Gracilaria lemaneiformis polysaccharides alleviate colitis by modulating the gut microbiota and intestinal barrier in mice

Abstract Background Constipation is a common gastrointestinal dysfunction which has a potential impact on people's immune state and their quality of life. Here we investigated the effects of constipation on experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Methods Constipation was induced by loperamide in female C57BL/6 mice. The alternations of gut microbiota, permeability of intestinal barrier and blood–brain barrier, and histopathology of colon were assessed after constipation induction. EAE was induced in the constipation mice. Fecal microbiota transplantation (FMT) was performed from constipation mice into microbiota-depleted mice. Clinical scores, histopathology of inflammation and demyelination, Treg/Th17 and Treg17/Teff17 imbalance both in the peripheral lymphatic organs and central nervous system, cytokines include TGF-β, GM-CSF, IL-10, IL-17A, IL-17F, IL-21, IL-22, and IL-23 in serum were assessed in different groups. Results Compared with the vehicle group, the constipation mice showed gut microbiota dysbiosis, colon inflammation and injury, and increased permeability of intestinal barrier and blood–brain barrier. We found that the clinical and pathological scores of the constipation EAE mice were severer than that of the EAE mice. Compared with the EAE mice, the constipation EAE mice showed reduced percentage of Treg and Treg17 cells, increased percentage of Th17 and Teff17 cells, and decreased ratio of Treg/Th17 and Treg17/Teff17 in the spleen, inguinal lymph nodes, brain, and spinal cord. Moreover, the serum levels of TGF-β, IL-10, and IL-21 were decreased while the GM-CSF, IL-17A, IL-17F, IL-22, and IL-23 were increased in the constipation EAE mice. In addition, these pathological processes could be transferred via their gut microbiota. Conclusions Our results verified that constipation induced gut microbiota dysbiosis exacerbated EAE via aggravating Treg/Th17 and Treg17/Teff17 imbalance and cytokines disturbance in C57BL/6 mice.

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Insights into the Impact of Microbiota in the Treatment of NAFLD/NASH and Its Potential as a Biomarker for Prognosis and Diagnosis

Biomedicines ◽

10.3390/biomedicines9020145 ◽

2021 ◽

Vol 9 (2) ◽

pp. 145

Author(s):

Julio Plaza-Díaz ◽

Patricio Solis-Urra ◽

Jerónimo Aragón-Vela ◽

Fernando Rodríguez-Rodríguez ◽

Jorge Olivares-Arancibia ◽

...

Keyword(s):

Gut Microbiota ◽

Fecal Microbiota Transplantation ◽

Liver Steatosis ◽

Intestinal Barrier ◽

Fecal Microbiota ◽

Current Treatment ◽

Immune Defense ◽

Alcoholic Fatty Liver ◽

The Impact

Non-alcoholic fatty liver disease (NAFLD) is an increasing cause of chronic liver illness associated with obesity and metabolic disorders, such as hypertension, dyslipidemia, or type 2 diabetes mellitus. A more severe type of NAFLD, non-alcoholic steatohepatitis (NASH), is considered an ongoing global health threat and dramatically increases the risks of cirrhosis, liver failure, and hepatocellular carcinoma. Several reports have demonstrated that liver steatosis is associated with the elevation of certain clinical and biochemical markers but with low predictive potential. In addition, current imaging methods are inaccurate and inadequate for quantification of liver steatosis and do not distinguish clearly between the microvesicular and the macrovesicular types. On the other hand, an unhealthy status usually presents an altered gut microbiota, associated with the loss of its functions. Indeed, NAFLD pathophysiology has been linked to lower microbial diversity and a weakened intestinal barrier, exposing the host to bacterial components and stimulating pathways of immune defense and inflammation via toll-like receptor signaling. Moreover, this activation of inflammation in hepatocytes induces progression from simple steatosis to NASH. In the present review, we aim to: (a) summarize studies on both human and animals addressed to determine the impact of alterations in gut microbiota in NASH; (b) evaluate the potential role of such alterations as biomarkers for prognosis and diagnosis of this disorder; and (c) discuss the involvement of microbiota in the current treatment for NAFLD/NASH (i.e., bariatric surgery, physical exercise and lifestyle, diet, probiotics and prebiotics, and fecal microbiota transplantation).

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The Influence of Gut Microbiota on the Cardiovascular System Under Conditions of Obesity and Chronic Stress

Current Hypertension Reports ◽

10.1007/s11906-021-01144-7 ◽

2021 ◽

Vol 23 (5) ◽

Author(s):

Piotr Dubinski ◽

Katarzyna Czarzasta ◽

Agnieszka Cudnoch-Jedrzejewska

Keyword(s):

Gut Microbiota ◽

Cardiovascular System ◽

Chronic Stress ◽

Human Body ◽

High Fat Diet ◽

Intestinal Barrier ◽

Microbial Composition ◽

Enhanced Absorption ◽

Bacterial Accumulation ◽

Metabolic Endotoxemia

Abstract Purpose of Review Based on the available data, it can be assumed that microbiota is an integral part of the human body. The most heavily colonized area of the human body is the gut, with bacterial accumulation ranging from 101–103 cells/g in the upper intestine to 1011–1012 cells/g in the colon. However, colonization of the gut is not the same throughout, as it was shown that there are differences between the composition of the microbiota in the intestine lumen and in the proximity of the mucus layer. Recent Findings Gut microbiota gradient can be differentially regulated by factors such as obesity and chronic stress. In particular, a high fat diet influences the gut microbial composition. It was also found that chronic stress may cause the development of obesity and thus change the organization of the intestinal barrier. Recent research has shown the significant effect of intestinal microflora on cardiovascular function. Enhanced absorption of bacterial fragments, such as lipopolysaccharide (LPS), promotes the onset of “metabolic endotoxemia,” which could activate toll-like receptors, which mediates an inflammatory response and in severe cases could cause cardiovascular diseases. It is presumed that the intestinal microbiota, and especially its metabolites (LPS and trimethylamine N-oxide (TMAO)), may play an important role in the pathogenesis of arterial hypertension, atherosclerosis, and heart failure. Summary This review focuses on how gut microbiota can change the morphological and functional activity of the cardiovascular system in the course of obesity and in conditions of chronic stress.

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Perturbation of gut microbiota plays an important role in micro/nanoplastics-induced gut barrier dysfunction

Nanoscale ◽

10.1039/d1nr00038a ◽

2021 ◽

Author(s):

Jiyan Qiao ◽

Rui Chen ◽

Mengjie Wang ◽

Ru Bai ◽

Xuejing Cui ◽

...

Keyword(s):

Gut Microbiota ◽

Intestinal Barrier ◽

Barrier Dysfunction ◽

Gut Barrier ◽

Bacterial Composition

Exposure to micro/nanoplastics (M/NPLs) deteriorates the intestinal barrier by disturbing the bacterial composition in the gut.

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Mediterranean Diet to Prevent the Development of Colon Diseases: A Meta-Analysis of Gut Microbiota Studies

Nutrients ◽

10.3390/nu13072234 ◽

2021 ◽

Vol 13 (7) ◽

pp. 2234

Author(s):

Oscar Illescas ◽

Miriam Rodríguez-Sosa ◽

Manuela Gariboldi

Keyword(s):

Gut Microbiota ◽

Mediterranean Diet ◽

Meta Analysis ◽

Intestinal Barrier ◽

Preventive Measure ◽

Bowel Diseases ◽

Preventive Method ◽

Inflammatory Bowel ◽

Colon Diseases ◽

Cancer And Inflammation

Gut microbiota dysbiosis is a common feature in colorectal cancer (CRC) and inflammatory bowel diseases (IBD). Adoption of the Mediterranean diet (MD) has been proposed as a therapeutic approach for the prevention of multiple diseases, and one of its mechanisms of action is the modulation of the microbiota. We aimed to determine whether MD can be used as a preventive measure against cancer and inflammation-related diseases of the gut, based on its capacity to modulate the local microbiota. A joint meta-analysis of publicly available 16S data derived from subjects following MD or other diets and from patients with CRC, IBD, or other gut-related diseases was conducted. We observed that the microbiota associated with MD was enriched in bacteria that promote an anti-inflammatory environment but low in taxa with pro-inflammatory properties capable of altering intestinal barrier functions. We found an opposite trend in patients with intestinal diseases, including cancer. Some of these differences were maintained even when MD was compared to healthy controls without a defined diet. Our findings highlight the unique effects of MD on the gut microbiota and suggest that integrating MD principles into a person’s lifestyle may serve as a preventive method against cancer and other gut-related diseases.

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The DNA Sensor AIM2 Protects against Streptozotocin-Induced Type 1 Diabetes by Regulating Intestinal Homeostasis via the IL-18 Pathway

Cells ◽

10.3390/cells9040959 ◽

2020 ◽

Vol 9 (4) ◽

pp. 959 ◽

Cited By ~ 2

Author(s):

Jefferson Antônio Leite ◽

Gabriela Pessenda ◽

Isabel C. Guerra-Gomes ◽

Alynne Karen Mendonça de Santana ◽

Camila André Pereira ◽

...

Keyword(s):

Type 1 Diabetes ◽

Gut Microbiota ◽

Bacterial Translocation ◽

Intestinal Barrier ◽

Intestinal Barrier Function ◽

Dna Sensor ◽

Proinflammatory Response

Pattern recognition receptors (PRRs), such as Nod2, Nlrp3, Tlr2, Trl4, and Tlr9, are directly involved in type 1 diabetes (T1D) susceptibility. However, the role of the cytosolic DNA sensor, AIM2, in T1D pathogenesis is still unknown. Here, we demonstrate that C57BL/6 mice lacking AIM2 (AIM2−/−) are prone to streptozotocin (STZ)-induced T1D, compared to WT C57BL/6 mice. The AIM2−/− mice phenotype is associated with a greater proinflammatory response in pancreatic tissues, alterations in gut microbiota and bacterial translocation to pancreatic lymph nodes (PLNs). These alterations are related to an increased intestinal permeability mediated by tight-junction disruption. Notably, AIM2−/− mice treated with broad-spectrum antibiotics (ABX) are protected from STZ-induced T1D and display a lower pancreatic proinflammatory response. Mechanistically, the AIM2 inflammasome is activated in vivo, leading to an IL-18 release in the ileum at 15 days after an STZ injection. IL-18 favors RegIIIγ production, thus mitigating gut microbiota alterations and reinforcing the intestinal barrier function. Together, our findings show a regulatory role of AIM2, mediated by IL-18, in shaping gut microbiota and reducing bacterial translocation and proinflammatory response against insulin-producing β cells, which ultimately results in protection against T1D onset in an STZ-induced diabetes model.

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Intestinal microbiota and their metabolic contribution to type 2 diabetes and obesity

Journal of Diabetes & Metabolic Disorders ◽

10.1007/s40200-021-00858-4 ◽

2021 ◽

Author(s):

A. L. Cunningham ◽

J. W. Stephens ◽

D. A. Harris

Keyword(s):

Type 2 Diabetes ◽

Gut Microbiota ◽

Current Knowledge ◽

Intestinal Barrier ◽

Short Chain Fatty Acids ◽

Global Epidemic ◽

Technological Advances ◽

Diabetes And Obesity

AbstractObesity and type 2 diabetes mellitus (T2DM) are common, chronic metabolic disorders with associated significant long-term health problems at global epidemic levels. It is recognised that gut microbiota play a central role in maintaining host homeostasis and through technological advances in both animal and human models it is becoming clear that gut microbiota are heavily involved in key pathophysiological roles in the aetiology and progression of both conditions. This review will focus on current knowledge regarding microbiota interactions with short chain fatty acids, the host inflammatory response, signaling pathways, integrity of the intestinal barrier, the interaction of the gut-brain axis and the subsequent impact on the metabolic health of the host.

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Bioactives and their metabolites from Tetrastigma hemsleyanum leaves ameliorate DSS-induced colitis via protecting intestinal barrier, mitigating oxidative stress and regulating gut microbiota

Food & Function ◽

10.1039/d1fo02588k ◽

2021 ◽

Author(s):

Tong Wu ◽

Xiaoya Wang ◽

Hua Xiong ◽

Zeyuan Deng ◽

Xin Peng ◽

...

Keyword(s):

Oxidative Stress ◽

Medicinal Plant ◽

Gut Microbiota ◽

Intestinal Barrier ◽

Tetrastigma Hemsleyanum ◽

Research Attention

Tetrastigma hemsleyanum, a precious edible and medicinal plant in China, has attracted extensive research attention in recent years due to its highly traditional value for the treatment of various diseases....

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