Changes in intestinal microbiota composition and metabolism coincide with increased intestinal permeability in young adults under prolonged physiological stress

Intimate partner violence and stress-related disorders: from epigenomics to resilience

Intimate Partner Violence (IPV) is a major public health problem to be addressed with innovative and interconnecting strategies for ensuring the psychophysical health of the surviving woman. According to the World Health Organization, 27% of women worldwide have experienced physical and sexual IPV in their lifetime. Most of the studies on gender-based violence focus on short-term effects, while long-term effects are often marginally included even though they represent the most serious and complex consequences. The molecular mechanisms underlying stress-related disorders in IPV victims are multiple and include dysregulation of the hypothalamic-pituitary-adrenal axis, inflammatory response, epigenetic modifications, neurotransmitter imbalances, structural changes in the brain, and oxidative stress. This review aims to explore the long-term health consequences of intimate partner violence (IPV), emphasizing the biological and psychological mechanisms underlying stress-related disorders and resilience. By integrating findings from epigenetics, microbiome research, and artificial intelligence (AI)-based data analysis, we highlight novel strategies for mitigating IPV-related trauma and improving recovery pathways. Genome-wide environment interaction studies, enhanced by AI-assisted data analysis, offer a promising public health approach for identifying factors that contribute to stress-related disorders and those that promote resilience, thus guiding more effective prevention and intervention strategies.

Psychological stress on cancer progression and immunosenescence

Diagnosis and treatment of cancer constitute a deeply stressful experience that involves unique and common problems and generates uncertainty, fear and emotional distress. Furthermore, there are reciprocal interactions between psychological stress and cancer in the clinical settings. Therefore, it is crucial to understand the links of stress with cancer. A growing body of epidemiological and preclinical studies have suggested that stress affects cancer progression, and metastasis and treatment outcomes. Furthermore, stress elicits premature aging and deterioration of the immune system (known as immunosenescence), causing vulnerability to infections, autoimmune diseases, and cancers. In this review, we describe recent advances in how stress affects cancer progression through specific stress hormones and receptor systems as well as intracellular molecular processes, and discuss how stress-evoked neuroendocrine molecules regulate local and systemic immune responses in the tumor microenvironment. Furthermore, we review the molecular mechanisms of immunosenescence and evidence of psychological stress-evoked immunosenescence, highlighting the clinical value for available psychological and/or pharmacological interventions for psychological stress in patients with cancer. Based on existing evidence and emerging mechanistic insights, factors linked with psychological stress, immunosenescence and complications in cancer survivors need to be determined in future studies, and screening programs should be added to follow-up.

Integrating metagenomics and metabolomics to study the gut microbiome and host relationships in sports across different energy systems

The gut microbiome plays a critical role in modulating host metabolism, influencing energy production, nutrient utilization, and overall physiological adaptation. In athletes, these microbial functions may be further specialized to meet the unique metabolic demands of different sports disciplines. This study explored the role of the gut microbiome in modulating host metabolism among Colombian athletes by comparing elite weightlifters (n = 16) and cyclists (n = 13) through integrative omics analysis. Fecal and plasma samples collected one month before an international event underwent metagenomic, metabolomic, and lipidomic profiling. Metagenomic analysis revealed significant microbial pathways, including L-arginine biosynthesis III and fatty acid biosynthesis initiation. Key metabolic pathways, such as phenylalanine, tyrosine, and tryptophan biosynthesis; arginine biosynthesis; and folate biosynthesis, were enriched in both athlete groups. Plasma metabolomics and lipidomics revealed distinct metabolic profiles and a separation between athlete types through multivariate models, with lipid-related pathways such as lipid droplet formation and glycolipid synthesis driving the differences. Notably, elevated carnitine, amino acid, and glycerolipid levels in weightlifters suggest energy system-specific metabolic adaptations. These findings underscore the complex relationship between the gut microbiota composition and metabolic responses tailored to athletic demands, laying the groundwork for personalized strategies to optimize performance. This research highlights the potential for targeted modulation of the gut microbiota as a basis for tailored interventions to support specific energy demands in athletic disciplines.

Ocular surface microbiome: Influences of physiological, environmental, and lifestyle factors

PURPOSE

The ocular surface (OS) microbiome is influenced by various factors and impacts on ocular health. Understanding its composition and dynamics is crucial for developing targeted interventions for ocular diseases. This study aims to identify host variables, including physiological, environmental, and lifestyle (PEL) factors, that influence the ocular microbiome composition and establish valid associations between the ocular microbiome and health outcomes.

METHODS

The 16S rRNA gene sequencing was performed on OS samples collected from 135 healthy individuals using eSwab. DNA was extracted, libraries prepared, and PCR products purified and analyzed. PEL confounding factors were identified, and a cross-validation strategy using various bioinformatics methods including Machine learning was used to identify features that classify microbial profiles.

RESULTS

Nationality, allergy, sport practice, and eyeglasses usage are significant PEL confounding factors influencing the eye microbiome. Alpha-diversity analysis revealed significant differences between Spanish and Italian subjects (p-value < 0.001), with a median Shannon index of 1.05 for Spanish subjects and 0.59 for Italian subjects. Additionally, 8 microbial genera were significantly associated with eyeglass usage. Beta-diversity analysis indicated significant differences in microbial community composition based on nationality, age, sport, and eyeglasses usage. Differential abundance analysis identified several microbial genera associated with these PEL factors. The Support Vector Machine (SVM) model for Nationality achieved an accuracy of 100%, with an AUC-ROC score of 1.0, indicating excellent performance in classifying microbial profiles.

CONCLUSION

This study underscores the importance of considering PEL factors when studying the ocular microbiome. Our findings highlight the complex interplay between environmental, lifestyle, and demographic factors in shaping the OS microbiome. Future research should further explore these interactions to develop personalized approaches for managing ocular health.

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.

Comprehensive insights into emerging advances in the Neurobiology of anorexia

BACKGROUND

Anorexia is a complex eating disorder influenced by genetic, environmental, psychological, and socio-cultural factors. Research into its molecular mechanisms and neural circuits has deepened our understanding of its pathogenesis. Recent advances in neuroscience, molecular biology, and genetics have revealed key molecular and neural circuit mechanisms underlying anorexia.

AIM OF REVIEW

Clarify the peripheral and central molecular mechanisms regulating various types of anorexia, identify key cytokines and neural circuits, and propose new strategies for its treatment. Key scientific concepts of review: Anorexia animal models, including activity-induced, genetic mutation, and inflammation-induced types, are explored for their relevance to studying the disorder. Anorexic behavior is regulated by cytokines, hormones (like GDF15, GLP-1, and leptin), and neural circuits such as AgRP, serotonergic, dopaminergic, and glutamatergic pathways. Disruptions in these pathways, including GABAergic signaling in AgRP neurons and 5-HT2C and D2 receptors, contribute to anorexia. Potential therapies target neurotransmitter receptors, ghrelin receptors, and the GDF15-GFRAL pathway, offering insights for treating anorexia, immune responses, and obesity.

Effect of 2000-meter rowing test on parameters of intestinal integrity in elite rowers during competitive phase - observational study

BACKGROUND

The epithelial wall leakage has been extensively studied in sports disciplines like running and cycling. However, little is known about gut permeability in other disciplines, like rowing, especially after the regular competition performance distance of 2000 m. Therefore, our study aimed to check gut permeability after the 2000-meter rowing test in the annual training cycle. The phenomenon of epithelial wall leakage has been the subject of investigations within athletic domains such as running and cycling. Nevertheless, there exists an insufficiency of understanding regarding gut permeability in alternative disciplines, such as rowing, particularly following the completion of a standard competitive distance of 2000 m. Hence, the principal objective of our study was to assess gut permeability after the completion of a 2000-meter rowing test.

METHODS

The study was performed at the beginning of a competitive training phase. Eighteen elite rowers of the Polish Rowing Team participated in study after applying the inclusion/exclusion criteria. The participants performed a 2000-meter ergometer test. Blood samples were taken before the test, after exercise, and after 1-hour of restitution. Parameters, such as I-FABP, LPS, LBP, and zonulin, were determined using appropriate biochemical tests.

RESULTS

There were no changes between pre- and post-exercise values in I-FABP, LBP, LPS, and zonulin. However, the I-FABP changed from 6,49 ± 2,15 to 8,3 ± 2,71 (ng/ml) during the recovery period, and LBP decreased from 2,73 ± 0,77 to 2,035 ± 0,53 (µg/ml) simultaneously. Other parameters have not changed.

CONCLUSION

The results of this study showed that intense physical effort performed during the training period is sufficient to negatively affect the gut integrity of rowers.

Effect of Probiotics on Improving Intestinal Mucosal Permeability and Inflammation after Surgery

Background/Aims

We explored the mechanisms underlying the improvement of postoperative ileus (POI) following probiotic pretreatment. We assessed intestinal permeability, inflammation, tight junction (TJ) protein expression in the gut epithelium, and plasma interleukin (IL)-17 levels in a guinea pig model of POI.

Methods

Guinea pigs were divided into control, POI, and probiotic groups. The POI and probiotic groups underwent surgery, but the probiotic group received probiotics before the procedure. The ileum and proximal colon were harvested. Intestinal permeability was measured via horseradish peroxidase permeability. Inflammation was evaluated via leukocyte count in the intestinal wall muscle layer, and calprotectin expression in each intestinal wall layer was analyzed immunohistochemically. TJ proteins were analyzed using immunohistochemical staining, and plasma IL-17 levels were measured using an enzyme-linked immunosorbent assay.

Results

The POI group exhibited increased intestinal permeability and inflammation, whereas probiotic pretreatment reduced the extent of these POI-induced changes. Probiotics restored the expression of TJ proteins occludin and zonula occludens-1 in the proximal colon, which were increased in the POI group. Calprotectin expression significantly increased in the muscle layer of the POI group and was downregulated in the probiotic group; however, no distinct differences were observed between the mucosal and submucosal layers. Plasma IL-17 levels did not significantly differ among the groups.

Conclusions

Probiotic pretreatment may relieve POI by reducing intestinal permeability and inflammation and TJ protein expression in the gut epithelium. These findings suggest a potential therapeutic approach for POI management.

The Gut Microbiota Characterization of a World-Class Mountain Trail Runner During a Complete Competition Season: A Case Report

In the present case study, the gut microbiota (GM) profile of a male elite mountain runner (34 years, 171 cm, 59 kg, VO2max = 92 mL/min/kg) was analyzed over a 5-month competitive period (6 samples). Gut microbiota diversity increased throughout the season, where higher levels coincided with peak performance, and shorter and longer races (42 km versus 172 km) produced different phenotypic GM changes. Shorter races promoted elevation of protective bacteria related to positive benefits (higher production of short-chain fatty acids, lactate resynthesis, and mucin degraders). By contrast, longer races promoted an elevation of opportunistic pathogenic bacteria while reducing protective commensal bacteria. The present findings indicate that a higher resilience of the GM after competitions may support rapid recovery from maximal exercise. Gut microbiota analyses before and after competition could represent a rapid indicator for the (patho) physiological impact of exercise and provide information on gut health and the recovery time needed.

Atractylodes macrocephala Rhizoma alleviates blood hyperviscosity induced by high-fat, high-sugar, and high-salt diet by inhibiting gut-liver inflammation and fibrinogen synthesis

ETHNOPHARMACOLOGICAL RELEVANCE

Unhealthy dietary patterns and lifestyle changes have been linked to increased blood viscosity, which is recognized as an important pathogenic factor in cardiovascular and cerebrovascular diseases. The underlying mechanism may involve chronic inflammation resulting from intestinal barrier disruption induced by unhealthy diets. The rhizome of Atractylodes macrocephala Koidz. (Called Baizhu in China), is a well-used "spleen-reinforcing" traditional Chinese medicinal herb used for thousands of years. Previous research has demonstrated its multiple gastrointestinal health benefits and its ability to regulate metabolic disorders. However, the effects of Baizhu on blood hyperviscosity induced by long-term unhealthy diets remain unclear.

AIM OF THE STUDY

This study aimed to investigate the effects of the aqueous extract of Baizhu on blood hyperviscosity induced by unhealthy diet and to explore the possible mechanisms.

MATERIALS AND METHODS

The blood hyperviscosity model in SD rats was established utilizing a high-fat, high-sugar, and high-salt diet (HFSSD). Subsequently, the rats underwent a twelve-week intervention with varying doses of Baizhu and a positive control. To evaluate the efficacy of Baizhu on blood hyperviscosity in model rats, we measured behavioral index, hemorheological parameters, inflammatory cytokines, hematology, adhesion molecules, as well as biochemical indicators in serum and liver. We also assessed the pathological states of the colon and liver. Furthermore, Western blotting, ELISA, IHC, and qRT-PCR were used to determine the effect of Baizhu on the IL-6/STAT3/ESRRG signaling pathway and FIB synthesis.

RESULTS

The intervention of Baizhu showed evident attenuating effects on blood viscosity and microcirculation disorders, and exhibit the capacity to moderately modulate parameters including grip, autonomous activities, vertigo time, TC, TG, LDL-c, inflammatory factors, adhesion factors, hematological indicators, etc. At the same time, it reduces liver lipid droplet deposition, restores intestinal integrity, and lowers LPS level in the serum. Subsequent experimental results showed that Baizhu downregulated the expression of TLR4 and NF-κB in colon tissue, as well as the expression of IL-6, TLR4, p-JAK2, p-STAT3, and ESRRG in liver tissue. Finally, we also found that Baizhu could regulate the levels of FIB in plasma and liver.

CONCLUSION

Baizhu protects HFSSD-induced rats from blood hyperviscosity, likely through repairing the intestinal barrier and inhibiting LPS/TLR4-associated liver inflammatory activation, thus suppressing FIB synthesis through the downregulation of IL-6/STAT3/ESRRG pathway.

Impact of liposomal hesperetin in broilers: prospects for improving performance, antioxidant potential, immunity, and resistance against Listeria monocytogenes

Liposomal encapsulated phytogenics, such as liposomal hesperetin, are considered novel substitutes for antibiotics in the broiler industry owing to their improved nutritional and therapeutic properties. Therefore, our key goal was to investigate liposomal hesperetin impact on broiler growth performance, health, antioxidant status, tight junction proteins (TJP), and resistance against Listeria monocytogenes. Four broiler groups were fed 0, 150, 250, or 400 mg/kg of liposomal hesperetin-supplemented diets and experimentally infected with L. monocytogenes strain. Herein, liposomal hesperetin, especially at higher concentrations, augmented broilers FCR with upregulation of genes encoding TJP (occludin, JAM-2, MUC-2), and antioxidant attributes (GPX-1, SOD-1, CAT, HO-1, NQO1, COX2), which reflect enhancing health and welfare of broilers. Muscle antioxidant biomarkers were enhanced; meanwhile, muscle MDA, ROS, and H2O2 levels were reduced in response to 400 mg/kg of liposomal hesperetin. Liposomal hesperetin fortification reduced L. monocytogenes loads and expression levels of its virulence-related genes (flaA, hlyA, and ami). Remarkably, histopathological alterations in intestinal and brain tissues of L. monocytogenes-infected broilers were restored post-inclusion at higher levels of liposomal hesperetin, which reflects increase of the birds' resistance to L. monocytogenes infection. Transcription levels of genes encoding cytokines/chemokines (MyD88, AVBD6, CCL20, IL-1β, IL-18), and autophagy (Bcl-2, LC3, AMPK, AKT, CHOP, Bip, p62, XBP1) were ameliorated following dietary liposomal hesperetin fortification, which suggests enhancement of the birds' immunity and health. Collectively, our research recommends liposomal hesperetin application in broiler diets owing to its promoting impact on growth performance, antioxidant status, immunity, health, and welfare besides its antibacterial, and antivirulence characteristics to fight against L. monocytogenes.

The association between defecation frequency and mortality in critically ill patients with suspected sepsis in Israel

BACKGROUND

The pivotal role of the gastrointestinal (GI) tract in sepsis is well recognized. This study aimed to evaluate the associations between defecation frequency as a basic assessment of GI function and the clinical outcomes of intensive care unit patients with suspected sepsis.

METHODS

This retrospective, single-center study included patients suspected of having sepsis. The number of defecations and consecutive days without defecation during the 72 hours preceding the suspected infection were assessed. The primary outcome was 30-day all-cause mortality. Multivariate regression analysis adjusting for potential confounders was employed to establish the associations between GI function and clinical outcomes.

RESULTS

The final analysis included 1,306 patients with a median age of 56.2 years (interquartile range [IQR], 39.6-69.1); 919 (70.4%) were male, and the median Acute Physiology and Chronic Health Evaluation II score was 22.0 (IQR, 17.0-27.0). The median Sequential Organ Failure Assessment score at the time of suspected infection was 5.0 (IQR, 3.0-7.0). Mortality rates were 20.3%, 28.0%, and 34.3% for patients with 0-2, 3-5, and >5 defecations, respectively (P<0.001). There was a strong correlation between the number of defecations and mortality (r=0.7, P=0.01). In multivariate analyses, each defecation was independently associated with increased mortality (adjusted odds ratio [aOR], 1.07; 95% CI, 1.01-1.12; P=0.01), while each consecutive day without a defecation was associated with reduced mortality (aOR, 0.83; 95% CI, 0.73-0.96; P=0.01).

CONCLUSIONS

A higher number of defecations in the 72 hours preceding suspected sepsis is associated with increased 30-day all-cause mortality, suggesting a potential association with GI tract dysfunction.

Time-restricted feeding mediated modulation of microbiota leads to changes in muscle physiology in Drosophila obesity models

Recent research has highlighted the essential role of the microbiome in maintaining skeletal muscle physiology. The microbiota influences muscle health by regulating lipid metabolism, protein synthesis, and insulin sensitivity. However, metabolic disturbances such as obesity can lead to dysbiosis, impairing muscle function. Time-restricted feeding (TRF) has been shown to mitigate obesity-related muscle dysfunction, but its effects on restoring healthy microbiomes remain poorly understood. This study utilizes 16S microbiome analysis and bacterial supplementation to investigate the bacterial communities influenced by TRF that may benefit skeletal muscle physiology. In wild-type and obese Drosophila models (axenic models devoid of natural microbial communities), the absence of microbiota influence muscle performance and metabolism differently. Specifically, axenic wild-type Drosophila exhibited reduced muscle performance, higher glucose levels, insulin resistance, ectopic lipid accumulation, and decreased ATP levels. Interestingly, in obese Drosophila (induced by a high-fat diet or predisposed obesity mutant Sk2), the absence of microbiota improved muscle performance, lowered glucose levels, reduced insulin resistance, and increased ATP levels. TRF was found to modulate microbiota composition, notably increasing Acetobacter pasteurianus (AP) and decreasing Staphylococcus aureus (SA) in both obesity models. Supplementation with AP improved muscle performance and reduced glucose and insulin resistance, while SA supplementation had the opposite effect. This study provides novel insights into the complex interactions between TRF, microbiota, and skeletal muscle physiology in different Drosophila models.

Acute stress triggers sex-dependent rapid alterations in the human small intestine microbiota composition

Background/aims

Digestive disorders of gut-brain interaction (DGBI) are very common, predominant in females, and usually associated with intestinal barrier dysfunction, dysbiosis, and stress. We previously found that females have increased susceptibility to intestinal barrier dysfunction in response to acute stress. However, whether this is associated with changes in the small bowel microbiota remains unknown. We have evaluated changes in the small intestinal microbiota in response to acute stress to better understand stress-induced intestinal barrier dysfunction.

Methods

Jejunal biopsies were obtained at baseline and 90 min after cold pain or sham stress. Autonomic (blood pressure and heart rate), hormonal (plasma cortisol and adrenocorticotropic hormone) and psychological (Subjective Stress Rating Scale) responses to cold pain and sham stress were monitored. Microbial DNA from the biopsies was analyzed using a 16S metabarcoding approach before and after cold pain stress and sham stress. Differences in diversity and relative abundance of microbial taxa were examined.

Results

Cold pain stress was associated with a significant decrease in alpha diversity (P = 0.015), which was more pronounced in females, along with significant sex differences in the abundance of specific taxa and the overall microbiota composition. Microbiota alterations significantly correlated with changes in psychological responses, hormones, and gene expression in the intestinal mucosal. Cold pain stress was also associated with activation of autonomic, hormonal and psychological response, with no differences between sexes.

Conclusions

Acute stress elicits rapid alterations in bacterial composition in the jejunum of healthy subjects and these changes are more pronounced in females. Our results may contribute to the understanding of female predominance in DGBI.

Could tolerance to DNA be broken in the gut in systemic lupus erythematosus?

The bacteria in the human colon outnumber the total number of nucleated cells in the human body by approximately 10:1. The DNA that the bacteria contain is enriched around 20-fold in immune stimulatory CpG motifs compared to the DNA of host cells. In addition, this DNA can have alternative more immunogeneic DNA structures and it may be presented to the immune system alongside other proinflammatory bacterial innate ligands such as LPS. To ensure that this immunostimulatory combination is not pathogenic, the luminal boundary of host tissues in the human gastrointestinal tract is protected by cells secreting bactericides together with the secreted enzyme DNASE1L3 that can break down bacterial DNA. Cells with RNA encoding DNASE1L3 are particularly abundant in the gut-associated lymphoid tissue where bacteria are specifically sampled into the body, alongside B cells noted for their T independent function. Importantly, individuals with loss of function mutations in DNASE1L3 develop anti-DNA antibodies and lupus symptoms. In this review, we explore the possibility that a perfect storm might break tolerance to DNA: when bacterial DNA from microbiota that is not digested by DNASE1L3 directly encounters B cells that are not necessarily restricted by T cell dependence.

Comparative Analysis of Intestinal Microbiota in Wild, Domesticated, and Cultured Gymnocypris potanini firmispinatus

The impact of the living environments on the intestinal microbiota of Gymnocypris potanini firmispinatus was studied by analyzing intestinal microbiota diversity, composition, and potential function among wild, domesticated, and cultured groups. The results showed that the fish living in the wild environment exhibited the highest alpha diversity of intestinal microbiota. Intestinal microbial communities in the three groups clustered by living environment, with domesticated and cultured groups showing higher similarity. The dominant phylum in the wild group was Proteobacteria, whereas Fusobacteria and Proteobacteria were the predominate bacteria in the domesticated and cultured groups. RsaHF231, Actinobacteria, Fusobacteria, Cyanobacteria, and Firmicutes were the five key bacteria differentially expressed among the groups. Functional prediction revealed significant variation in the L-cysteine degradation III pathway (PWY-5329) between wild and domesticated groups, and in the vitamin E biosynthesis pathway (PWY-1422) between wild and cultured groups (p < 0.05). These findings highlight the differences in microbiota communities between wild and farmed fish, which are essential for enhancing the cultivation of G. p. firmispinatus and for the formulation of specific probiotics and functional feeds.

Innovative mechanisms of micro- and nanoplastic-induced brain injury: Emphasis on the microbiota-gut-brain axis

Micro- and nanoplastics (MNPs), emerging environmental pollutants, infiltrate marine, terrestrial, and freshwater systems via diverse pathways, culminating in their accumulation in the human body through food chain transmission, posing potential health risks. Researches have demonstrated that MNPs disrupt gut microbiota equilibrium and compromise intestinal barrier integrity, as well as traverse the blood-brain barrier, leading to brain damage. Moreover, the complex interaction between the gut and the nervous system, facilitated by the "gut-brain axis," indicates an additional pathway for MNPs-induced brain damage. This has intensified scientific interest in the intercommunication between MNPs and the gut-brain axis. While existing studies have documented microbial imbalances and metabolic disruptions subsequent to MNPs exposure, the precise mechanisms by which the microbiota-gut-brain axis contributes to MNPs-induced central nervous system damage remain unclear. This review synthesizes current knowledge on the microbiota-gut-brain axis, elucidating the pathogenesis of MNPs-induced gut microbiota dysbiosis and its consequent brain injury. It emphasizes the complex interrelation between MNPs and the microbiota-gut-brain axis, advocating for the gut microbiota as a novel therapeutic target to alleviate MNP-induced brain harm.

Meeting report of the seventh annual Tri-Service Microbiome Consortium Symposium

The Tri-Service Microbiome Consortium (TSMC) was founded to enhance collaboration, coordination, and communication of microbiome research among DoD organizations and to facilitate resource, material and information sharing among consortium members, which includes collaborators in academia and industry. The 2023 annual symposium was a hybrid meeting held in Washington DC on 26-27 September 2023 concurrent with the virtual attendance, with oral and poster presentations and discussions centered on microbiome-related topics within five broad thematic areas: 1) Environmental Microbiome Characterization; 2) Microbiome Analysis; 3) Human Microbiome Characterization; 4) Microbiome Engineering; and 5) In Vitro and In Vivo Microbiome Models. Collectively, the symposium provided an update on the scope of current DoD and DoD-affiliated microbiome research efforts and fostered collaborative opportunities. This report summarizes the presentations and outcomes of the 7th annual TSMC symposium.

Associations Between Brain Morphology, Inflammatory Markers, and Symptoms of Fatigue, Depression, or Anxiety in Active and Remitted Crohn's Disease

BACKGROUND

Fatigue and psychosocial impairments are highly prevalent in IBD, particularly during active disease. Disturbed brain-gut interactions may contribute to these symptoms. This study examined associations between brain structure, faecal calprotectin, and symptoms of fatigue, depression, and anxiety in persons with Crohn's disease [CD] in different disease states.

METHODS

In this prospective observational study, n = 109 participants [n = 67 persons with CD, n = 42 healthy controls] underwent cranial magnetic resonance imaging, provided stool samples for analysis of faecal calprotectin, and completed questionnaires to assess symptoms of fatigue, depression, and anxiety. We analysed differences in grey matter volume [GMV] between patients and controls, and associations between regional GMV alterations, neuropsychiatric symptoms, and faecal calprotectin.

RESULTS

Symptoms of fatigue, depression, and anxiety were increased in patients with CD compared with controls, with highest scores in active CD. Patients exhibited regionally reduced GMV in cortical and subcortical sensorimotor regions, occipitotemporal and medial frontal areas. Regional GMV differences showed a significant negative association with fatigue, but not with depression or anxiety. Subgroup analyses revealed symptom-GMV associations for fatigue in remitted but not in active CD, whereas fatigue was positively associated with faecal calprotectin in active but not in remitted disease.

CONCLUSION

Our findings support disturbed brain-gut interactions in CD which may be particularly relevant for fatigue during remitted disease. Reduced GMV in the precentral gyrus and other sensorimotor areas could reflect key contributions to fatigue pathophysiology in CD. A sensorimotor model of fatigue in CD could also pave the way for novel treatment approaches.

Physical Exercise and the Gut Microbiome: A Bidirectional Relationship Influencing Health and Performance

Background/Objectives: The human gut microbiome is a complex ecosystem of microorganisms that can influence our health and exercise habits. On the other hand, physical exercise can also impact our microbiome, affecting our health. Our narrative review examines the bidirectional relationship between physical activity and the gut microbiome, as well as the potential for targeted probiotic regimens to enhance sports performance. Methods: We conducted a comprehensive literature review to select articles published up till January 2024 on the topics of physical exercise, sports, probiotics, and gut microbiota from major scientific databases, incorporating over 100 studies. Results: We found that the impact of physical activity on the gut microbiome varies with the type and intensity of exercise. Moderate exercise promotes a healthy immune system, while high-intensity exercise for a long duration can cause a leaky gut and consequent systemic inflammation, which may disrupt the microbial balance. Combining aerobic and resistance training significantly affects bacterial diversity, linked to a lower prevalence of chronic metabolic disorders. Furthermore, exercise enhances gut microbiome diversity, increases SCFA production, improves nutrient utilization, and modulates neural and hormonal pathways, improving gut barrier integrity. Our findings also showed probiotic supplementation is associated with decreased inflammation, enhanced sports performance, and fewer gastrointestinal disturbances, suggesting that the relationship between the gut microbiome and physical activity is mutually influential. Conclusions: The bidirectional relationship between physical activity and the gut microbiome is exemplified by how exercise can promote beneficial bacteria while a healthy gut microbiome can potentially enhance exercise ability through various mechanisms. These findings underscore the importance of adding potential tailored exercise regimens and probiotic supplementation that consider individual microbiome profiles into exercise programs.

Characteristics of the Gut Microbiota Composition of the Arctic Zone Residents in the Far Eastern Region

Background. In many studies over the past decade, scientists have made a connection between the composition of gut microbiota and human health. A number of publications have shown that gut bacteria are involved in many metabolic and physiological processes of the organism. The composition of the gut microbiome is unique for each person and is formed under the influence of various factors associated with both the individual characteristics of the body and the characteristics of the environment. Different regional characteristics make it necessary for the body to adapt to certain conditions, including temperature fluctuations. Living in areas with low temperatures, such as the Arctic zone, dictates the need for increased energy consumption, which affects the composition of the gut microbiome. Methods. In our study, an extensive questionnaire was conducted among the participants, where many questions were included about the dietary preferences of the study participants, which allowed them us to further divide them into groups according to their diets. Stool samples were collected from participants from 3 groups: Arctic native, Arctic newcomer and the control group. The next step was the isolation of bacterial DNA and sequencing the 16S rRNA gene. The analysis of the results of the diversity of the intestinal microbiota was carried out both with and without taking into account the dietary preferences of the participants. Results. As a result of comparing the intestinal microbiota obtained from residents of the Arctic zone with the gut microbiota of residents of other regions with a milder climate, significant differences are found. These differences may be related to limited food resources and a reduction in the variety of food products characteristic of this Arctic region. t was also found that representatives of the bacterial families Christensenellaceae and Muribaculaceae dominated the control group, both with traditional nutrition and with a dairy-free diet in comparison with the Arctic groups. The control group was dominated by representatives of the Prevotellaceae, Enterobacteriaceae and Comamonadaceae families compared to the Arctic group (with a traditional diet). The results also show that the number of representatives of the families Desulfovibrionaceae (with traditional diet) and Enterobacteriaceae (with milk-free diet) is growing in the Arctic group. Conclusions. In the course of this work, bacterial families characteristic of people living in the Arc-tic zone of the Far Eastern region of the Russian Federation were identified. Poor diet, difficult climatic conditions, and problems with logistics and medical care can have a strong impact on the health of this population. The main type of diet for the inhabitants of the Arctic is the traditional type of diet. They consume a large number of low-cost products, obtainget animal protein from poultry and canned food, and also eat a small number of fresh vegetables and fruits. Such a diet is due to the social status of the study participants and the climatic and geographical features of the region (difficulties in agriculture). With such a diet, we observe a decrease in representatives of the Christensenellaceae, Muribaculaceae, Eubacteriaceae, and Prevotellaceae families and an increase in representatives of the Enterobacteriaceae and Desulfovibrionaceae families among Arctic residents. This imbalance in the futuremay cause, this population may to develop various diseases in the future, including chronic diseases such as obesity, intestinal dysbiosis, inflammatory bowel diseases, and type 2 diabetes.

Regular Exercise Training Induces More Changes on Intestinal Glucose Uptake from Blood and Microbiota Composition in Leaner Compared to Heavier Individuals in Monozygotic Twins Discordant for BMI

BACKGROUND/OBJECTIVES

Obesity impairs intestinal glucose uptake (GU) (intestinal uptake of circulating glucose from blood) and alters gut microbiome. Exercise improves intestinal insulin-stimulated GU and alters microbiome. Genetics influence the risk of obesity and gut microbiome. However, the role of genetics on the effects of exercise on intestinal GU and microbiome is unclear.

METHODS

Twelve monozygotic twin pairs discordant for BMI (age 40.4 ± 4.5 years, BMI heavier 36.7 ± 6.0, leaner 29.1 ± 5.7, 8 female pairs) performed a six-month-long training intervention. Small intestine and colonic insulin-stimulated GU was studied using [18F]FDG-PET and microbiota from fecal samples with 16s rRNA.

RESULTS

Ten pairs completed the intervention. At baseline, heavier twins had lower small intestine and colonic GU (p < 0.05). Response to exercise differed between twins (p = 0.05), with leaner twins increasing colonic GU. Alpha and beta diversity did not differ at baseline. During the intervention, beta diversity changed significantly, most prominently at the mid-point (p < 0.01). Beta diversity changes were only significant in the leaner twins when the twin groups were analyzed separately. Exercise was associated with changes at the phylum level, mainly at the mid-point (pFDR < 0.05); at the genus level, several microbes increased, such as Lactobacillus and Sellimonas (pFDR < 0.05). In type 1 analyses, many genera changes were associated with exercise, and fewer, such as Lactobacillus, were also associated with dietary sugar consumption (p < 0.05).

CONCLUSIONS

Obesity impairs insulin-stimulated intestinal GU independent of genetics. Though both twin groups exhibited some microbiota changes, most changes in insulin-stimulated colon GU and microbiota were significant in the leaner twins.

Exploring the effects of environmentally relevant concentrations of tris(2-chloroethyl) phosphate on tadpole health: A comprehensive analysis of intestinal microbiota and hepatic transcriptome

Tris(2-chloroethyl) phosphate (TCEP), a chlorinated organophosphate ester, is commonly found in aquatic environments. Due to its various toxic effects, it may pose a risk to the health of aquatic organisms. However, the potential impacts of TCEP exposure on the intestinal microbiota and hepatic function in amphibians have not been reported. This study investigated the impact of long-term exposure to environmentally relevant concentrations of TCEP (0, 3, and 90 μg/L) on the intestinal microbiota and hepatic transcriptome of Polypedates megacephalus tadpoles. The results showed that the body size of the tadpoles decreased significantly with an increase in TCEP concentration. Additionally, TCEP exposure affected the diversity and composition of the intestinal microbiota in tadpoles, leading to significant changes in the relative abundance of certain bacterial groups (the genera Aeromonas decreased and Citrobacter increased) and potentially promoting a more even distribution of microbial species, as indicated by a significant increase in the Simpson index. Moreover, the impact of TCEP on hepatic gene expression profiles in tadpoles was significant, with the majority of differentially expressed genes (DEGs) (709 out of 906 total DEGs in 3 μg/L of TCEP versus control, and 344 out of 387 DEGs in 90 μg/L of TCEP versus control) being significantly down-regulated, which were primarily related to immune response and immune system process. Notably, exposure to TCEP significantly reduced the relative abundance of the genera Aeromonas and Cetobacterium in the tadpole intestine. This reduction was positively correlated with the down-regulated expression of immune-related genes in the liver of corresponding tadpoles. In summary, these findings provide empirical evidence of the potential health risks to tadpoles exposed to TCEP at environmentally relevant concentrations.

Ionizing Radiation Dose Differentially Affects the Host-Microbe Relationship over Time

Microorganisms that colonize in or on a host play significant roles in regulating the host's immunological fitness and bioenergy production, thus controlling the host's stress responses. Radiation elicits a pro-inflammatory and bioenergy-expensive state, which could influence the gut microbial compositions and, therefore, the host-microbe bidirectional relationship. To test this hypothesis, young adult mice were exposed to total body irradiation (TBI) at doses of 9.5 Gy and 11 Gy, respectively. The irradiated mice were euthanized on days 1, 3, and 9 post TBI, and their descending colon contents (DCCs) were collected. The 16S ribosomal RNAs from the DCCs were screened to find the differentially enriched bacterial taxa due to TBI. Subsequently, these data were analyzed to identify the metagenome-specific biofunctions. The bacterial community of the DCCs showed increased levels of diversity as time progressed following TBI. The abundance profile was the most divergent at day 9 post 11 Gy TBI. For instance, an anti-inflammatory and energy-harvesting bacterium, namely, Firmicutes, became highly abundant and co-expressed in the DCC with pro-inflammatory Deferribacteres at day 9 post 11 Gy TBI. A systems evaluation found a diverging trend in the regulation profiles of the functional networks that were linked to the bacteria and metabolites of the DCCs, respectively. Additionally, the network clusters associated with lipid metabolism and bioenergy synthesis were found to be activated in the DCC bacteria but inhibited in the metabolite space at day 9 post 11 Gy. Taking these results together, the present analysis indicated a disrupted mouse-bacteria symbiotic relationship as time progressed after lethal irradiation. This information can help develop precise interventions to ameliorate the symptoms triggered by TBI.

Emerging mycotoxins and preventive strategies related to gut microbiota changes: probiotics, prebiotics, and postbiotics - a systematic review

Recent research has focused on the involvement of the gut microbiota in various diseases, where probiotics, prebiotics, synbiotics, and postbiotics (PPSP) exert beneficial effects through modulation of the microbiome. This systematic review aims to provide insight into the interplay among emerging mycotoxins, gut microbiota, and PPSP. The review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. In this review, unregulated yet highly recurrent mycotoxins are classified as emerging mycotoxins. The most frequently observed mycotoxins included those from the Fusarium genus-enniatins (n = 11) and beauvericin (n = 11)-and the Alternaria genus-alternariol monomethyl ether, altertoxin, and tentoxin (n = 10). Among probiotics, the most studied genera were Lactobacillus, Bifidobacterium, and the yeast Saccharomyces cerevisiae. Inulin and cellulose were the most found prebiotics. Data on synbiotics and postbiotics are scarce. Studies have shown that both the gut microbiota and PPSP can detoxify and mitigate the harmful effects of emerging mycotoxins. PPSP not only reduced mycotoxin bioaccessibility, but also counteracted their detrimental effects by activating health-promoting pathways such as short-chain fatty acid production, genoprotection, and reduction of oxidative stress. However, both quantitative and qualitative data remain limited, indicating a need for further in vivo and long-term studies. The formulation of PPSP as functional foods, feeds, or nutraceuticals should be considered a preventive strategy against the toxicity of emerging mycotoxins, for which, there is no established regulatory framework.

Differences in intestinal bacteria in traumatic injury survivors with and without probable posttraumatic stress disorder

BACKGROUND

Posttraumatic stress disorder (PTSD) is a common consequence of traumatic injury, yet certain biological factors contributing to PTSD are poorly understood. The gut microbiome may influence mental health outcomes, but its role in heterogeneous PTSD presentations requires elucidation.

METHODS

Bacterial composition was examined in adults 2-4 years post-trauma with probable PTSD (n = 24) versus trauma-exposed controls without probable PTSD (n = 24). 16S rRNA sequencing and bioinformatic tools assessed microbial diversity and abundance. Relationships between taxa and PTSD symptom clusters were evaluated.

RESULTS

No differences were found in overall microbial community structure between groups. The probable PTSD group exhibited significantly reduced Actinobacteriota and increased Verrucomicrobiota phylum abundance compared to controls. Specific taxa showed notable inverse associations with negative mood/cognition versus hyperarousal symptoms. Prevotella and Ruminococcaceae were negatively associated with negative mood but positively associated with hyperarousal.

CONCLUSIONS

Results demonstrate microbial signatures of probable PTSD subtypes, highlighting the microbiome as a potential mediator of heterogeneous trauma psychopathology. Definition of PTSD microbial correlates provides a foundation for personalized psychobiotic interventions targeting predominant symptom profiles.

Probiotics for pancreatic β-cell function: from possible mechanism of action to assessment of effectiveness

Type 2 diabetes (T2D) is a metabolic disease characterized by chronic hyperglycemia because of insulin resistance (IR) and\or pancreatic β-cell dysfunction. Last century research showed that gut microbiota has a direct effect on metabolism and metabolic diseases. New studies into the human microbiome and its connection with the host is making it possible to develop new therapies for a wide variety of diseases. Inflammation is a well-known precursor to metabolic syndrome, which increases the risk of hypertension, visceral obesity, and dyslipidemia, which can lead to T2D through the damage of pancreatic β-cell and reduce insulin secretion. Current understanding for beneficial effects of probiotics in T2D strictly rely on both animal and clinical data, which mostly focused on their impact on IR, anthropometric parameters, glycemic control and markers of chronic systemic inflammation. From the other hand, there is a lack of evidence-based probiotic efficacy on pancreatic β-cell function in terms of T2D and related metabolic disorders. Therefore, current review will focus on the efficacy of probiotics for the protection of β-cells damage and it`s mechanism in patients with T2D.

Could environmental exposure and climate change Be a key factor in the rising incidence of early onset colorectal cancer?

The emergence of early onset colorectal cancer (EOCRC) is believed to result from the complex interplay between external environmental factors and internal molecular processes. This review investigates the potential association between environmental exposure to chemicals and climate change and the increased incidence of EOCRC, focusing on their effects on gut microbiota (GM) dynamics. The manuscript explores the birth cohort effect, suggesting that individuals born after 1950 may be at higher risk of developing EOCRC due to cumulative environmental exposures. Furthermore, we also reviewed the impact of environmental pollution, including particulate matter and endocrine disrupting chemicals (EDCs), as well as global warming, on GM disturbance. Environmental exposures have the potential to disrupt GM composition and diversity, leading to dysbiosis, chronic inflammation, and oxidative stress, which are known risk factors associated with EOCRC. Particulate matter can enter the gastrointestinal tract, modifying GM composition and promoting the proliferation of pathogenic bacteria while diminishing beneficial bacteria. Similarly, EDCs, can induce GM alterations and inflammation, further increasing the risk of EOCRC. Additionally, global warming can influence GM through shifts in gut environmental conditions, affecting the host's immune response and potentially increasing EOCRC risk. To summarize, environmental exposure to chemicals and climate change since 1950 has been implicated as contributing factors to the rising incidence of EOCRC. Disruptions in gut microbiota homeostasis play a crucial role in mediating these associations. Consequently, there is a pressing need for enhanced environmental policies aimed at minimizing exposure to pollutants, safeguarding public health, and mitigating the burden of EOCRC.

The Role of Gut Microbiota in Different Types of Physical Activity and Their Intensity: Systematic Review and Meta-Analysis

BACKGROUND

Intense exercise during training requires dietary modulation to support health and performance and differs in different types of activities. Diet, supplementation with prebiotics and probiotics, and, more recently, even physical activity can potentially improve health outcomes by modifying and protecting the gut microbiota. A systematic review and meta-analysis were conducted to investigate the modulation of gut microbiota in different types and intensities of physical activity and different lifestyles of athletes.

METHODS

The systematic review and meta-analysis were conducted according to the PRISMA guidelines, and the protocol was registered in PROSPERO (CRD42024500826).

RESULTS

Out of 1318 studies, only 10 met the criteria for inclusion in the meta-analysis. The pilot study's meta-regression analysis highlights the role of type and intensity of exercise in changing the B/B (Bacillota/Bacteroidota) ratio (p = 0.001).

CONCLUSIONS

As gut training becomes more popular among athletes, it is necessary to map interactions between microbiota and different types of physical activity, personalized diets, physical activities, and ergogenic supplements to enhance performance and athletic wellness.

Gene Expression Analysis before and after the Pelvic Flexure in the Epithelium of the Equine Hindgut

Previous research demonstrated the distribution of distinct microbial communities in the equine hindgut surrounding the pelvic flexure. The current study evaluated gene expression in epithelial tissues surrounding the pelvic flexure to characterize patterns that might correlate with microbial distribution. Gene expression was determined by analyzing RNA sequence data from the pelvic flexure, the left and right ventral colon, and the left and right dorsal colon. An average of 18,330 genes were expressed across the five tissues sampled. Most of the genes showed some level of expression in all five tissues. Tissue-restricted patterns of expression were also observed. Genes with restricted expression in the left ventral and left dorsal colons have communication, signaling, and regulatory functions that correlate with their known physiology. In contrast, genes expressed exclusively in the pelvic flexure have diverse functions. The ontology of genes differentially expressed between the pelvic flexure and the surrounding tissues was associated with immune functions and signaling processes. Despite being non-significant, these enrichment trends were reinforced by the functions of statistically significant expression differences between tissues of the hindgut. These results provide insight into the physiology of the equine hindgut epithelium that might influence the microbiota and its distribution.

'It takes a village': deciphering the role of the gut microbiome in the health and performance of military personnel

The human gut microbiome can be impacted by a range of environmental and lifestyle factors including diet, antibiotics, physical fitness and acute and chronic stressors. There is also evidence to suggest that specific compositional and/or functional features of the gut microbiome are mediators of aspects of health and performance including disease susceptibility, cognitive and physical states and the immune response. Therefore, understanding microbe-to-microbe and nutrient-to-microbe interactions in the gut and how they interact with host biology (eg, via the gut-brain axis) could enable better design of interventions aimed at modulating the gut microbiome to improve the health and performance of the military. Accordingly, this review summarises a thematic session hosted at the 6th International Conference on Soldier Physical Performance which provided an overview of military-relevant research related to the gut microbiome. It articulates a timely opportunity to leverage this rapidly advancing area to improve personnel health and military performance.

The Contrasting Effects of Two Distinct Exercise Training Modalities on Exhaustive Exercise-Induced Muscle Damage in Mice May Be Associated with Alterations in the Gut Microbiota

Exhaustive exercise is known to induce muscle damage characterized by inflammation and oxidative stress. Although "regular" and "weekend warrior" exercise regimens have been shown to confer comparable health benefits in human studies, such as reduced risks of all-cause, cardiovascular disease (CVD), and cancer mortality, their differential impacts on muscle damage post-exhaustive exercise remain unclear. This study aimed to compare the effects of long-term, moderate-intensity (LTMI) and short-term, high-intensity (STHI) training modalities, matched for total exercise volume, on gut microbiota, short-chain fatty acids (SCFAs), and exhaustive exercise-induced muscle damage in mice, as well as to evaluate the correlation between these factors. LTMI is considered a regular exercise regimen, while STHI shares some similarities with the "weekend warrior" pattern, such as promoting exercise intensity and condensing training sessions into a short period. Our findings indicate that LTMI training significantly enhanced the abundance of SCFA-producing bacteria, including Akkermansia, Prevotellaceae_NK3B31_group, Odoribacter, Alistipes, and Lactobacillus, thereby increasing SCFA levels and attenuating muscle damage following exhaustive swimming. In contrast, STHI training increased the abundance of opportunistic pathogens such as Staphylococcus and Bilophila, without altering SCFA levels, and was associated with exacerbated muscle damage. Moreover, we observed a significant negative correlation between the abundance of SCFA-producing bacteria and SCFA levels with the expression of inflammatory cytokines in the muscle of mice post-exhaustive exercise. Conversely, the abundance of Staphylococcus and Bilophila showed a notable positive correlation with these cytokines. Additionally, the effects of LTMI and STHI on exhaustive exercise-induced muscle damage were transmissible to untrained mice via fecal microbiota transplantation, suggesting that gut microbiota changes induced by these training modalities may contribute to their contrasting impacts on muscle damage. These results underscore the significance of selecting an appropriate training modality prior to engaging in exhaustive exercise, with implications for athletic training and injury prevention.

A Rapid and Reliable Spectrofluorimetric Method to Measure the Urinary Lactulose/Mannitol Ratio for Dysbiosis Assessment

Gut microbiota plays a crucial role in human health homeostasis, and the result of its alteration, known as dysbiosis, leads to several pathologies (e.g., inflammatory bowel disease, metabolic syndrome, and Crohn's disease). Traditional methods used to assess dysbiosis include the dual sugar absorption test and the urinary lactulose/mannitol ratio (LMR) measurement using mass spectrometry. Despite its precision, this approach is costly and requires specialized equipment. Hence, we developed a rapid and reliable spectrofluorimetric method for measuring LMR in urine, offering a more accessible alternative. This spectrofluorimetric assay quantifies the fluorescence of nicotinamide adenine dinucleotide (NADH) and nicotinamide adenine dinucleotide phosphate (NADPH) produced during the enzymatic oxidation of mannitol and lactulose, respectively. The assay requires 100 µL of urine samples and detects LMR values lower (eubiosis) and higher (dysbiosis) than 0.05, ultimately being amenable to high-throughput screening and automatization, making it practical for clinical and research settings. A validation of the method demonstrated its high precision, accuracy, and robustness. Additionally, this study confirmed analyte stability under various storage conditions, ensuring reliable results even with delayed analysis. Overall, this spectrofluorimetric technique reduces costs, time, and the environmental impact associated with traditional mass spectrometry methods, making it a viable option for widespread use in the assessment of dysbiosis.

Mathematical Modeling of Vedolizumab Treatment's Effect on Microbiota and Intestinal Permeability in Inflammatory Bowel Disease Patients

Growing evidence suggests that impaired gut permeability and gut microbiota alterations are involved in the pathogenesis of Inflammatory Bowel Diseases (IBDs), which include Ulcerative Colitis (UC) and Crohn's Disease (CD). Vedolizumab is an anti-α4β7 antibody approved for IBD treatment, used as the first treatment or second-line therapy when the first line results in inadequate effectiveness. The aim of this study is to develop a mathematical model capable of describing the pathophysiological mechanisms of Vedolizumab treatment in IBD patients. In particular, the relationship between drug concentration in the blood, colonic mucosal permeability and fecal microbiota composition was investigated and modeled to detect and predict trends in order to support and tailor Vedolizumab therapies. To pursue this aim, clinical data from a pilot study on a cluster of 11 IBD patients were analyzed. Enrolled patients underwent colonoscopy in three phases (before (t0), after 24 weeks of (t1) and after 52 weeks of (t2 ) Vedolizumab treatment) to collect mucosal biopsies for transepithelial electrical resistance (TEER) evaluation (permeability to ions), intestinal permeability measurement and histological analysis. Moreover, fecal samples were collected for the intestinal microbiota analysis at the three time points. The collected data were compared to those of 11 healthy subjects at t0, who underwent colonoscopy for screening surveillance, and used to implement a three-compartmental mathematical model (comprising central blood, peripheral blood and the intestine). The latter extends previous evidence from the literature, based on the regression of experimental data, to link drug concentration in the peripheral blood compartment with Roseburia abundance and intestinal permeability. The clinical data showed that Vedolizumab treatment leads to an increase in TEER and a reduction in intestinal permeability to a paracellular probe, improving tissue inflammation status. Microbiota analysis showed increasing values of Roseburia, albeit not statistically significant. This trend was adequately reproduced by the mathematical model, which offers a useful tool to describe the pathophysiological effects of Vedolizumab therapy on colonic mucosal permeability and fecal microbiota composition. The model's satisfactory predictive capabilities and simplicity shed light on the relationship between the drug, the microbiota and permeability and allow for its straightforward extension to diverse therapeutic conditions.

Moderate-intensity continuous training and high-intensity interval training modulate the composition of the oral microbiota of elderly adults: Randomized controlled trial

OBJECTIVE

We investigates the effects of 16-week high-intensity interval training and moderate-intensity continuous training on the composition of the oral microbiota. To the best of our knowledge, at the time of writing this paper no other scholars had described the oral metagenomic changes associated with prescribed exercise in older adults.

METHODS

Forty-three participants aged 60-74 years were randomized 1:1:1 to a control group, high-intensity interval training or moderate-intensity continuous training twice weekly for 16 weeks. Saliva samples were sequenced at baseline, week 8 and week 16 of intervention.

RESULTS

High-intensity interval training produced significant differences over time in Richness and a clear trend to decreased Simpson and Shannon diversity indices. In contrast, Simpson and Shannon indices showed an upward trend over time with moderate-intensity continuous training, which also decreased Firmicutes and increased Bacteroidetes levels. Significant differences in the abundance of pathogenic species were also observed after the participants completed the exercise interventions of either type.

CONCLUSIONS

Both types of exercise promoted subtle changes in the oral microbiota, confirming the modulatory effect of high-intensity interval training and moderate-intensity continuous training on the oral microbiome. Clinical trial registration NCT05220670.

Comparative analysis of circulating metabolomic profiles identifies shared metabolic alterations across distinct multistressor military training exercises

Military training provides insight into metabolic responses under unique physiological demands that can be comprehensively characterized by global metabolomic profiling to identify potential strategies for improving performance. This study identified shared changes in metabolomic profiles across three distinct military training exercises, varying in magnitude and type of stress. Blood samples collected before and after three real or simulated military training exercises were analyzed using the same untargeted metabolomic profiling platform. Exercises included a 2-wk survival training course (ST, n = 36), a 4-day cross-country ski march arctic training (AT, n = 24), and a 28-day controlled diet- and exercise-induced energy deficit (CED, n = 26). Log2-fold changes of greater than ±1 in 191, 121, and 64 metabolites were identified in the ST, AT, and CED datasets, respectively. Most metabolite changes were within the lipid (57-63%) and amino acid metabolism (18-19%) pathways and changes in 87 were shared across studies. The largest and most consistent increases in shared metabolites were found in the acylcarnitine, fatty acid, ketone, and glutathione metabolism pathways, whereas the largest decreases were in the diacylglycerol and urea cycle metabolism pathways. Multiple shared metabolites were consistently correlated with biomarkers of inflammation, tissue damage, and anabolic hormones across studies. These three studies of real and simulated military training revealed overlapping alterations in metabolomic profiles despite differences in environment and the stressors involved. Consistent changes in metabolites related to lipid metabolism, ketogenesis, and oxidative stress suggest a potential common metabolomic signature associated with inflammation, tissue damage, and suppression of anabolic signaling that may characterize the unique physiological demands of military training.NEW & NOTEWORTHY The extent to which metabolomic responses are shared across diverse military training environments is unknown. Global metabolomic profiling across three distinct military training exercises identified shared metabolic responses with the largest changes observed for metabolites related to fatty acids, acylcarnitines, ketone metabolism, and oxidative stress. These changes also correlated with alterations in markers of tissue damage, inflammation, and anabolic signaling and comprise a potential common metabolomic signature underlying the unique physiological demands of military training.

Gut flora in multiple sclerosis: implications for pathogenesis and treatment

ABSTRACT

Multiple sclerosis is an inflammatory disorder characterized by inflammation, demyelination, and neurodegeneration in the central nervous system. Although current first-line therapies can help manage symptoms and slow down disease progression, there is no cure for multiple sclerosis. The gut-brain axis refers to complex communications between the gut flora and the immune, nervous, and endocrine systems, which bridges the functions of the gut and the brain. Disruptions in the gut flora, termed dysbiosis, can lead to systemic inflammation, leaky gut syndrome, and increased susceptibility to infections. The pathogenesis of multiple sclerosis involves a combination of genetic and environmental factors, and gut flora may play a pivotal role in regulating immune responses related to multiple sclerosis. To develop more effective therapies for multiple sclerosis, we should further uncover the disease processes involved in multiple sclerosis and gain a better understanding of the gut-brain axis. This review provides an overview of the role of the gut flora in multiple sclerosis.

Stress-induced mucin 13 reductions drive intestinal microbiome shifts and despair behaviors

Depression is a prevalent psychological condition with limited treatment options. While its etiology is multifactorial, both chronic stress and changes in microbiome composition are associated with disease pathology. Stress is known to induce microbiome dysbiosis, defined here as a change in microbial composition associated with a pathological condition. This state of dysbiosis is known to feedback on depressive symptoms. While studies have demonstrated that targeted restoration of the microbiome can alleviate depressive-like symptoms in mice, translating these findings to human patients has proven challenging due to the complexity of the human microbiome. As such, there is an urgent need to identify factors upstream of microbial dysbiosis. Here we investigate the role of mucin 13 as an upstream mediator of microbiome composition changes in the context of stress. Using a model of chronic stress, we show that the glycocalyx protein, mucin 13, is selectively reduced after psychological stress exposure. We further demonstrate that the reduction of Muc13 is mediated by the Hnf4 transcription factor family. Finally, we determine that deleting Muc13 is sufficient to drive microbiome shifts and despair behaviors. These findings shed light on the mechanisms behind stress-induced microbial changes and reveal a novel regulator of mucin 13 expression.

Gut-brain barrier dysfunction bridge autistic-like behavior in mouse model of maternal separation stress: A behavioral, histopathological, and molecular study

Autism spectrum disorder (ASD) is a fast-growing neurodevelopmental disorder throughout the world. Experiencing early life stresses (ELS) like maternal separation (MS) is associated with autistic-like behaviors. It has been proposed that disturbance in the gut-brain axis-mediated psychiatric disorders following MS. The role of disruption in the integrity of gut-brain barrier in ASD remains unclear. Addressing this knowledge gap, in this study we aimed to investigate role of the gut-brain barrier integrity in mediating autistic-like behaviors in mouse models of MS stress. To do this, mice neonates are separated daily from their mothers from postnatal day (PND) 2 to PND 14 for 3 hours. During PND58-60, behavioral tests related to autistic-like behaviors including three-chamber sociability, shuttle box, and resident-intruder tests were performed. Then, prefrontal cortex (PFC), hippocampus, and colon samples were dissected out for histopathological and molecular evaluations. Results showed that MS is associated with impaired sociability and social preference indexes, aggressive behaviors, and impaired passive avoidance memory. The gene expression of CLDN1 decreased in the colon, and the gene expression of CLDN5, CLDN12, and MMP9 increased in the PFC of the MS mice. MS is associated with decrease in the diameter of CA1 and CA3 areas of the hippocampus. In addition, MS led to histopathological changes in the colon. We concluded that, probably, disturbance in the gut-brain barrier integrities mediated the autistic-like behavior in MS stress in mice.

Dietary Strategies to Improve Exercise Performance by Modulating the Gut Microbiota

Numerous research studies have shown that moderate physical exercise exerts positive effects on gastrointestinal tract health and increases the variety and relative number of beneficial microorganisms in the intestinal microbiota. Increasingly, studies have shown that the gut microbiota is critical for energy metabolism, immunological response, oxidative stress, skeletal muscle metabolism, and the regulation of the neuroendocrine system, which are significant for the physiological function of exercise. Dietary modulation targeting the gut microbiota is an effective prescription for improving exercise performance and alleviating exercise fatigue. This article discusses the connection between exercise and the makeup of the gut microbiota, as well as the detrimental effects of excessive exercise on gut health. Herein, we elaborate on the possible mechanism of the gut microbiota in improving exercise performance, which involves enhancing skeletal muscle function, reducing oxidative stress, and regulating the neuroendocrine system. The effects of dietary nutrition strategies and probiotic supplementation on exercise from the perspective of the gut microbiota are also discussed in this paper. A deeper understanding of the potential mechanism by which the gut microbiota exerts positive effects on exercise and dietary nutrition recommendations targeting the gut microbiota is significant for improving exercise performance. However, further investigation is required to fully comprehend the intricate mechanisms at work.

The Effect of Clostridium butyricum on Gut Microbial Changes and Functional Profiles of Metabolism in High-fat Diet-fed Rats Depending on Age and Sex

Background/Aims

A high-fat diet (HFD) causes dysbiosis and promotes inflammatory responses in the colon. This study aims to evaluate the effects of Clostridium butyricum on HFD-induced gut microbial changes in rats.

Methods

Six-week-old Fischer-344 rats with both sexes were given a control or HFD during 8 weeks, and 1-to-100-fold diluted Clostridium butyricum were administered by gavage. Fecal microbiota analyses were conducted using 16S ribosomal RNA metagenomic sequencing and predictive functional profiling of microbial communities in metabolism.

Results

A significant increase in Ruminococcaceae and Lachnospiraceae, which are butyric acid-producing bacterial families, was observed in the probiotics groups depending on sex. In contrast, Akkermansia muciniphila, which increased through a HFD regardless of sex, and decreased in the probiotics groups. A. muciniphila positively correlated with Claudin-1 expression in males (P < 0.001) and negatively correlated with the expression of Claudin-2 (P = 0.042), IL-1β (P = 0.037), and IL-6 (P = 0.044) in females. In terms of functional analyses, a HFD decreased the relative abundances of M00131 (carbohydrate metabolism module), M00579, and M00608 (energy metabolism), and increased those of M00307 (carbohydrate metabolism), regardless of sex. However, these changes recovered especially in male C. butyricum groups. Furthermore, M00131, M00579, and M00608 showed a positive correlation and M00307 showed a negative correlation with the relative abundance of A. muciniphila (P < 0.001).

Conclusion

The beneficial effects of C. butyricum on HFD-induced gut dysbiosis in young male rats originate from the functional profiles of carbohydrate and energy metabolism.

Intestinal Barrier Dysfunction and Gut Microbiota in Non-Alcoholic Fatty Liver Disease: Assessment, Mechanisms, and Therapeutic Considerations

Non-alcoholic fatty liver disease (NAFLD) is a type of metabolic stress liver injury closely related to insulin resistance (IR) and genetic susceptibility without alcohol consumption, which encompasses a spectrum of liver disorders ranging from simple hepatic lipid accumulation, known as steatosis, to the more severe form of steatohepatitis (NASH). NASH can progress to cirrhosis and hepatocellular carcinoma (HCC), posing significant health risks. As a multisystem disease, NAFLD is closely associated with systemic insulin resistance, central obesity, and metabolic disorders, which contribute to its pathogenesis and the development of extrahepatic complications, such as cardiovascular disease (CVD), type 2 diabetes mellitus, chronic kidney disease, and certain extrahepatic cancers. Recent evidence highlights the indispensable roles of intestinal barrier dysfunction and gut microbiota in the onset and progression of NAFLD/NASH. This review provides a comprehensive insight into the role of intestinal barrier dysfunction and gut microbiota in NAFLD, including intestinal barrier function and assessment, inflammatory factors, TLR4 signaling, and the gut-liver axis. Finally, we conclude with a discussion on the potential therapeutic strategies targeting gut permeability and gut microbiota in individuals with NAFLD/NASH, such as interventions with medications/probiotics, fecal transplantation (FMT), and modifications in lifestyle, including exercise and diet.

Effects of Exercise on Gut Microbiota of Adults: A Systematic Review and Meta-Analysis

BACKGROUND

The equilibrium between gut microbiota (GM) and the host plays a pivotal role in maintaining overall health, influencing various physiological and metabolic functions. Emerging research suggests that exercise modulates the abundance and functionality of gut bacteria, yet the comprehensive effects on GM diversity remain to be synthesized.

OBJECTIVES AND DESIGN

The study aims to quantitatively examine the effect of exercise on the diversity of gut microbiota of adults using a systemic review and meta-analysis approach.

METHODS

PubMed, Ebsco, Embase, Web of Science, Cochrane Central Register of Controlled Trials, the China National Knowledge Infrastructure, and Wanfang Data were searched from their inception to September 2023. Exercise intervention studies with a control group that describe and compare the composition of GM in adults, using 16S rRNA gene sequencing, were included in this meta-analysis.

RESULTS

A total of 25 studies were included in this meta-analysis with a total of 1044 participants. Based on a fixed-effects model [Chi2 = 29.40, df = 20 (p = 0.08); I2 = 32%], the pooled analysis showed that compared with the control group, exercise intervention can significantly increase the alpha diversity of adult GM, using the Shannon index as an example [WMD = 0.05, 95% CI (0.00, 0.09); Z = 1.99 (p = 0.05)]. In addition, exercise interventions were found to significantly alter GM, notably decreasing Bacteroidetes and increasing Firmicutes, indicating a shift in the Firmicutes/Bacteroidetes ratio. The subgroup analysis indicates that females and older adults appear to exhibit more significant changes in the Shannon Index and observed OTUs.

CONCLUSIONS

Exercise may be a promising way to improve GM in adults. In particular, the Shannon index was significantly increased after exercise. Distinct responses in GM diversity to exercise interventions based on gender and age implicated that more research was needed.

The value of increased intestinal permeability in the pathogenesis of internal diseases

In the process of evolution in the gastrointestinal tract, a system of protection against bacterial and food antigens from getting into the blood was formed. The causes of increased intestinal permeability (IIP) can be microbiota imbalance, use of antibiotics, non-steroidal anti-inflammatory drugs, stress, diet rich in fructose, glucose, sucrose and long-chain fatty acids. The appearance of IIP may be of paramount importance in the pathogenesis of autoimmune diseases. A diet low in fermentable oligodimonosaccharides and polyols, pre- and probiotics, polyphenols, vitamins, short-chain fatty acids, dietary fiber, glutamine contributes to the reduction of IIP. It has been established that the cytoprotector rebamipide strengthens the barrier function throughout the gastrointestinal tract, which is reflected in practical recommendations for its use in diseases accompanied by IIP. The study of this direction will contribute to the emergence of a new strategy for the treatment of internal diseases.

Metabolites: a converging node of host and microbe to explain meta-organism

Meta-organisms encompassing the host and resident microbiota play a significant role in combatting diseases and responding to stress. Hence, there is growing traction to build a knowledge base about this ecosystem, particularly to characterize the bidirectional relationship between the host and microbiota. In this context, metabolomics has emerged as the major converging node of this entire ecosystem. Systematic comprehension of this resourceful omics component can elucidate the organism-specific response trajectory and the communication grid across the ecosystem embodying meta-organisms. Translating this knowledge into designing nutraceuticals and next-generation therapy are ongoing. Its major hindrance is a significant knowledge gap about the underlying mechanisms maintaining a delicate balance within this ecosystem. To bridge this knowledge gap, a holistic picture of the available information has been presented with a primary focus on the microbiota-metabolite relationship dynamics. The central theme of this article is the gut-brain axis and the participating microbial metabolites that impact cerebral functions.

Fermented foods: Harnessing their potential to modulate the microbiota-gut-brain axis for mental health

Over the past two decades, whole food supplementation strategies have been leveraged to target mental health. In addition, there has been increasing attention on the ability of gut microbes, so called psychobiotics, to positively impact behaviour though the microbiota-gut-brain axis. Fermented foods offer themselves as a combined whole food microbiota modulating intervention. Indeed, they contain potentially beneficial microbes, microbial metabolites and other bioactives, which are being harnessed to target the microbiota-gut-brain axis for positive benefits. This review highlights the diverse nature of fermented foods in terms of the raw materials used and type of fermentation employed, and summarises their potential to shape composition of the gut microbiota, the gut to brain communication pathways including the immune system and, ultimately, modulate the microbiota-gut-brain axis. Throughout, we identify knowledge gaps and challenges faced in designing human studies for investigating the mental health-promoting potential of individual fermented foods or components thereof. Importantly, we also suggest solutions that can advance understanding of the therapeutic merit of fermented foods to modulate the microbiota-gut-brain axis.

Effects of medical plants on alleviating the effects of heat stress on chickens

Over the past decades, global climate change has led to a significant increase in the average ambient temperature causing heat stress (HS) waves. This increase has resulted in more frequent heat waves during the summer periods. HS can have detrimental effects on poultry, including growth retardation, imbalance in immune/antioxidant pathways, inflammation, intestinal dysfunction, and economic losses in the poultry industry. Therefore, it is crucial to find an effective, safe, applicable, and economically efficient method for reducing these negative influences. Medicinal plants (MPs) contain various bioactive compounds with antioxidant, antimicrobial, anti-inflammatory, and immunomodulatory effects. Due to the biological activities of MPs, it could be used as promising thermotolerance agents in poultry diets during HS conditions. Nutritional supplementation with MPs has been shown to improve growth performance, antioxidant status, immunity, and intestinal health in heat-exposed chickens. As a result, several types of herbs have been supplemented to mitigate the harmful effects of heat stress in chickens. Therefore, several types of herbs have been supplemented to mitigate the harmful effects of heat stress in chickens. This review aims to discuss the negative consequences of HS in poultry and explore the use of different traditional MPs to enhance the health status of chickens.

Stressed to the Core: Inflammation and Intestinal Permeability Link Stress-Related Gut Microbiota Shifts to Mental Health Outcomes

Stress levels are surging, alongside the incidence of stress-related psychiatric disorders. Perhaps a related phenomenon, especially in urban areas, the human gut contains fewer bacterial species than ever before. Although the functional implications of this absence are unclear, one consequence may be reduced stress resilience. Preclinical and clinical evidence has shown how stress exposure can alter the gut microbiota and their metabolites, affecting host physiology. Also, stress-related shifts in the gut microbiota jeopardize tight junctions of the gut barrier. In this context, bacteria and bacterial products can translocate from the gut to the bloodstream, lymph nodes, and other organs, thereby modifying systemic inflammatory responses. Heightened circulating inflammation can be an etiological factor in stress-related psychiatric disorders, including some cases of depression. In this review, we detail preclinical and clinical evidence that traces these brain-to-gut-to-brain pathways that underlie stress-related psychiatric disorders and potentially affect their responsivity to conventional psychiatric medications. We also review evidence for interventions that modulate the gut microbiota (e.g., antibiotics, probiotics, prebiotics) to reduce stress responses and psychiatric symptoms. Lastly, we discuss challenges to translation and opportunities for innovations that could impact future psychiatric clinical practice.

Fecal supernatants from dogs with idiopathic epilepsy activate enteric neurons

Introduction

Alterations in the composition and function of the gut microbiome have been reported in idiopathic epilepsy (IE), however, interactions of gut microbes with the enteric nervous system (ENS) in this context require further study. This pilot study examined how gastrointestinal microbiota (GIM), their metabolites, and nutrients contained in intestinal contents communicate with the ENS.

Methods

Fecal supernatants (FS) from healthy dogs and dogs with IE, including drug-naïve, phenobarbital (PB) responsive, and PB non-responsive dogs, were applied to cultured myenteric neurons to test their activation using voltage-sensitive dye neuroimaging. Additionally, the concentrations of short-chain fatty acids (SCFAs) in the FS were quantified.

Results

Our findings indicate that FS from all examined groups elicited neuronal activation. Notably, FS from PB non-responsive dogs with IE induced action potential discharge in a higher proportion of enteric neurons compared to healthy controls, which exhibited the lowest burst frequency overall. Furthermore, the highest burst frequency in enteric neurons was observed upon exposure to FS from drug-naïve dogs with IE. This frequency was significantly higher compared to that observed in PB non-responsive dogs with IE and showed a tendency to surpass that of healthy controls.

Discussion

Although observed disparities in SCFA concentrations across the various FS samples might be associated with the induced neuronal activity, a direct correlation remains elusive at this point. The obtained results hint at an involvement of the ENS in canine IE and set the basis for future studies.

Gut-Brain Axis Impact on Canine Anxiety Disorders: New Challenges for Behavioral Veterinary Medicine

Anxiety disorders in dogs are ever-growing and represent an important concern in the veterinary behavior field. These disorders are often disregarded in veterinary clinical practice, negatively impacting the animal's and owner's quality of life. Moreover, these anxiety disorders can potentially result in the abandonment or euthanasia of dogs. Growing evidence shows that the gut microbiota is a central player in the gut-brain axis. A variety of microorganisms inhabit the intestines of dogs, which are essential in maintaining intestinal homeostasis. These microbes can impact mental health through several mechanisms, including metabolic, neural, endocrine, and immune-mediated pathways. The disruption of a balanced composition of resident commensal communities, or dysbiosis, is implicated in several pathological conditions, including mental disorders such as anxiety. Studies carried out in rodent models and humans demonstrate that the intestinal microbiota can influence mental health through these mechanisms, including anxiety disorders. Furthermore, novel therapeutic strategies using prebiotics and probiotics have been shown to ameliorate anxiety-related symptoms. However, regarding the canine veterinary behavior field, there is still a lack of insightful research on this topic. In this review, we explore the few but relevant studies performed on canine anxiety disorders. We agree that innovative bacterial therapeutical approaches for canine anxiety disorders will become a promising field of investigation and certainly pave the way for new approaches to these behavioral conditions.