Two faces of microbiota in inflammatory and autoimmune diseases: triggers and drugs

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

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

Serological markers of intestinal barrier impairment do not correlate with duration of diabetes and glycated hemoglobin in adult patients with type 1 and type 2 diabetes mellitus

Growing evidence suggests that diabetes mellitus is associated with impairment of the intestinal barrier. However, it is not clear so far if the impairment of the intestinal barrier is a consequence of prolonged hyperglycemia or the consequence of external factors influencing the gut microbiota and intestinal mucosa integrity. Aim of the study was to perform an estimation of relationship between serological markers of impairment of the intestinal barrier: intestinal fatty acid-binding protein (I-FABP), cytokeratin 18 caspase-cleaved fragment (cCK-18), and soluble CD14 (sCD14) and markers of prolonged hyperglycemia, such as the duration of diabetes mellitus and glycated hemoglobin (HbA1c) via a correlation analysis in patients with diabetes mellitus. In 40 adult patients with type 1 diabetes mellitus and 30 adult patients with type 2 diabetes mellitus the estimation has been performed. Statistically significant positive correlation was found between cCK-18 and HbA1c (r=0.5047, p=0.0275) in patients with type 1 diabetes mellitus with fading insulitis (T1D). In patients with type 1 diabetes mellitus with ongoing insulitis (T1D/INS) and in patients with type 2 diabetes mellitus (T2D), no statistically significant positive correlations were found between serological markers of intestinal barrier impairment (I-FABP, cCK-18, sCD14) and duration of diabetes or levels of HbA1c. Similarly, in cumulative cohort of patients with T1D/INS and patients with T1D we revealed statistically positive correlation only between HbA1c and cCK-18 (r=0.3414, p=0.0311). Surprisingly, we found statistically significant negative correlation between the duration of diabetes mellitus and cCK-18 (r=-0.3050, p=0.0313) only in cumulative group of diabetic patients (T1D, T1D/INS, and T2D). Based on our results, we hypothesize that the actual condition of the intestinal barrier in diabetic patients is much more dependent on variable interactions between host genetic factors, gut microbiota, and environmental factors rather than effects of long-standing hyperglycemia (assessed by duration of diabetes mellitus or HbA1c).

Fecal Microbial Transplantation in Critically Ill Patients-Structured Review and Perspectives

The human gut microbiota consists of bacteria, archaea, fungi, and viruses. It is a dynamic ecosystem shaped by several factors that play an essential role in both healthy and diseased states of humans. A disturbance of the gut microbiota, also termed "dysbiosis", is associated with increased host susceptibility to a range of diseases. Because of splanchnic ischemia, exposure to antibiotics, and/or the underlying disease, critically ill patients loose 90% of the commensal organisms in their gut within hours after the insult. This is followed by a rapid overgrowth of potentially pathogenic and pro-inflammatory bacteria that alter metabolic, immune, and even neurocognitive functions and that turn the gut into the driver of systemic inflammation and multiorgan failure. Indeed, restoring healthy microbiota by means of fecal microbiota transplantation (FMT) in the critically ill is an attractive and plausible concept in intensive care. Nonetheless, available data from controlled studies are limited to probiotics and FMT for severe C. difficile infection or severe inflammatory bowel disease. Case series and observational trials have generated hypotheses that FMT might be feasible and safe in immunocompromised patients, refractory sepsis, or severe antibiotic-associated diarrhea in ICU. There is a burning need to test these hypotheses in randomized controlled trials powered for the determination of patient-centered outcomes.

Effects of therapeutic probiotics on modulation of microRNAs

Probiotics are beneficial bacteria that exist within the human gut, and which are also present in different food products and supplements. They have been investigated for some decades, due to their potential beneficial impact on human health. Probiotics compete with pathogenic microorganisms for adhesion sites within the gut, to antagonize them or to regulate the host immune response resulting in preventive and therapeutic effects. Therefore, dysbiosis, defined as an impairment in the gut microbiota, could play a role in various pathological conditions, such as lactose intolerance, gastrointestinal and urogenital infections, various cancers, cystic fibrosis, allergies, inflammatory bowel disease, and can also be caused by antibiotic side effects. MicroRNAs (miRNAs) are short non-coding RNAs that can regulate gene expression in a post-transcriptional manner. miRNAs are biochemical biomarkers that play an important role in almost all cellular signaling pathways in many healthy and disease states. For the first time, the present review summarizes current evidence suggesting that the beneficial properties of probiotics could be explained based on the pivotal role of miRNAs. Video Abstract.

A Novel Fusion of IL-10 Engineered to Traffic across Intestinal Epithelium to Treat Colitis

IL-10 is a potent anti-inflammatory cytokine capable of suppressing a number of proinflammatory signals associated with intestinal inflammatory diseases, such as ulcerative colitis and Crohn's disease. Clinical use of human IL-10 (hIL-10) has been limited by anemia and thrombocytopenia following systemic injection, side effects that might be eliminated by a gut-restricted distribution. We have identified a transcytosis pathway used by cholix, an exotoxin secreted by nonpandemic forms of the intestinal pathogen Vibrio cholerae A nontoxic fragment of the first 386 aa of cholix was genetically fused to hIL-10 to produce recombinant AMT-101. In vitro and in vivo characterization of AMT-101 showed it to efficiently cross healthy human intestinal epithelium (SMI-100) by a vesicular transcytosis process, activate hIL-10 receptors in an engineered U2OS osteosarcoma cell line, and increase cellular phospho-STAT3 levels in J774.2 mouse macrophage cells. AMT-101 was taken up by inflamed intestinal mucosa and activated pSTAT3 in the lamina propria with limited systemic distribution. AMT-101 administered to healthy mice by oral gavage or to cynomolgus monkeys (nonhuman primates) by colonic spray increased circulating levels of IL-1R antagonist (IL-1Ra). Oral gavage of AMT-101 in two mouse models of induced colitis prevented associated pathological events and plasma cytokine changes. Overall, these studies suggest that AMT-101 can efficiently overcome the epithelial barrier to focus biologically active IL-10 to the intestinal lamina propria.

Anorexia nervosa: Gut microbiota-immune-brain interactions

Anorexia nervosa is a psychiatric disorder defined by an extremely low body weight, a devastating fear of weight gain, and body image disturbance, however the etiopathogenesis remains unclear. The objective of the article is to provide a comprehensive review on the potential role of gut microbiota in pathogenesis of anorexia nervosa. Recent advances in sequencing techniques used for microbial detection revealed that this disease is associated with disruption of the composition of normal gut microbiota (dysbiosis), manifested by low microbial diversity and taxonomic differences as compared to healthy individuals. Microorganisms present in the gut represent a part of the so called "microbiota-gut-brain" axis that affect the central nervous system and thus human behavior via the production of various neuroactive compounds. In addition, cells of the immune system are equipped with receptors for these neuroactive substances. Microbiota of the intestinal system also represent a very important antigenic source. These antigens can mimic some host neuropeptides and neurohormones and thus trigger the production of autoantibodies which cross-react with these compounds. The levels and affinities of these antibodies are thought to be associated with neuropsychiatric conditions including anxiety, depression, and eating and sleep disorders. The study of microbiota function in diseases could bring new insights to the pathogenetic mechanisms.

Clinical intervention using Bifidobacterium strains in celiac disease children reveals novel microbial modulators of TNF-α and short-chain fatty acids

BACKGROUND & AIMS

Celiac disease (CD) is an immune-mediated systemic disease, caused by ingestion of gluten in genetically predisposed individuals. Gut microbiota dysbiosis might play a significant role in pathogenesis of chronic enteropathies and its modulation can be used as an intervention strategy in CD as well. In this study, we aimed to identify correlations between fecal microbiota, serum tumor necrosis factor alpha (TNF-α) and fecal short-chain fatty acids (SCFAs) in healthy children and children with CD after administration of probiotic Bifidobacterium breve BR03 and B632.

METHODS

A double-blind placebo-controlled study enrolled 40 children with CD (CD) and 16 healthy children (HC). CD children were randomly allocated into two groups, of which 20 belonged to the placebo (PL) group and 20 to the Probiotic (PR) group. The PR group received a probiotic formulation containing a mixture of 2 strains, B. breve BR03 (DSM 16604) and B. breve B632 (DSM 24706) in 1:1 ratio for 3 months. Subsequently, for statistical analysis, blood and fecal samples from CD children (on enrolment - T0 and after 3 months, at the end of intervention with probiotic/placebo - T1) and HC children were used. The HC group was sampled only once (T0).

RESULTS

Verrucomicrobia, Parcubacteria and some yet unknown phyla of Bacteria and Archaea may be involved in the disease, indicated by a strong correlation to TNF-α. Likewise, Proteobacteria strongly correlated with fecal SCFAs concentration. The effect of probiotic administration has disclosed a negative correlation between Verrucomicrobia, some unknown phyla of Bacteria, Synergistetes, Euryarchaeota and some SCFAs, turning them into an important target in microbiome restoration process. Synergistetes and Euryarchaeota may have a role in the anti-inflammatory process in healthy human gut.

CONCLUSIONS

Our results highlight new phyla, which may have an important relation to disease-related parameters, CD itself and health.

Dysbiosis a risk factor for celiac disease

Celiac disease remains one of the most challenging pathologies of the small intestine. It involves multiple pathogenic pathways and there are no disease-changing pharmacological agents available against it yet. The term microbiota refers to the community of microorganisms that inhabit a particular region of the body. Normal gut microbiota has a vital role in maintaining the intestinal homeostasis and promoting health. Celiac disease is associated with microbiota alteration, especially with an increase in the number of Gram-negative bacteria and a decrease in the number of Gram-positive bacteria. There is a strong relationship between intestinal dysbiosis and celiac disease, and recent studies are aimed at determining whether the celiac disease is a risk factor for dysbiosis or dysbiosis is for celiac disease. Therefore, the aim of this review was to assess the latest findings regarding the gut microbiota and its impact on the celiac disease, including therapeutic aspects.

The Microbiota Determines Susceptibility to Experimental Autoimmune Uveoretinitis

The microbiota is a crucial modulator of the immune system. Here, we evaluated how its absence or reduction modifies the inflammatory response in the murine model of experimental autoimmune uveoretinitis (EAU). We induced EAU in germ-free (GF) or conventionally housed (CV) mice and in CV mice treated with a combination of broad-spectrum antibiotics either from the day of EAU induction or from one week prior to induction of disease. The severity of the inflammation was assessed by fundus biomicroscopy or by histology, including immunohistology. The immunophenotyping of T cells in local and distant lymph nodes was performed by flow cytometry. We found that GF mice and mice where the microbiota was reduced one week before EAU induction were protected from severe autoimmune inflammation. GF mice had lower numbers of infiltrating macrophages and significantly less T cell infiltration in the retina than CV mice with EAU. GF mice also had reduced numbers of IFN-γ and IL-17-producing T cells and increased numbers of regulatory T cells in the eye-draining lymph nodes. These data suggest that the presence of microbiota during autoantigen recognition regulates the inflammatory response by influencing the adaptive immune response.

The Association of Chronic Hepatitis C with Respiratory Microbiota Disturbance on the Basis of Decreased Haemophilus Spp. Colonization

Background

Haemophilus species are the most common microbiota in humans. The aim of this paper was to investigate Haemophilus spp., mainly H. parainfluenzae prevalence, in the upper respiratory tract of chronic hepatitis C (CHC-positive) patients with or without therapy using pegylated interferon alfa and ribavirin.

Material/Methods

We collected 462 samples from 54 healthy people and 100 CHC-positive patients at various stages: before (group A), during (group B), and after (group C) antiviral therapy. Identification of bacterial isolates including biotypes and antimicrobials susceptibility was accomplished by means of standard microbiological methods.

Results

In 70.4% of healthy people (control group) and in 27.0% of CHC-positive patients, the presence of haemophili, mainly H. parainfluenzae was observed, and those differences were statistically significant (p<0.0001). Statistically significant differences in Haemophilus spp. colonization were also observed among healthy people and CHC-positive patients from group A (p=0.0012) and from B or C groups (p<0.0001). Resistance to ampicillin in beta-lactamase-positive isolates and multidrug resistance (MDR) of H. parainfluenzae was detected mainly in group A.

Conclusions

The obtained data suggest that chronic hepatitis C, together with antiviral therapy, may influence the respiratory tract microbiota composition as found using haemophili, mainly H. parainfluenzae.

Administration of Bifidobacterium breve Decreases the Production of TNF-α in Children with Celiac Disease

BACKGROUND

Increasing evidence suggests that not only genetics, but also environmental factors like gut microbiota dysbiosis play an important role in the pathogenesis of celiac disease (CD).

AIM

The aim of our study was to investigate the effect of two probiotic strains Bifidobacterium breve BR03 and B. breve B632 on serum production of anti-inflammatory cytokine interleukin 10 (IL-10) and pro-inflammatory cytokine tumor necrosis factor alpha (TNF-α) in children with CD.

METHODS

The study was a double-blinded, placebo-controlled trial that included 49 children with CD on gluten-free diet (GFD) randomized into two groups and 18 healthy children in the control group. The first group (24 children with CD) daily received B. breve BR03 and B632 (2 × 10(9) colony-forming units) and the second group (25 children with CD) received placebo for 3 months.

RESULTS

TNF-α levels were significantly decreased in the first group after receiving B. breve for 3 months. On follow-up, 3 months after receiving probiotics, TNF-α levels increased again. Children with CD who were on GFD for less than 1 year showed similar baseline TNF-α levels as children who were on GFD for more than 1 year. IL-10 levels were in all groups of patients below detection level.

CONCLUSIONS

Probiotic intervention with B. breve strains has shown a positive effect on decreasing the production of pro-inflammatory cytokine TNF-α in children with CD on GFD.

Immune response to gut Escherichia coli and susceptibility to adjuvant arthritis in the rats

We have investigated the humoral immune response to antigens of predominant gut aerobic bacterial strains (i.e. Escherichia coli) over the course of adjuvant arthritis and oil-induced arthritis in two inbred rat strains: Dark Agouti (DA) and Albino Oxford (AO). We report the presence of antibodies specific to proteins of E. coli in molecular weight range between 20-30 kDa in sera of diseased DA rats, and the absence of these antibodies in the sera of AO rats. In DA rats, CFA and IFA provoked a stronger antibody response to E. coli, especially of the IgG2b antibody class. Intramuscular administration of E. coli preceding the adjuvant arthritis induction had no effect on the development and course of disease, as well as on the activation of T cells in the draining inguinal lymph nodes. Higher serum levels of natural and induced IgA antibodies, combined with a higher CD3+CD26+ cell percentage were found in AO rats. The observed correlation between the serologic response to commensal flora and rats' genetic background as a defining factor for arthritis susceptibility may contribute to the process of creating a favorable (or less favorable) milieu for arthritis development.

Prevalence of hyperthyroidism according to type of vegetarian diet

OBJECTIVE

Vegetarian diets may be associated with low prevalence of autoimmune disease, as observed in rural sub-Saharan Africans. Graves' disease, an autoimmune disorder, is the most common cause of hyperthyroidism. We studied prevalence of hyperthyroidism according to dietary pattern in a population with a high proportion of vegetarians.

DESIGN

Cross-sectional prevalence study. The association between diet and prevalence of hyperthyroidism was examined using multivariate logistic regression analyses controlling for sociodemographic characteristics and salt use.

SETTING

The Adventist Health Study-2 conducted in the USA and Canada.

SUBJECTS

Church members (n 65 981) provided demographic, dietary, lifestyle and medical history data by questionnaire.

RESULTS

The prevalence of self-reported hyperthyroidism was 0·9 %. Male gender (OR=0·32; 95 % CI 0·26, 0·41) and moderate or high income (OR=0·67; 95 % CI 0·52, 0·88 and OR=0·73; 95 % CI 0·58, 0·91, respectively) protected against hyperthyroidism, while obesity and prevalent CVD were associated with increased risk (OR=1·25; 95 % CI 1·02, 1·54 and OR=1·92; 95 % CI 1·53, 2·42, respectively). Vegan, lacto-ovo and pesco vegetarian diets were associated with lower risk compared with omnivorous diets (OR=0·49; 95 % CI 0·33, OR=0·72, 0·65; 95 % CI 0·53, 0·81 and OR=0·74; 95 % CI 0·56, 1·00, respectively).

CONCLUSIONS

Exclusion of all animal foods was associated with half the prevalence of hyperthyroidism compared with omnivorous diets. Lacto-ovo and pesco vegetarian diets were associated with intermediate protection. Further study of potential mechanisms is warranted.

Long term follow up of celiac disease-is atherosclerosis a problem?

Celiac disease (CD) is a lifelong condition and it often involves impaired nutrition, wide spectrum of symptoms and it requires constant dietetic treatment. The impact of the gluten-free diet on patients’ nutritional status and on the other biochemical parameters is being widely investigated. In this article we looked into particular risk factors that might lead to increased prevalence of atherosclerosis in CD patients, including nutritional status, gluten-free diet, lipids profile and concomitant disease—type 1 diabetes mellitus. Here, we present the current data and research on these risk factors of atherosclerosis with respect to celiac disease.

Early life events influence whole-of-life metabolic health via gut microflora and gut permeability

The capacity of our gut microbial communities to maintain a stable and balanced state, termed 'resilience', in spite of perturbations is vital to our achieving and maintaining optimal health. A loss of microbial resilience is observed in a number of diseases including obesity, diabetes and metabolic syndrome. There are large gaps in our understanding of why an individual's co-evolved microflora consortium fail to develop resilience thereby establishing a trajectory towards poor metabolic health. This review examines the connections between the developing gut microbiota and intestinal barrier function in the neonate, infant and during the first years of life. We propose that the effects of early life events on the gut microflora and permeability, whilst it is in a dynamic and vulnerable state, are fundamental in shaping the microbial consortia's resilience and that it is the maintenance of resilience that is pivotal for metabolic health throughout life. We review the literature supporting this concept suggesting new potential research directions aimed at developing a greater understanding of the longitudinal effects of the gut microflora on metabolic health and potential interventions to recalibrate the 'at risk' infant gut microflora in the direction of enhanced metabolic health.

Perspectives in immunopharmacology: the future of immunosuppression

Modulation of immune responses for therapeutic purposes is a particularly relevant area, given the central role of anomalous immunity in a wide variety of diseases, from the most typically immune-related syndromes (autoimmune diseases, allergy and asthma, immunodeficiencies) to those in which altered immunity and inflammation define the pathological outcomes (chronic infections, tumors, chronic inflammatory and degenerative diseases, metabolic disorders, etc.). This brief review will summarize some of the most promising perspectives of immunopharmacology, in particular in the area of immunosuppression, by considering the following aspects:

Lectin staining shows no evidence of involvement of glycocalyx/mucous layer carbohydrate structures in development of celiac disease

The presence of unique carbohydrate structures in the glycocalyx/mucous layer of the intestine may be involved in a susceptibility to celiac disease (CD) by serving as attachment sites for bacteria. This host-microbiota interaction may influence the development of CD and possibly other diseases with autoimmune components. We examined duodenal biopsies from a total of 30 children, of which 10 had both celiac disease (CD) and type 1 diabetes (T1D); 10 had CD alone; and 10 were suspected of having gastrointestinal disease, but had normal duodenal histology (non-CD controls). Patients with both CD and T1D were examined before and after remission following a gluten-free diet. We performed lectin histochemistry using peanut agglutinin (PNA) and Ulex europaeus agglutinin (UEA) staining for Gal-β(1,3)-GalNAc and Fucα1-2Gal-R, respectively, of the glycocalyx/mucous layer. The staining was scored based on dissemination of stained structures on a scale from 0 to 3. Evaluation of the scores revealed no difference between biopsies obtained before and after remission in the group of children with both CD and T1D. A comparison of this pre-remission group with the children who had CD alone or the non-CD controls also showed no significant differences. Based on our material, we found no indication that the presence of Gal-β(1,3)-GalNAc or Fucα1-2Gal-R is involved in the susceptibility to CD, or that the disease process affects the expression of these carbohydrates.