both affect the response to treatment in cancer patients. In-depth understanding of age-associated alterations in the gut microbiota and immunity will shed light on the risk of cancer development and progression in the elderly. Here, we describe the aging-associated changes of the gut microbiota in cancer, and review the evolving understanding of the gut microbiota-targeted intervention strategies. Furthermore, we summarize the knowledge on the cellular and molecular mechanisms of immunosenescence and its impact on cancer. Finally, we discuss the latest knowledge about the relationships between gut microbiota and immunosenescence, with implications for cancer therapy. Intervention strategies targeting the gut microbiota may attenuate inflammaging and rejuvenate immune function to provide antitumor benefits in elderly patients.

Lacticaseibacillus rhamnosus GG alleviates sleep deprivation-induced intestinal barrier dysfunction and neuroinflammation in mice

Consuming probiotic products is a solution that people are willing to choose to augment health. As a global health hazard, sleep deprivation (SD) can cause both physical and mental diseases. The present study investigated the protective effects of Lacticaseibacillus rhamnosus GG (LGG), a widely used probiotic, on a SD mouse model. Here, it has been shown that SD induced intestinal damage in mice, while LGG supplementation attenuated disruption of the intestinal barrier and enhanced the antioxidant capacity. Microbiome analysis revealed that SD caused dysbiosis in the gut microbiota, characterized by increased levels of Clostridium XlVa, Alistipes, and Desulfovibrio, as well as decreased levels of Ruminococcus, which were partially ameliorated by LGG. Moreover, SD resulted in elevated pro-inflammatory cytokine concentrations in both the intestine and the brain, while LGG provided protection in both organs. LGG supplementation significantly improved locomotor activity in SD mice. Although heat-killed LGG showed some protective effects in SD mice, its overall efficacy was inferior to that of live LGG. In terms of mechanism, it was found that AG1478, an inhibitor of the epidermal growth factor receptor (EGFR) tyrosine kinase, could diminish the protective effects of LGG. In conclusion, LGG demonstrated the ability to alleviate SD-induced intestinal barrier dysfunction through EGFR activation and alleviate neuroinflammation.

The Role and Mechanism of Probiotics Supplementation in Blood Glucose Regulation: A Review

With economic growth and improved living standards, the incidence of metabolic diseases such as diabetes mellitus caused by over-nutrition has risen sharply worldwide. Elevated blood glucose and complications in patients seriously affect the quality of life and increase the economic burden. There are limitations and side effects of current hypoglycemic drugs, while probiotics, which are safe, economical, and effective, have good application prospects in disease prevention and remodeling of intestinal microecological health and are gradually becoming a research hotspot for diabetes prevention and treatment, capable of lowering blood glucose and alleviating complications, among other things. Probiotic supplementation is a microbiologically based approach to the treatment of type 2 diabetes mellitus (T2DM), which can achieve anti-diabetic efficacy through the regulation of different tissues and metabolic pathways. In this study, we summarize recent findings that probiotic intake can achieve blood glucose regulation by modulating intestinal flora, decreasing chronic low-grade inflammation, modulating glucagon-like peptide-1 (GLP-1), decreasing oxidative stress, ameliorating insulin resistance, and increasing short-chain fatty acids (SCFAs) content. Moreover, the mechanism, application, development prospect, and challenges of probiotics regulating blood glucose were discussed to provide theoretical references and a guiding basis for the development of probiotic preparations and related functional foods regulating blood glucose.

Lactiplantibacillus plantarum P9 for chronic diarrhea in young adults: a large double-blind, randomized, placebo-controlled trial

Current treatments for chronic diarrhea have limited efficacy and several side effects. Probiotics have the potential to alleviate symptoms of diarrhea. This randomized, double-blind, placebo-controlled trial evaluates the effects of administering the probiotic Lactiplantibacillus plantarum P9 (P9) strain in young adults with chronic diarrhea (Clinical Trial Registration Number: ChiCTR2000038410). The intervention period lasts for 28 days, followed by a 14-day post-intervention period. Participants are randomized into the P9 (n = 93) and placebo (n = 96) groups, with 170 individuals completing the double-blind intervention phase (n = 85 per group). The primary endpoint is the diarrhea symptom severity score. Both intention-to-treat (n = 189) and per-protocol (n = 170) analyses reveal a modest yet statistically significant reduction in diarrhea severity compared to the placebo group (20.0%, P = 0.050; 21.4%, P = 0.048, respectively). In conclusion, the results of this study support the use of probiotics in managing chronic diarrhea in young adults. However, the lack of blood parameter assessment and the short intervention period represent limitations of this study.

Dysfunction of the Murine Liver with Aging and Its Improvement with the Continuous Consumption of Enterococcus faecalis EC-12

Chronic inflammation is involved in the development of age-related diseases. Given its persistence, controlling chronic inflammation is essential for preventing age-related diseases. In this study, we investigated the effects of Enterococcus faecalis EC-12 (EC-12), which has immunomodulatory and antioxidant effects, on liver gene expression and aging phenomena in mice. Short-term EC-12 administration stimulated the expression of genes involved in lipid synthesis and metabolism in the liver. Furthermore, long-term EC-12 administration from 10 weeks to 1.5 years of age resulted in significant increases in blood interleukin (IL)-6 and IL-10 concentrations (both p < 0.05) and a significant decrease in the monocyte chemotactic protein-1 concentration (p < 0.05). These results indicated pathologic improvement, such as suppression of fat degeneration in the liver. These results suggest that continuous EC-12 intake from a young age can suppress liver function abnormalities, which is one of the aging phenomena in old age, and contribute to health in old age.

Role of the afferent lymph as an immunological conduit to analyze tissue antigenic and inflammatory load

The lymphatic fluid is the conduit by which part of the tissue "omics" is transported to the draining lymph node for immunosurveillance. Following cannulation of the pre-nodal cervical and mesenteric afferent lymphatics, herein we investigate the lymph proteomic composition, uncovering that its composition varies according to the tissue of origin. Tissue specificity is also reflected in the dendritic cell-major histocompatibility complex class II-eluted immunopeptidome harvested from the cervical and mesenteric nodes. Following inflammatory disruption of the gut barrier, the lymph antigenic and inflammatory loads are analyzed in both mice and subjects with inflammatory bowel diseases. Gastrointestinal tissue damage reflects the lymph inflammatory and damage-associated molecular pattern signatures, microbiome-derived by-products, and immunomodulatory molecules, including metabolites of the gut-brain axis, mapped in the afferent mesenteric lymph. Our data point to the relevance of the lymphatic fluid to probe the tissue-specific antigenic and inflammatory load transported to the draining lymph node for immunosurveillance.

From Gut Microbiota to Brain Waves: The Potential of the Microbiome and EEG as Biomarkers for Cognitive Impairment

Alzheimer's disease (AD) is a prevalent neurodegenerative disorder and a leading cause of dementia. Aging is a significant risk factor for AD, emphasizing the importance of early detection since symptoms cannot be reversed once the advanced stage is reached. Currently, there is no established method for early AD diagnosis. However, emerging evidence suggests that the microbiome has an impact on cognitive function. The gut microbiome and the brain communicate bidirectionally through the gut-brain axis, with systemic inflammation identified as a key connection that may contribute to AD. Gut dysbiosis is more prevalent in individuals with AD compared to their cognitively healthy counterparts, leading to increased gut permeability and subsequent systemic inflammation, potentially causing neuroinflammation. Detecting brain activity traditionally involves invasive and expensive methods, but electroencephalography (EEG) poses as a non-invasive alternative. EEG measures brain activity and multiple studies indicate distinct patterns in individuals with AD. Furthermore, EEG patterns in individuals with mild cognitive impairment differ from those in the advanced stage of AD, suggesting its potential as a method for early indication of AD. This review aims to consolidate existing knowledge on the microbiome and EEG as potential biomarkers for early-stage AD, highlighting the current state of research and suggesting avenues for further investigation.

Plasma taurine level is linked to symptom burden and clinical outcomes in post-COVID condition

BACKGROUND

A subset of individuals (10-20%) experience post-COVID condition (PCC) subsequent to initial SARS-CoV-2 infection, which lacks effective treatment. PCC carries a substantial global burden associated with negative economic and health impacts. This study aims to evaluate the association between plasma taurine levels with self-reported symptoms and adverse clinical outcomes in patients with PCC.

METHODS AND FINDINGS

We analyzed the plasma proteome and metabolome of 117 individuals during their acute COVID-19 hospitalization and at the convalescence phase six-month post infection. Findings were compared with 28 age and sex-matched healthy controls. Plasma taurine levels were negatively associated with PCC symptoms and correlated with markers of inflammation, tryptophan metabolism, and gut dysbiosis. Stratifying patients based on the trajectories of plasma taurine levels during six-month follow-up revealed a significant association with adverse clinical events. Increase in taurine levels during the transition to convalescence were associated with a reduction in adverse events independent of comorbidities and acute COVID-19 severity. In a multivariate analysis, increased plasma taurine level between acute and convalescence phase was associated with marked protection from adverse clinical events with a hazard ratio of 0.13 (95% CI: 0.05-0.35; p<0.001).

CONCLUSIONS

Taurine emerges as a promising predictive biomarker and potential therapeutic target in PCC. Taurine supplementation has already demonstrated clinical benefits in various diseases and warrants exploration in large-scale clinical trials for alleviating PCC.

Taurine Alleviates Experimental Colitis by Enhancing Intestinal Barrier Function and Inhibiting Inflammatory Response through TLR4/NF-κB Signaling

Taurine (Tau) is a semiessential amino acid in mammals with preventive and therapeutic effects on several intestinal disorders. However, the exact function of taurine in ulcerative colitis (UC) is still largely unclear. In this study, we used two taurine-deficient mouse models (CSAD-/- and TauT-/- mice) to explore the influence of taurine on the progression of UC in both dextran sulfate sodium (DSS)-induced colitis and LPS-stimulated Caco-2 cells. We found that cysteine sulfinic acid decarboxylase (CSAD) and taurine transporter (TauT) expressions and taurine levels were markedly reduced in colonic tissues of mice treated with DSS. The CSAD and TauT knockouts exacerbated DSS-induced clinical symptoms and pathological damage and aggravated the intestinal barrier dysfunction and the colonic mucosal inflammatory response. Conversely, taurine pretreatment enhanced the intestinal barrier functions by increasing goblet cells and upregulating tight junction protein expression. Importantly, taurine bound with TLR4 and inhibited the TLR4/NF-κB pathway, ultimately reducing proinflammatory factors (TNF-α and IL-6) and oxidative stress. Our findings highlight the essential role of taurine in maintaining the intestinal barrier integrity and inhibiting intestinal inflammation, indicating that taurine is a promising supplement for colitis treatment.

The comparative anti-oxidant and anti-inflammatory efficacy of postbiotics and probiotics through Nrf-2 and NF-kB pathways in DSS-induced colitis model

IBD is a disorder which could be caused by oxidative stress. This investigation aims to determine if probiotics and postbiotics can control oxidative stress and inflammation and compare the effectiveness of these two probiotic and postbiotic mixtures of substances. 88 strains of Lactobacillus and Bifidobacterium were tested for antioxidant activity. Male wild-type C57BL/6 mice were divided into four experimental groups, namely high fat diet (HFD) + PBS, HFD + DSS, HFD + DSS + 109 cfu/ml of probiotics, and HFD + DSS + 109 cfu/ml of postbiotics. The phenotypical indices and pathological scores were assessed. The expression of genes related to NF-kB and Nrf2 signaling pathways and enzymes associated with oxidant/anti-oxidant activities, and proinflammatory/inflammatory cytokines were assessed. In contrast to the groups exposed to DSS, mice treated with probiotics mixture and postbiotics mixture alongside DSS displayed alleviation of DSS-induced adverse effects on phenotypical characteristics, as well as molecular indices such as the Nrf2 and NF-kB related genes, with a greater emphasis on the postbiotics component. In accordance with the findings of the present investigation, it can be inferred that even in using a high-fat dietary regimen as an inducer of oxidative stress, the emergence of inflammation can be effectively addressed through the utilization of probiotics and, more specifically, postbiotics.

Two Enterococcus faecium Isolates Demonstrated Modulating Effects on the Dysbiosis of Mice Gut Microbiota Induced by Antibiotic Treatment

Broad-spectrum antibiotics are frequently used to treat bacteria-induced infections, but the overuse of antibiotics may induce the gut microbiota dysbiosis and disrupt gastrointestinal tract function. Probiotics can be applied to restore disturbed gut microbiota and repair abnormal intestinal metabolism. In the present study, two strains of Enterococcus faecium (named DC-K7 and DC-K9) were isolated and characterized from the fecal samples of infant dogs. The genomic features of E. faecium DC-K7 and DC-K9 were analyzed, the carbohydrate-active enzyme (CAZyme)-encoding genes were predicted, and their abilities to produce short-chain fatty acids (SCFAs) were investigated. The bacteriocin-encoding genes in the genome sequences of E. faecium DC-K7 and DC-K9 were analyzed, and the gene cluster of Enterolysin-A, which encoded a 401-amino-acid peptide, was predicted. Moreover, the modulating effects of E. faecium DC-K7 and DC-K9 on the gut microbiota dysbiosis induced by antibiotics were analyzed. The current results demonstrated that oral administrations of E. faecium DC-K7 and DC-K9 could enhance the relative abundances of beneficial microbes and decrease the relative abundances of harmful microbes. Therefore, the isolated E. faecium DC-K7 and DC-K9 were proven to be able to alter the gut microbiota dysbiosis induced by antibiotic treatment.

High-fat diet, microbiome-gut-brain axis signaling, and anxiety-like behavior in male rats

Obesity, associated with the intake of a high-fat diet (HFD), and anxiety are common among those living in modern urban societies. Recent studies suggest a role of microbiome-gut-brain axis signaling, including a role for brain serotonergic systems in the relationship between HFD and anxiety. Evidence suggests the gut microbiome and the serotonergic brain system together may play an important role in this response. Here we conducted a nine-week HFD protocol in male rats, followed by an analysis of the gut microbiome diversity and community composition, brainstem serotonergic gene expression (tph2, htr1a, and slc6a4), and anxiety-related defensive behavioral responses. We show that HFD intake decreased alpha diversity and altered the community composition of the gut microbiome in association with obesity, increased brainstem tph2, htr1a and slc6a4 mRNA expression, including in the caudal part of the dorsomedial dorsal raphe nucleus (cDRD), a subregion previously associated with stress- and anxiety-related behavioral responses, and, finally, increased anxiety-related defensive behavioral responses. The HFD increased the Firmicutes/Bacteroidetes ratio relative to control diet, as well as higher relative abundances of Blautia, and decreases in Prevotella. We found that tph2, htr1a and slc6a4 mRNA expression were increased in subregions of the dorsal raphe nucleus in the HFD, relative to control diet. Specific bacterial taxa were associated with increased serotonergic gene expression in the cDRD. Thus, we propose that HFD-induced obesity is associated with altered microbiome-gut-serotonergic brain axis signaling, leading to increased anxiety-related defensive behavioral responses in rats.

Curcumin attenuates aflatoxin B1-induced ileum injury in ducks by inhibiting NLRP3 inflammasome and regulating TLR4/NF-κB signaling pathway

Aflatoxin B1 (AFB1) is a widespread toxic contamination in feed for animals. The primary active component of turmeric, curcumin (Cur), is an antioxidant and an anti-inflammatory. However, it is yet unknown how AFB1 affects the intestinal epithelial barrier and whether Cur acts as a protective mechanism when exposed to AFB1. Here, we explored the mechanism of AFB1-induced intestinal injury from intestinal epithelial barrier, inflammation, pyroptosis, and intestinal flora, and evaluated the protective role of Cur. We found that AFB1 caused weight loss and intestinal morphological damage that is mainly characterized by shortened intestinal villi, deepened crypts, and damaged intestinal epithelium. Exposure to AFB1 decreased the expression of Claudin-1, MUC2, ZO-1, and Occludin and increased the expression of pyroptosis-related factors (NLRP3, GSDMD, Caspase-1, IL-1β, and IL-18) and inflammation-related factors (TLR4, NF-κB, IκB, IFN-γ, and TNF-α). Furthermore, ileal gut microbiota was altered, and simultaneously, the Lactobacillus abundance was decreased. The gut microbiota interacts with a wide range of physiologic functions and disease development in the host through its metabolites, and disturbances in gut microbial metabolism can cause functional impairment of the ileum. Meanwhile, Cur can ameliorate histological ileum injuries and intestinal flora disturbance caused by AFB1. We found that Cur reversed the effects of AFB1 through modulating both NLRP3 inflammasome and the TLR4/NF-κB signaling pathway. In conclusion, AFB1 can induce inflammatory damage and pyroptosis in duck ileum, while Cur has obviously protective effects on all the above damages.

Efficacy of Laurus nobilis L. for Tight Junction Protein Imbalance in Leaky Gut Syndrome

Laurus nobilis L. (LNL) belongs to the evergreen Lauraceae family. It is native to the Mediterranean and widely distributed in the southern United States, Europe, and the Middle East. LNL is rich in active ingredients of the sesquiterpene lactone series and has been reported to have antioxidant, anti-inflammatory, and anticancer effects. And parthenolide, known as a sesquiterpene lactone-based compound, inhibits the activation of lipopolysaccharide-binding protein (LBP), which is a major trigger for leaky gut syndrome. However, the effectiveness of LNL in improving the state of increased intestinal permeability has not yet been reported. Therefore, we demonstrated the efficacy of LNL, which is known to be rich in parthenolide, in improving intestinal permeability induced by IL-13. We investigated the improvement in permeability and analyzed major tight junction proteins (TJs), permeability-related mechanisms, weight and disease activity indices, and corresponding cytokine mechanisms. LNL maintained TJs homeostasis and clinical improvement by reducing increased claudin-2 through the inhibition of IL-13/STAT6 activation in TJ-damaged conditions. These results are expected to be effective in preventing leaky gut syndrome through the TJ balance and to further improve intestinal-related diseases, such as inflammatory bowel disease.

Polyphenolic Compounds: Orchestrating Intestinal Microbiota Harmony during Aging

In the aging process, physiological decline occurs, posing a substantial threat to the physical and mental well-being of the elderly and contributing to the onset of age-related diseases. While traditional perspectives considered the maintenance of life as influenced by a myriad of factors, including environmental, genetic, epigenetic, and lifestyle elements such as exercise and diet, the pivotal role of symbiotic microorganisms had been understated. Presently, it is acknowledged that the intestinal microbiota plays a profound role in overall health by signaling to both the central and peripheral nervous systems, as well as other distant organs. Disruption in this bidirectional communication between bacteria and the host results in dysbiosis, fostering the development of various diseases, including neurological disorders, cardiovascular diseases, and cancer. This review aims to delve into the intricate biological mechanisms underpinning dysbiosis associated with aging and the clinical ramifications of such dysregulation. Furthermore, we aspire to explore bioactive compounds endowed with functional properties capable of modulating and restoring balance in this aging-related dysbiotic process through epigenetics alterations.

Culture media and format alter cellular composition and barrier integrity of porcine colonoid-derived monolayers

Intestinal organoid technology has revolutionized our approach to in vitro cell culture due in part to their three-dimensional structures being more like the native tissue from which they were derived with respect to cellular composition and architecture. For this reason, organoids are becoming the new gold standard for undertaking intestinal epithelial cell research. Unfortunately, their otherwise advantageous three-dimensional geometry prevents easy access to the apical epithelium, which is a major limitation when studying interactions between dietary or microbial components and host tissues. To overcome this problem, we developed porcine colonoid-derived monolayers cultured on both permeable Transwell inserts and tissue culture treated polystyrene plates. We found that seeding density and culture format altered the expression of genes encoding markers of specific cell types (stem cells, colonocytes, goblets, and enteroendocrine cells), and barrier maturation (tight junctions). Additionally, we found that changes to the formulation of the culture medium altered the cellular composition of colonoids and of monolayers derived from them, resulting in cultures with an increasingly differentiated phenotype that was similar to that of their tissue of origin.

Biotics: An emerging food supplement for health improvement in the era of immune modulation

The involvement of the commensal microbiota in immune function is a multifold process. Biotics, such as probiotics, prebiotics, synbiotics, and paraprobiotics, have been subjected to animal and human trials demonstrating the association between gut microbes and immunity biomarkers leading to improvement in overall health. In recent years, studies on human microbiome interaction have established the multifarious role of biotics in maintaining overall health. The consumption of biotics has been extensively reported to help in maintaining microbial diversity, enhancing gut-associated mucosal immune homeostasis, and providing protection against a wide range of lifestyle disorders. However, the establishment of biotics as an alternative therapy for a range of health conditions is yet to be ascertained. Despite the fact that scientific literature has demonstrated the correlation between biotics and immune modulation, most in vivo and in vitro reports are inconclusive on the dosage required. This review provides valuable insights into the immunomodulatory effects of biotics consumption based on evidence obtained from animal models and clinical trials. Furthermore, we highlight the optimal dosages of biotics that have been reported to deliver maximum health benefits. By identifying critical research gaps, we have suggested a roadmap for future investigations to advance our understanding of the intricate crosstalk between biotics and immune homeostasis.