The colon revisited or the key to wellness, health and disease

Phase angle and impedance ratio as meta-inflammation biomarkers after a colon cleansing protocol in a group of overweight young women

Objective. Blood C-reactive protein (CRP) and the electrical bioimpedance spectroscopy (EBIS) variables phase angle (PhA) and impedance ratio (IR) have been proposed as biomarkers of metainflammation in overweight/obesity. CRP involves taking blood samples, while PhA and IR imply a less-than-2-minute-non-invasive procedure. In this study, values for these variables and percent body fat mass (PBFM) were obtained and compared before and immediately after a colon cleansing protocol (CCP), aimed at modulating intestinal microbiota and reducing metainflammation, as dysbiosis and the latter are intrinsically related, as well as along a period of 8 weeks after it.Approach. 20 female volunteers (20.9-24.9 years old) participated: 12 in an overweight group (OG), and 8 in a lean group (LG). TheOGwas divided in two subgroups (n= 6, each): control (CSG) and experimental (ESG). TheESGunderwent a 6-day CCP at week 2, while 5 volunteers in theCSGunderwent it at week 9.Main results.Pre/post-CCP mean values for the variables in theOGwere: PBFM (34.3/31.3%), CRP (3.7/0.6 mg dl-1), PhA (6.9/7.5°) and IR*10 (0.78/0.77). CalculatedR2correlation factors among these variables are all above 0.89. The favourable changes first seen in theESGwere still present 8 weeks after the CCP.Significance.(a) the CCP drastically lowers meta-inflammation, (b) EBIS can be used to measure metainflammation, before and after treatment, (c) for microbiota modulation, CCP could be a good alternative to more drastic procedures like faecal microbiota transplantation; (d) reestablishing eubiosis by CCP could be an effective coadjutant in the treatment of overweight young adult women.

Recent insights of obesity-induced gut and adipose tissue dysbiosis in type 2 diabetes

An imbalance in microbial homeostasis, referred to as dysbiosis, is critically associated with the progression of obesity-induced metabolic disorders including type 2 diabetes (T2D). Alteration in gut microbial diversity and the abundance of pathogenic bacteria disrupt metabolic homeostasis and potentiate chronic inflammation, due to intestinal leakage or release of a diverse range of microbial metabolites. The obesity-associated shifts in gut microbial diversity worsen the triglyceride and cholesterol level that regulates adipogenesis, lipolysis, and fatty acid oxidation. Moreover, an intricate interaction of the gut-brain axis coupled with the altered microbiome profile and microbiome-derived metabolites disrupt bidirectional communication for instigating insulin resistance. Furthermore, a distinct microbial community within visceral adipose tissue is associated with its dysfunction in obese T2D individuals. The specific bacterial signature was found in the mesenteric adipose tissue of T2D patients. Recently, it has been shown that in Crohn's disease, the gut-derived bacterium Clostridium innocuum translocated to the mesenteric adipose tissue and modulates its function by inducing M2 macrophage polarization, increasing adipogenesis, and promoting microbial surveillance. Considering these facts, modulation of microbiota in the gut and adipose tissue could serve as one of the contemporary approaches to manage T2D by using prebiotics, probiotics, or faecal microbial transplantation. Altogether, this review consolidates the current knowledge on gut and adipose tissue dysbiosis and its role in the development and progression of obesity-induced T2D. It emphasizes the significance of the gut microbiota and its metabolites as well as the alteration of adipose tissue microbiome profile for promoting adipose tissue dysfunction, and identifying novel therapeutic strategies, providing valuable insights and directions for future research and potential clinical interventions.

Protective Effects of Selenium Nanoparticles against Bisphenol A-Induced Toxicity in Porcine Intestinal Epithelial Cells

Bisphenol A (BPA) is widely used to harden plastics and polycarbonates and causes serious toxic effects in multiple organs, including the intestines. Selenium, as an essential nutrient element for humans and animals, exhibits a predominant effect in various physiological processes. Selenium nanoparticles have attracted more and more attention due to their outstanding biological activity and biosafety. We prepared chitosan-coated selenium nanoparticles (SeNPs) and further compared the protective effects, and investigated the underlying mechanism of SeNPs and inorganic selenium (Na₂SeO₃) on BPA-induced toxicity in porcine intestinal epithelial cells (IPEC-J2). The particle size, zeta potential, and microstructure of SeNPs were detected by using a nano-selenium particle size meter and a transmission electron microscope. IPEC-J2 cells were exposed to BPA alone or simultaneously exposed to BPA and SeNPs or Na₂SeO₃. The CCK8 assay was performed to screen the optimal concentration of BPA exposure and the optimal concentration of SeNPs and Na₂SeO₃ treatment. The apoptosis rate was detected by flow cytometry. Real-time PCR and Western blot methods were used to analyze the mRNA and protein expression of factors related to tight junctions, apoptosis, inflammatory responses and endoplasmic reticulum stress. Increased death and morphological damage were observed after BPA exposure, and these increases were attenuated by SeNPs and Na₂SeO₃ treatment. BPA exposure disturbed the tight junction function involved with decreased expression of tight junction protein Zonula occludens 1 (ZO-1), occludin, and claudin-1 proteins. Proinflammatory response mediated by the transcription factor nuclear factor-k-gene binding (NF-κB), such as elevated levels of interleukin-1β(IL-1β), interleukin-6 (IL-6), interferon-γ (IFN-γ), interleukin-17 (IL-17), and tumor necrosis factor-α (TNF-α) expression was induced at 6 and 24 h after BPA exposure. BPA exposure also disturbed the oxidant/antioxidant status and led to oxidative stress. IPEC-J2 cell apoptosis was induced by BPA exposure, as indicated by increased BCL-2-associated X protein (Bax), caspase 3, caspase 8, and caspase 9 expression and decreased B-cell lymphoma-2 (Bcl-2) and Bcl-xl expression. BPA exposure activated the endoplasmic reticulum stress (ERS) mediated by the receptor protein kinase receptor-like endoplasmic reticulum kinase (PERK), Inositol requiring enzyme 1 (IRE1α), and activating transcription factor 6 (ATF6). We found that treatment with SeNPs and Na₂SeO₃ can alleviate the intestinal damage caused by BPA. SeNPs were superior to Na₂SeO₃ and counteracted BPA-induced tight junction function injury, proinflammatory response, oxidative stress, apoptosis, and ERS stress. Our findings suggest that SeNPs protect intestinal epithelial cells from BPA-induced damage, partly through inhibiting ER stress activation and subsequently attenuating proinflammatory responses and oxidative stress and suppressing apoptosis, thus enhancing the intestinal epithelial barrier function. Our data indicate that selenium nanoparticles may represent an effective and reliable tool for preventing BPA toxicity in animals and humans.

Vagus Nerve Stimulation: A Personalized Therapeutic Approach for Crohn's and Other Inflammatory Bowel Diseases

Inflammatory bowel diseases, including Crohn's disease and ulcerative colitis, are incurable autoimmune diseases characterized by chronic inflammation of the gastrointestinal tract. There is increasing evidence that inappropriate interaction between the enteric nervous system and central nervous system and/or low activity of the vagus nerve, which connects the enteric and central nervous systems, could play a crucial role in their pathogenesis. Therefore, it has been suggested that appropriate neuroprosthetic stimulation of the vagus nerve could lead to the modulation of the inflammation of the gastrointestinal tract and consequent long-term control of these autoimmune diseases. In the present paper, we provide a comprehensive overview of (1) the cellular and molecular bases of the immune system, (2) the way central and enteric nervous systems interact and contribute to the immune responses, (3) the pathogenesis of the inflammatory bowel disease, and (4) the therapeutic use of vagus nerve stimulation, and in particular, the transcutaneous stimulation of the auricular branch of the vagus nerve. Then, we expose the working hypotheses for the modulation of the molecular processes that are responsible for intestinal inflammation in autoimmune diseases and the way we could develop personalized neuroprosthetic therapeutic devices and procedures in favor of the patients.

Dual-Hit Model of Parkinson's Disease: Impact of Dysbiosis on 6-Hydroxydopamine-Insulted Mice-Neuroprotective and Anti-Inflammatory Effects of Butyrate

Recent evidence highlights Parkinson’s disease (PD) initiation in the gut as the prodromal phase of neurodegeneration. Gut impairment due to microbial dysbiosis could affect PD pathogenesis and progression. Here, we propose a two-hit model of PD through ceftriaxone (CFX)-induced dysbiosis and gut inflammation before the 6-hydroxydopamine (6-OHDA) intrastriatal injection to mimic dysfunctional gut-associated mechanisms preceding PD onset. Therefore, we showed that dysbiosis and gut damage amplified PD progression, worsening motor deficits induced by 6-OHDA up to 14 days post intrastriatal injection. This effect was accompanied by a significant increase in neuronal dopaminergic loss (reduced tyrosine hydroxylase expression and increased Bcl-2/Bax ratio). Notably, CFX pretreatment also enhanced systemic and colon inflammation of dual-hit subjected mice. The exacerbated inflammatory response ran in tandem with a worsening of colonic architecture and gut microbiota perturbation. Finally, we demonstrated the beneficial effect of post-biotic sodium butyrate in limiting at once motor deficits, neuroinflammation, and colon damage and re-shaping microbiota composition in this novel dual-hit model of PD. Taken together, the bidirectional communication of the microbiota–gut–brain axis and the recapitulation of PD prodromal/pathogenic features make this new paradigm a useful tool for testing or repurposing new multi-target compounds in the treatment of PD.

A geometrical method for modeling bioelectrical impedance measurements and remove the hook effect deviations

OBJECTIVE

to describe a simple and straightforward method to calculate the circle parameters that can be used to fit Electrical Bioimpedance Spectroscopy (EBIS) raw data to the complex plane and remove the hook effect, a deviation of that model especially seen at higher frequencies and considered as an artifact due to instrumental limitations.

APPROACH

under the assumption that raw EBIS data in the middle frequencies best represent the beta dispersion, the authors of this article propose a geometrical procedure to calculate parameters for this dispersion and remove the hook effect. For this purpose, data obtained with two different devices were used with apparently very good results.

MAIN RESULTS

the results of this study suggest that circle parameters for the beta dispersion can be obtained, but, also, that the residuals of the hook effect correction seem to adjust to a circle and, therefore, they could also be parameterized using the same approach.

SIGNIFICANCE

the method proposed in this article is very easy to perform and could help end EBIS users not familiar with mathematical models and fitting processes, to better understand and interpret their data.

Environmental contaminant BPA causes intestinal damage by disrupting cellular repair and injury homeostasis in vivo and in vitro

Our previous studies have shown that the environmental contaminant bisphenol A (BPA) exhibits strong intestinal toxicity and can readily cause intestinal barrier dysfunction. However, the causal relationship between adverse biological processes of BPA-induced intestinal tissue and the role of key signaling molecules in it requires further investigation. In this study, we established a mouse and intestinal epithelial cell model of BPA treatment to determine the underlying molecular mechanisms of BPA-induced intestinal injury. The results showed that the BPA treatment increased the intestinal permeability and disrupted the barrier function by increasing the chemical marker content and tight junction expression in intestinal tissues and blood circulation. BPA also altered the oxidative and antioxidant status of intestinal epithelial cells by increasing ROS and RNS contents and decreasing the activity levels of SOD, GPx, CAT, and T-AOC. BPA further induced inflammatory responses by upregulating the gene abundance of key factors of the innate immune system (TLR2, TLR4, MyD88, and NF-κB), the transcriptional activity of NF-kB, and the secretion of pro-inflammatory cytokines (IL-1β, IL-6, IL-8, and TNF-α). Moreover, apoptosis was activated by BPA, whereas cell proliferation was inhibited by BPA. Mechanistically, co-treatment of intestinal epithelial cells with BPA using the oxidative stress scavenger NAC, the NF-κB-specific inhibitor JSH-23, and the apoptosis inhibitor Z-VAD-FMK, respectively, showed that BPA activates the innate immune response by inducing oxidative stress. Consequently, apoptosis is promoted, and cell proliferation is inhibited, ultimately disrupting the intestinal barrier function. Our findings provide insight into the pathogenesis of BPA-induced gut injury.

Association of Intestinal Disorders with Parkinson's Disease and Alzheimer's Disease: A Systematic Review and Meta-Analysis

Parkinson's disease (PD) and Alzheimer's disease (AD) are the most common neurodegenerative disorders, with an overall global incidence of 40 million. Many studies have revealed the association of intestinal disorders and bacterial infections with PD, but few studies have found such a relationship with AD. In this meta-analysis, related articles published up to September 2018 were searched in PubMed. Of the 2121 related articles screened initially, 56 were found to be eligible. Data on the risks of PD and AD due to five intestinal disorders and infection with Helicobacter pylori, as a representative intestinal microbe, were obtained, and a fixed- or random-effects model was used to pool the odds ratios (ORs) with 95% confidence interval (CIs) from individual studies. The combined OR for all types of intestinal disorders with an increased risk of PD was 3.36 (95% CI: 2.70-4.17). The ORs for each category were as follows: constipation, 4.05 (95% CI, 3.24-5.06); inflammatory bowel disease (IBD), 1.16 (95% CI, 0.89-1.52); irritable bowel syndrome (IBS), 1.75 (95% CI, 0.55-5.56); small intestinal bacterial overgrowth, 5.15 (95% CI, 3.33-7.96); and diarrhea, 1.27 (95% CI, 0.28-5.75). The combined OR of all types of intestinal disorders with an increased risk of AD was 1.52 (95% CI, 1.09-2.13). The ORs for IBS and IBD were 1.42 (95% CI, 1.02-1.99) and 2.40 (95% CI, 1.00-5.76), respectively. The risk estimates of H. pylori infection in PD and AD patients were as follows: OR, 1.65 (95% CI, 1.43-1.91) and OR, 1.40 (95% CI, 1.12-1.76), respectively. These findings suggest that PD and AD are significantly associated with intestinal disorders. The negative roles of H. pylori in the development of PD or AD should be evaluated to shed new light on the diagnosis and treatment of PD and AD. National governments should periodically inspect the intestinal condition of residents and extend health plans to improve intestinal health to prevent potential neurological disorders.

Gut microbiota, dysbiosis and colon lavage

Gut microbial dysbiosis is considered an alteration of diversity and abundance of intestinal microbes, which contributes to the onset of many disorders. Several factors cause dysbiosis, depending on life-style (nutrition, stress, environment, smoking, physical activity) or particular diseases (inflammatory, autoimmune, chronic diseases). Drugs (i.e. antibiotics, anticancer drugs), as well as medical and surgical procedures, can often cause dysbiosis. Mechanical bowel preparations (MBP) and the so called "bowel cleansing" have an immediate impact on intestinal microbial composition. Whether these "acute" changes may lead to any clinical consequences is still unknown. It is tempting to speculate that such dysbiosis fostering events, at least in patients already presenting abdominal complaints, such as irritable bowel syndrome (IBS), or inflammatory bowel disease (IBD) patients, may drive additional or more severe symptoms. Recently, the possibility of using probiotic supplementation has been addressed in the literature, with the purpose to counteract intestinal dysfunctional changes observed in relation to a dysbiotic state. Whereas probiotics are recognized to be effective and safe in restoring gut microbiota dysbiosis, preliminary evidence suggest that this approach may prove helpful even in case of transient dysbiotic states related to colonoscopy bowel preparation.

Inflammation and Gut-Brain Axis During Type 2 Diabetes: Focus on the Crosstalk Between Intestinal Immune Cells and Enteric Nervous System

The gut-brain axis is now considered as a major actor in the control of glycemia. Recent discoveries show that the enteric nervous system (ENS) informs the hypothalamus of the nutritional state in order to control glucose entry in tissues. During type 2 diabetes (T2D), this way of communication is completely disturbed leading to the establishment of hyperglycemia and insulin-resistance. Indeed, the ENS neurons are largely targeted by nutrients (e.g., lipids, peptides) but also by inflammatory factors from different origin (i.e., host cells and gut microbiota). Inflammation, and more particularly in the intestine, contributes to the development of numerous pathologies such as intestinal bowel diseases, Parkinson diseases and T2D. Therefore, targeting the couple ENS/inflammation could represent an attractive therapeutic solution to treat metabolic diseases. In this review, we focus on the role of the crosstalk between intestinal immune cells and ENS neurons in the control of glycemia. In addition, given the growing evidence showing the key role of the gut microbiota in physiology, we will also briefly discuss its potential contribution and role on the immune and neuronal systems.