Changes of gut bacteria and immune parameters in liver transplant recipients

BACKGROUND: Liver transplantation is one of the most effective therapeutic options for patients with end-stage liver diseases, and gut microbiota is actively involved in potential infections in pretransplant and posttransplant patients. However, the diversity of gut microbiota and its relationship with the immune parameter of liver transplantation recipients are not well understood. METHODS: We collected fresh feces and blood samples from 190 participants in China from November 2004 to May 2008, including 28 healthy volunteers, 51 cirrhotic patients and 111 liver-transplanted patients. Six interesting gut bacteria, plasma endotoxin, serum cytokines (i.e., tumor necrosis factor alpha and interleukin-6) and fecal secretory IgA (SIgA) were investigated by real-time quantitative PCR, chromogenic limulus amoebocyte assay, sandwich-type enzyme-linked immunosorbent assay and radioimmunoassay, respectively. RESULTS: All Eubacteria, Bifidobacterium spp., Faecalibacterium prausnitzii and Lactobacillus spp. were significantly lower in the liver transplantation recipients while Enterobacteriaceae and Enterococcus spp. were significantly higher (P<0.05). Except for Enterococcus spp., other bacteria showed a tendency to restore to normal level along with the time after liver transplantation. Plasma endotoxin, interleukin-6 and fecal SIgA in cirrhotic patients increased significantly, but not in liver transplantation recipients. Plasma endotoxin and interleukin-6 were negatively correlated with all Eubacteria and the Bacteroides-Prevotella group, while tumor necrosis factor alpha was not significantly correlated with these six gut bacteria in cirrhotic patients.CONCLUSIONS: Our study demonstrates that abundant gut bacteria were altered significantly in both cirrhotic and liver transplantation patients, while plasma endotoxin and interleukin-6 increased remarkably in cirrhotic patients, showing significant correlations with gut microbiota. Interestingly, our data show a tendency for these gut bacteria to restore to normal levels in liver transplantation recipients.

Tauroursodeoxycholic acid(TUDCA)improves intestinal barrier function associated with TGR5-MLCK pathway and the alteration of serum metabolites and gut bacteria in weaned piglets

Background:Tauroursodeoxycholic acid(TUDCA),a hydrophilic bile acid,is the main medicinal component of bear bile and is commonly used to treat a variety of hepatobiliary diseases.Meanwhile,TUDCA has been shown to modulate the intestinal barrier function and alleviate DSS-induced colitis in mice.However,the effect of TUDCA on the intestinal barrier of weaned piglets remains largely unclear.Methods:The weaned piglets and porcine IPEC-J2 intestinal epithelial cells were used to investigate the effects of TUDCA on intestinal barrier function in weaned piglets and explore the possible underlying mechanisms.In vivo,72 healthy weaned piglets were randomly allocated into 2 groups according to their gender and body weight,and piglets were fed the basal diet with 0(control,CON)and 200 mg/kg TUDCA for 30 d,respectively.Three female and three male piglets reflecting the average bodyweight were slaughtered in each group and samples were collected.In vitro,IPEC-J2 cells were subjected to 100μmol/L TUDCA to explore the possible underlying mechanisms.Results:Our results demonstrated that dietary TUDCA supplementation significantly reduced the diarrhea incidence of weaned piglets,possibly attributing to the TUDCA-enhanced intestinal barrier function and immunity.In addition,TUDCA supplementation altered serum metabolites and the relative abundance of certain gut bacteria,which might contribute to the improved intestinal barrier function.Furthermore,the in-vitro results showed that TUDCA improved the E.coli-induced epithelial barrier impairment of IPEC-J2 cells and increased Takeda G-coupled protein receptor 5(TGR5)protein expression.However,knockdown of TGR5 and inhibition of myosin light chain kinase(MLCK)pathway abolished the TUDCA-improved epithelial barrier impairment in E.coli-treated IPEC-J2 cells,indicating the involvement of TGR5-MLCK in this process.Conclusions:These findings showed that TUDCA improved intestinal barrier function associated with TGR5-MLCK pathway and the alteration of serum metabolites and gut bacteria in weaned piglets,suggesting the potential application of TUDCA in improving gut health in piglet production.

Gut Bacteria and Nutritional Status of Nigerian Children at an Internally Displaced Persons’ Camp in Benue State, Nigeria: A Pilot Study

This study was conducted to determine the gut bacteria and nutritional status of children (n = 30) aged 2 - 11 in Benue’s largest internally displaced persons (IDP) camp since information on this is lacking. Gut bacteria were identified using culture techniques, while Body Mass Index (Kg/m2), Weight-for-Height (WHZ), and Weight-for-Age (WAZ) z scores were computed from anthropometric measurements. Socio-demographic and economic variables were collected via structured questionnaires. IBM SPSS v25 was used to analyze the data, with p Salmonella spp., Shigella spp., and Escherichia coli compared to children from a nearby private school (n = 10), except for E. coli, where the prevalence was equal. The results for BMI revealed that 23 (57.5%) of the children had a healthy weight while 17 (42.5%) were underweight.WAZ z-scores were between (-0.02 - 2.51) with evidence of mildly underweight (20%) and mildly overweight (5%) children. WHZ z-scores were between -0.03 - 2.37, with moderately wasted (30%) and severely wasted (5%) found. To ensure better health outcomes for residents, conditions in the camp must be improved.

A Comparative Study on Rat Intestinal Epithelial Cells and Resident Gut Bacteria (ii) Effect of Arsenite

Objective In order to use facultative gut bacteria as an alternate to animals for the initial gastrointestinal toxicity screening of heavy metals, a comparative study on rat intestinal epithelial cells and resident gut bacteria was undertaken. Methods in vitro growth rate of four gut bacteria, dehydrogenase （DHA） and esterase （EA） activity test, intestinal epithelial and bacterial cell membrane enzymes and in situ effect of arsenite were analysed. Results Growth profile of mixed resident population of gut bacteria and pure isolates of Escherichia coli, Pseudomonas sp., Lactobacillus sp., and Staphylococcus sp. revealed an arsenite （2-20 ppm） concentration-dependent inhibition. The viability pattern of epithelial cells also showed similar changes. DHA and EA tests revealed significant inhibition （40%-72%） with arsenite exposure of 5 and 10 ppm in isolated gut bacteria and epithelial cells. Decrease in membrane alkaline phosphatase and Ca^2＋-Mg^2＋-ATPase activities was in the range of 33%-55% in four bacteria at the arsenite exposure of 10 ppm, whereas it was 60%-65% in intestinal epithelial villus cells, in situ incubation of arsenite using intestinal loops also showed more or less similar changes in membrane enzymes of resident gut bacterial population and epithelial cells. Conclusion The results indicate that facultative gut bacteria can be used as suitable in vitro model for the preliminary screening of arsenical gastrointestinal cytotoxic effects.

A faster killing effect of plastid-mediated RNA interference on a leaf beetle through induced dysbiosis of the gut bacteria

The expression of double-stranded RNAs(dsRNAs)from the plastid genome has been proven to be an effective method for controlling herbivorous pests by targeting essential insect genes.However,there are limitations to the efficiency of plastid-mediated RNA interference(PM-RNAi)due to the initial damage caused by the insects and their slow response to RNA interference.In this study,we developed transplastomic poplar plants that express dsRNAs targeting the b-Actin(dsACT)and Srp54k(dsSRP54K)genes of Plagiodera versicolora.Feeding experiments showed that transplastomic poplar plants can cause significantly higher mortality in P.versicolora larvae compared with nuclear transgenic or wild-type poplar plants.The efficient killing effect of PM-RNAi on P.versicolora larvae was found to be dependent on the presence of gut bacteria.Importantly,foliar application of a gut bacterial strain,Pseudomonas putida,will induce dysbiosis in the gut bacteria of P.versicolora larvae,leading to a significant acceleration in the speed of killing by PM-RNAi.Overall,our findings suggest that interfering with gut bacteria could be a promising strategy to enhance the effectiveness of PM-RNAi for insect pest control,offering a novel and effective approach for crop protection based on RNAi technology.

Evaluation of five antibiotics on larval gut bacterial diversity of Plutella xylostella （Lepidoptera： Plutellidae）

Larvae of the diamondback moth, Plutella xylostella L. （Lepidoptera： Plutelli- dae）, have rich microbial communities inhabiting the gut, and these bacteria contribute to the fitness of the pest. In this study we evaluated the effects of five antibiotics （rifampicin, ampicillin, tetracycline, streptomycin sulfate and chloramphenicol） on the gut bacterial di- versity ofP xylostella larvae. We screened five different concentrations for each antibiotic in a leaf disc assay, and found that rifampicin and streptomycin sulfate at 3 mg/mL signif- icantly reduced the diversity of the bacterial community, and some bacterial species could be rapidly eliminated. The number of gut bacteria in the rifampicin group and strepto- mycin sulfate group decreased more rapidly than the others. With the increase of antibiotic concentration, the removal efficiency was improved, whereas toxic effects became more apparent. All antibiotics reduced larval growth and development, and eventually caused high mortality, malformation of the prepupae, and hindered pupation and adult emergence. Among the five antibiotics, tetracycline was the most toxic and streptomycin sulfate was a relatively mild one. Some dominant bacteria were not affected by feeding antibiotics alone. Denaturing gradient gel electrophoresis graph showed that the most abundant and diverse bacteria in P xylostella larval gut appeared in the cabbage feeding group, and diet change and antibiotics intake influenced gut flora abundance. Species diversity was significantly reduced in the artificial diet and antibiotics treatment groups. After feeding on the artificial diet with rifampicin, streptomycin sulfate and their mixture for 10 days, larval gut bacteria could not be completely removed as detected with the agarose gel electrophoresis method.

Functional roles of gut bacteria imbalance in cholangiopathies

Cholangiopathies are caused by bile duct damage or inflammation followed by cholestasis leading to liver fibrosis.Bile duct epithelial cells,cholangiocytes,are a primary target for cholangiopathies.Ductular reaction is often observed in cholangiopathies and the proliferation of cholangiocytes is associated with ductular reaction and liver fibrogenesis.Accumulating evidence suggests that patients with chol-angiopathies have different gut bacterial profiles from healthy individuals,indicating the association between gut microbiota and cholangiopathies.Bile acids are produced by hepatocytes and modified by gut bacteria.Bile acids regulate cholangiocyte proliferation but effects vary depending on the type of bile acids.Recent studies suggest that therapies targeting gut bacteria,such as antibiotics administration and gut bacteria depletion or therapies using gut bacteria-associated bile acids,such as ursodeoxycholic acid(UDCA)administration,may be useful for treatments of cholangiopathies,although data are contro-versial depending on animal models or cohorts.This review summarizes current understandings of functional roles of gut bacterial imbalance and strategies for treatments of cholangiopathies targeting gut bacteria.

Multifunctional role of oral bacteria in the progression of nonalcoholic fatty liver disease

Non-alcoholic fatty liver disease(NAFLD)encompasses a spectrum of liver disorders of varying severity,ultimately leading to fibrosis.This spectrum primarily consists of NAFL and non-alcoholic steatohepatitis.The pathogenesis of NAFLD is closely associated with disturbances in the gut micr-obiota and impairment of the intestinal barrier.Non-gut commensal flora,particularly bacteria,play a pivotal role in the progression of NAFLD.Notably,Porphyromonas gingivalis,a principal bacterium involved in periodontitis,is known to facilitate lipid accumulation,augment immune responses,and induce insulin resistance,thereby exacerbating fibrosis in cases of periodontitis-associated NAFLD.The influence of oral microbiota on NAFLD via the“oral-gut-liver”axis is gaining recognition,offering a novel perspective for NAFLD management through microbial imbalance correction.This review endeavors to encapsulate the intricate roles of oral bacteria in NAFLD and explore underlying mechanisms,emphasizing microbial control strategies as a viable therapeutic avenue for NAFLD.

Modulative effect of Physalis alkekengi on both gut bacterial and fungal micro-ecosystem

Objective: Gut microbiome is an intricate micro-ecosystem mediating the human health and drug efficacy. Physalis alkekengi(PAL) is an edible and time-honored traditional Chinese medicine. Several pharmacological effects of PAL have been verified and gut bacteria are implied in its therapeutic actions.However, the detailed modulation of PAL on gut bacterial species and on gut fungi remains largely unknown. We, therefore, designed a preliminary experiment in normal mice to reveal the modulation effect of PAL on both gut bacteria and fungi, and explore the interaction between them.Methods: Herein, the aqueous extract of PAL was orally administrated to normal C57BL/6 mice for four weeks. The full-length 16S rRNA and ITS1/2 gene sequencing were explored to detect the taxa of gut bacteria and gut fungi after PAL treatment, respectively.Results: Oral administration of PAL notably enriched anti-infammatory bacterial species such as Duncaniella spp. and Kineothrix alysoides, whereas decreased pro-infammatory species such as Mucispirillum schaedleri. Simultaneously, PAL increased the abundance of gut fungi Aspergillus ochraceus,Cladosporium sp. and Alternaria sp., and decreased Penicillium janthinellum. Correlation network analysis identified two co-existing microbial groups(groups 1 and 2) that were negatively associated with each other. The group 1 comprised PAL-enriched bacteria and fungi, while group 2 was mainly normal chow-enriched bacteria and fungi. In group 1, Antrodia monomitica, Aspergillus clavatus, Mortierella kuhlmanii and Sarcinomyces sp. MA 4787 were positively correlated with Bifidobacterium globosum,Romboutsia ilealis and so on. In group 2, Chaetomium subspirilliferum, Septoria orchidearum and Cephaliophora tropica were positively related to Lactobacillus spp.Conclusion: Altogether, this preliminary study first demonstrated the modulation effect of PAL on both gut bacteria and gut fungi, which may shed light on the elucidation of PAL’s pharmacological mechanism.

Antibiotic-induced gut bacteria depletion has no effect on HBV replication in HBV immune tolerance mouse model

Commensal microbiota is closely related to Hepatitis B virus(HBV)infection.Gut bacteria maturation accelerates HBV immune clearance in hydrodynamic injection(HDI)HBV mouse model.However,the effect of gut bacteria on HBV replication in recombinant adeno-associated virus(AAV)-HBV mouse model with immune tolerance remains obscure.We aim to investigate its role on HBV replication in AAV-HBV mouse model.C57BL/6 mice were administrated with broad-spectrum antibiotic mixtures(ABX)to deplete gut bacteria and intravenously injected with AAV-HBV to establish persistent HBV replication.Gut microbiota community was analyzed by fecal qPCR assay and 16S ribosomal RNA(rRNA)gene sequencing.HBV replication markers in blood and liver were determined by ELISA,qPCR assay and Western blot at indicated time points.Immune response in AAV-HBV mouse model was activated through HDI of HBV plasmid or poly(I:C)and then detected by quantifying the percentage of IFN-γ^(+)/CD8^(+)T cells in the spleen via flow cytometry as well as the splenic IFN-γmRNA level via qPCR assay.We found that antibiotic exposure remarkably decreased gut bacteria abundance and diversity.Antibiotic treatment failed to alter the levels of serological HBV antigens,intrahepatic HBV RNA transcripts and HBc protein in AAV-HBV mouse model,but contributed to HBsAg increase after breaking of immune tolerance.Overall,our data uncovered that antibiotic-induced gut bacteria depletion has no effect on HBV replication in immune tolerant AAV-HBV mouse model,providing new thoughts for elucidating the correlation between gut bacteria dysbiosis by antibiotic abuse and clinical chronic HBV infection.

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.

Skin-gut axis:The relationship between intestinal bacteria and skin health

The gut microbiome is an emerging area of interest in medicine. Imbalances in the gut microbiome have been linked to a number of disease states such as obesity and type 2 diabetes. The relationship between normally residing intestinal bacteria(the gut microbiota) and their potential role in the pathogenesis of skin diseases is an area of research for which we are only beginning to understand. Small studies have demonstrated underlying changes in the gut microbiome of patients with certain dermatological diseases. Interestingly, studies suggest that probiotics may have a role in the treatment of atopic dermatitis. However, the concept of the "skin-gut axis" is a newly emerging and important avenue of investigation, still lacking in pathobiological explanations. This review will introduce and describe the intestinal microbiome as it relates to skin health in a complex communication network between the immune system, endocrine system, metabolic system, and nervous system.

Gut commensal bacteria, Paneth cells and their relations to radiation enteropathy

In steady state, the intestinal epithelium forms an important part of the gut barrier to defend against luminal bacterial attack. However, the intestinal epithelium is compromised by ionizing irradiation due to its inherent selfrenewing capacity. In this process, small intestinal bacterial overgrowth is a critical event that reciprocally alters the immune milieu. In other words, intestinal bacterial dysbiosis induces inflammation in response to intestinal injuries, thus influencing the repair process of irradiated lesions. In fact, it is accepted that commensal bacteria can generally enhance the host radiation sensitivity. To address the determination of radiation sensitivity, we hypothesize that Paneth cells press a critical "button" because these cells are central to intestinal health and disease by using their peptides, which are responsible for controlling stem cell development in the small intestine and luminal bacterial diversity. Herein,the most important question is whether Paneth cells alter their secretion profiles in the situation of ionizing irradiation. On this basis, the tolerance of Paneth cells to ionizing radiation and related mechanisms by which radiation affects Paneth cell survival and death will be discussed in this review. We hope that the relevant results will be helpful in developing new approaches against radiation enteropathy.

Midgut bacterial communities in the giant Asian honeybee （Apis dorsata） across 4 developmental stages： A comparative study

Bacterial communities are known to play important roles during the developmental stages of insects, but current knowledge of bacteria associated with the midgut of Apis dorsata, the giant Asian honeybee, is limited. Using polymerase chain reaction-denaturing gradient gel electrophoresis analysis （PCR-DGGE） and 16S rRNA sequencing, the aim of this study was to determine the dynamics of bacterial community structure across four A. dorsata life stages in different geographical locations. The results reveal that bacterial diversity increased as the bee progressed through larval stage to newly emerged worker and old worker. However, in the pupal stage, no bands identified as bacteria could be observed. Overall, 2 bacterial phyla （Proteobacteria and Firmicutes） and 4 classes （Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, and Bacilli） were identified, but the frequency varied among the different stages and locations. The classes of Gammaproteobacteria and Bacilli dominated among larval, newly emerged worker and old worker developmental stages.

The Effects of Shrimp Gut Probiotic Bacteria on the Shrimp Larvae (Penaeus Chinensis)

The survival rates of shrimp larvae in different stage are higher than those of control groups when probiotic bacteria strains X4B 1 and X1B 1 which are isolated from gut of adult shrimp are added into the little volume rearing sea water of shrimp larvae. The effects of probiotic bacteria are evaluated by challenge test (pathogenic bacteria Z 3G 2 isolated from disease shrimp larvae in the hatchery of Jimo town) and low salinity stress resistance tests on shrimp larvae, the survival rate and lengths of the shrimp larvae in the experiment are determined. Results indicate that 1. The survival rate, ability of resistant to low salinity, lengths of the delivered shrimp larvae are improved after the strains of probiotic bacteria, X4B 1 or X1B 1, are added into the rearing sea water of hatchery. 2. The addition of the probiotic bacteria could not influence the change of the bacteria number, NH3 N and COD value in the rearing sea water. 3. The probiotic bacteria used in the experiment have many enzymes such as Lipase, Amylase, Gelatinase and Lecithinase. These enzymes may help the probiotic bacteria to digest the food components fed to shrimp larvae and increase the digestive efficiency of post larvae. This may be one of the reasons why these probiotic bacteria are beneficial to the shrimp larvae.

Emerging roles of lactic acid bacteria in protection against colorectal cancer

Colorectal cancer(CRC)is the third leading cause of cancer deaths worldwide and the fourth most common cancer diagnosed among men and women in the United States.Considering the risk factors of CRC,dietary therapy has become one of the most effective approaches in reducing CRC morbidity and mortality.The use of probiotics is increasing in popularity for both the prevention and treatment of a variety of diseases.As the most common types of microbes used as probiotics,lactic acid bacteria(LAB)are comprised of an ecologically diverse group of microorganisms united by formation of lactic acid as the primary metabolite of sugar metabolism.LAB have been successfully used in managing diarrhea,food allergies,and inflammatory bowel disease.LAB also demonstrated a host of properties in preventing colorectal cancer development by inhibiting initiation or progression through multiple pathways.In this review,we discuss recent insights into cellular and molecular mechanisms of LAB in CRC prevention including apoptosis,antioxidant DNA damages,immune responses,and epigenetics.The emerging experimental findings from clinical trials as well as the proposed mechanisms of gut microbiota in carcinogenesis will also be briefly discussed.

Effects of Ligustrum robustum on gut microbes and obesity in rats

AIM: To investigate the anti-obesity and antibacterial effects of Ligustrum robustum(L. robustum) in vivoand in vitro and its possible mechanisms. METHODS: The effects of L. robustum aqueous extract(LR) on various gut bacteria in vitro were evaluated. The effects of LR on high-fat diet-fed(HFD) rats in vivo were also assessed. Culture methods,quantitative polymerase chain reaction,and terminalrestriction fragment length polymorphism were used to analyze the effects of LR on gut bacteria. Biochemical tests were also performed to detect the changes in obesity-related indicators after LR treatment. RESULTS: LR treatment lowered adipose weight and decreased Lee's index,blood glucose,total cholesterol,and lipid in the tested groups relative to control(P < 0.05). To determine the reasons for these changes,we assessed the potential bacteriostatic and bactericidal effects of LR on specific bacterial species in vitro. LR affected the richness,diversity,and evenness of gut bacteria,increased fecal Lactobacillus,and decreased Enterococci in HFD rats(P < 0.05). CONCLUSION: L. robustum may be a safe and effective food for weight loss and obesity control,and the effects of L. robustum might be mediated by the regulation of gut bacteria.

The Effect of the Hot Water Extracts of the <i>Paecilomyces hepiali </i>and <i>Cordyceps militaris</i>Mycelia on the Growth of Gastrointestinal Bacteria

The gastrointestinal health is very important aspect concerning human health. It refers to nutrient and vitamin absorption, food digestion and various infectious diseases. The Paecilomyces hepiali and Cordyceps militaris are highly enriched with cordycepin and ergosterol which are considered as anti bacterial substances. Present study finds out comparative effect of hot water extract of particular fungal material on growth of six species of gastrointestinal bacteria that belong to both aerobic and anaerobic and, consist with harmful and commensal categories. The appropriate concentration level of hot water extract of both strains was identified. The individual specific bacterial growing media were prepared and calculated;amounts of bacteria cultures were inoculated by using micro pipettes. The optical density and number of bacterial colonies were measured after 24 hours. The pure mycelial extract of P. hepiali with 2 × 10-3 g/ml of concentration has significant effect on depleting the growth of E. coli, E. faecalis, S. aureus, L. gasseri and B. ovatus bacteria. B. longum has no significant effect by particular extract. Same type of extract of C. militaris has significantly reduced the growth of every bacteria used in this study. Hot water extract of C. militaris cultivated on soy bean has significant growth retardation toward E. coli, E. faecalis, S. aureus and L. gasseri. It has stimulated the growth of B. ovatus and B. longum which are considered as beneficial bacteria for human gut. This study shows that extracts of both mycelia include antimicrobial substances like cordycepin and ergosterol which can be used as food supplements to enhance human gut health.

发酵枸杞多糖通过调节肠道微生态缓解葡聚糖硫酸钠诱导的溃疡性结肠炎

为探究多糖益生元调节肠道微生态作用机制,采用ELISA法、组织病理学分析、免疫组化分析、16S rRNA高通量测序、气相色谱-质谱联用等方法,研究发酵多糖对葡聚糖硫酸钠(DSS)诱导结肠炎模型小鼠肠道菌群和短链脂肪酸(SCFAs)变化的影响及其与肠道炎症水平、屏障蛋白表达的关系。结果发现,发酵枸杞多糖(FLBP)可显著降低小鼠肠道炎症水平,改善结肠组织结构,上调紧密连接蛋白Claudin-1和ZO-1表达量,同时显著增加肠道SCFAs含量。肠道菌群分析结果表明,FLBP可富集小鼠肠道杜氏芽孢杆菌(Dubosiella)和阿克曼氏菌属(Akkermansia),降低Turicibacter菌属、肠杆菌属(Faecalibaculum)、埃希氏菌-志贺菌属(Escherichia-Shigella)丰度。研究结果表明,FLBP激活重塑的杜氏芽孢杆菌在改善结肠炎中占主导作用,显著提升SCFAs含量,增强肠道屏障,降低肠道炎症。研究旨在为改善结肠炎提供更安全有益的选择,并为开发FLBP功能性食品提供理论依据。

Bacterial biofilms in human gastrointestinal tract: An intricate balance between health and inflammatory bowel diseases

Inflammatory bowel disease (IBD) has been a worldwide health problem. It is characterized by severe intestinal inflammation due to immune responses against the gut microbes in genetically susceptible individuals. The understanding of gut microbiota for its composition and complex interaction in normal and diseased conditions has been assisted by the use of molecular, metagenomics and meta transcriptomics studies. The alteration of intestinal microbiota is the key determinant in the degree of inflammation caused and the prolonged course of disease. The relationship between luminal gut bacteria and innate immunity is also of prime significance. Such developments have further led to the search of specific (including bacteria and fungi) as a causative agent of IBD. Although detailed research has been done for the role of gut microbiota in IBD, molecular mechanisms and related gene expression are still not well understood in this disease, which hampers the generation of effective therapeutic agents for IBD. This paper assessed various factors contributing to IBD, genetic dysbiosis and pathogenic influence in the gut microbiota, interactions such as microbiome-host immune system interaction and microbe-microbe interactions involved in IBD, currently available IBD therapies, followed by a detailed review on bacterial infections that might be involved in IBD, globally and specifically in India.