scholarly journals Role of the Intestinal Microbiome, Intestinal Barrier and Psychobiotics in Depression

Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 927
Author(s):  
Paulina Trzeciak ◽  
Mariola Herbet

The intestinal microbiota plays an important role in the pathophysiology of depression. As determined, the microbiota influences the shaping and modulation of the functioning of the gut–brain axis. The intestinal microbiota has a significant impact on processes related to neurotransmitter synthesis, the myelination of neurons in the prefrontal cortex, and is also involved in the development of the amygdala and hippocampus. Intestinal bacteria are also a source of vitamins, the deficiency of which is believed to be related to the response to antidepressant therapy and may lead to exacerbation of depressive symptoms. Additionally, it is known that, in periods of excessive activation of stress reactions, the immune system also plays an important role, negatively affecting the tightness of the intestinal barrier and intestinal microflora. In this review, we have summarized the role of the gut microbiota, its metabolites, and diet in susceptibility to depression. We also describe abnormalities in the functioning of the intestinal barrier caused by increased activity of the immune system in response to stressors. Moreover, the presented study discusses the role of psychobiotics in the prevention and treatment of depression through their influence on the intestinal barrier, immune processes, and functioning of the nervous system.

2021 ◽  
pp. 34-37
Author(s):  
I. N. Ekimov ◽  
O. V. Pravdina

Disorders of interstitial barrier permeability as one of the promising mechanisms of psoriasis formation and development is a trend of the last decades. In the analysis of modern works devoted to the evaluation of the role of intestinal barrier damage in the development of psoriasis, several ways of assessing intestinal permeability have been noted (including measurement of transepithelial electrical responses using a Ussing chamber, measurement of excretion of orally injected molecules, determination of dynamics and kinetics of LPS intestinal bacteria, immunohistochemical confocal analysis of uniform Z-sections perpendicular to the epithelial cell surface, etc.). However, most authors emphasize the diagnostic significance and availability of biomarker detection. Among the described biomarkers, claudin-3, fecal zonulin, α1-antitrypsin, calprotectin and intestinal fatty acid binding protein (I-FABP) are the most valuable. Through these methods of assessing intestinal permeability and the results of their studies, a number of authors practically prove the correlation between the violation of the intestinal microbiota, intestinal barrier permeability and the development of psoriasis, as well as its severity. This aspect is promising to the therapy of patients with psoriasis, which includes correction of intestinal microbiota and intestinal wall permeability.


Nutrients ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 823 ◽  
Author(s):  
Kathyayini P. Gopalakrishna ◽  
Timothy W. Hand

The intestinal microbiome plays an important role in maintaining health throughout life. The microbiota develops progressively after birth and is influenced by many factors, including the mode of delivery, antibiotics, and diet. Maternal milk is critically important to the development of the neonatal intestinal microbiota. Different bioactive components of milk, such as human milk oligosaccharides, lactoferrin, and secretory immunoglobulins, modify the composition of the neonatal microbiota. In this article, we review the role of each of these maternal milk-derived bioactive factors on the microbiota and how this modulation of intestinal bacteria shapes health, and disease.


Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Hannes Petruschke ◽  
Christian Schori ◽  
Sebastian Canzler ◽  
Sarah Riesbeck ◽  
Anja Poehlein ◽  
...  

Abstract Background The intestinal microbiota plays a crucial role in protecting the host from pathogenic microbes, modulating immunity and regulating metabolic processes. We studied the simplified human intestinal microbiota (SIHUMIx) consisting of eight bacterial species with a particular focus on the discovery of novel small proteins with less than 100 amino acids (= sProteins), some of which may contribute to shape the simplified human intestinal microbiota. Although sProteins carry out a wide range of important functions, they are still often missed in genome annotations, and little is known about their structure and function in individual microbes and especially in microbial communities. Results We created a multi-species integrated proteogenomics search database (iPtgxDB) to enable a comprehensive identification of novel sProteins. Six of the eight SIHUMIx species, for which no complete genomes were available, were sequenced and de novo assembled. Several proteomics approaches including two earlier optimized sProtein enrichment strategies were applied to specifically increase the chances for novel sProtein discovery. The search of tandem mass spectrometry (MS/MS) data against the multi-species iPtgxDB enabled the identification of 31 novel sProteins, of which the expression of 30 was supported by metatranscriptomics data. Using synthetic peptides, we were able to validate the expression of 25 novel sProteins. The comparison of sProtein expression in each single strain versus a multi-species community cultivation showed that six of these sProteins were only identified in the SIHUMIx community indicating a potentially important role of sProteins in the organization of microbial communities. Two of these novel sProteins have a potential antimicrobial function. Metabolic modelling revealed that a third sProtein is located in a genomic region encoding several enzymes relevant for the community metabolism within SIHUMIx. Conclusions We outline an integrated experimental and bioinformatics workflow for the discovery of novel sProteins in a simplified intestinal model system that can be generically applied to other microbial communities. The further analysis of novel sProteins uniquely expressed in the SIHUMIx multi-species community is expected to enable new insights into the role of sProteins on the functionality of bacterial communities such as those of the human intestinal tract.


2021 ◽  
Vol 10 (10) ◽  
pp. 2072
Author(s):  
Phoebe Lin ◽  
Scott M. McClintic ◽  
Urooba Nadeem ◽  
Dimitra Skondra

Blindness from age-related macular degeneration (AMD) is an escalating problem, yet AMD pathogenesis is incompletely understood and treatments are limited. The intestinal microbiota is highly influential in ocular and extraocular diseases with inflammatory components, such as AMD. This article reviews data supporting the role of the intestinal microbiota in AMD pathogenesis. Multiple groups have found an intestinal dysbiosis in advanced AMD. There is growing evidence that environmental factors associated with AMD progression potentially work through the intestinal microbiota. A high-fat diet in apo-E-/- mice exacerbated wet and dry AMD features, presumably through changes in the intestinal microbiome, though other independent mechanisms related to lipid metabolism are also likely at play. AREDS supplementation reversed some adverse intestinal microbial changes in AMD patients. Part of the mechanism of intestinal microbial effects on retinal disease progression is via microbiota-induced microglial activation. The microbiota are at the intersection of genetics and AMD. Higher genetic risk was associated with lower intestinal bacterial diversity in AMD. Microbiota-induced metabolite production and gene expression occur in pathways important in AMD pathogenesis. These studies suggest a crucial link between the intestinal microbiota and AMD pathogenesis, thus providing a novel potential therapeutic target. Thus, the need for large longitudinal studies in patients and germ-free or gnotobiotic animal models has never been more pressing.


Author(s):  
Yu. O. Shulpekova ◽  
G. H. Babaeva ◽  
V. Yu. Rusyaev

Aim. This review aims to describe the nature of changes in the intestinal microbiota in irritable bowel syndrome (IBS) and provide a pathogenetic justification of the feasibility of a therapeutic impact on microbiota. General findings. An important aspect of the interaction of intestinal bacteria with the “host” cells is their contact with pattern recognition receptors of enterocytes, dendritic cell receptors, as well as a transcellular transport of antigens in the region of Peyer’s patches. The area of interaction of intestinal bacteria and the human body is not limited to the intestines. Intestinal bacteria demonstrate a significant humoral effect due to signalling molecules, some of which exhibit neurotransmitter properties. The study of the bacterial cross-feeding for various species, i.e. mutual use of nutrient substrates produced by bacteria of various species, is of a great interest. The development of a lowactivity inflammation in IBS can partly be explained by the increased interaction of flagellin with the corresponding receptor, as well as the influx of excess bacteria from the small intestine. The majority of studies on IBS have demonstrated the predominance of intestinal bacteria with pro-inflammatory potential (Enterobacteriaceae) and the lack of bacteria with a pronounced anti-inflammatory, antimicrobial and enzymatic action (Lactobacillus and Bifidobacterium), as well as increased mucus degradation. Similar changes are observed in inflammatory bowel diseases. Reduced microbial diversity increases susceptibility to intestinal infections and parasitoses, including those caused by protozoa conditionally pathogenic for adults, such as Blastocystis hominis hominis, Dientamoeba fragilis, Giardia lamblia. With the help of nutrition correction, the use of probiotics and functional foods containing certain probiotic strains, plant fibres (primarily psyllium) and, in some cases, nonabsorbable antibiotics, a positive effect can be achieved in a significant number of IBS patients. Recent works have shown that clinical improvement is accompanied by a change in the composition of the intestinal microbiota.Conclusion. For the pathogenetic treatment of irritable bowel syndrome, the use of non-drug treatment is justified, such as diet optimization and prescription of plant fibres and probiotic bacterial strains. The positive effect of such an approach is largely determined by modification of the intestinal microbiota composition. This opens up prospects for a further, more targeted impact on the intestinal microbiome.


Nutrients ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1464 ◽  
Author(s):  
Yala Stevens ◽  
Evelien Van Rymenant ◽  
Charlotte Grootaert ◽  
John Van Camp ◽  
Sam Possemiers ◽  
...  

Citrus flavanones, with hesperidin and naringin as the most abundant representatives, have various beneficial effects, including anti-oxidative and anti-inflammatory activities. Evidence also indicates that they may impact the intestinal microbiome and are metabolized by the microbiota as well, thereby affecting their bioavailability. In this review, we provide an overview on the current evidence on the intestinal fate of hesperidin and naringin, their interaction with the gut microbiota, and their effects on intestinal barrier function and intestinal inflammation. These topics will be discussed as they may contribute to gastrointestinal health in various diseases. Evidence shows that hesperidin and naringin are metabolized by intestinal bacteria, mainly in the (proximal) colon, resulting in the formation of their aglycones hesperetin and naringenin and various smaller phenolics. Studies have also shown that citrus flavanones and their metabolites are able to influence the microbiota composition and activity and exert beneficial effects on intestinal barrier function and gastrointestinal inflammation. Although the exact underlying mechanisms of action are not completely clear and more research in human subjects is needed, evidence so far suggests that citrus flavanones as well as their metabolites have the potential to contribute to improved gastrointestinal function and health.


Author(s):  
Dirk Elewaut ◽  
Heleen Cypers ◽  
Matthew L. Stoll ◽  
Charles O. Elson

A significant overlap exists between spondyloarthritis (SpA) and inflammatory bowel disease (IBD), particularly in the IL-23/IL-17 pathway. Shared immunologic mechanisms include aberrant innate immune responses, an excess of Th1/Th17-mediated immunity, and inadequate immune regulation. Many genetic factors associated with IBD are involved in host–pathogen interactions and intestinal barrier function, and the intestinal microbiota do appear to play an important role in disease development. Hence the current hypothesis for IBD pathogenesis is that it stems from a dysregulated immune response to intestinal microbiota in a genetically susceptible host. In SpA, evidence for a role of intestinal microbiota is less abundant, but given the overlap with IBD, it is plausible that gut microbiota are important players in SpA pathogenesis as well. However, there are significant genetic differences between these two conditions, as well as differing responses to biologic therapy.


2015 ◽  
Vol 6 (2) ◽  
pp. 173-179 ◽  
Author(s):  
Y. Vandenplas

This review summarises how the composition of the gastro-intestinal microbiota depends on pre- and postnatal factors, and birth itself. The impact of method of delivery, feeding during infancy and medications, such as antibiotics and anti-acid medication, on the composition of the gastro-intestinal microbiota has clearly been shown. However, the duration of the impact of these factors is not well established. The gastro-intestinal microbiome composition is associated with many auto-immune mediated diseases. Although causality has not been obviously demonstrated, there is a strong tendency in this direction. Nevertheless, results of the manipulation of the gastro-intestinal microbiome composition in these conditions are often disappointing. A better understanding on factors determining the longterm composition of the gastro-intestinal microbiome and its health consequences are a priority research topic. A better understanding of the association between the microbiome and the immune system may have a tremendous impact on general health.


Gut ◽  
2017 ◽  
Vol 66 (12) ◽  
pp. 2110-2120 ◽  
Author(s):  
Judith-Mira Pohl ◽  
Sebastian Gutweiler ◽  
Stephanie Thiebes ◽  
Julia K Volke ◽  
Ludger Klein-Hitpass ◽  
...  

ObjectivePostoperative ileus (POI), the most frequent complication after intestinal surgery, depends on dendritic cells (DCs) and macrophages. Here, we have investigated the mechanism that activates these cells and the contribution of the intestinal microbiota for POI induction.DesignPOI was induced by manipulating the intestine of mice, which selectively lack DCs, monocytes or macrophages. The disease severity in the small and large intestine was analysed by determining the distribution of orally applied fluorescein isothiocyanate-dextran and by measuring the excretion time of a retrogradely inserted glass ball. The impact of the microbiota on intestinal peristalsis was evaluated after oral antibiotic treatment.ResultsWe found thatCd11c-Cre+Irf4flox/floxmice lack CD103+CD11b+DCs, a DC subset unique to the intestine whose function is poorly understood. Their absence in the intestinal muscularis reduced pathogenic inducible nitric oxide synthase (iNOS) production by monocytes and macrophages and ameliorated POI. Pathogenic iNOS was produced in the jejunum by resident Ly6C–macrophages and infiltrating chemokine receptor 2-dependent Ly6C+monocytes, but in the colon only by the latter demonstrating differential tolerance mechanisms along the intestinal tract. Consistently, depletion of both cell subsets reduced small intestinal POI, whereas the depletion of Ly6C+monocytes alone was sufficient to prevent large intestinal POI. The differential role of monocytes and macrophages in small and large intestinal POI suggested a potential role of the intestinal microbiota. Indeed, antibiotic treatment reduced iNOS levels and ameliorated POI.ConclusionsOur findings reveal that CD103+CD11b+DCs and the intestinal microbiome are a prerequisite for the activation of intestinal monocytes and macrophages and for dysregulating intestinal motility in POI.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Miao Wu ◽  
Jiawei Bai ◽  
Chengtai Ma ◽  
Jie Wei ◽  
Xianjin Du

Tumor immunotherapy is the fourth therapy after surgery, chemotherapy, and radiotherapy. It has made great breakthroughs in the treatment of some epithelial tumors and hematological tumors. However, its adverse reactions are common or even more serious, and the response rate in some solid tumors is not satisfactory. With the maturity of genomics and metabolomics technologies, the effect of intestinal microbiota in tumor development and treatment has gradually been recognized. The microbiota may affect tumor immunity by regulating the host immune system and tumor microenvironment. Some bacteria help fight tumors by activating immunity, while some bacteria mediate immunosuppression to help cancer cells escape from the immune system. More and more studies have revealed that the effects and complications of tumor immunotherapy are related to the composition of the gut microbiota. The composition of the intestinal microbiota that is sensitive to treatment or prone to adverse reactions has certain characteristics. These characteristics may be used as biomarkers to predict the prognosis of immunotherapy and may also be developed as “immune potentiators” to assist immunotherapy. Some clinical and preclinical studies have proved that microbial intervention, including microbial transplantation, can improve the sensitivity of immunotherapy or reduce adverse reactions to a certain extent. With the development of gene editing technology and nanotechnology, the design and development of engineered bacteria that contribute to immunotherapy has become a new research hotspot. Based on the relationship between the intestinal microbiota and immunotherapy, the correct mining of microbial information and the development of reasonable and feasible microbial intervention methods are expected to optimize tumor immunotherapy to a large extent and bring new breakthroughs in tumor treatment.


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