Induction effects of Faecalibacterium prausnitzii and its extracellular vesicles on toll-like receptor signaling pathway gene expression and cytokine level in human intestinal epithelial cells

Development of fermented Atemoya (Annona cherimola × Annona squamosa)-Amazake increased intestinal next-generation probiotics

Akkermansia muciniphila and Faecalibacterium prausnitzii are next-generation probiotics, which has been reported to protect disease and effectively utilize various carbohydrates (starch and pectin) as nutrients for growth. Atemoya exhibiting fruity flavor, which is suitable for enhancing aroma and attenuating unpleasant taste caused by the koji metabolites. Results indicated that malic acid was increased (from 42.4 to 70.1 mg/100 g) in fermented Atemoya-Amazake. In addition, fermented Atemoya-Amazake elevated growthes in A. muciniphila and F. prausnitzii. Similarly, the populations of Parabacteroides (5.7 fold) and Akkermansia (1.66 fold) were elevated by fermented Atemoya-Amazake treatment in an in vitro simulated gastrointestinal system compared to the control group. Results revealed that fermented Atemoya-Amazake modulated the intestinal microbiota through increasing the production of short-chain fatty acids (exhibiting anti-pathogenic activity) for 2.1, 2.5, 2.6, and 2.1 folds in acetic acid, propionic acid, isobutyric acid, and butyric acid, respectively; suggesting this fermented Atemoya-Amazake could be applied in intestinal protection.

Probiotic-derived extracellular vesicles alleviate AFB1-induced intestinal injury by modulating the gut microbiota and AHR activation

BACKGROUND

Aflatoxin B1 (AFB1) is a mycotoxin that widely found in the environment and mouldy foods. AFB1 initially targets the intestine, and AFB1-induced intestinal injury cannot be ignored. Lactobacillus amylovorus (LA), a predominant species of Lactobacillus, plays a role in carbohydrate metabolism. Extracellular vesicles (EVs), small lipid membrane vesicles, are widely involved in diverse cellular processes. However, the mechanism by which Lactobacillus amylovorus-QC1H-derived EVs (LA.EVs) protect against AFB1-induced intestinal injury remains unclear.

RESULTS

In our study, a new strain named Lactobacillus amylovorus-QC1H (LA-QC1H) was isolated from pig faeces. Then, EVs derived from LA-QC1H were extracted via ultracentrifugation. Our results showed that LA.EVs significantly alleviated AFB1-induced intestinal injury by inhibiting the production of proinflammatory cytokines, decreasing intestinal permeability and increasing the expression of tight junction proteins. Moreover, 16 S rRNA analysis revealed that LA.EVs modulated AFB1-induced gut dysbiosis in mice. However, LA.EVs did not exert beneficial effects in antibiotic-treated mice. LA.EVs treatment increased intestinal levels of indole-3-acetic acid (IAA) and activated intestinal aryl hydrocarbon receptor (AHR)/interleukin-22 (IL-22) signalling in AFB1-exposed mice. Inhibition of intestinal AHR signalling markedly weakened the protective effect of LA.EVs in AFB1-exposed mice.

CONCLUSIONS

LA.EVs alleviated AFB1-induced intestinal injury by modulating the gut microbiota, activating the intestinal AHR/IL-22 signalling, reducing the inflammatory response and promoting intestinal barrier repair in mice.

Direct and macrophage stimulation mediated effects of active, inactive, and cell-free supernatant forms of Akkermansia muciniphila and Faecalibacterium duncaniae on hepcidin gene expression in HepG2 cells

Hepcidin is a crucial regulator of iron homeostasis with protective effects on liver fibrosis. Additionally, gut microbiota can also affect liver fibrosis and iron metabolism. Although the hepatoprotective potential of Akkermansia muciniphila and Faecalibacterium duncaniae, formerly known as F. prausnitzii, has been reported, however, their effects on hepcidin expression remain unknown. We investigated the direct and macrophage stimulation-mediated effects of active, heat-inactivated, and cell-free supernatant (CFS) forms of A. muciniphila and F. duncaniae on hepcidin expression in HepG2 cells by RT-qPCR analysis. Following stimulation of phorbol-12-myristate-13-acetate (PMA) -differentiated THP-1 cells with A. muciniphila and F. duncaniae, IL-6 concentration was assessed via ELISA. Additionally, the resulting supernatant was treated with HepG2 cells to evaluate the effect of macrophage stimulation on hepcidin gene expression. The expression of genes mediating iron absorption and export was also examined in HepG2 and Caco-2 cells via RT-qPCR. All forms of F. duncaniae increased hepcidin expression while active and heat-inactivated/CFS forms of A. muciniphila upregulated and downregulated its expression, respectively. Active, heat-inactivated, and CFS forms of A. muciniphila and F. duncaniae upregulated hepcidin expression, consistent with the elevation of IL-6 released from THP-1-stimulated cells as a macrophage stimulation effect in HepG2 cells. A. muciniphila and F. duncaniae in active, inactive, and CFS forms altered the expression of hepatocyte and intestinal iron-mediated absorption /exporter genes, namely dcytb and dmt1, and fpn in HepG2 and Caco-2 cells, respectively. In conclusion, A. muciniphila and F. duncaniae affect not only directly but also through macrophage stimulation the expression of hepcidin gene in HepG2 cells. These findings underscore the potential of A. muciniphila and F. duncaniae as a potential therapeutic target for liver fibrosis by modulating hepcidin and intestinal and hepatocyte iron metabolism mediated gene expression.

Investigating the causal relationship of gut microbiota with GERD and BE: a bidirectional mendelian randomization

BACKGROUND

Gut microbiota(GM) have been proven associated with lots of gastrointestinal diseases, but its causal relationship with Gastroesophageal reflux disease(GERD) and Barrett's esophagus(BE) hasn't been explored. We aimed to uncover the causal relation between GM and GERD/BE and potential mediators by utilizing Mendelian Randomization(MR) analysis.

METHODS

Summary statistics of GM(comprising 301 bacteria taxa and 205 metabolism pathways) were extracted from MiBioGen Consortium(N = 18,340) and Dutch Microbiome Project(N = 7,738), GERD and BE from a multitrait meta-analysis(NGERD=602,604, NBE=56,429). Bidirectional two-sample MR analysis and linkage disequilibrium score regression(LDSC) were used to explore the genetic correlation between GM and GERD/BE. Mediation MR analysis was performed for the risk factors of GERD/BE, including Body mass index(BMI), weight, type 2 diabetes, major depressive disorder(MDD), smoking initiation, alcohol consumption, and dietary intake(including carbohydrate, sugar, fat, protein intake), to detect the potential mediators between GM and GERD/BE.

RESULTS

11 bacterial taxa and 13 metabolism pathways were found associated with GERD, and 18 taxa and 5 pathways exhibited causal relationship with BE. Mediation MR analysis suggested weight and BMI played a crucial role in these relationships. LDSC identified 1 taxon and 4 metabolism pathways related to GERD, and 1 taxon related to BE. Specie Faecalibacterium prausnitzii had a suggestive impact on both GERD(OR = 1.087, 95%CI = 1.01-1.17) and BE(OR = 1.388, 95%CI = 1.03-1.86) and LDSC had determined their correlation. Reverse MR indicated that BE impacted 10 taxa and 4 pathways.

CONCLUSIONS

This study established a causal link between gut microbiota and GERD/BE, and identified the probable mediators. It offers new insights into the role of gut microbiota in the development and progression of GERD and BE in the host.

Effects of dietary Artemisia annua supplementation on growth performance, antioxidant capacity, immune function, and gut microbiota of geese

This experiment aimed to study the effect of 1% Artemisia annua added to the diet on growth performance, antioxidant capacity, immunity and intestinal morphology, and gut microbiota of geese. Seventy-two 35-day-old male geese (Zi goose) with similar body weight were selected and randomly divided into 2 groups. Each treatment group of 36 geese was divided into 6 subgroups, each having 6 male geese. The experiment lasted for 21 d. Control group (CON) was fed a basal diet and the experimental group (AAL) was fed a basal diet + 1% Artemisia annua. BW, ADG, and ADFI of the AAL group increased (p < 0.05) and the FCR decreased (p < 0.05) compared with the CON group. The addition of Artemisia annua to the diet increased catalase (CAT), glutathione peroxidase (GSH-px), and superoxide dismutase (SOD) enzyme activities, increased total antioxidant capacity (T-AOC), and decreased malondialdehyde (MDA) content in serum and jejunum of geese (p < 0.05). Meanwhile, serum IgA, IgG, IgM, and lysozyme (LZM), increased at different time points in the AAL group compared to the CON group (p < 0.05), and decrease in the content of interferon-γ (IFN-γ) , IL-6 (p < 0.05), but no effect on complement C3 and C4. Morphological observation of the small intestine showed that the jejunal crypt depth was decreased in the AAL group (p < 0.05) while elevating the jejunal villus height/crypt depth (p < 0.05). 16S rRNA sequencing results showed the Artemisia annua increased the diversity of cecum microbiota, increasing the relative abundance of Bacteroides, Fecalibacterium, and Paraprevotella. In conclusion, the addition of 1% Artemisia annua to the diet could improve the growth performance, antioxidant and immune ability of geese, as well as improve the development of the jejunum intestinal tract of geese, and change the structure of the cecum microbiota, which had a positive effect on the growth and development of geese. Artemisia annua can be further developed as a feed additive.

Multi-omics analysis reveals the molecular regulatory network underlying the prevention of Lactiplantibacillus plantarum against LPS-induced salpingitis in laying hens

BACKGROUND

Salpingitis is one of the common diseases in laying hen production, which greatly decreases the economic outcome of laying hen farming. Lactiplantibacillus plantarum was effective in preventing local or systemic inflammation, however rare studies were reported on its prevention against salpingitis. This study aimed to investigate the preventive molecular regulatory network of microencapsulated Lactiplantibacillus plantarum (MLP) against salpingitis through multi-omics analysis, including microbiome, transcriptome and metabolome analyses.

RESULTS

The results revealed that supplementation of MLP in diet significantly alleviated the inflammation and atrophy of uterus caused by lipopolysaccharide (LPS) in hens (P < 0.05). The concentrations of plasma IL-2 and IL-10 in hens of MLP-LPS group were higher than those in hens of LPS-stimulation group (CN-LPS group) (P < 0.05). The expression levels of TLR2, MYD88, NF-κB, COX2, and TNF-α were significantly decreased in the hens fed diet supplemented with MLP and suffered with LPS stimulation (MLP-LPS group) compared with those in the hens of CN-LPS group (P < 0.05). Differentially expressed genes (DEGs) induced by  MLP were involved in inflammation, reproduction, and calcium ion transport. At the genus level, the MLP supplementation significantly increased  the abundance of Phascolarctobacterium, whereas decreased the abundance of Candidatus_Saccharimonas in LPS challenged hens (P < 0.05). The metabolites altered by dietary supplementation with MLP were mainly involved in galactose, uronic acid, histidine, pyruvate and primary bile acid metabolism. Dietary supplementation with MLP inversely regulates LPS-induced differential metabolites such as LysoPA (24:0/0:0) (P < 0.05).

CONCLUSIONS

In summary, dietary supplementation with microencapsulated Lactiplantibacillus plantarum prevented salpingitis by modulating the abundances of Candidatus_Saccharimonas, Phascolarctobacterium, Ruminococcus_torques_group and Eubacterium_hallii_group while downregulating the levels of plasma metabolites, p-tolyl sulfate, o-cresol and N-acetylhistamine and upregulating S-lactoylglutathione, simultaneously increasing the expressions of CPNE4, CNTN3 and ACAN genes in the uterus, and ultimately inhibiting oviducal inflammation.

F. prausnitzii-derived extracellular vesicles attenuate experimental colitis by regulating intestinal homeostasis in mice

BACKGROUND

Emerging evidence has shown that extracellular vesicles (EVs) derived from gut bacteria play a crucial role in microbiota-host interactions. Here, we aimed to evaluate the attenuating effect of EVs derived from a reduced commensal bacterium, F. prausnitzii (Fp-EVs), in inflammatory bowel disease (IBD) on dextran sulfate sodium (DSS)-induced colitis in mice.

RESULTS

Fp-EVs isolated by ultracentrifugation and typically exhibited a double concave disc shape with an average diameter of 172 nm. Fp-EVs treatment reduced DSS-induced weight loss, disease activity index (DAI) score, colon length shortening, histological damage, neutrophil infiltration and increased intestinal epithelial apoptotic cells in DSS-induced colitis mice. Fp-EVs upregulated the protein expression of zona occludens (ZO)-1 and Occludin and increased the ratio of Tregs in the colon tissue of colitis mice. Furthermore, Fp-EVs downregulated the expression of the proinflammatory cytokines interleukin-1β (IL-1β), IL-2, IL-6, IL-12a, IL-17a, Interferon-γ (IFN-γ), tumor necrosis factor - α (TNF-α), granulocyte-macrophage colony stimulating factor (GM-CSF) and upregulated the anti-inflammatory cytokines IL-4, IL-10, and transforming growth factor β (TGF-β) in DSS-treated mice. Moreover, Fp-EV treatment markedly reduced the phosphorylation of these proteins Nuclear factor-κB (NF-κB) and Mitogen activated protein kinase (MAPK), and regulated the expression of nuclear factor erythroid 2-related factor (Nrf2) and heme oxygenase-1 (HO-1).

CONCLUSION

Our findings revealed that Fp-EVs attenuated DSS-induced colitis by modulating the intestinal mucosal barrier function and immunological profile. Our findings reveal that Fp-EVs attenuate DSS-induced colitis by modulating intestinal mucosal barrier function and the immunological profile.

Immunostimulating Commensal Bacteria and Their Potential Use as Therapeutics

The gut microbiome is intimately intertwined with the host immune system, having effects on the systemic immune system. Dysbiosis of the gut microbiome has been linked not only to gastrointestinal disorders but also conditions of the skin, lungs, and brain. Commensal bacteria can affect the immune status of the host through a stimulation of the innate immune system, training of the adaptive immune system, and competitive exclusion of pathogens. Commensal bacteria improve immune response through the production of immunomodulating compounds such as microbe-associated molecular patterns (MAMPs), short-chain fatty acids (SCFAs), and secondary bile acids. The microbiome, especially when in dysbiosis, is plastic and can be manipulated through the introduction of beneficial bacteria or the adjustment of nutrients to stimulate the expansion of beneficial taxa. The complex nature of the gastrointestinal tract (GIT) ecosystem complicates the use of these methods, as similar treatments have various results in individuals with different residential microbiomes and differential health statuses. A more complete understanding of the interaction between commensal species, host genetics, and the host immune system is needed for effective microbiome interventions to be developed and implemented in a clinical setting.

Faecalibacterium: a bacterial genus with promising human health applications

In humans, many diseases are associated with alterations in gut microbiota, namely increases or decreases in the abundance of specific bacterial groups. One example is the genus Faecalibacterium. Numerous studies have underscored that low levels of Faecalibacterium are correlated with inflammatory conditions, with inflammatory bowel disease (IBD) in the forefront. Its representation is also diminished in the case of several diseases, including colorectal cancer (CRC), dermatitis, and depression. Additionally, the relative presence of this genus is considered to reflect, at least in part, intestinal health status because Faecalibacterium is frequently present at reduced levels in individuals with gastrointestinal diseases or disorders. In this review, we first thoroughly describe updates to the taxonomy of Faecalibacterium, which has transformed a single-species taxon to a multispecies taxon over the last decade. We then explore the links discovered between Faecalibacterium abundance and various diseases since the first IBD-focused studies were published. Next, we examine current available strategies for modulating Faecalibacterium levels in the gut. Finally, we summarize the mechanisms underlying the beneficial effects that have been attributed to this genus. Together, epidemiological and experimental data strongly support the use of Faecalibacterium as a next-generation probiotic (NGP) or live biotherapeutic product (LBP).

Diet, commensal microbiota-derived extracellular vesicles, and host immunity

The gut microbiota has co-evolved with its host, and commensal bacteria can influence both the host's immune development and function. Recently, a role has emerged for bacterial extracellular vesicles (BEVs) as potent immune modulators. BEVs are nanosized membrane vesicles produced by all bacteria, possessing the membrane characteristics of the originating bacterium and carrying an internal cargo that may include nucleic acid, proteins, lipids, and metabolites. Thus, BEVs possess multiple avenues for regulating immune processes, and have been implicated in allergic, autoimmune, and metabolic diseases. BEVs are biodistributed locally in the gut, and also systemically, and thus have the potential to affect both the local and systemic immune responses. The production of gut microbiota-derived BEVs is regulated by host factors such as diet and antibiotic usage. Specifically, all aspects of nutrition, including macronutrients (protein, carbohydrates, and fat), micronutrients (vitamins and minerals), and food additives (the antimicrobial sodium benzoate), can regulate BEV production. This review summarizes current knowledge of the powerful links between nutrition, antibiotics, gut microbiota-derived BEV, and their effects on immunity and disease development. It highlights the potential of targeting or utilizing gut microbiota-derived BEV as a therapeutic intervention.

The role and mechanisms of gram-negative bacterial outer membrane vesicles in inflammatory diseases

Outer membrane vesicles (OMVs) are spherical, bilayered, and nanosized membrane vesicles that are secreted from gram-negative bacteria. OMVs play a pivotal role in delivering lipopolysaccharide, proteins and other virulence factors to target cells. Multiple studies have found that OMVs participate in various inflammatory diseases, including periodontal disease, gastrointestinal inflammation, pulmonary inflammation and sepsis, by triggering pattern recognition receptors, activating inflammasomes and inducing mitochondrial dysfunction. OMVs also affect inflammation in distant organs or tissues via long-distance cargo transport in various diseases, including atherosclerosis and Alzheimer's disease. In this review, we primarily summarize the role of OMVs in inflammatory diseases, describe the mechanism through which OMVs participate in inflammatory signal cascades, and discuss the effects of OMVs on pathogenic processes in distant organs or tissues with the aim of providing novel insights into the role and mechanism of OMVs in inflammatory diseases and the prevention and treatment of OMV-mediated inflammatory diseases.

A Reciprocal Link between Oral, Gut Microbiota during Periodontitis: The Potential Role of Probiotics in Reducing Dysbiosis-Induced Inflammation

Human body is colonized by a florid microbial community of bacteria, archaea, fungi, protists, helminths, and viruses, known as microbiota, which co-evolves with the host and influences its health through all stages of its life. It is well known that oral microorganisms form highly structurally and functionally organized multi-species biofilms and establish a network of complex mutual inter-species interactions having a primary function in synergy, signaling, or antagonism. This ecological model allows the microorganisms to increase their resistance to antimicrobial agents and settle a balanced microbes-host symbiotic relationship that ensures oral and global health status in humans. The host-associated microbiome is an important factor in human health and disease. Therefore, to develop novel diagnostic, therapeutic, and preventive strategies, microbiome's functions and the reciprocal interactions every microbiome entertains with other microbial communities in the human body are being investigated. This review provides an analysis of the literature about the close connection between the two largest microbial communities in humans: the oral and the gut microbiomes. Furthermore, it focuses on how the alteration of their microbial and functional characteristics can lead to and reciprocally influence the onset of both oral and intestinal microbiome-associated illness, along with the potential role of probiotics in ameliorating inflammation and microbial dysbiosis.

Downregulation of ACE, AGTR1, and ACE2 genes mediating SARS-CoV-2 pathogenesis by gut microbiota members and their postbiotics on Caco-2 cells

INTRODUCTION

Coronavirus disease-2019 (COVID-19) is a complex infection caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that can cause also gastrointestinal symptoms. There are various factors that determine the host susceptibility and severity of infection, including the renin-angiotensin system, the immune response, and the gut microbiota. In this regard, we aimed to investigate the gene expression of ACE, AGTR1, ACE2, and TMPRSS2, which mediate SARS-CoV-2 pathogenesis by Akkermansia muciniphila, Faecalibacterium prausnitzii, Bacteroides thetaiotaomicron, and Bacteroides fragilis on Caco-2 cells. Also, the enrichment analysis considering the studied genes was analyzed on raw data from the microarray analysis of COVID-19 patients.

MATERIALS AND METHODS

Caco-2 cells were treated with live, heat-inactivated form and cell free supernatants of A. muciniphila, F. prausnitzii, B. thetaiotaomicron and B. fragilis for overnight. After RNA extraction and cDNA synthesis, the expression of studied genes was assessed by RT-qPCR. DNA methylation of studied genes was analyzed by Partek® Genomics Suite® software on the GSE174818 dataset. We used GSE164805 and GSE166552 datasets from COVID-19 patients to perform enrichment analysis by considering the mentioned genes via GEO2R, DAVID. Finally, the related microRNAs to GO terms concerned on the studied genes were identified by miRPath.

RESULTS

The downregulation of ACE, AGTR1, and ACE2 genes by A. muciniphila, F. prausnitzii, B. thetaiotaomicron, and B. fragilis in live, heat-inactivated, and cell-free supernatants was reported for the first time. These genes had hypomethylated DNA status in COVID-19 patients' raw data. The highest fold enrichment in upregulated RAS pathways and immune responses belonged to ACE, AGTR1, and ACE2 by considering the protein-protein interaction network. The common miRNAs targeting the studied genes were reported as miR-124-3p and miR-26b-5p. In combination with our experimental data and bioinformatic analysis, we showed the potential of A. muciniphila, F. prausnitzii, B. thetaiotaomicron, and B. fragilis and postbiotics to reduce ACE, ATR1, and ACE2 expression, which are essential genes that drive upregulated biological processes in COVID-19 patients.

CONCLUSION

Accordingly, due to the potential of studied bacteria on the alteration of ACE, AGTR1, ACE2 genes expression, understanding their correlation with demonstrated miRNAs expression could be valuable. These findings suggest the importance of considering targeted gut microbiota intervention when designing the possible therapeutic strategy for controlling the COVID-19.

Commensal bacteria-derived extracellular vesicles suppress ulcerative colitis through regulating the macrophages polarization and remodeling the gut microbiota

Background

The extracellular vesicles (EVs) traffic constitutes an essential pathway of cellular communication. And the molecules in EVs produced by procaryotes help in maintaining homeostasis, addressing microbial imbalance and infections, and regulating the immune system. Despite the fact that Clostridium butyricum (C. butyricum) is commonly used for treating ulcerative colitis (UC), the potential role of C. butyricum-secreted EVs in commensals-host crosstalk remains unclear.

Results

Here, we performed flow cytometry, western blot, immunohistochemistry and 16S rRNA analysis to explore the role of C. butyricum-derived EVs on macrophage polarization and gut microbiota composition in a dextran sulfate sodium (DSS)-induced UC mouse model. The antibiotic cocktail-induced microbiome depletion and faecal transplantations were used to further investigate the mechanisms by which EVs regulate macrophage balance. Our findings showed that C. butyricum-derived EVs improved the remission of murine colitis and polarized the transformation of macrophages to the M2 type. Furthermore, C. butyricum-derived EVs restored gut dysbiosis and altered the relative abundance of Helicobacter, Escherichia-Shigella, Lactobacillus, Akkermansia and Bacteroides, which, in turn, faecal transplantations from EVs-treated mice relieved the symptoms of UC and improved the impact of EVs on the reprogramming of the M2 macrophages.

Conclusion

C. butyricum-derived EVs could protect against DSS-induced colitis by regulating the repolarization of M2 macrophages and remodelling the composition of gut microbiota, suggesting the potential efficacy of EVs from commensal and probiotic Clostridium species against UC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12934-022-01812-6.

Faecalibacterium prausnitzii Ameliorates Colorectal Tumorigenesis and Suppresses Proliferation of HCT116 Colorectal Cancer Cells

Faecalibacterium prausnitzii is one of the most abundant commensals of gut microbiota that is not commonly administered as a probiotic supplement. Being one of the gut’s major butyrate-producing bacteria, its clinical significance and uses are on the rise and it has been shown to have anti-inflammatory and gut microbiota-modulating properties in the treatment of inflammatory bowel illness, Crohn’s disease, and colorectal cancer. Colorectal cancer (CRC) is a silent killer disease that has become one of the leading causes of cancer-related death worldwide. This study aimed to evaluate the anti-tumorigenic and antiproliferative role of F. prausnitzii as well as to study its effects on the diversity of gut microbiota in rats. Findings showed that F. prausnitzii probiotic significantly reduced the colonic aberrant crypt foci frequency and formation in Azoxymethane (AOM)-induced CRC in rats. In addition, the administration of F. prausnitzii lowered the lipid peroxidation levels in the colon tissues. For in vitro 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay, the cell-free supernatant of F. prausnitzii suppressed the growth of HCT116 colorectal cancer cells in a time/dose-dependent manner. 16S rRNA gene sequencing using rat stool samples showed that the administration of F. prausnitzii modulated the gut microbiota of the rats and enhanced its diversity. Hence, these findings suggest that F. prausnitzii as a probiotic supplement can be used in CRC prevention and management; however, more studies are warranted to understand its cellular and molecular mechanisms of action.

The immunomodulatory effects of Qushi Jianpi Hewei Decoction (QJHD) for patients with COVID-19 by metagenomics and transcriptomic sequencing

Ethnopharmacological relevance

Several studies have confirmed that intestinal microflora dysbiosis correlates with the severity of COVID-19 patients. Clinical meta-analysis and our data show that the circulating miRNAs like miRNA-146 and the levels of serum cytokines in the peripheral blood are closely related to mild to moderate COVID-19 patients. Despite the widespread use of traditional herbal medicine for COVID-19 in China, the mechanisms remain largely uncovered.

Aim of the study

We conducted an observational case-control study to verify the efficacy and safety of traditional Chinese herbal medicine Qushi Jianpi Hewei Decoction (QJHD) for mild to moderate COVID-19 patients, and investigated the potential biomolecular mechanisms through metagenomics and transcriptomic sequencing methods.

Materials and methods

QJHD was given orally twice a day individually for 14 to 28 days. A total of 10 patients were enrolled in the study and given QJHD. We observed advantages in clinical cure time rate, and the relief of gastrointestinal symptoms as compared with reports in the literature. The metagenomics sequencing data of fecal microflora and transcriptomic sequencing data of blood cell in patients with SARS-Cov-2 infection patients were selected compared to the healthy control donors.

Results

No serious adverse events were reported. Meanwhile, the transcriptome analysis showed a decrease of the hsa-miR-21-5p expression in peripheral blood without QJHD. The species composition analysis showed an increase in the expression of Faecalibacterium prausnitzii in the intestinal tract; The interleukin-10 (IL-10) expression also in COVID-19 patient decreased in peripheral blood compared with healthy control donors. And we found an improvement in these parameters in patients taking QJHD.

Conclusions

Our findings show that QJHD could improve clinical outcomes of mild to moderate COVID-19 patients, probably through beneficial immunomodulatory effects by regulating Faecalibacterium prausnitzii in the intestinal tract and hsa-miR-21 and IL-10 expression in peripheral blood. (chictr.org.cn, ChiCTR2000030305)

The anti-inflammatory effects of Akkermansia muciniphila and its derivates in HFD/CCL4-induced murine model of liver injury

Inflammation plays a critical role in the promotion of hepatocyte damage and liver fibrosis. In recent years the protective role of Akkermansia muciniphila, a next-generation beneficial microbe, has been suggested for metabolic and inflammatory disorders. In this study, we aimed to evaluate the effects of live and pasteurized A. muciniphila and its extra cellular vesicles (EVs) on inflammatory markers involved in liver fibrosis in a mouse model of a high-fat diet (HFD)/carbon tetrachloride (CCl₄)-induced liver injury. Firstly, the responses of hepatic stellate cells (HSCs) to live and pasteurized A. muciniphila and its EVs were examined in the quiescent and LPS-activated LX-2 cells. Next, the anti-inflammatory effects of different forms of A. muciniphila were examined in the mouse model of HFD/CCl₄-induced liver injury. The gene expression of various inflammatory markers was evaluated in liver, colon, and white adipose tissues. The cytokine secretion in the liver and white adipose tissues was also measured by ELISA. The results showed that administration of live and pasteurized A. muciniphila and its EVs leads to amelioration in HSCs activation. Based on data obtained from the histopathological analysis, an improvement in gut health was observed through enhancing the epithelium and mucosal layer thickness and strengthening the intestinal integrity in all treatments. Moreover, live A. muciniphila and its EVs had inhibitory effects on liver inflammation and hepatocytes damage. In addition, the tissue cytokine production and inflammatory gene expression levels revealed that live A. muciniphila and its EVs had more pronounced anti-inflammatory effects on liver and adipose tissues. Furthermore, EVs had better effects on the modulation of gene expression related to TLRs, PPARs, and immune response in the liver. In conclusion, the present results showed that oral administration of A. muciniphila and its derivatives for four weeks could enhance the intestinal integrity and anti-inflammatory responses of the colon, adipose, and liver tissues and subsequently prevent liver injury in HFD/CCL₄ mice.

The Protective Effects of Live and Pasteurized Akkermansia muciniphila and Its Extracellular Vesicles against HFD/CCl4-Induced Liver Injury

Akkermansia muciniphila, as a member of the gut microbiota, has been proposed as a next-generation probiotic. Liver fibrosis is the main determinant of liver dysfunction and mortality in patients with chronic liver disease. In this study, we aimed to determine the beneficial effects of live and pasteurized A. muciniphila and its extracellular vesicles (EVs) on the prevention of liver fibrosis. The response of hepatic stellate cells (HSCs) to live and pasteurized A. muciniphila and its EVs was examined in quiescent, lipopolysaccharide (LPS)-activated LX-2 cells. Liver fibrosis was induced in 8-week-old C57BL/6 mice, using a high-fat diet (HFD) and carbon tetrachloride (CCl4) administration for 4 weeks. The mice were concomitantly treated via oral gavage with three forms of bacteria. The relative expression of different fibrosis and inflammatory markers was assessed in the tissues. Histological markers, serum biochemical parameters, and cytokine production were also analyzed, and their correlations with the relative abundance of targeted fecal bacteria were examined. All A. muciniphila preparations exhibited protective effects against HSC activation; however, EVs showed the greatest activity in HSC regression. Oral gavage with A. muciniphila ameliorated the serum biochemical and inflammatory cytokines and improved liver and colon histopathological damages. The relative expression of fibrosis and inflammatory biomarkers was substantially attenuated in the tissues of all treated mice. The composition of targeted stool bacteria in the live A. muciniphila group was clearly different from that in the fibrosis group. This study indicated that A. muciniphila and its derivatives could successfully protect against HFD/CCl4-induced liver injury. However, further studies are needed to prove the beneficial effects of A. muciniphila on the liver. IMPORTANCE Akkermansia muciniphila, as a member of the gut microbiota, has been proposed as a next-generation probiotic. Liver fibrosis is the main determinant of liver dysfunction and mortality in patients with chronic liver disease. In this study, we aimed to determine the beneficial effects of live and pasteurized A. muciniphila and its extracellular vesicles (EVs) on the prevention of liver fibrosis. The results of the present study indicated that oral administration of live and pasteurized A. muciniphila and its EVs could normalize the fecal targeted bacteria composition, improve the intestinal permeability, modulate inflammatory responses, and subsequently prevent liver injury in HFD/CCl4-administered mice. Following the improvement of intestinal and liver histopathology, HFD/CCl4-induced kidney damage and adipose tissue inflammation were also ameliorated by different A. muciniphila treatments.

Oral Health and the Altered Colonic Mucosa-Associated Gut Microbiota

BACKGROUND

Systemic diseases have been associated with oral health and gut microbiota. We examined the association between oral health and the community composition and structure of the adherent colonic gut microbiota.

METHODS

We obtained 197 snap-frozen colonic biopsies from 62 colonoscopy-confirmed polyp-free individuals. Microbial DNA was sequenced for the 16S rRNA V4 region using the Illumina MiSeq, and the sequences were assigned to the operational taxonomic unit based on SILVA. We used a questionnaire to ascertain tooth loss, gum disease, and lifestyle factors. We compared biodiversity and relative abundance of bacterial taxa based on the amount of tooth loss and the presence of gum disease. The multivariable negative binomial regression model for panel data was used to estimate the association between the bacterial count and oral health. False discovery rate-adjusted P value (q value) < .05 indicated statistical significance.

RESULTS

More tooth loss and gum disease were associated with lower bacterial alpha diversity. The relative abundance of Faecalibacterium was lower (q values < .05) with more tooth loss. The association was significant after adjusting for age, ethnicity, obesity, smoking, alcohol use, hypertension, diabetes, and the colon segment. The relative abundance of Bacteroides was higher in those with gum disease.

CONCLUSIONS

Oral health was associated with alteration in the community composition and structure of the adherent gut bacteria in the colon. The reduced anti-inflammatory Faecalibacterium in participants with more tooth loss may indicate systemic inflammation. Future studies are warranted to confirm our findings and investigate the systemic role of Faecalibacterium.

Applications of Lactobacillus acidophilus-Fermented Mango Protected Clostridioides difficile Infection and Developed as an Innovative Probiotic Jam

Clostridioides difficile infection (CDI) is a large intestine disease caused by toxins produced by the spore-forming bacterium C. difficile, which belongs to Gram-positive bacillus. Using antibiotics treatment disturbances in the gut microbiota and toxins produced by C. difficile disrupt the intestinal barrier. Some evidence indicates fecal microbiota transplantation and probiotics may decrease the risk of CDI recurrence. This study aimed to evaluate the efficacy of fermented mango by using the lactic acid bacteria Lactobacillus acidophilus and develop innovative products in the form of fermented mango jam. L. acidophilus-fermented mango products inhibited the growth of C. difficile while promoting the growth of next-generation probiotic Faecalibacterium prausnitzii. Both supernatant and precipitate of mango-fermented products prevented cell death in gut enterocyte-like Caco-2 cells against C. difficile infection. Mango-fermented products also protected gut barrier function by elevating the expression of tight junction proteins. Moreover, L. acidophilus-fermented mango jam with high hydrostatic pressure treatment had favorable textural characteristics and sensory quality.

Sex-based differences in fecal short-chain fatty acid and gut microbiota in irritable bowel syndrome patients

OBJECTIVE

To explore alterations in fecal short-chain fatty acids (SCFA) and gut microbiota in patients with diarrhea-predominant irritable bowel disease (IBS-D) and their relationships with clinical manifestations.

METHODS

We recruited 162 patients with IBS-D and 66 healthy controls (HC). Their manifestations and psychological status were evaluated using the IBS severity scoring system and the Hospital Anxiety and Depression Scale (HADS). Colorectal visceral sensitivity was evaluated using a barostat. Systemic inflammation was evaluated using plasma cytokine levels. Fecal SCFA were quantified using ultra-performance liquid chromatography-tandem mass spectrometry, and fecal microbiota communities were analyzed using 16S rRNA sequencing.

RESULTS

More men presented with IBS-D than women in our patient cohort. Patients with IBS-D had more severe manifestations, higher HADS score, and a higher rate of previous infectious enteritis than HC. Notably, female patients had significantly higher HADS scores than male patients. Male patients had significantly higher levels of plasma interleukin (IL)-12, fecal propionate and colorectal visceral sensitivity than male HC, while no differences were observed between female patients and female HC. Fecal acetate, butyrate and valerate correlated with the initial visceral sensory threshold, stressors, and IL-10 and IL-12 levels. The propionate-producing Prevotella 9 genus was significantly increased in male patients and positively correlated with fecal propionate.

CONCLUSION

Distinct sex-based differences in clinical manifestations, fecal SCFA and microbiota richness are found in Chinese patients with IBS-D, which may be used to diagnose dysbiosis in these patients.

From the Role of Microbiota in Gut-Lung Axis to SARS-CoV-2 Pathogenesis

Severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) is responsible for the outbreak of a new viral respiratory infection. It has been demonstrated that the microbiota has a crucial role in establishing immune responses against respiratory infections, which are controlled by a bidirectional cross-talk, known as the “gut-lung axis.” The effects of microbiota on antiviral immune responses, including dendritic cell (DC) function and lymphocyte homing in the gut-lung axis, have been reported in the recent literature. Additionally, the gut microbiota composition affects (and is affected by) the expression of angiotensin-converting enzyme-2 (ACE2), which is the main receptor for SARS-CoV-2 and contributes to regulate inflammation. Several studies demonstrated an altered microbiota composition in patients infected with SARS-CoV-2, compared to healthy individuals. Furthermore, it has been shown that vaccine efficacy against viral respiratory infection is influenced by probiotics pretreatment. Therefore, the importance of the gut microbiota composition in the lung immune system and ACE2 expression could be valuable to provide optimal therapeutic approaches for SARS-CoV-2 and to preserve the symbiotic relationship of the microbiota with the host.

Could dysbiosis of inflammatory and anti-inflammatory gut bacteria have an implications in the development of type 2 diabetes? A pilot investigation

Objective

Differential alterations in gut microbiota and chronic low-grade inflammation play a critical role in the development of Type 2 diabetes (T2D). Here we aimed to investigate if dysbiosis of inflammation and anti-inflammation-associated gut bacterial communities in fecal samples of individuals had any influence on T2D using a 16S rRNA gene of V3 region sequencing at Illumina MiSeq platform.

Results

Our findings showed that a higher abundance of inflammatory bacteria such as Lactobacillus ruminis, Ruminococcus gnavus, Bacteroides caccae, Butyricimonas, and Collinsella aerofaciens, and lower abundance of anti-inflammatory bacteria such as Faecalibacterium prausnitzii, and Butyrivibrio that likely play a role in the development of T2D. Our findings hint the potential of indigenous microbiota in developing diagnostic markers and therapeutic targets in T2D.

Novel Odoribacter splanchnicus Strain and Its Outer Membrane Vesicles Exert Immunoregulatory Effects in vitro

Odoribacter splanchnicus, belonging to the order Bacteroidales, is a common, short-chain fatty acid producing member of the human intestinal microbiota. A decreased abundance of Odoribacter has been linked to different microbiota-associated diseases, such as non-alcoholic fatty liver disease, cystic fibrosis and inflammatory bowel disease (IBD). The type strain of O. splanchnicus has been genome-sequenced, but otherwise very little is known about this anaerobic bacterium. The species surfaces in many microbiota studies and, consequently, comprehension on its interactions with the host is needed. In this study, we isolated a novel strain of O. splanchnicus from a healthy fecal donor, identified it by genome sequencing and addressed its adhesive, epithelium reinforcing and immunoregulatory properties. Our results show that O. splanchnicus strain 57 is non-adherent to enterocytes or mucus, does not reinforce nor compromise Caco-2 monolayer integrity and most likely harbors penta-acylated, less endotoxic lipid A as part of its lipopolysaccharide (LPS) structure based on the lack of gene lpxM and in vitro results on low-level NF-κB activity. The studies by transmission electron microscopy revealed that O. splanchnicus produces outer membrane vesicles (OMV). O. splanchnicus cells, culture supernatant i.e., spent medium or OMVs did not induce interleukin-8 (IL-8) response in HT-29 enterocyte cells suggesting a very low proinflammatory capacity. On the contrary, the treatment of HT-29 cells with O. splanchnicus cells, spent medium or OMVs prior to exposure to Escherichia coli LPS elicited a significant decrease in IL-8 production as compared to E. coli LPS treatment alone. Moreover, O. splanchnicus spent supernatant induced IL-10 production by immune cells, suggesting anti-inflammatory activity. Our in vitro findings indicate that O. splanchnicus and its effector molecules transported in OMVs could potentially exert anti-inflammatory action in the gut epithelium. Taken together, O. splanchnicus seems to be a commensal with a primarily beneficial interaction with the host.

The effect of Faecalibacterium prausnitzii and its extracellular vesicles on the permeability of intestinal epithelial cells and expression of PPARs and ANGPTL4 in the Caco-2 cell culture model

Background and Objectives

Gut microbiota such as Faecalibacterium prausnitzii play a major role in the regulation of gut barrier, inflammation and metabolic functions. Microbiota-derived extracellular vehicles (EVs) have been recently introduced as functional units mediating the eukaryotic and prokaryotic cell-microbiota interactions. In this paper, the effect of F. prausnitzii and its EVs on mRNA expression levels of tight junction genes (ZO1 and OCLN) as well as PPARs and ANGPTL4 genes in the human epithelial colorectal adenocarcinoma (Caco-2) cell line was evaluated.

Methods

F. prausnitzii was cultured on the Brain Heart Infusion (BHI) broth medium under anaerobic conditions, and its EVs were extracted by ultracentrifugation. This bacterium and its EVs were treated on the Caco-2 cells. After 24 h, the expression of the genes encoding TJ proteins such as ZO1 and OCLN, PPARs and ANGPTL4 was evaluated by quantitative real-time PCR.

Results

Unlike F. prausnitzii, its EVs significantly increased the expression of ZO1 and OCLN genes, and PPARα, PPARγ and PPARβ/δ genes (except at a concentration of 100 µg/ml) as well as ANGPTL4 gene.

Conclusions

The results of this study demonstrated that F. prausnitzii-derived EVs increased the intestinal barrier permeability via TJs (ZO1 and OCLN) as well as PPAR-α, PPAR-γ and PPAR β/δ genes and their targeted gene (ANGPTL4) in the Caco-2 cell line. Accordingly, it is suggested that F. prausnitzii-derived EVs can be considered as a new bacterial postbiotic to cure dysbiosis-associated diseases including obesity and its related metabolic dysfunctions, according to the leaky gut hypothesis.

Primary human colonic mucosal barrier crosstalk with super oxygen-sensitive Faecalibacterium prausnitzii in continuous culture

Background

The gut microbiome plays an important role in human health and disease. Gnotobiotic animal and in vitro cell-based models provide some informative insights into mechanistic crosstalk. However, there is no existing system for a long-term co-culture of a human colonic mucosal barrier with super oxygen-sensitive commensal microbes, hindering the study of human-microbe interactions in a controlled manner.

Methods

Here, we investigated the effects of an abundant super oxygen-sensitive commensal anaerobe, Faecalibacterium prausnitzii, on a primary human mucosal barrier using a Gut-MIcrobiome (GuMI) physiome platform that we designed and fabricated.

Findings

Long-term continuous co-culture of F. prausnitzii for two days with colon epithelia, enabled by continuous flow of completely anoxic apical media and aerobic basal media, resulted in a strictly anaerobic apical environment fostering growth of and butyrate production by F. prausnitzii, while maintaining a stable colon epithelial barrier. We identified elevated differentiation and hypoxia-responsive genes and pathways in the platform compared with conventional aerobic static culture of the colon epithelia, attributable to a combination of anaerobic environment and continuous medium replenishment. Furthermore, we demonstrated anti-inflammatory effects of F. prausnitzii through HDAC and the TLR-NFKB axis. Finally, we identified that butyrate largely contributes to the anti-inflammatory effects by downregulating TLR3 and TLR4.

Conclusions

Our results are consistent with some clinical observations regarding F. prausnitzii, thus motivating further studies employing this platform with more complex engineered colon tissues for understanding the interaction between the human colonic mucosal barrier and microbiota, pathogens, or engineered bacteria.

Akkermansia muciniphila-Derived Extracellular Vesicles as a Mucosal Delivery Vector for Amelioration of Obesity in Mice

Recent evidence suggests that probiotics can restore the mucosal barrier integrity, ameliorate inflammation, and promote homeostasis required for metabolism in obesity by affecting the gut microbiota composition. In this study, we investigated the effect of Akkermansia muciniphila and its extracellular vesicles (EVs) on obesity-related genes in microarray datasets and evaluated the cell line and C57BL/6 mice by conducting RT-PCR and ELISA assays. A. muciniphila-derived EVs caused a more significant loss in body and fat weight of high-fat diet (HFD)-fed mice, compared with the bacterium itself. Moreover, treatment with A. muciniphila and EVs had significant effects on lipid metabolism and expression of inflammatory markers in adipose tissues. Both treatments improved the intestinal barrier integrity, inflammation, energy balance, and blood parameters (i.e., lipid profile and glucose level). Our findings showed that A. muciniphila-derived EVs contain various biomolecules, which can have a positive impact on obesity by affecting the involved genes. Also, our results showed that A. muciniphila and its EVs had a significant relationship with intestinal homeostasis, which highlights their positive role in obesity treatment. In conclusion, A. muciniphila-derived EVs can be used as new therapeutic strategies to ameliorate HFD-induced obesity by affecting various mechanisms.