scholarly journals Secretory IgA in Intestinal Mucosal Secretions as an Adaptive Barrier against Microbial Cells

2020 ◽  
Vol 21 (23) ◽  
pp. 9254
Author(s):  
Bernadeta Pietrzak ◽  
Katarzyna Tomela ◽  
Agnieszka Olejnik-Schmidt ◽  
Andrzej Mackiewicz ◽  
Marcin Schmidt
Keyword(s):  
Gut Microbiota ◽  
Plasma Cells ◽  
Intestinal Barrier ◽  
Secretory Iga ◽  
Microbiota Composition ◽  
Lymphoid Follicles ◽  
Lymphoid Structures ◽  
Antibody Class ◽  
Mucosal Secretions ◽  
Gut Microbiota Composition

Secretory IgA (SIgA) is the dominant antibody class in mucosal secretions. The majority of plasma cells producing IgA are located within mucosal membranes lining the intestines. SIgA protects against the adhesion of pathogens and their penetration into the intestinal barrier. Moreover, SIgA regulates gut microbiota composition and provides intestinal homeostasis. In this review, we present mechanisms of SIgA generation: T cell-dependent and -independent; in different non-organized and organized lymphoid structures in intestinal lamina propria (i.e., Peyer’s patches and isolated lymphoid follicles). We also summarize recent advances in understanding of SIgA functions in intestinal mucosal secretions with focus on its role in regulating gut microbiota composition and generation of tolerogenic responses toward its members.

scholarly journals Effects of Dietary Fibres on Acute Indomethacin-Induced Intestinal Hyperpermeability in the Elderly: A Randomised Placebo Controlled Parallel Clinical Trial

Nutrients ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1954
Author(s):  
John-Peter Ganda Mall ◽  
Frida Fart ◽  
Julia A. Sabet ◽  
Carl Mårten Lindqvist ◽  
Ragnhild Nestestog ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Barrier Function ◽  
Intestinal Barrier ◽  
The Elderly ◽  
Intestinal Barrier Function ◽  
Elderly Subjects ◽  
Microbiota Composition ◽  
Dietary Fibres ◽  
Gut Microbiota Composition

The effect of dietary fibres on intestinal barrier function has not been well studied, especially in the elderly. We aimed to investigate the potential of the dietary fibres oat β-glucan and wheat arabinoxylan to strengthen the intestinal barrier function and counteract acute non-steroid anti-inflammatory drug (indomethacin)-induced hyperpermeability in the elderly. A general population of elderly subjects (≥65 years, n = 49) was randomised to a daily supplementation (12g/day) of oat β-glucan, arabinoxylan or placebo (maltodextrin) for six weeks. The primary outcome was change in acute indomethacin-induced intestinal permeability from baseline, assessed by an in vivo multi-sugar permeability test. Secondary outcomes were changes from baseline in: gut microbiota composition, systemic inflammatory status and self-reported health. Despite a majority of the study population (85%) showing a habitual fibre intake below the recommendation, no significant effects on acute indomethacin-induced intestinal hyperpermeability in vivo or gut microbiota composition were observed after six weeks intervention with either dietary fibre, compared to placebo.

scholarly journals IgA-deficient humans exhibit gut microbiota dysbiosis despite secretion of compensatory IgM

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jason R. Catanzaro ◽  
Juliet D. Strauss ◽  
Agata Bielecka ◽  
Anthony F. Porto ◽  
Francis M. Lobo ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
16S Rrna Gene Sequencing ◽  
Iga Deficiency ◽  
Secretory Iga ◽  
Rrna Gene ◽  
Healthy Controls ◽  
Microbiota Composition ◽  
Antibody Isotype ◽  
Selective Iga Deficiency ◽  
Gut Microbiota Composition

Abstract Immunoglobulin A is the dominant antibody isotype found in mucosal secretions and enforces host-microbiota symbiosis in mice, yet selective IgA-deficiency (sIgAd) in humans is often described as asymptomatic. Here, we determined the effects of IgA deficiency on human gut microbiota composition and evaluated the possibility that mucosal secretion of IgM can compensate for a lack of secretory IgA. We used 16S rRNA gene sequencing and bacterial cell sorting to evaluate gut microbiota composition and taxa-specific antibody coating of the gut microbiota in 15 sIgAd subjects and matched controls. Despite the secretion of compensatory IgM into the gut lumen, sIgAd subjects displayed an altered gut microbiota composition as compared to healthy controls. These alterations were characterized by a trend towards decreased overall microbial diversity as well as significant shifts in the relative abundances of specific microbial taxa. While secretory IgA in healthy controls targeted a defined subset of the microbiota via high-level coating, compensatory IgM in sIgAd subjects showed less specificity than IgA and bound a broader subset of the microbiota. We conclude that IgA plays a critical and non-redundant role in controlling gut microbiota composition in humans and that secretory IgA has evolved to maintain a diverse and stable gut microbial community.

Oleanolic acid protection against experimental autoimmune myocarditis modulates the microbiota and the intestinal barrier integrity

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
M.L Nieto Callejo ◽  
I Gallardo ◽  
B Gutierrez ◽  
M.I Cabero ◽  
L Ruiz ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Intestinal Barrier ◽  
Funding Source ◽  
Microbiota Composition ◽  
Autoimmune Myocarditis ◽  
Gut Dysbiosis ◽  
Experimental Autoimmune Myocarditis ◽  
Gut Damage ◽  
Gut Microbiota Composition ◽  
Experimental Autoimmune

Abstract Background Autoimmune myocarditis is a cause of dilated cardiomyopathy and heart failure. Recent studies have indicated that leaky gut may allow environmental factors to enter the body and trigger the initiation/development of autoimmune disease. Moreover, there is a growing literature supporting that, beside myocardial fibrosis, a leaky intestinal barrier and gut dysbiosis are pathogenic factors linked to heart failure. The natural triterpene oleanolic acid (OA) has been shown to beneficially influence the severity of the experimental autoimmune myocarditis (EAM), a preclinical model of human myocarditis, via anti-oxidant and immunomodulatory mechanisms. Herein, we investigate gastrointestinal (GI) disturbances and the gut microbiota composition associated with EAM as potential therapeutic target of OA. Methods and results BALB/c mice were α-myosin-inmunized to induce EAM and treated with OA (25 mg/kg/day, i.p). On day 21, heart fibrosis and parameters related to gut damage such as oxidative stress (O2- ions, lipid peroxidation), gut permeability (D-lactate; I-FABP), inflammation and mucins were determined in serum and/or colon. Fecal microbial profiles were identified by 16S rRNA gene sequencing analysis. Firstly, histological analysis of hearts showed presence of fibrosis (Sirius Red stain) in EAM mice, whereas these effects were not detectable in myocardium from healthy or OA-treated EAM mice. In addition, OA preserved the mucin-containing goblet cells along the colon (Alcian Blue/PAS stain). Consistently, serum levels of the epithelial gut damage markers, including D-lactate and iFABP were significantly reduced in OA treated-EAM mice. The beneficial OA effects also included a decrease in the pro-inflammatory mediators sPLA2-IIA and IL-1β and a protection from the oxidative stress response (DHE stain and TBARS) in serum and colonic tissue of EAM-mice. Furthermore, gut microbiota composition showed a lower bacterial diversity and different relative abundance of certain bacterial taxa in EAM-mice compared to control mice. The families of Muribaculaceae, Lachnospiraceae, and Ruminococcaceae were significantly affected in EAM mice, and only Muribaculaceae recovered levels similar to the healthy-control group, after treatment with OA. Conclusion Our data show that in addition to the heart, the intestinal barrier and gut microbiota are altered in myocarditis, and that OA treatment could ameliorate this profile. Our data contribute to the idea that gut dysbiosis and GI dysfunction influences myocarditis pathogenesis, and provides new findings regarding the beneficial activity of OA in EAM, suggesting that it may be an interesting candidate to be explored for the treatment of human patients. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): MINECO, ISCIII, CIBERCV-ISCIII

scholarly journals Effect of Gluten-Free Diet on Gut Microbiota Composition in Patients with Celiac Disease and Non-Celiac Gluten/Wheat Sensitivity

Nutrients ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1832 ◽  
Author(s):  
Giacomo Caio ◽  
Lisa Lungaro ◽  
Nicola Segata ◽  
Matteo Guarino ◽  
Giorgio Zoli ◽  
...  
Keyword(s):  
Celiac Disease ◽  
Gut Microbiota ◽  
Intestinal Barrier ◽  
Gluten Free Diet ◽  
Microbiota Composition ◽  
Gluten Free ◽  
Gluten Proteins ◽  
Wheat Sensitivity ◽  
Long Life ◽  
Gut Microbiota Composition

Celiac disease (CD) and non-celiac gluten/wheat sensitivity (NCG/WS) are the two most frequent conditions belonging to gluten-related disorders (GRDs). Both these diseases are triggered and worsened by gluten proteins ingestion, although other components, such as amylase/trypsin inhibitors (ATI) and fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs), seem to be involved in the NCG/WS onset. Therefore, the only effective treatment to date is the long-life adherence to a strictly gluten-free diet. Recently, increasing attention has been paid to the intestinal barrier, a dynamic system comprising various components, which regulate the delicate crosstalk between metabolic, motor, neuroendocrine and immunological functions. Among the elements characterizing the intestinal barrier, the microbiota plays a key role, modulating the gut integrity maintenance, the immune response and the inflammation process, linked to the CD and NCG/WS outbreak. This narrative review addresses the most recent findings on the gut microbiota modulation induced by the gluten-free diet (GFD) in healthy, CD and NCG/WS patients.

scholarly journals IgA-deficient humans exhibit gut microbiota dysbiosis despite production of compensatory IgM

2018 ◽  
Author(s):  
Jason R Catanzaro ◽  
Juliet D Strauss ◽  
Agata Bielecka ◽  
Anthony F Porto ◽  
Francis M Lobo ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
16S Rrna Gene Sequencing ◽  
Iga Deficiency ◽  
Secretory Iga ◽  
Intestinal Lumen ◽  
Rrna Gene ◽  
Microbiota Composition ◽  
Antibody Isotype ◽  
Selective Iga Deficiency ◽  
Gut Microbiota Composition

ABSTRACTImmunoglobulin A is the dominant antibody isotype found in mucosal secretions and enforces host-microbiota symbiosis in mice, yet selective IgA-deficiency (sIgAd) is the most common primary immunodeficiency in humans and is often described as asymptomatic. Here, we determined the effects of IgA deficiency on human gut microbiota composition and evaluated the possibility that secretion of IgM can compensate for a lack of secretory IgA. We used 16S rRNA gene sequencing and bacterial cell sorting to evaluate gut microbiota composition and IgA or IgM coating of the gut microbiota in 15 sIgAd subjects and 15 matched controls. Although sIgAd subjects secreted a significant amount of IgM into the intestinal lumen, this was insufficient to fully compensate for the lack of secretory IgA. Indeed, sIgAd subjects displayed an altered gut microbiota composition as compared to healthy controls, which was characterized by a trend towards decreased overall microbial diversity and significant shifts in the relative abundances of specific microbial taxa. While IgA targets a defined subset of the microbiota via high-level coating, compensatory IgM binds a broader subset of the microbiota in a less targeted manner. We conclude that IgA plays a critical and non-redundant role in controlling gut microbiota composition in humans and that secretory IgA has evolved to maintain a diverse and stable gut microbial community that promotes human health, enhances resistance to infection, and is resilient to perturbation.

scholarly journals Food Components and Dietary Habits: Keys for a Healthy Gut Microbiota Composition

Nutrients ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2393 ◽  
Author(s):  
Rinninella ◽  
Cintoni ◽  
Raoul ◽  
Lopetuso ◽  
Scaldaferri ◽  
...  
Keyword(s):  
Immune System ◽  
Gut Microbiota ◽  
Dietary Habits ◽  
Food Additives ◽  
Intestinal Barrier ◽  
Health Concern ◽  
Microbiota Composition ◽  
Food Components ◽  
The Impact ◽  
Gut Microbiota Composition

The gut microbiota is a changing ecosystem, containing trillions of bacteria, continuously shaped by many factors, such as dietary habits, seasonality, lifestyle, stress, antibiotics use, or diseases. A healthy host–microorganisms balance must be respected in order to optimally maintain the intestinal barrier and immune system functions and, consequently, prevent disease development. In the past several decades, the adoption of modern dietary habits has become a growing health concern, as it is strongly associated with obesity and related metabolic diseases, promoting inflammation and both structural and behavioral changes in gut microbiota. In this context, novel dietary strategies are emerging to prevent diseases and maintain health. However, the consequences of these different diets on gut microbiota modulation are still largely unknown, and could potentially lead to alterations of gut microbiota, intestinal barrier, and the immune system. The present review aimed to focus on the impact of single food components (macronutrients and micronutrients), salt, food additives, and different dietary habits (i.e., vegan and vegetarian, gluten-free, ketogenic, high sugar, low FODMAP, Western-type, and Mediterranean diets) on gut microbiota composition in order to define the optimal diet for a healthy modulation of gut microbiota.

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