Microbiota activation and regulation of innate and adaptive immunity

Infections, genetics, and Alzheimer's disease: Exploring the pathogenic factors for innovative therapies

Alzheimer's disease (AD) is a progressive neurodegenerative condition that creates a significant global health challenge and profoundly affects patients and their families. Recent research has highlighted the critical role of microorganisms, particularly viral infections, in the pathogenesis of AD. The involvement of viral infections in AD pathogenesis is predominantly attributed to their ability to induce neuroinflammation and amyloid beta (Aβ) deposition in the brain. The extant research exploring the relationship between viruses and AD has focused largely on Herpesviridae family. Traces of Herpesviruses, such as Herpes Simplex Virus-1 and Epstein Barr Virus, have been found in the brains of patients with AD. These viruses are thought to contribute to the disease progression by triggering chronic inflammatory responses in the brain. They can remain dormant in the brain, and become reactivated due to stress, a secondary viral infection, or immune-senescence in older adults. This review focuses on the association between Herpesviridae and bacterial infections with AD. We explore the genetic factors that might regulate viral illness and discuss clinical trials investigating antiviral and anti-inflammatory agents as possible therapeutic strategies to mitigate cognitive decline in patients with AD. In summary, understanding the interplay between infections, genetic factors, and AD pathogenesis may pave the way for novel therapeutic approaches, facilitating better management and possibly even prevent this debilitating disease.

The conspiring role of gut microbiota as primer of autoimmune thyroid diseases: A scoping focus

The thyroid gland is the body's largest single organ specialized for endocrine hormone production, and still unraveled mechanisms regulate its interaction between the hypothalamic-pituitary-thyroid axis and composition of the gut microbiota: in particular, a disrupted integrity of the intestinal barrier, causing dysbiosis and increasing detrimental substances or reducing beneficial metabolites, such as short-chain fatty acids (SCFAs) with proinflammatory effects, may be crucial for the induction of an autoimmune thyroid disease. More specifically, Lactobacilli and Bifidobacteria have a role in this partnership through a "molecular mimicry" mechanism, as their protein sequences share structural similarity with thyroid peroxidase and thyroglobulin. Lactobacilli can also increase T helper 17 cells, modifying the number of colonic regulatory T cells, largely implicated in the maintenance of immunological tolerance at the gut barrier. Additionally, Blautia and Anaerostipes work beneficially with butyric acid, one of the SCFAs, promoting antimicrobial peptide synthesis from the intestinal cells and bolstering the innate immune system's ability to struggle against pathogens, which can also influence thyroid hormone levels by regulating iodine uptake and metabolism. This review aims to summarize the current knowledge about the contribution of gut microbiota changes in triggering immune abnormalities leading to autoimmune thyroid diseases.

Combining gut microbiota modulation and immunotherapy: A promising approach for treating microsatellite stable colorectal cancer

Colorectal cancer (CRC) is one of the most prevalent and lethal cancers worldwide, ranking third in incidence and second in mortality. While immunotherapy has shown promise in patients with deficient mismatch repair (dMMR) or high microsatellite instability (MSI-H), its effectiveness in proficient mismatch repair (pMMR) or microsatellite stable (MSS) CRC remains limited. Recent advances highlight the gut microbiota as a potential modulator of anti-tumor immunity. The gut microbiome can significantly influence the efficacy of immune checkpoint inhibitors (ICIs), especially in pMMR/MSS CRC, by modulating immune responses and systemic inflammation. This review explores the role of the gut microbiota in pMMR/MSS CRC, the mechanisms by which it may enhance immunotherapy, and current strategies for microbiota modulation. We discuss the potential benefits of combining microbiota-targeting interventions with immunotherapy to improve treatment outcomes for pMMR/MSS CRC patients.

Utilizing Flaxseed as an Antimicrobial Alternative in Chickens: Integrative Review for Salmonella enterica and Eimeria

This review provides an integrative framework for understanding flaxseed (Linum utassitissimum) as an antimicrobial alternative for poultry production. We begin by familiarizing the reader with the global legislation of antibiotics in animal husbandry; highlighting gaps and current issues for Salmonella enterica (S. enterica) and Eimeria (coccidiosis-inducing). We then discuss the natural, symbiotic characteristics of the Galliformes order (chicken-like birds) and Linum (the flaxes). The key immunological themes in this review include: (i) flaxseed's regulation of innate and adaptive immunity in chickens, (ii) flaxseed's ability to accelerate chicken recovery from infection with S. enterica and Eimeria, and (iii) flaxseed's strengthening of immunity via vitamin B6 antagonism. Research indicates that whole flaxseed increases adaptive immune capacity by augmenting cecal Bacteroides and short-chain fatty acids while also attenuating the heterophil to lymphocyte ratio in chickens. Moreover, flaxseed accelerates chicken recovery from infection with Salmonella Enteritidis or Eimeria tenella; however, future work is needed to better understand (i) defatted flaxseed's superior performance against Eimeria species and (ii) Eimeria maxima's resilience against whole flaxseed. In the context of vitamin B6 antagonism, we propose that 15% whole flaxseed overcomes S. enterica's insult to estrogen synthesis by sustaining the activity of phosphatidylethanolamine methyltransferase (PEMT) in liver. We also propose that 10% defatted flaxseed (as a metformin homologue) strengthens chicken immunity by safeguarding gonadal physiology and by increasing plasma thymidine bioavailability. The concepts in this review can be used as a template for conducting advanced immunological studies in poultry science.

Anti-Inflammatory and Anti-Oxidant Impacts of Lentinan Combined with Probiotics in Ulcerative Colitis

Multi-methods have been developed to control ulcerative colitis. This research targeted to probe that lentinan combined with probiotics suppresses inflammation and oxidative stress responses in a dextran sulfate sodium (DSS)-induced colitis model. A mouse model of colitis was induced through oral administration with 2.5% DSS and treated with lentinan and probiotics independently or in combination. Then, bodyweight and Disease Activity Index (DAI) of mice were determined. Histopathology of colon tissue was analyzed, and apoptosis, inflammation and oxidative stress in the colon tissue of mice were observed. An HT-29 cell model of colitis was established by DSS stimulation and cultured with lentinan and/or probiotics to examine cell proliferation and apoptosis. The data discovered that after DSS induction of colitis, mice developed weight loss, increased DAI score, and shortened the length of colon. Also, severe histopathology of the colon, and increased apoptosis, inflammation and oxidative stress were recognizable. Lentinan could alleviate DSS-induced colitis, and the highest dose was the most significant. Probiotics could also relieve UC in mice, and mixed probiotics had a better therapeutic effect than single probiotics. Lentinan combined with probiotics could further alleviate DSS-induced colitis damage. In addition, lentinan combined with probiotics impaired apoptosis and enhanced proliferation of DSS-treated HT-29 cells. In a word, lentinan combined with probiotics reduces the inflammatory response and oxidative stress of UC.

Tinidazole mouth rinse for the treatment of oral lichen planus: an observational pilot study

BACKGROUND

Given the limited treatment options available for oral lichen planus (OLP), a study was undertaken to obtain preliminary information on the therapeutic efficacy of tinidazole mouth rinse in patients with OLP.

METHODS

A prospective, open-label pilot study was conducted to assess the efficacy of thrice-daily tinidazole mouth rinse for one week in OLP patients (n = 27). Reticulation/erythema/ulceration (REU) scores and visual analog scale (VAS) scores were used to measure lesions at baseline and after one week of treatment. Mucosal samples were collected, and the abundance of Fusobacterium nucleatum was quantified using RT-PCR. Statistical analysis using t-test, Wilcoxon signed rank test and Pearson correlation test.

RESULTS

After treatment, VAS scores significantly decreased in both reticular (P = 0.03) and erosive OLP patients (P = 0.003). However, REU scores significantly decreased only in erosive OLP patients (P = 0.002). The relative abundance of Fusobacterium nucleatum on the damaged mucosa surface significantly decreased in all OLP patients (P = 0.01). In erosive OLP patients, the triamcinolone group showed a significantly greater improvement in VAS scores compared to the tinidazole group (P = 0.01). However, there was no statistically significant correlation between the relative abundance of Fusobacterium nucleatum and REU scores in OLP patients (r = 0.0754, P = 0.61).

CONCLUSION

Tinidazole mouth rinse showed potential in reducing disease severity in OLP patients and was well-tolerated, suggesting its viability as a local therapeutic option. However, randomized controlled studies are warranted to confirm these preliminary findings.

The interaction between oral microbiota and gut microbiota in atherosclerosis

Atherosclerosis (AS) is a complex disease caused by multiple pathological factors threatening human health-the pathogenesis is yet to be fully elucidated. In recent years, studies have exhibited that the onset of AS is closely involved with oral and gut microbiota, which may initiate or worsen atherosclerotic processes through several mechanisms. As for how the two microbiomes affect AS, existing mechanisms include invading plaque, producing active metabolites, releasing lipopolysaccharide (LPS), and inducing elevated levels of inflammatory mediators. Considering the possible profound connection between oral and gut microbiota, the effect of the interaction between the two microbiomes on the initiation and progression of AS has been investigated. Findings are oral microbiota can lead to gut dysbiosis, and exacerbate intestinal inflammation. Nevertheless, relevant research is not commendably refined and a concrete review is needed. Hence, in this review, we summarize the most recent mechanisms of the oral microbiota and gut microbiota on AS, illustrate an overview of the current clinical and epidemiological evidence to support the bidirectional connection between the two microbiomes and AS.

Effects of the commensal microbiota on spleen and mesenteric lymph node immune function: investigation in a germ-free piglet model

Commensal microbial-host interaction is crucial for host metabolism, growth, development, and immunity. However, research on microbial-host immunity in large animal models has been limited. This study was conducted to investigate the effects of the commensal microbiota on immune function in two model groups: germ-free (GF) and specific-pathogen-free (SPF) piglets. The weight and organ index of the spleen of the GF piglet were larger than those in the SPF piglet (P < 0.05). The histological structure of the red pulp area and mean area of germinal centers were larger in the SPF piglet than in the GF piglet (P < 0.05), whereas the areas of staining of B cells and T cells in the spleen and mesenteric lymph nodes (MLNs) were lower in the GF piglet (P < 0.05). We identified immune-related genes in the spleen and MLNs using RNA sequencing, and used real-time quantitative PCR to analyze the expression of core genes identified in gene set enrichment analysis. The expression levels of genes in the transforming growth factor-β/SMAD3 signaling pathway, Toll-like receptor 2/MyD88/nuclear factor-κB signaling pathway, and pro-inflammatory factor genes IL-6 and TNF-α in the spleen and MLNs were higher in the SPF piglet and in splenic lymphocytes compared with those in the GF and control group, respectively, under treatment with acetic acid, propionic acid, butyric acid, lipopolysaccharide (LPS), or concanavalin A (ConA). The abundances of plasma cells, CD8++ T cells, follicular helper T cells, and resting natural killer cells in the spleen and MLNs were significantly greater in the SPF piglet than in the GF piglet (P < 0.05). In conclusion, the commensal microbiota influenced the immune tissue structure, abundances of immune cells, and expression of immune-related pathways, indicating the importance of the commensal microbiota for spleen and MLNs development and function. In our study, GF piglet was used as the research model, eliminating the interference of microbiota in the experiment, and providing a suitable and efficient large animal research model for exploring the mechanism of "microbial-host" interactions.

Dysbiosis in inflammatory bowel diseases: egg, not chicken

There is agreement that inflammatory bowel diseases are, both in terms of species composition and function, associated with an altered intestinal microbiome. This is usually described by the term "dysbiosis," but this is a vague definition lacking quantitative precision. In this brief narrative review, the evidence concerning the primary or secondary role of this dysbiotic state is critically evaluated. Among others, the following facts argue against a primary etiological impact: 1) There is no specific dysbiotic microbiome in IBD, 2) the presence or absence of mucosal inflammation has a profound impact on the composition of the microbiome, 3) dysbiosis is not specific for IBD but linked to many unrelated diseases, 4) antibiotics, probiotics, and microbiome transfer have a very limited therapeutic effect, 5) the microbiome in concordant twins is similar to disease-discordant twins, and 6) the microbiome in relatives of IBD patients later developing IBD is altered, but these individuals already display subclinical inflammation.

Autoprobiotics in the Treatment of Patients with Colorectal Cancer in the Early Postoperative Period

Despite great advances in the treatment of oncological diseases, the development of medical technologies to prevent or reduce complications of therapy, in particular, those associated with surgery and the introduction of antibiotics, remains relevant. The aim of this study is to evaluate the effectiveness of the use of autoprobiotics based on indigenous non-pathogenic strains of Enterococcus faecium and Enterococcus hirae as a personalized functional food product (PFFP) in the complex therapy of colorectal cancer (CRC) in the early postoperative period. A total of 36 patients diagnosed with CRC were enrolled in the study. Study group A comprised 24 CRC patients who received autoprobiotic therapy in the early postoperative period, while the control group C included 12 CRC patients without autoprobiotic therapy. Prior to surgery and between days 14 and 16 post-surgery, comprehensive evaluations were conducted on all patients, encompassing the following: stool and gastroenterological complaints analysis, examination of the gut microbiota (bacteriological study, quantitative polymerase chain reaction, metagenome analysis), and analysis of interleukins in the serum. Results: The use of autoprobiotics led to a decrease in dyspeptic complaints after surgery. It was also associated with the absence of postoperative complications, did not cause any side effects, and led to a decrease in the level of pro-inflammatory cytokines (IL-6 and IL-18) in the blood serum. The use of autoprobiotics led to positive changes in the structure of escherichia and enterococci populations, the elimination of Parvomonas micra and Fusobacterium nucleatum, and a decrease in the quantitative content of Clostridium perfringens and Akkermansia muciniphila. Metagenomic analysis (16S rRNA) revealed an increase in alpha diversity. Conclusion: The introduction of autoprobiotics in the postoperative period is a highly effective and safe approach in the complex treatment of CRC. Future studies will allow the discovery of additional fine mechanisms of autoprobiotic therapy and its impact on the digestive, immune, endocrine, and neural systems.

Multi-omics analysis of immune-related microbiome and prognostic model in head and neck squamous cell carcinoma

OBJECTIVES

The aim of our study is to explore the transcriptional and microbial characteristics of head and neck cancer's immune phenotypes using a multi-omics approach.

MATERIALS AND METHODS

Employing TCGA data, we analyzed head and neck squamous cell carcinoma (HNSCC) immune cells with CIBERSORT and identified differentially expressed genes using DESeq2. Microbial profiles, obtained from the TCMA database, were analyzed using LEfSe algorithm to identify differential microbes in immune cell infiltration (ICI) subgroups. Random Forest algorithm and deep neural network (DNN) were employed to select microbial features and developed a prognosis model.

RESULTS

We categorized HNSCC into three immune subtypes, finding ICI-2 with the worst prognosis and distinct microbial diversity. Our immune-related microbiome (IRM) model outperformed the TNM staging model in predicting survival, linking higher IRM model scores with poorer prognosis, and demonstrating clinical utility over TNM staging. Patients categorized as low-risk by the IRM model showed higher sensitivity to cisplatin and sorafenib treatments.

CONCLUSIONS

This study offers a comprehensive exploration of the ICI landscape in HNSCC. We provide a detailed scenario of immune regulation in HNSCC and report a correlation between differing ICI patterns, intratumor microbiome, and prognosis. This research aids in identifying prime candidates for optimizing treatment strategies in HNSCC.

CLINICAL RELEVANCE

This study revealed the microbial signatures associated with immunophenotyping of HNSCC and further found the microbial signatures associated with prognosis. The prognostic model based on IRM microbes is helpful for early prediction of patient prognosis and assisting clinical decision-making.

Peptidoglycan in osteoarthritis synovial tissue is associated with joint inflammation

OBJECTIVES

Peptidoglycan (PG) is an arthritogenic bacterial cell wall component whose role in human osteoarthritis is poorly understood. The purpose of this study was to determine if PG is present in synovial tissue of osteoarthritis patients at the time of primary total knee arthroplasty (TKA), and if its presence is associated with inflammation and patient reported outcomes.

METHODS

Intraoperative synovial tissue and synovial fluid samples were obtained from 56 patients undergoing primary TKA, none of whom had history of infection. PG in synovial tissue was detected by immunohistochemistry (IHC) and immunofluorescence microscopy (IFM). Synovial tissue inflammation and fibrosis were assessed by histopathology and synovial fluid cytokine quantification. Primary human fibroblasts isolated from arthritis synovial tissue were stimulated with PG to determine inflammatory cytokine response.

RESULTS

A total of 33/56 (59%) of primary TKA synovial tissue samples were positive for PG by IHC, and PG staining colocalized with markers of synovial macrophages and fibroblasts by IFM. Synovial tissue inflammation and elevated IL-6 in synovial fluid positively correlated with PG positivity. Primary human fibroblasts stimulated with PG secreted high levels of IL-6, consistent with ex vivo findings. Interestingly, we observed a significant inverse correlation between PG and age at time of TKA, indicating younger age at time of TKA was associated with higher PG levels.

CONCLUSION

Peptidoglycan is commonly found in synovial tissue from patients undergoing TKA. Our data indicate that PG may play an important role in inflammatory synovitis, particularly in patients who undergo TKA at a relatively younger age.

Association between oocyte donors' or recipients' body mass index and clinical outcomes after first single blastocyst transfers-the uterus is the most affected

OBJECTIVE

To assess whether high body mass index (BMI) in either oocyte donors or recipients is associated with poorer outcomes after the first single blastocyst transfer.

DESIGN

Retrospective study including 1,394 first blastocyst single embryo transfers (SETs) conducted by 1,394 recipients during oocyte donation cycles with the gametes retrieved from 1,394 women (January 2019-July 2021). Four BMI clusters were defined for both donors and recipients (underweight: <18.5 kg; normal weight: 18.5-24.9 kg; overweight: 25-29.9 kg; and obese: ≥30 kg).

SETTING

Network of private IVF centers.

PATIENTS

A total of 1,394 recipients aged 42.4 ± 4.0 and with a BMI of 23.2 ± 3.8 kg/m2, and 1,394 donors aged 26.1 ± 4.2 and with a BMI of 21.9 ± 2.5 kg/m2.

INTERVENTION

All oocytes were vitrified at 2 egg banks and warmed at 8 in vitro fertilization clinics that were part of the same network. Intracytoplasmic sperm injection, blastocyst culture, and either fresh or vitrified-warmed SETs were conducted. Putative confounders were investigated, and the data were adjusted through regression analyses.

MAIN OUTCOME MEASURES

The primary outcome was the live birth rate (LBR) per SET according to donors' and/or recipients' BMI. The main secondary outcome was the miscarriage rate (<22 gestational weeks) per clinical pregnancy.

RESULTS

The LBR per blastocyst SET showed no significant association with donors' BMI. Regarding recipients' BMI, instead, the multivariate odds ratio was significant in obese vs. normal-weight recipients (0.58, 95% confidence interval, 0.37-0.91). The miscarriage rate per clinical pregnancy was also significantly associated with recipients' obesity, with a multivariate odds ratio of 2.31 (95% confidence interval, 1.18-4.51) vs. normal-weight patients. A generalized additive model method was used to represent the relationship between predicted LBR or miscarriage rates and donors' or recipients' BMI; it pictured a scenario where the former outcome moderately but continuously decreases with increasing recipients' BMI to then sharply decline in the BMI range of 25-35 kg/m2. The miscarriage rate, instead, increases almost linearly with respect to both donors' and recipients' increasing BMI.

CONCLUSION

Obesity mostly affects the uterus, especially because of higher miscarriage rates. Yet, poorer outcomes can be appreciated already with a BMI of 25 kg/m2 in both oocyte donors and recipients. Finer markers of nutritional homeostasis are therefore desirable; recipients should be counseled about poorer expected outcomes in cases of overweight and obesity; and oocyte banks should avoid assigning oocytes from overweight donors to overweight and obese recipients.

TLR4, IgA and EpCAM Expression in Colorectal Cancer and Their Possible Association with Microbiota as a Pathogenic Factor; An Immunohistochemical and Genetic Study

BACKGROUND

The pathogenesis of inflammatory bowel disease (IBD) and colorectal cancer (CRC) is thought to be related to immune response against gut microbiota. TLR4, IgA, and EpCAM have a role in intestinal local immune response and their altered expression related to both IBD and CRC. Lipopolysaccharide (LPS) is the main activator of TLR4. The objective of this study is to evaluate the possible role of intestinal microbiota in the pathogenesis of IBD and CRC through expression of TLR4, IgA and EpCAM.

METHODS

One hundred five cases were divided into (Group 1/ Control: 10 sections of normal colonic mucosa, Group 2/CRC: 51 cases, Group 3/IBD: 44 cases). Immunohistochemistry for TLR4, IgA, and EpCAM was done. LPS was assessed in all groups. TLR4 gene and protein expression were assessed in colorectal cancer cell line by RT-PCR and immunocytochemistry.

RESULTS

There was a significant correlation between TLR4 and tumor grade (P value 0.003 and 0.01 respectively). A significant correlation was found between IgA expression and T stage (P value 0.02) and between EpCAM expression and histologic type (P value 0.02). In comparison of CRC patients to controls; there was a statistically significant different expression of TLR4 positivity, IgA positivity and EpCAM (P value <0.001, 0.004, <0.001 respectively). Patients with CRC were compared to colitis patients and there was a statistically significant different expression of IgA positivity and EpCAM expression (P value <0.001). There was significant higher expression of TLR4 in CRC cell line than the fibroblast by both PCR and immunocytochemistry (P-value: 0.003 and 0.024 respectively). LPS level in CRC patients was significantly higher than the control and IBD groups (P values <0.001 and <0.001 respectively).

CONCLUSION

TLR4, IgA, EpCAM expression in both CRC and IBD might be related to the pathogenic role of microbiota and could represent potential prevention modalities and therapeutic targets.

Clinical Relevance of Vaginal and Endometrial Microbiome Investigation in Women with Repeated Implantation Failure and Recurrent Pregnancy Loss

Recent studies have investigated if and how the vaginal and endometrial microbiome might affect endometrial receptivity and reproductive health. Although there is no consensus on the existence of a core uterine microbiome yet, evidence shows that the dominance of Lactobacillus spp. in the female reproductive tract is generally associated with eubiosis and improved chances of successful implantation and an ongoing pregnancy. Conversely, vaginal and endometrial dysbiosis can cause local inflammation and an increase of pro-inflammatory cytokines, compromising the integrity and receptivity of the endometrial mucosa and potentially hampering successful embryonic implantation. This review provides a critical appraisal of the influence of the vaginal and endometrial microbiome as parts of the female reproductive tract on fertility outcomes, focusing on repeated implantation failure (RIF) and recurrent pregnancy loss (RPL). It seems that RIF as well as RPL are both associated with an increase in microbiome diversity and a loss of Lactobacillus dominance in the lower female reproductive system.

Ento-A alleviates DSS-induced experimental colitis in mice by remolding intestinal microbiota to regulate SCFAs metabolism and the Th17 signaling pathway

Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized by changes in the metabolism of short chain fatty acids (SCFAs), dysregulation of gut microbiota, and an imbalance of Treg/Th17. Herein, we explore the effects of the Ento-A (an alcohol extract of Periplaneta americana L.) on a mouse model of UC. First, a chronic and recurrent UC model was constructed in BALB/c mice by 2.2% DSS administration. UC mice were continuously treated for 14 days with Ento-A (50, 100, 200 mg/kg, i.g.) or a negative control. Ento-A alleviated many of the pathological changes observed in UC mice, such as body weight loss, disease activity index, changes in colon length, and colonic mucosal damage index. Ento-A also decreased levels of proinflammatory cytokines (IL-1β, IL-6, IL-17A, and TNF-α), increased levels of anti-inflammatory cytokines (IL-10 and TGF-β1) and repaired the intestinal mucosal barrier. Additionally, Ento-A regulated the proportions of Th17 cells, and Treg cells in mesenteric lymph nodes harvested from treated mice (as assessed by Flow cytometry), and the expression levels of IL-17A and Foxp3 in colon (as assessed by immunohistochemistry). 16 S rRNA gene sequencing revealed that Ento-A regulated gut microbiota. GC-MS analysis demonstrated that Ento-A also restored SCFAs content in the intestinal tract. Finally, transcriptomic analysis revealed that Ento-A regulated the IL-17 signaling pathway. In summary, Ento-A regulates the diversity and abundance of intestinal flora in UC mice, enhancing the secretion of SCFAs, subsequently regulating the IL-17 signaling pathway, and ultimately repairing the intestinal mucosal barrier.

Antimicrobial Protein LECT2-b Helps Maintain Gut Microbiota Homeostasis via Selectively Targeting Certain Pathogenic Bacteria

Antimicrobial peptides/proteins (AMPs) constitute a critical component of gut immunity in animals, protecting the gut from pathogenic bacteria. However, the interactions between AMPs and gut microbiota remain elusive. In this study, we show that leukocyte-derived chemotaxin-2 (LECT2)-b, a recently discovered AMP, helps maintain gut homeostasis in grass carp (Ctenopharyngodon idella), one of the major farmed fish species globally, by directly regulating the gut microbiota. Knockdown of LECT2-b resulted in dysregulation of the gut microbiota. Specifically, LECT2-b deficiency led to the dominance of Proteobacteria, consisting of proinflammatory bacterial species, over Firmicutes, which includes anti-inflammatory bacteria. In addition, the opportunistic pathogenic bacteria genus Aeromonas became the dominant genus replacing the probiotic bacteria Lactobacillus and Bacillus. Further analysis revealed that this effect was due to the direct and selective inhibition of certain pathogenic bacterial species by LECT2-b. Moreover, LECT2-b knockdown promoted biofilm formation by gut microbiota, resulting in tissue damage and inflammation. Importantly, LECT2-b treatment alleviated the negative effects induced by LECT2-b knockdown. These findings highlight the crucial role of LECT2-b in maintaining the gut microbiota homeostasis and mucosal health. Overall, our study provides important data for understanding the roles of AMPs in the regulation of gut homeostasis in animals.

Global burden of inflammatory bowel disease 1990-2019: A systematic examination of the disease burden and twenty-year forecast

BACKGROUND

Inflammatory bowel disease (IBD) is an idiopathic intestinal disease with various levels and trends in different countries and regions. Understanding the current burden and trends of IBD in various geographical locations is essential to establish effective strategies for prevention and treatment. We report the average annual percentage change (AAPC) and estimated annual percentage change (EAPC) in age-standardized rates (ASR) of IBD in different regions based on the Global Burden of Disease (GBD) study from 1990-2019, and the relationships between IBD and the human development index (HDI) and socio-demographic index (SDI). The prevalence trends of IBD were predicted by gender from 2019-2039.

AIM

To comprehensively investigate IBD data, providing further insights into the management of this chronic disease.

METHODS

We collected the information on the incidence of IBD from the GBD study from 1990-2019 to calculate the AAPC and EAPC in ASR of IBD in different regions. The relationships between IBD, HDI, and SDI were analyzed. The Nordpred and Bayesian age-period-cohort models were used to predict the prevalence trends of IBD by gender from 2019-2039, and the reliability of the results was validated. Statistics of all the data in this study were performed using R software (version 4.2.1).

RESULTS

North America consistently had the highest IBD ASR, while Oceania consistently had the lowest. East Asia had the fastest average annual growth in ASR (2.54%), whereas Central Europe had the fastest decline (1.38%). Countries with a low age-standardized incidence rates in 1990 showed faster growth in IBD while there was no significant correlation in 2019. Additionally, IBD increased faster in countries with a low age-standardized death rates in 1990, whereas the opposite was true in 2019. Analysis of SDI and IBD ASR showed that countries with a high SDI generally had a higher IBD ASR. Finally, the projections showed a declining trend in the incidence of IBD from 2019-2039, but a gradual increase in the number of cases.

CONCLUSION

As the global population increases and ages, early monitoring and prevention of IBD is important to reduce the disease burden, especially in countries with a high incidence of IBD.

Global burden of inflammatory bowel disease 1990-2019: A systematic examination of the disease burden and twenty-year forecast

BACKGROUND

Inflammatory bowel disease (IBD) is an idiopathic intestinal disease with various levels and trends in different countries and regions. Understanding the current burden and trends of IBD in various geographical locations is essential to establish effective strategies for prevention and treatment. We report the average annual percentage change (AAPC) and estimated annual percentage change (EAPC) in age-standardized rates (ASR) of IBD in different regions based on the Global Burden of Disease (GBD) study from 1990-2019, and the relationships between IBD and the human development index (HDI) and socio-demographic index (SDI). The prevalence trends of IBD were predicted by gender from 2019-2039.

AIM

To comprehensively investigate IBD data, providing further insights into the management of this chronic disease.

METHODS

We collected the information on the incidence of IBD from the GBD study from 1990-2019 to calculate the AAPC and EAPC in ASR of IBD in different regions. The relationships between IBD, HDI, and SDI were analyzed. The Nordpred and Bayesian age-period-cohort models were used to predict the prevalence trends of IBD by gender from 2019-2039, and the reliability of the results was validated. Statistics of all the data in this study were performed using R software (version 4.2.1).

RESULTS

North America consistently had the highest IBD ASR, while Oceania consistently had the lowest. East Asia had the fastest average annual growth in ASR (2.54%), whereas Central Europe had the fastest decline (1.38%). Countries with a low age-standardized incidence rates in 1990 showed faster growth in IBD while there was no significant correlation in 2019. Additionally, IBD increased faster in countries with a low age-standardized death rates in 1990, whereas the opposite was true in 2019. Analysis of SDI and IBD ASR showed that countries with a high SDI generally had a higher IBD ASR. Finally, the projections showed a declining trend in the incidence of IBD from 2019-2039, but a gradual increase in the number of cases.

CONCLUSION

As the global population increases and ages, early monitoring and prevention of IBD is important to reduce the disease burden, especially in countries with a high incidence of IBD.

Changes in intestinal flora of mice induced by rEg.P29 epitope peptide vaccines

OBJECTIVE

Cystic echinococcosis (CE), a zoonotic parasitic disease caused by Echinococcus granulosus, remains a public health and socioeconomic issue worldwide, making its prevention and treatment of vital importance. The aim of this study was to investigate changes in the intestinal microbiota of mice immunized with three peptide vaccines based on the recombinant antigen of E. granulosus, P29 (rEg.P29), with the hope of providing more valuable information for the development of vaccines against CE.

METHODS

Three peptide vaccines, rEg.P29T , rEg.P29B , and rEg.P29T + B , were prepared based on rEg.P29, and a subcutaneous immunization model was established. The intestinal floras of mice in the different immunization groups were analyzed by 16 S rRNA gene sequencing.

RESULTS

The intestinal microbiota analysis at both immunization time points revealed that Firmicutes, Bacteroidota, and Verrucomicrobiota were the predominant flora at the phylum level, while at the genus level, Akkermansia, unclassified_Muribaculaceae, Lachnospiraceae_NK4A136_group, and uncultured_rumen bacterium were the dominant genera. Some probiotics in the intestines of mice were significantly increased after immunization with the peptide vaccines, such as Lactobacillus_taiwanensis, Lactobacillus_reuteri, Lachnospiraceae_NK4A136_group, Bacteroides_acidifaciens, and so forth. Meanwhile, some harmful or conditionally pathogenic bacteria were decreased, such as Turicibacter sanguinis, Desulfovibrio_fairfieldensis, Clostridium_sp, and so forth, most of which are associated with inflammatory or infectious diseases. Kyoto Encyclopaedia of Genes and Genomes enrichment analysis revealed that the differential flora were enriched in multiple metabolic pathways, primarily biological systems, human diseases, metabolism, cellular processes, and environmental information processing.

CONCLUSION

In this study, we comprehensively analyzed and compared changes in the intestinal microbiota of mice immunized with three peptide vaccines as well as their related metabolic pathways, providing a theoretical background for the development of novel vaccines against E. granulosus.

Microbiota-derived short-chain fatty acids functions in the biology of B lymphocytes: From differentiation to antibody formation

Gut bacteria produce various metabolites from dietary fiber, the most abundant of which are short-chain fatty acids (SCFAs) such as acetate, propionate, and butyrate. Many biological functions, such as host metabolism and the immune system, are regulated by SCFAs because they act on a wide variety of cell types. A growing body of documents has shown that microbiota SCFAs directly regulate B-cell growth, proliferation, and immunoglobulin (Ig) production. As histone deacetylase (HDAC) inhibitors, SCFAs alter gene expression to enhance the expression of critical regulators of B cell growth. In particular, microbiota SCFAs increase the production of acetyl coenzyme A (acetyl-CoA), adenosine triphosphate (ATP), and fatty acids in B cells, which provide the energy and building blocks needed for the growth of plasma B cells. SCFAs play a significant role in promoting the involvement of B cells in host immunity during both homeostatic conditions and disease states. In this context, SCFAs stimulate B-cell activation and promote the differentiation of plasma B cells in response to B cell receptor (BCR)-activating antigens or co-stimulatory receptor ligands. The result may be increased production of IgA. Microbiota SCFAs were found to lower both overall and antigen-specific IgE levels, indicating their potential to mitigate IgE-related allergic reactions, much like their effect on class-switch recombination (CSR) towards IgG and IgA. Therefore, in the future, the therapeutic advantage should be to use specific and diffusible chemicals, such as SCFAs, which show a strong immunoregulatory function of B cells. This review focuses on the role of microbiota-produced SCFAs in regulating B cell development and antibody production, both in health and diseases.

Immunogenic molecules associated with gut bacterial cell walls: chemical structures, immune-modulating functions, and mechanisms

Interactions between gut microbiome and host immune system are fundamental to maintaining the intestinal mucosal barrier and homeostasis. At the host-gut microbiome interface, cell wall-derived molecules from gut commensal bacteria have been reported to play a pivotal role in training and remodeling host immune responses. In this article, we review gut bacterial cell wall-derived molecules with characterized chemical structures, including peptidoglycan and lipid-related molecules that impact host health and disease processes via regulating innate and adaptive immunity. Also, we aim to discuss the structures, immune responses, and underlying mechanisms of these immunogenic molecules. Based on current advances, we propose cell wall-derived components as important sources of medicinal agents for the treatment of infection and immune diseases.

Impact of the Microbiota on Viral Infections

The mammalian gastrointestinal tract (GIT) hosts a diverse and highly active microbiota composed of bacteria, eukaryotes, archaea, and viruses. Studies of the GIT microbiota date back more than a century, although modern techniques, including mouse models, sequencing technology, and novel therapeutics in humans, have been foundational to our understanding of the roles of commensal microbes in health and disease. Here, we review the impacts of the GIT microbiota on viral infection, both within the GIT and systemically. GIT-associated microbes and their metabolites alter the course of viral infection through a variety of mechanisms, including direct interactions with virions, alteration of the GIT landscape, and extensive regulation of innate and adaptive immunity. Mechanistic understanding of the full breadth of interactions between the GIT microbiota and the host is still lacking in many ways but will be vital for the development of novel therapeutics for viral and nonviral diseases alike.

Vaccination against microbiota motility protects mice from the detrimental impact of dietary emulsifier consumption

Dietary emulsifiers, including carboxymethylcellulose (CMC) and polysorbate 80 (P80), perturb gut microbiota composition and gene expression, resulting in a microbiota with enhanced capacity to activate host pro-inflammatory gene expression and invade the intestine's inner mucus layer. Such microbiota alterations promote intestinal inflammation, which can have a variety of phenotypic consequences including increased adiposity. Bacterial flagellin is a key mediator of emulsifiers' impact in that this molecule enables motility and is itself a pro-inflammatory agonist. Hence, we reasoned that training the adaptive mucosal immune system to exclude microbes that express flagellin might protect against emulsifiers. Investigating this notion found that immunizing mice with flagellin elicited an increase in mucosal anti-flagellin IgA and IgA-coated microbiota that would have otherwise developed in response to CMC and P80 consumption. Yet, eliciting these responses in advance via flagellin immunization prevented CMC/P80-induced increases in microbiota expression of pro-inflammatory agonists including LPS and flagellin. Furthermore, such immunization prevented CMC/P80-induced microbiota encroachment and deleterious pro-inflammatory consequences associated therewith, including colon shortening and increased adiposity. Hence, eliciting mucosal immune responses to pathobiont surface components, including flagellin, may be a means of combatting the array of inflammatory diseases that are promoted by emulsifiers and perhaps other modern microbiota stressors.

Microbiota dysbiosis caused by dietetic patterns as a promoter of Alzheimer's disease through metabolic syndrome mechanisms

Microbiota dysbiosis and metabolic syndrome, consequences of a non-adequate diet, generate a feedback pathogenic state implicated in Alzheimer's disease development. The lower production of short chain fatty acids (SCFAs) under dysbiosis status leads to lipid homeostasis deregulation and decreases Angptl4 release and AMPK activation in the adipose tissue, promoting higher lipid storage (adipocyte hypertrophy) and cholesterol levels. Also, low SCFA generation reduces GPR41 and GPR43 receptor activation at the adipose tissue (increasing leptin release and leptin receptor resistance) and intestinal levels, reducing the release of GLP-1 and YPP. Therefore, lower satiety sensation and energy expenditure occur, promoting a weight gaining environment mediated by higher food intake and lipid storage, developing dyslipemia. In this context, higher glucose levels, together with higher free fatty acids in the bloodstream, promote glycolipotoxicity, provoking a reduction in insulin released, insulin receptor resistance, advanced glycation products (AGEs) and type 2 diabetes. Intestinal dysbiosis and low SCFAs reduce bacterial biodiversity, increasing lipopolysaccharide (LPS)-producing bacteria and intestinal barrier permeability. Higher amounts of LPS pass to the bloodstream (endotoxemia), causing a low-grade chronic inflammatory state characterized by higher levels of leptin, IL-1β, IL-6 and TNF-α, together with a reduced release of adiponectin and IL-10. At the brain and neuronal levels, the generated insulin resistance, low-grade chronic inflammation, leptin resistance, AGE production and LPS increase directly impact the secretase enzymes and tau hyperphosphorylation, creating an enabling environment for β-amyloid senile plaque and tau tangled formations and, as a consequence, Alzheimer's initiation, development and maintenance.

Inflammation, Autoinflammation and Autoimmunity in Inflammatory Bowel Diseases

In this review, the role of innate and adaptive immunity in the pathogenesis of inflammatory bowel diseases (IBD) is reported. In IBD, an altered innate immunity is often found, with increased Th17 and decreased Treg cells infiltrating the intestinal mucosa. An associated increase in inflammatory cytokines, such as IL-1 and TNF-α, and a decrease in anti-inflammatory cytokines, such as IL-10, concur in favoring the persistent inflammation of the gut mucosa. Autoinflammation is highlighted with insights in the role of inflammasomes, which activation by exogenous or endogenous triggers might be favored by mutations of NOD and NLRP proteins. Autoimmunity mechanisms also take place in IBD pathogenesis and in this context of a persistent immune stimulation by bacterial antigens and antigens derived from intestinal cells degradation, the adaptive immune response takes place and results in antibodies and autoantibodies production, a frequent finding in these diseases. Inflammation, autoinflammation and autoimmunity concur in altering the mucus layer and enhancing intestinal permeability, which sustains the vicious cycle of further mucosal inflammation.

Regulation of short-chain fatty acids in the immune system

A growing body of research suggests that short-chain fatty acids (SCFAs), metabolites produced by intestinal symbiotic bacteria that ferment dietary fibers (DFs), play a crucial role in the health status of symbiotes. SCFAs act on a variety of cell types to regulate important biological processes, including host metabolism, intestinal function, and immune function. SCFAs also affect the function and fate of immune cells. This finding provides a new concept in immune metabolism and a better understanding of the regulatory role of SCFAs in the immune system, which impacts the prevention and treatment of disease. The mechanism by which SCFAs induce or regulate the immune response is becoming increasingly clear. This review summarizes the different mechanisms through which SCFAs act in cells. According to the latest research, the regulatory role of SCFAs in the innate immune system, including in NLRP3 inflammasomes, receptors of TLR family members, neutrophils, macrophages, natural killer cells, eosinophils, basophils and innate lymphocyte subsets, is emphasized. The regulatory role of SCFAs in the adaptive immune system, including in T-cell subsets, B cells, and plasma cells, is also highlighted. In addition, we discuss the role that SCFAs play in regulating allergic airway inflammation, colitis, and osteoporosis by influencing the immune system. These findings provide evidence for determining treatment options based on metabolic regulation.

Peptidoglycan in osteoarthritis synovial tissue is associated with joint inflammation

Objectives

Peptidoglycan (PG) is an arthritogenic bacterial cell wall component whose role in human osteoarthritis is poorly understood. The purpose of this study was to determine if PG is present in synovial tissue of osteoarthritis patients at the time of primary total knee arthroplasty (TKA), and if its presence is associated with inflammation and patient reported outcomes.

Methods

Intraoperative synovial tissue and synovial fluid samples were obtained from 56 patients undergoing primary TKA, none of whom had history of infection. PG in synovial tissue was detected by immunohistochemistry (IHC). Synovial tissue inflammation and fibrosis were assessed by histopathology and synovial fluid cytokine quantification. Primary human fibroblasts isolated from arthritis synovial tissue were stimulated with PG to determine inflammatory cytokine response.

Results

A total of 33/56 (59%) of primary TKA synovial tissue samples were positive for PG by IHC, with mean 8 PG occurrences per 10 mm2 of tissue in PG-positive samples. Synovial tissue inflammation and elevated IL-6 in synovial fluid positively correlated with PG positivity. Primary human fibroblasts stimulated with PG secreted high levels of IL-6, consistent with ex vivo findings. Interestingly, we observed a significant inverse correlation between PG and age at time of TKA, indicating younger age at time of TKA was associated with higher PG levels.

Conclusion

Peptidoglycan is commonly found in synovial tissue from patients undergoing TKA. Our data indicate that PG may play an important role in inflammatory synovitis, particularly in patients who undergo TKA at a relatively younger age.

Modulation of allergic contact dermatitis via gut microbiota modified by diet, vitamins, probiotics, prebiotics, and antibiotics

Allergic contact dermatitis is one of the most common recorded occupational diseases. There are many different substances that the skin comes into contact with on a daily basis and that can cause ACD, e.g., preservatives, surfactants, and antimicrobial agents. The development of a mouse model of ACD has provided insight into the immune mechanisms involved. Drugs used in the treatment of skin diseases have many side effects. Therefore, alternative methods of suppressing the immune response to reduce the symptoms of skin diseases are being sought. In recent years, high hopes have been placed on dietary modulation and supplementation to affect the intestinal microbial composition and promote anti-inflammatory responses. In addition, other studies have shown the crucial role of intestinal microbiota in many immune-mediated diseases. Recognition and characterization of pro- and anti-inflammatory nutrients and supplements may be crucial to support the treatment of diseases such as atopic dermatitis, acne vulgaris, psoriasis, and allergic contact dermatitis.

Effect of exogenous galectin-9, a natural TIM-3 ligand, on the severity of TNBS- and DSS-induced colitis in mice

Inflammatory bowel disease (IBD) have a complex pathogenesis that is yet to be completely understood. However, a strong correlation between Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling and IBD has been observed. T-cell immunoglobulin and mucin domain-containing-3 (Tim-3) has been reported to regulate TLR4/NF-κB by interacting with Galectin-9 (Gal-9), and recombinant Gal-9 can activate Tim-3; however, its potential properties in IBD and the underlying mechanism remain unclear. This study aimed to determine how Gal-9 affects experimental colitis in mice. Dextran sodium sulfate (DSS) and 2,4,6-trinitrobenzene sulfonic acid (TNBS) were used to establish colitis in mice, and the severity of the illness was assessed based on body weight, colon length, and histology. Therefore, we explored the effects of Gal-9 treatment on colitis. Furthermore, we analyzed the effect of Gal-9 on the expression of Tim-3 and TLR4/NF-κB pathway in colonic tissues and the serum levels of interferon-gamma (IFN-γ), interleukin (IL)-1β, and IL-6. Tim-3 expression in the colon was notably decreased in mice with TNBS-induced colitis, whereas TLR4/NF-kB expression was significantly increased. Intraperitoneal injection of Gal-9 dramatically decreased the disease activity index and attenuated the level of intestinal mucosal inflammation in TNBS-induced colitis mice (p < 0.05). Intraperitoneal administration of Gal-9 significantly increased Tim-3 expression in the colon and decreased the serum concentrations of IFN-γ, IL-1β, and IL-6. Additionally, Gal-9 treatment significantly downregulated the expression of TLR4 signaling pathway-related proteins. In contrast, Gal-9 did not reduce the severity of DSS-induced colitis. In summary, exogenous Gal-9 increased Tim-3 expression, inhibited the TLR4/NF-κB pathway, and alleviated TNBS-induced colitis in mice but not DSS-induced colitis in mice, revealing its potential therapeutic ramifications for IBD.

Recurrent implantation failure: A comprehensive summary from etiology to treatment

Implantation is the first step in human reproduction. Successful implantation depends on the crosstalk between embryo and endometrium. Recurrent implantation failure (RIF) is a clinical phenomenon characterized by a lack of implantation after the transfer of several embryos and disturbs approximately 10% couples undergoing in vitro fertilization and embryo transfer. Despite increasing literature on RIF, there is still no widely accepted definition or standard protocol for the diagnosis and treatment of RIF. Progress in predicting and preventing RIF has been hampered by a lack of widely accepted definitions. Most couples with RIF can become pregnant after clinical intervention. The prognosis for couples with RIF is related to maternal age. RIF can be caused by immunology, thrombophilias, endometrial receptivity, microbiome, anatomical abnormalities, male factors, and embryo aneuploidy. It is important to determine the most possible etiologies, and individualized treatment aimed at the primary cause seems to be an effective method for increasing the implantation rate. Couples with RIF require psychological support and appropriate clinical intervention. Further studies are required to evaluate diagnostic method and he effectiveness of each therapy, and guide clinical treatment.

SARS-CoV-2 Infection, Inflammation, Immunonutrition, and Pathogenesis of COVID-19

The COVID-19 pandemic, caused by the coronavirus, SARS-CoV-2, has claimed millions of lives worldwide in the past two years. Fatalities among the elderly with underlying cardiovascular disease, lung disease, and diabetes have particularly been high. A bibliometrics analysis on author's keywords was carried out, and searched for possible links between various coronavirus studies over the past 50 years, and integrated them. We found keywords like immune system, immunity, nutrition, malnutrition, micronutrients, exercise, inflammation, and hyperinflammation were highly related to each other. Based on these findings, we hypothesized that the human immune system is a multilevel super complex system, which employs multiple strategies to contain microorganism infections and restore homeostasis. It was also found that the behavior of the immune system is not able to be described by a single immunological theory. However, one main strategy is "self-destroy and rebuild", which consists of a series of inflammatory responses: 1) active self-destruction of damaged/dysfunctional somatic cells; 2) removal of debris and cells; 3) rebuilding tissues. Thus, invading microorganisms' clearance could be only a passive bystander response to this destroy-rebuild process. Microbial infections could be self-limiting and promoted as an indispensable essential nutrition for the vast number of genes existing in the microorganisms. The transient nutrition surge resulting from the degradation of the self-destroyed cell debris coupled with the existing nutrition state in the patient may play an important role in the pathogenesis of COVID-19. Finally, a few possible coping strategies to mitigate COVID-19, including vaccination, are discussed.

Hepatobiliary Impairments in Patients with Inflammatory Bowel Diseases: The Current Approach

Inflammatory bowel disease (IBD) refers to chronic conditions with a low mortality but high disability. The multisystemic nature of these diseases can explain the appearance of some extraintestinal manifestations, including liver damage. Abnormal liver biochemical tests can be identified in approximately one third of patients with IBD and chronic liver disease in 5% of them. Among the liver diseases associated with IBD are primary sclerosing cholangitis, cholelithiasis, fatty liver disease, hepatic amyloidosis, granulomatous hepatitis, drug-induced liver injury, venous thromboembolism, primary biliary cholangitis, IgG4-related cholangiopathy, autoimmune hepatitis, liver abscesses or the reactivation of viral hepatitis. The most common disease is primary sclerosing cholangitis, a condition diagnosed especially in patients with ulcerative colitis. The progress registered in recent years in the therapeutic management of IBD has not eliminated the risk of drug-induced liver disease. Additionally, the immunosuppression encountered in these patients increases the risk of opportunistic infections, including the reactivation of viral hepatitis. Currently, one of the concerns consists of establishing an efficiency and safety profile of the use of direct-acting antiviral agents (DAA) among patients with hepatitis C and IBD. Early diagnosis and optimal treatment of liver complications can improve the prognoses of these patients.

Alterations in Gut Microbiota Profiles of Mice Infected with Echinococcus granulosus sensu lato Microbiota Profiles of Mice Infected with E. granulosus s.l

OBJECTIVE

Cystic echinococcosis is a kind of parasitic disease that seriously endangers human and animal health. At present, its prevention and treatment still do not achieve the desired results. The aims of this study were to explore the effect of CE on intestinal microflora in mice.

METHODS

In this study, 16S rRNA metagenome sequencing and bioinformatics were used to analyze the intestinal flora of mice infected with E. granulosus s.l. Changes in intestinal microbial community abundance were investigated and the differences in microbial populations of mice infected with E. granulosus s.l. were screened.

RESULTS

Our results show that at the phylum level, nine abundant taxa were identified, the relative abundance of Firmicutes and Proteobacteria were enriched in infected mice, whereas Bacteroidetes and Patescibacteria were enriched in control mice (P < 0.01). At the class level, 13 abundant taxa were identified, the relative abundance of Bacilli was enriched in control mice, but decreased in infected mice (P < 0.01). At the order level, 15 abundant taxa were identified, the relative abundance of Lactobacillales was enriched in control mice, but decreased in infected mice (P < 0.01). At the family level, 28 abundant taxa were identified, enriched bacteria in the infected mice was Streptococcaceae, while the enriched bacteria in the control group was Lactobacillaceae (P < 0.01). At the genus level, 79 abundant taxa were identified, enriched bacteria in the infected mice was Streptococcus, while the enriched bacteria in the control group was uncultured_bacterium_f_Eggerthellaceae (P < 0.01). At the species level, 80 abundant taxa were identified, enriched bacteria in the infected mice was uncultured_bacterium_g_Streptococcus, while the enriched bacteria in the control group was uncultured_bacterium_f_Eggerthellaceae (P < 0.01). 39 KEGG pathways were identified that were differentially enriched between the infected and control mice.

CONCLUSION

This study comprehensively demonstrates the differential intestinal microbiota of infected mice and analyzes the metabolic pathways related to the specific microbiota. This could provide new targets and research direction for the treatment and prevention of diseases caused by E. granulosus s.l.

Crohn's Disease Patients Uniquely Contain Inflammatory Responses to Flagellin in a CD4 Effector Memory Subset

BACKGROUND

Specific microbial antigens stimulate production of antibodies indicative of the aberrant immune response in Crohn's disease (CD). We tested for T cell reactivity linkage to B cell responses and now report on the prevalence, functionality, and phenotypic differences of flagellin-specific T cells among CD patients, ulcerative colitis (UC) patients, and control subjects and association with clinical features and flagellin seropositivity within CD patients.

METHODS

Sera from non-inflammatory bowel disease control subjects, CD patients, and UC patients were probed for antibody reactivity to gut bacterial recombinant flagellin antigens. Peripheral blood mononuclear cells were measured for flagellin antigen (CBir1, A4 Fla2, FlaX) or control (Candida albicans, and CytoStim) reactivity analyzed by flow cytometry for CD154 and cytokine expression on CD4+ T cells. Supernatants from post-flagellin-stimulated and unstimulated cells were used to measure effects on epithelial barrier function.

RESULTS

CD patients had a significantly higher percentage of flagellin-specific CD154+ CD4+ cells that have an effector memory T helper 1 and T helper 17 phenotype compared with UC patients and healthy control subjects. There was a positive correlation between the frequency of flagellin-specific CD154+ CD4+ effector memory T cells and serum levels of anti-flagellin immunoglobulin G in the CD patients. In addition, A4 Fla2-reactive T cells from active CD patients produced cytokines that can decrease barrier function in a gut epithelium.

CONCLUSIONS

These findings demonstrate a Crohn's-associated flagellin-reactive CD4 cell subset distinct from UC patients and control subjects. There is a link between these cells and flagellin seropositivity. This CD4 cell subset could reflect a particular endophenotype of CD, leading to novel insight into its pathology and treatment.

Interaction between microbiota and immunity and its implication in colorectal cancer

Colorectal cancer (CRC) is one of the leading causes of cancer-related death in the world. Besides genetic causes, colonic inflammation is one of the major risk factors for CRC development, which is synergistically regulated by multiple components, including innate and adaptive immune cells, cytokine signaling, and microbiota. The complex interaction between CRC and the gut microbiome has emerged as an important area of current CRC research. Metagenomic profiling has identified a number of prominent CRC-associated bacteria that are enriched in CRC patients, linking the microbiota composition to colitis and cancer development. Some microbiota species have been reported to promote colitis and CRC development in preclinical models, while a few others are identified as immune modulators to induce potent protective immunity against colitis and CRC. Mechanistically, microbiota regulates the activation of different immune cell populations, inflammation, and CRC via crosstalk between innate and adaptive immune signaling pathways, including nuclear factor kappa B (NF-κB), type I interferon, and inflammasome. In this review, we provide an overview of the potential interactions between gut microbiota and host immunity and how their crosstalk could synergistically regulate inflammation and CRC, thus highlighting the potential roles and mechanisms of gut microbiota in the development of microbiota-based therapies to prevent or alleviate colitis and CRC.

Insulin resistance corresponds with a progressive increase in NOD1 in high fat diet-fed mice

PURPOSE

Innate immune components participate in obesity-induced inflammation, which can contribute to endocrine dysfunction during metabolic diseases. However, the chronological activation of specific immune proteins such as Nucleotide-binding oligomerization domain-containing protein 1 (NOD1) and relevance to cellular crosstalk during the progression of obesity-associated insulin resistance (IR) is not known.

METHODS

The NOD1 signaling in various insulin-sensitive metabolic tissues during the progression of diet-insulin resistance was assessed in C57BL/6J mice fed with 60% high-fat diet (HFD) for 4, 8, 12, and 16 weeks. Intestinal permeability was measured using FITC-dextran. NOD1 activating potential was analyzed using HEK-Blue mNOD1 cells.

RESULTS

HFD-fed mice showed progressive induction of glucose intolerance and impairment of insulin signaling in key metabolic tissues. We found a time-dependent increase in intestinal permeability coupled with transport and accumulation of NOD1 activating ligand in the serum of HFD-fed mice. We also observed a progressive accumulation of γ-D-glutamyl-meso-diaminopimelic acid (DAP), a microbial peptidoglycan ligand known to activate NOD1, in serum samples of the HFD-fed mice. There was also a progressive increase in transcripts levels of NOD1 in bone marrow-derived macrophages during HFD-feeding. In addition, skeletal muscle, adipose and liver, the key insulin sensitive metabolic tissues also had a time-dependent increase in transcripts of NOD1 and Rip2 and a corresponding activation of pro-inflammatory responses in these tissues.

CONCLUSION

These data highlight the correlation of inflammation and insulin resistance to NOD1 activation in the bone marrow derived macrophages and insulin responsive metabolic tissues during high fat diet feeding in mice.

Microbiota in health and diseases

The role of microbiota in health and diseases is being highlighted by numerous studies since its discovery. Depending on the localized regions, microbiota can be classified into gut, oral, respiratory, and skin microbiota. The microbial communities are in symbiosis with the host, contributing to homeostasis and regulating immune function. However, microbiota dysbiosis can lead to dysregulation of bodily functions and diseases including cardiovascular diseases (CVDs), cancers, respiratory diseases, etc. In this review, we discuss the current knowledge of how microbiota links to host health or pathogenesis. We first summarize the research of microbiota in healthy conditions, including the gut-brain axis, colonization resistance and immune modulation. Then, we highlight the pathogenesis of microbiota dysbiosis in disease development and progression, primarily associated with dysregulation of community composition, modulation of host immune response, and induction of chronic inflammation. Finally, we introduce the clinical approaches that utilize microbiota for disease treatment, such as microbiota modulation and fecal microbial transplantation.

Distinct gut and vaginal microbiota profile in women with recurrent implantation failure and unexplained infertility

BACKGROUND

Female reproductive tract dysbiosis impacts implantation. However, whether gut dysbiosis influences implantation failure and whether it accompanies reproductive tract dysbiosis remains scantly explored. Herein, we examined the gut-vaginal microbiota axis in infertile women.

METHODS

We recruited 11 fertile women as the controls, and a cohort of 20 infertile women, 10 of whom had recurrent implantation failure (RIF), and another 10 had unexplained infertility (UE). Using amplicon sequencing, which employs PCR to create sequences of DNA called amplicon, we compared the diversity, structure, and composition of faecal and vaginal bacteria of the controls with that of the infertile cohort. Of note, we could only sequence 8 vaginal samples in each group (n = 24/31).

RESULT

Compared with the controls, α-diversity and β-diversity of the gut bacteria among the infertile groups differed significantly (p < 0.05). Taxa analysis revealed enrichment of Gram-positive bacteria in the RIF group, whereas Gram-negative bacteria were relatively abundant in the UE group. Strikingly, mucus-producing genera declined in the infertile cohort (p < 0.05). Hungatella, associated with trimethylamine N-oxide (TMAO) production, were enriched in the infertile cohort (p < 0.05). Vaginal microbiota was dominated by the genus Lactobacillus, with Lactobacillus iners AB-1 being the most abundant species across the groups. Compared with the infertile cohort, overgrowth of anaerobic bacteria, associated with vaginal dysbiosis, such as Leptotrichia and Snethia, occurred in the controls.

CONCLUSION

The gut microbiota had little influence on the vaginal microbiota. Gut dysbiosis and vaginal eubiosis occurred in the infertile women, whereas the opposite trend occurred in the controls.

KLF5 protects the intestinal epithelium against Th17 immune response in a murine colitis model

Inflammatory bowel disease (IBD) is a chronic illness characterized by dysregulated immune cascades in the intestines, in which the Th17 immune response plays an important role. We demonstrated that mice with intestinal epithelium–specific deletion of Krüppel-like factor 5 (Klf5) developed Th17-dependent colonic inflammation. In the absence of KLF5, there was aberrant cellular localization of phosphorylated STAT3, an essential mediator of the Th17-associated cytokine, IL-22, which is required for epithelial tissue regeneration. In contrast, mitigation of IL-17A with anti–IL-17A neutralizing antibody attenuated colitis in Klf5-deficient mice. There was also a considerable shift in the colonic microbiota of Klf5-deficient mice that phenocopied human IBD. Notably, the inflammatory response due to Klf5 deletion was alleviated by antibiotic treatment, implicating the role of microbiota in pathogenesis. Finally, human colitic tissues had reduced KLF5 levels when compared with healthy tissues. Together, these findings demonstrated the importance of KLF5 in protecting the intestinal epithelium against Th17-mediated immune and inflammatory responses. The mice described herein may serve as a potential model for human IBD.

The role of gut microbiota in hepatitis B disease progression and treatment

Current therapeutic interventions can only suppress hepatitis B virus (HBV) replication or reduce complications without a cure. Therefore, further development of new treatment methods is critical for the global eradication of HBV. Accumulating evidence suggests that the liver and gut share an interconnected relationship referred to as the 'Gut-Liver Axis', where exchanges happen bi-directionally. The gut itself is the host to a unique microbiota profile which has metabolic, immunological, neurological and nutritional functions. Gut microbiota is not only constantly intersecting with the liver but also associated with hepatic injury when dysbiosis occurs. In recent years, there has been increased interest in gut microbiota and its implications on liver disease treatment. Progress has been made in understanding the complex relationship between chronic hepatitis B (CHB) and gut microbiota. New investigative techniques such as colony-free sequencing enabled new perspectives into this field. Mouse models and human studies revealed that HBV infection is associated with significant alteration of gut microbiota, which differ depending on the stage of CHB disease progression. Different mechanisms of the hepatic injury from gut microbiota dysbiosis have also been proposed based on findings of increased intestinal permeability to toxins, disruption of normal bacterial metabolism, and colonization of the gut by oral microbiota. New treatment methods targeting gut microbiota in CHB, such as probiotics and faecal microbiota transplant, have also gained promising results in recent years. The current review recapitulated the most recent investigations into the relationship between gut microbiota and CHB to provide research directions towards the new therapeutic target of CHB.

Breast Milk: A Meal Worth Having

A mother is gifted with breast milk, the natural source of nutrition for her infant. In addition to the wealth of macro and micro-nutrients, human milk also contains many microorganisms, few of which originate from the mother, while others are acquired from the mouth of the infant and the surroundings. Among these microbes, the most commonly residing bacteria are Staphylococci, Streptococci, Lactobacilli and Bifidobacteria. These microorganisms initiate and help the development of the milk microbiota as well as the microbiota of the gastrointestinal tract in infants, and contribute to developing immune regulatory factors such as cytokines, growth factors, lactoferrin among others. These factors play an important role in reducing the risk of developing chronic diseases like type 2 diabetes, asthma and others later in life. In this review, we will summarize the known benefits of breastfeeding and highlight the role of the breast milk microbiota and its cross-talk with the immune system in breastfed babies during the early years of life.

MICROBIOME AND UVEITIDES. A REVIEW

Microorganisms inhabiting all surfaces of mucous membranes and skin and forming a complex ecosystem with the host is called microbiota. The term microbiome is used for the aggregate genome of microbiota. The microbiota plays important role in the mechanisms of number of physiological and pathological processes, especially of the hosts immune system. The origin and course of autoimmune diseases not only of the digestive tract, but also of the distant organs, including the eye, are significantly influenced by intestinal microbiota. The role of microbiota and its changes (dysbiosis) in the etiopathogenesis of uveitis has so far been studied mainly in experimental models. Reduction of severity of non-infectious intraocular inflammation in germ-free mice or in conventional mice treated with broad-spectrum antibiotics was observed in both the induced experimental autoimmune uveitis model (EAU) and the spontaneous R161H model. Studies have confirmed that autoreactive T cell activation occurs in the intestinal wall in the absence of retinal antigen. Recent experiments focused on the effect of probiotic administration on the composition of intestinal microbiota and on the course of autoimmune uveitis. Our study group demonstrated significant prophylactic effect of the administration of the probiotic Escherichia coli Nissle 1917 on the intensity of inflammation in EAU. To date, only a few studies have been published investigating intestinal dysbiosis in patients with uveitis (e.g., in Behcets disease or Vogt-Koyanagi-Harada syndrome). The results of preclinical studies will be presumably used in clinical practice, mainly in the sense of prophylaxis and therapy, such as change in the lifestyle, diet and especially the therapeutic use of probiotics or the transfer of faecal microbiota.

Clinical Parasitology and Parasitome Maps as Old and New Tools to Improve Clinical Microbiomics

A growing body of evidence shows that dysbiotic gut microbiota may correlate with a wide range of disorders; hence, the clinical use of microbiota maps and fecal microbiota transplantation (FMT) can be exploited in the clinic of some infectious diseases. Through direct or indirect ecological and functional competition, FMT may stimulate decolonization of pathogens or opportunistic pathogens, modulating immune response and colonic inflammation, and restoring intestinal homeostasis, which reduces host damage. Herein, we discuss how diagnostic parasitology may contribute to designing clinical metagenomic pipelines and FMT programs, especially in pediatric subjects. The consequences of more specialized diagnostics in the context of gut microbiota communities may improve the clinical parasitology and extend its applications to the prevention and treatment of several communicable and even noncommunicable disorders.

Bioaccessibility of Anthocyanins on in vitro Digestion Mmodels: Factors Implicated and Role in Functional Foods Development

BACKGROUND

Worldwide, the prevalence of obesity and related non-communicable chronic diseases is high and continues to grow. In that sense, anthocyanins (ANC) have shown beneficial health effects in preventing obesity and metabolic risk factors. Moreover, the demand for functional foods incorporating these compounds has risen significantly in the past years. Thus, there is a need for validations of the functional properties of these formulations; nevertheless, in vivo assays are complex and require a lot of resources. One approach for estimating bioactive compounds' functionality and health benefits is to evaluate their bioaccessibility on a specific food matrix, determined by various factors. This article aims to review different factors influencing the bioaccessibility of ANC evaluated on in vitro digestion models as a functionality parameter, elucidating the effect of chemical composition, raw materials, food matrices, and vehicles for the delivery of ANC.

METHODS

Study searches were performed using PubMed, Web of Science, Scopus, and Science Direct databases.

RESULTS

Different factors influenced bioaccessibility and stability of ANC studied by in vitro digestion which are: i) the raw material used for ANC obtention; ii) food processing; iii) other food components; iv) the extraction method and solvents used; v) the structure of ANC; vi) delivery system (e.g., microencapsulation); vii) pH of the medium; viii) the digestion stage.

CONCLUSION

Simulated digestion systems allow to determine free or encapsulated ANC bioaccessibility in different food matrices, which offers advantages in determining the potential functionality of a food product.

Genomic association and further characterisation of faecal immunoglobulin A deficiency in German Shepherd dogs

BACKGROUND

Immunoglobulin A (IgA) deficiency, chronic enteropathies and exocrine pancreatic insufficiency (EPI) have a high prevalence in German Shepherd dogs (GSD). This prospective study determined the prevalence of faecal IgA deficiency (IgAD) in GSD and investigated several candidate genes and the canine genome for a region or locus co-segregating with IgAD in GSD. Faecal IgA concentrations were quantified and genomic DNA was extracted from 8 GSD with an undetectable faecal IgA (classified as IgAD) and 80 non-IgAD GSD. The canine minimal screening set II microsatellite markers were genotyped, with evidence of an association at p < 1.0 × 10-3 . Faecal IgA concentrations were also tested for an association with patient clinical and biochemical variables.

RESULTS

Allele frequencies observed using the candidate gene approach were not associated with faecal IgAD in GSD. In the genome-wide association study (GWAS), the microsatellite marker FH2361 on canine chromosome 33 approached statistical significance for a link with IgAD in GSD (p = 1.2 × 10-3 ). A subsequent GWAS in 11 GSD with EPI and 80 control GSD revealed a significant association between EPI and FH2361 (p = 8.2 × 10-4 ).

CONCLUSIONS

The lack of an association with the phenotype of faecal IgAD in GSD using the candidate gene approach and GWAS might suggests that faecal IgAD in GSD is a relative or transient state of deficiency. However, the prevalence of faecal IgAD in GSD appears to be low (<3%). The relationship between faecal IgAD, EPI and loci close to FH2361 on canine chromosome 33 in GSD warrants further investigation.

The Role of Gut Microbiota in Hypertension Pathogenesis and the Efficacy of Antihypertensive Drugs

PURPOSE OF HEADING

To review the relationship between intestinal microbes and hypertension and its impact on the efficacy of antihypertensive drugs, and help to address some of these knowledge gaps.

RECENT FINDINGS

Hypertension is associated with cardiovascular diseases and is the most important modifiable risk factor for all-cause morbidity and mortality worldwide. The pathogenesis of hypertension is complex, including factors such as dietary, environmental and genetics. Recently, the studies have shown that the gut microbiota influences the occurrence and development of hypertension through a variety of ways, including affecting the production of short-chain fatty acids, dysfunction of the brain-gut axis, and changes in serotonin content that cause the imbalance of vagus and sympathetic nerve output associated with hypertension. However, patients with hypertension typically take antihypertensive drugs orally on a long-term basis, and most antihypertensive drugs are absorbed by the gastrointestinal tract. Studies have shown that the pharmacokinetics and metabolism of antihypertensive drugs may be influenced by microbiota, or antihypertensive drugs act directly on the intestinal flora to exert efficacy, including regulation of intestinal microbial metabolism, intestinal inflammation, and intestinal sympathetic nervous system disorders. The intestinal flora can affect the pharmacokinetics and metabolism of antihypertensive drugs in the rats, and intestinal microbiota also can be the target "organ" by antihypertensive drugs.

Human Microbiota Flagellins Drive Adaptive Immune Responses in Crohn's Disease

BACKGROUND AND AIMS

Crohn's disease and ulcerative colitis are characterized by dysregulated adaptive immune responses to the microbiota in genetically susceptible individuals, but the specificity of these responses remains largely undefined. Therefore, we developed a microbiota antigen microarray to characterize microbial antibody reactivity, particularly to human-derived microbiota flagellins, in inflammatory bowel disease.

METHODS

Sera from healthy volunteers (n = 87) at the University of Alabama at Birmingham and from patients recruited from the Kirklin Clinic of University of Alabama at Birmingham Hospital, including patients with Crohn's disease (n = 152) and ulcerative colitis (n = 170), were individually probed against microbiota bacterial flagellins of both mouse and human origin and analyzed for IgG and IgA antibody responses. Circulating flagellin-reactive T effector (CD4⁺CD154⁺) and T regulatory (CD4⁺CD137⁺) cells were isolated and evaluated in selected patients. Resulting adaptive immune responses were compared with corresponding clinical data to determine relevancy to disease behavior.

RESULTS

We show that patients with IBD express selective patterns of antibody reactivity to microbiota flagellins. Patients with Crohn's disease, but not patients with ulcerative colitis, display augmented serum IgG to human ileal-localized Lachnospiraceae flagellins, with a subset of patients having high responses to more than 10 flagellins. Elevated responses to CBir1, a mouse Lachnospiraceae flagellin used clinically to diagnose CD, correlated with multi-Lachnospiraceae flagellin reactivity. In this subset of patients with CD, multi-flagellin reactivity was associated with elevated flagellin-specific CD154⁺CD45RA^- T memory cells, a reduced ratio of flagellin-reactive CD4⁺ T regulatory to T effector cells, and a high frequency of disease complications.

CONCLUSIONS

Patients with Crohn's disease display strong adaptive immune response to human-derived Lachnospiraceae flagellins, which may be targeted for prognosis and future personalized therapies.