Pre- and posttherapy assessment of intestinal soluble mediators in IBD: where we stand and future perspectives

Effects of Short-Chain Fatty Acids on Human Oral Epithelial Cells and the Potential Impact on Periodontal Disease: A Systematic Review of In Vitro Studies

Short-chain fatty acids (SCFA), bacterial metabolites released from dental biofilm, are supposed to target the oral epithelium. There is, however, no consensus on how SCFA affect the oral epithelial cells. The objective of the present study was to systematically review the available in vitro evidence of the impact of SCFA on human oral epithelial cells in the context of periodontal disease. A comprehensive electronic search using five databases along with a grey literature search was performed. In vitro studies that evaluated the effects of SCFA on human oral epithelial cells were eligible for inclusion. Risk of bias was assessed by the University of Bristol's tool for assessing risk of bias in cell culture studies. Certainty in cumulative evidence was evaluated using GRADE criteria (grading of recommendations assessment, development, and evaluation). Of 3591 records identified, 10 were eligible for inclusion. A meta-analysis was not possible due to the heterogeneity between the studies. The risk of bias across the studies was considered "serious" due to the presence of methodological biases. Despite these limitations, this review showed that SCFA negatively affect the viability of oral epithelial cells by activating a series of cellular events that includes apoptosis, autophagy, and pyroptosis. SCFA impair the integrity and presumably the transmigration of leucocytes through the epithelial layer by changing junctional and adhesion protein expression, respectively. SCFA also affect the expression of chemokines and cytokines in oral epithelial cells. Future research needs to identify the underlying signaling cascades and to translate the in vitro findings into preclinical models.

Food Components and Dietary Habits: Keys for a Healthy 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.

Inflammatory Bowel Disease: Updates on Molecular Targets for Biologics

Therapy for inflammatory bowel disease (IBD) has changed, with several new agents being evaluated. The era of anti-tumor necrosis factor (anti-TNF) antibody therapy saw remarkable progress in IBD therapy. Some patients, however, do not respond to anti-TNF treatment, or their response decreases over time. This phenomenon highlights the need to identify new molecular targets for therapy in IBD. The targets of new therapeutic molecules in IBD must aim to restore immune dysregulation by the inhibition of proinflammatory cytokines (TNF-α, interleukin [IL]-6, IL-13, IL-17, IL-18, and IL-21) and augmentation of the effect of anti-inflammatory cytokines (IL-10, IL-11, and transforming growth factor β) and to pursue new anti-inflammatory targets, such as regulatory T-cell therapy, Smad7 antisense, Janus-activated kinase inhibition, Toll-like receptor stimulation, leukocyte adhesion, and blockade of T-cell homing via integrins and mucosal addressin cellular adhesion molecule-1. In addition, potential molecular targets could restore mucosal barrier function and stimulate mucosal healing. Despite these potential targets, the value and clinical significance of most new molecules remain unclear, and clinical efficacy and safety must be better defined before their implementation in clinical practice. This article aims to review the promising and emerging molecular targets that could be clinically meaningful for novel therapeutic approaches.

Calpain-2 Inhibitor Therapy Reduces Murine Colitis and Colitis-associated Cancer

BACKGROUND

An important role has emerged for calpain enzymes in regulating inflammation with one isoform, calpain-2, particularly important for macrophage activation. The goal of this study was to determine the therapeutic potential of a synthetic calpain-2 inhibitor, zLLY-CH2F, for colitis and inflammation-associated colorectal cancer.

METHODS

Mice were then subjected to the azoxymethane/dextran sulfate sodium model of colitis and colitis-associated cancer incorporating intervention with daily injections of 0.75 mg/kg calpain-2 inhibitor beginning after the first signs of colitis.

RESULTS

Calpain-2 inhibitor treatment alleviated weight loss and bloody diarrhea, and reduced inflammatory infiltration into colon tissues and inflammatory cytokine mRNA. Calpain-2 inhibitor intervention also reduced total colitis-associated cancer tumor volume by up to 70% in vehicle control mice and decreased cancer pathology scores of blinded histological colon tissue analyses. Mechanistic investigations showed that calpain-2 inhibition during macrophage activation reduced inhibitor of kappa beta (IκB) degradation and nuclear factor kappa beta (NFκB) nuclear localization as well as secretion of specific inflammatory cytokines. In addition, calpain-2 inhibitor treatment of CT26.WT mouse and HT-29 human colorectal cancer cells decreased proliferation and reduced IκB degradation and NFκB translocation.

CONCLUSIONS

Overall, these findings suggest that intervention with a calpain-2 inhibitor may reduce colitis and colitis-associated cancer through a two-hit process of limiting macrophage activation and inhibiting growth of the colorectal cancer cells themselves.