E-cigarettes compromise the gut barrier and trigger inflammation

Chronic Exposure to Both Electronic and Conventional Cigarettes Alters Ileum and Colon Turnover, Immune Function, and Barrier Integrity in Mice

Although the effects of cigarette smoke (CS) on the development of several intestinal diseases is well documented, the impact of e-cigarette aerosol (e-cig) on digestive health is largely unknown. To compare the effects of e-cig and CS on mouse ileum and colon, animals were chronically exposed for 6 months by nose-only inhalation to e-cig at 18 or 30 W power, or to 3R4F CS. Results showed that e-cig exposure decreased colon cell proliferation. Several other proliferative defects were observed in response to both e-cig and CS exposure, including up- and down-regulation of cyclin D1 protein levels in the ileum and colon, respectively. E-cig and CS exposure reduced myeloperoxidase activity in the ileum. In the colon, both exposures disrupted gene expression of cytokines and T cell transcription factors. For tight junction genes, ZO-1- and occludin-protein expression levels were reduced in the ileum and colon, respectively, by e-cig and CS exposure. The 16S sequencing of microbiota showed specific mild dysbiosis, according to the type of exposure. Overall, e-cig exposure led to altered proliferation, inflammation, and barrier function in both the ileum and colon, and therefore may be a gut hazard on par with conventional CS.

Health outcomes of electronic cigarettes

ABSTRACT

The usage of electronic cigarettes (e-cigarettes) sparked an outbreak of unidentified vaping-related lung disease in the US during late 2019. With e-cigarettes becoming more and more popular, smokers have more options other than conventional cigarettes. Under these circumstances, a comprehensive evaluation of the general safety of new tobacco and tobacco-related products, represented by e-cigarettes, to human health is necessary. In this review, we summarize the current research on potential negative impacts of e-cigarette exposure on human health. In particular, studies detailing the relationship between e-cigarettes and the digestive system are summarized, with mechanisms mainly including hepatic metabolic dysfunction, impaired gut barrier, and worsened outcomes of inflammatory bowel disease (IBD). Although believed to be safer than traditional cigarettes, e-cigarettes exert adverse effects on systemic health and induce the development of multiple diseases containing asthma, cardiovascular disease, and IBD. Moreover, nicotine-containing e-cigarettes have a negative impact on the childhood development and increase the risk of arterial stiffness compared to the non-nicotine e-cigarettes. However, non-nicotine e-cigarette components have detrimental effects including promoting liver damage and metabolic disorders.

Development of an Inflamed High Throughput Stem-cell-based Gut Epithelium Model to Assess the Impact of Annexin A1

OBJECTIVE AND DESIGN

Annexin A1 (ANXA1) plays a role in maintaining intestinal hemostasis, especially following mucosal inflammation. The published data about ANXA1 was derived from experimental animal models where there is an overlapping between epithelial and immune cells. There is no in vitro gut epithelial model that can assess the direct effect of ANXA1 on the gut epithelium.

METHODS

We developed high-throughput stem-cell-based murine epithelial cells and bacterial lipopolysaccharides (LPS) were used to induce inflammation. The impact of ANXA1 and its functional part (Ac2-26) was evaluated in the inflamed model. Intestinal integrity was assessed by the transepithelial electrical resistance (TEER), and FITC-Dextran permeability. Epithelial junction proteins were assessed using confocal microscopy and RT-qPCR. Inflammatory cytokines were evaluated by RT-qPCR and ELISA.

RESULTS

LPS challenge mediated a damage in the epithelial cells as shown by a drop in the TEER and an increase in FITC-dextran permeability; reduced the expression of epithelial junctional proteins (Occludin, ZO-1, and Cadherin) and increased the expression of the gut leaky protein, Claudin - 2. ANXA1 and Ac2-26 treatment reduced the previous damaging effects. In addition, ANXA1 and Ac2-26 inhibited the inflammatory responses mediated by the LPS and increased the transcription of the anti-inflammatory cytokine, IL-10.

CONCLUSION

ANXA1 and Ac2-26 directly protect the epithelial integrity by affecting the expression of epithelial junction and inflammatory markers. The inflamed gut model is a reliable tool to study intestinal inflammatory diseases, and to evaluate the efficacy of potential anti-inflammatory drugs and the screening of new drugs that could be candidates for inflammatory bowel disease.

Dual Exposure to E-Cigarette Vapour and Cigarette Smoke Results in Poorer Airway Cell, Monocyte, and Macrophage Function Than Single Exposure

E-cigarette users predominantly also continue to smoke cigarettes. These Dual Users either consume e-cigarettes in locations where smoking is not allowed, but vaping is, or to reduce their consumption of cigarettes, believing it will lead to harm reduction. Whilst it is known that e-cigarette vapour is chemically less complex than cigarette smoke, it has a distinct chemical profile, and very little is known about the health impacts of exposure to both chemical profiles vs. either alone. We simultaneously exposed cells in vitro to non-toxic levels of e-cigarette vapour extract (EVE) and cigarette smoke extract (CSE) to determine their effects on 16HBE14o- airway epithelial cell metabolism and inflammatory response, as well as immune cell (THP-1 cells and monocyte-derived macrophages (MDM) from healthy volunteers) migration, phagocytosis, and inflammatory response. We observed increased toxicity, reduced metabolism (a marker of proliferation) in airway epithelial cells, and reduced monocyte migration, macrophage phagocytosis, and altered chemokine production after exposure to either CSE or EVE. These cellular responses were greater after dual exposure to CSE and EVE. The airway epithelial cells from smokers showed reduced metabolism after EVE (the Switcher model) and dual CSE and EVE exposure. When EVE and CSE were allowed to interact, the chemicals were found to be altered, and new chemicals were also found compared to the CSE and EVE profiles. Dual exposure to e-cigarette vapour and cigarette smoke led to worse functional outcomes in cells compared to either single exposure alone, adding to limited data that dual use may be more dangerous than smoking only.

Astragalus polysaccharide: implication for intestinal barrier, anti-inflammation, and animal production

Intestine is responsible for nutrients absorption and plays a key role in defending against various dietary allergens, antigens, toxins, and pathogens. Accumulating evidence reported a critical role of intestine in maintaining animal and human health. Since the use of antibiotics as growth promoters in animal feed has been restricted in many countries, alternatives to antibiotics have been globally investigated, and polysaccharides are considered as environmentally friendly and promising alternatives to improve intestinal health, which has become a research hotspot due to its antibiotic substitution effect. Astragalus polysaccharide (APS), a biological macromolecule, is extracted from astragalus and has been reported to exhibit complex biological activities involved in intestinal barrier integrity maintenance, intestinal microbiota regulation, short-chain fatty acids (SCFAs) production, and immune response regulation, which are critical for intestine health. The biological activity of APS is related to its chemical structure. In this review, we outlined the source and structure of APS, highlighted recent findings on the regulation of APS on physical barrier, biochemical barrier, immunological barrier, and immune response as well as the latest progress of APS as an antibiotic substitute in animal production. We hope this review could provide scientific basis and new insights for the application of APS in nutrition, clinical medicine and health by understanding particular effects of APS on intestine health, anti-inflammation, and animal production.

Development of Ac2-26 Mesoporous Microparticle System as a Potential Therapeutic Agent for Inflammatory Bowel Diseases

Introduction

Inflammatory bowel diseases (IBDs) disrupt the intestinal epithelium, leading to severe chronic inflammation. Current therapies cause adverse effects and are expensive, invasive, and ineffective for most patients. Annexin A1 (AnxA1) is a pivotal endogenous anti-inflammatory and tissue repair protein in IBD. Nanostructured compounds loading AnxA1 or its active N-terminal mimetic peptides improve IBD symptomatology.

Methods

To further explore their potential as a therapeutic candidate, the AnxA1 N-terminal mimetic peptide Ac2-26 was incorporated into SBA-15 ordered mesoporous silica and covered with EL30D-55 to deliver it by oral treatment into the inflamed gut.

Results

The systems SBA-Ac2-26 developed measurements revealed self-assembled rod-shaped particles, likely on the external surface of SBA-15, and 88% of peptide incorporation. SBA-15 carried the peptide Ac2-26 into cultured Raw 264.7 macrophages and Caco-2 epithelial cells. Moreover, oral administration of Eudragit-SBA-15-Ac2-26 (200 μg; once a day; for 4 days) reduced colitis clinical symptoms, inflammation, and improved epithelium recovery in mice under dextran-sodium sulfate-induced colitis.

Discussion

The absorption of SBA-15 in gut epithelial cells is typically low; however, the permeable inflamed barrier can enable microparticles to cross, being phagocyted by macrophages. These findings suggest that Ac2-26 is successfully delivered and binds to its receptors in both epithelial and immune cells, aligning with the clinical results.

Conclusion

Our findings demonstrate a simple and cost-effective approach to delivering Ac2-26 orally into the inflamed gut, highlighting its potential as non-invasive IBD therapy.

Validating Enteroid-Derived Monolayers from Murine Gut Organoids for Toxicological Testing of Inorganic Particles: Proof-of-Concept with Food-Grade Titanium Dioxide

Human exposure to foodborne inorganic nanoparticles (NPs) is a growing concern. However, identifying potential hazards linked to NP ingestion often requires long-term exposure in animals. Owing these constraints, intestinal organoids are a promising alternative to in vivo experiments; as such, an in vitro approach should enable a rapid and reliable assessment of the effects of ingested chemicals on the gut. However, this remains to be validated for inorganic substances. In our study, a transcriptomic analysis and immunofluorescence staining were performed to compare the effects of food-grade TiO2 (fg-TiO2) on enteroid-derived monolayers (EDMs) from murine intestinal organoids to the known impacts of TiO2 on intestinal epithelium. After their ability to respond to a pro-inflammatory cytokine cocktail was validated, EDMs were exposed to 0, 0.1, 1, or 10 µg fg-TiO2/mL for 24 h. A dose-related increase of the muc2, vilin 1, and chromogranin A gene markers of cell differentiation was observed. In addition, fg-TiO2 induced apoptosis and dose-dependent genotoxicity, while a decreased expression of genes encoding for antimicrobial peptides, and of genes related to tight junction function, was observed. These results validated the use of EDMs as a reliable model for the toxicity testing of foodborne NPs likely to affect the intestinal barrier.

The cardiovascular consequences of electronic cigarette smoking: a narrative review

INTRODUCTION

E-cigarettes have emerged as a popular alternative to traditional tobacco smoking in recent years. Despite their growing popularity, concerns have arisen regarding the cardiovascular implications of e-cigarette use.

AREAS COVERED

This narrative review aims to highlight the latest evidence on the impact of e-cigarettes on cardiovascular health.

EXPERT OPINION

Numerous studies have demonstrated that e-cigarette use can lead to acute adverse cardiovascular effects. Inhalation of e-cigarette aerosols exposes users to a wide range of potentially harmful substances that have been implicated in critical pathophysiologic pathways of cardiovascular disease, namely endothelial dysfunction, oxidative stress, inflammation, sympathetic overdrive, and arterial stiffness. While long-term epidemiological studies specifically focusing on the cardiovascular effects of e-cigarettes are still relatively scarce, early evidence suggests a potential association between e-cigarette use and an increased risk of adverse cardiovascular events. However, it is essential to recognize that e-cigarettes are relatively new products, and the full extent of their long-term cardiovascular impact has not been fully elucidated. In the meantime, promoting tobacco cessation strategies that are evidence-based and regulated, along with rigorous monitoring of e-cigarette use patterns and associated health outcomes, are essential steps in safeguarding cardiovascular health in the face of this emerging public health challenge.

The impact of e-cigarette exposure on different organ systems: A review of recent evidence and future perspectives

The use of electronic cigarettes (e-cigs) is rapidly increasing worldwide and is promoted as a smoking cessation tool. The impact of traditional cigs on human health has been well-defined in both animal and human studies. In contrast, little is known about the adverse effects of e-cigs exposure on human health. This review summarizes the impact of e-cigs exposure on different organ systems based on the rapidly expanding recent evidence from experimental and human studies. A number of growing studies have shown the adverse effects of e-cigs exposure on various organ systems. The summarized data in this review indicate that while e-cigs use causes less adverse effects on different organs compared to traditional cigs, its long-term exposure may lead to serious health effects. Data on short-term organ effects are limited and there is no sufficient evidence on long-term organ effects. Moreover, the adverse effects of secondhand and third hand e-cigs vapour exposure have not been thoroughly investigated in previous studies. Although some studies demonstrated e-cigs used as a smoking cessation tool, there is a lack of strong evidence to support it. While some researchers suggested e-cigs as a safer alternative to tobacco smoking, their long-term exposure health effects remain largely unknown. Therefore, more epidemiological and prospective studies including mechanistic studies are needed to address the potential adverse health effects of e-cigs to draw a firm conclusion about their safe use. A wide variation in e-cigs products and the lack of standardized testing methods are the major barriers to evaluating the existing data. Specific regulatory guidelines for both e-cigs components and the manufacturing process may be effective to protect consumer health.

E-Cigarette Vapour Alters High-Fat Diet-Induced Systemic Inflammatory Responses but Has No Effect on High-Fat Diet-Induced Changes in Gut Microbiota

Background: The gut microbiome, which can be altered by different diets or smoking, has been implicated in the pathogenesis of lung conditions. E-cigarette vaping is now recognised to have detrimental health effects, with several of these being similar to cigarette smoking. However, whether e-cigarettes can alter high-fat diet (HFD)-induced systemic effects and gut microbiota is unknown. In this study, we investigated the effects of HFD in the absence/presence of e-cigarette exposure on systemic inflammation, lipid metabolic markers, and the gut microbiome. Methods: Mice were fed a HFD (or chow) in the absence/presence of e-vapour exposure (±nicotine) and serum inflammation, lipid levels, and microbial diversity were assessed. Results: HFD increased the circulating levels of both triglycerides and non-esterified fatty acids, which were significantly reduced by e-vapour exposure in HFD-fed mice. Serum TNF-α was increased by HFD consumption or e-vapour. HFD had a significant effect on microbial diversity, but there were no additional effects of e-vapour exposure. Conclusions: This study highlights both similarities and differences in how the body responds to e-cigarette vapours, and it is therefore likely that the long-term sequelae of e-cigarette vapour exposure/vaping might not involve the significant alteration of the gut microbiome.

Isolation of RNA from the Murine Colonic Tissue and qRT-PCR for Inflammatory Cytokines

E-cigarette (E-cig) inhalation affects health status by modulating inflammation profiles in several organs, including the brain, lung, heart, and colon. The effect of flavored fourth-generation pod-based E-cigs (JUUL) on murine gut inflammation is modulated by both flavor and exposure period. Exposure of mice to JUUL mango and JUUL mint for one month upregulated inflammatory cytokines, particularly TNF-α, IL-6, and Cxcl-1 (IL-8). JUUL Mango effects were more prominent than those incurred by JUUL Mint after one month of exposure. However, JUUL Mango reduced the expression of colonic inflammatory cytokines after three months of exposure. In this protocol, we detail the process of RNA isolation from the mouse colon and the use of extracted RNA in profiling the inflammatory milieu. Efficient RNA extraction from the murine colon is the most important step in the evaluation of inflammatory transcripts in the colon.

A Living Organoid Biobank of Crohn's Disease Patients Reveals Molecular Subtypes for Personalized Therapeutics

Crohn's disease (CD) is a complex, clinically heterogeneous disease of multifactorial origin; there is no perfect pre-clinical model, little insight into the basis for such heterogeneity, and still no cure. To address these unmet needs, we sought to explore the translational potential of adult stem cell-derived organoids that not only retain their tissue identity, but also their genetic and epigenetic disease-driving traits. We prospectively created a biobank of CD patient-derived organoid cultures (PDOs) using biopsied tissues from colons of 34 consecutive subjects representing all clinical subtypes (Montreal Classification B1-B3 and perianal disease). PDOs were generated also from healthy subjects. Comparative gene expression analyses enabled benchmarking of PDOs as tools for modeling the colonic epithelium in active disease and revealed that despite the clinical heterogeneity there are two major molecular subtypes: immune-deficient infectious-CD [IDICD] and stress and senescence-induced fibrostenotic-CD [S2FCD]. The transcriptome, genome and phenome show a surprising degree of internal consistency within each molecular subtype. The spectrum of morphometric, phenotypic, and functional changes within the "living biobank" reveals distinct differences between the molecular subtypes. These insights enabled drug screens that reversed subtype-specific phenotypes, e.g., impaired microbial clearance in IDICD was reversed using agonists for nuclear receptors, and senescence in S2FCD was rectified using senotherapeutics, but not vice versa . Phenotyped-genotyped CD-PDOs may fill the gap between basic biology and patient trials by enabling pre-clinical Phase '0' human trials for personalized therapeutics.

GRAPHIC ABSTRACT

In Brief

This work creates a prospectively biobanked phenotyped-genotyped Crohn's disease patient-derived organoids (CD-PDOs) as platforms for molecular subtyping of disease and for ushering personalized therapeutics.

HIGHLIGHTS

Prospectively biobanked CD-organoids recapitulate the disease epithelium in patientsThe phenome-transcriptome-genome of CD-organoids converge on two molecular subtypesOne subtype shows impaired microbial clearance, another increased cellular senescencePhenotyped-genotyped PDOs are then used for integrative and personalized therapeutics.

The mediating roles of the oral microbiome in saliva and subgingival sites between e-cigarette smoking and gingival inflammation

BACKGROUND

Electronic cigarettes (ECs) have been widely used by young individuals in the U.S. while being considered less harmful than conventional tobacco cigarettes. However, ECs have increasingly been regarded as a health risk, producing detrimental chemicals that may cause, combined with poor oral hygiene, substantial inflammation in gingival and subgingival sites. In this paper, we first report that EC smoking significantly increases the odds of gingival inflammation. Then, through mediation analysis, we seek to identify and explain the mechanism that underlies the relationship between EC smoking and gingival inflammation via the oral microbiome.

METHODS

We collected saliva and subgingival samples from 75 EC users and 75 non-users between 18 and 34 years in age and profiled their microbial compositions via 16S rRNA amplicon sequencing. We conducted raw sequence data processing, denoising and taxonomic annotations using QIIME2 based on the expanded human oral microbiome database (eHOMD). We then created functional annotations (i.e., KEGG pathways) using PICRUSt2.

RESULTS

We found significant increases in α-diversity for EC users and disparities in β-diversity between EC users and non-users. We also found significant disparities between EC users and non-users in the relative abundance of 36 microbial taxa in the saliva site and 71 microbial taxa in the subgingival site. Finally, we found that 1 microbial taxon in the saliva site and 18 microbial taxa in the subgingival site significantly mediated the effects of EC smoking on gingival inflammation. The mediators on the genus level, for example, include Actinomyces, Rothia, Neisseria, and Enterococcus in the subgingival site. In addition, we report significant disparities between EC users and non-users in the relative abundance of 71 KEGG pathways in the subgingival site.

CONCLUSIONS

These findings reveal that continued EC use can further increase microbial dysbiosis that may lead to periodontal disease. Our findings also suggest that continued surveillance for the effect of ECs on the oral microbiome and its transmission to oral diseases is needed.

Assays with Patient-Derived Organoids to Evaluate the Impact of Microbial Infection on Base Excision Repair (BER) Enzymes

Microbes play an important role in regulating cellular responses and the induction of chronic diseases. Infection and chronic inflammation can cause DNA damage, and the accumulation of mutations leads to cancer development. The well-known examples of cancer-associated microbes are Helicobacter pylori in gastric cancer and Fusobacterium nucleatum (Fn), Bacteroides fragilis, and E.coli NC101 in colorectal cancer (CRC). These carcinopathogens modify the expressions of the base excision repair enzymes and cause DNA damage. This chapter will show how Fn can initiate CRC through the downregulation of a critical enzyme of the base excision repair (BER) pathway that subsequently causes accumulation of DNA damage. We used the stem cell-based organoid model and enteroid-derived monolayer (EDM) from the murine and human colon to assess the impact of infection on the expression of BER enzymes on the transcriptional and translational levels and to develop other functional assays. For example, we used this EDM model to assess the inflammatory response, DNA damage response, and physiological responses, where we correlated the level of these parameters to BER enzyme levels.

E-cigarette Use and Disease Outcomes in Inflammatory Bowel Diseases: A Case-Control Study

INTRODUCTION

Traditional cigarette use adversely impacts disease outcomes in Crohn's disease (CD). There has been a worldwide increase in the use of e-cigarettes over the past decade. The impact of use of nicotine containing e-cigarettes on disease outcomes in CD or ulcerative colitis (UC) has not been well defined.

METHODS

This was a retrospective case-control study of patients with CD or UC who were current users of nicotine containing e-cigarettes (cases). Each case was matched to two non-vaping controls. Our primary study outcome was a composite of new biologic initiation, switch of existing biologic therapy, or IBD-related hospitalization or surgery over 2 years. Multivariable models adjusting for relevant covariates were construction.

RESULTS

The study consisted of 127 patients with IBD who were current e-cigarette users compared to 251 controls. Current e-cigarette users were younger than non-users and were more likely to have had an IBD-related surgery previously. On multivariable analysis among those with CD, current e-cigarette use was not associated with higher risk of study outcome (OR 0.82, 95% CI 0.36-1.87). No difference was observed separately among those who were current or former smokers. Similarly, in those with UC, current e-cigarette use was not associated with the primary outcome (OR 1.05, 95% CI 0.33-3.39).

CONCLUSION

Current e-cigarette use was not associated with worse outcomes among patients with IBD. However, larger studies particularly of patients de novo initiating vaping are needed to draw robust conclusions. Patients should be discouraged from initiating vaping recognizing overall adverse health effects.

Polystyrene nanoplastics deteriorate LPS-modulated duodenal permeability and inflammation in mice via ROS drived-NF-κB/NLRP3 pathway

The widespread occurrence of nanoplastics (NPs), has markedly affected the ecosystem and has become a global threat to animals and human health. There is growing evidence showing that polystyrene nanoparticles (PSNPs) exposure induced enteritis and the intestinal barrier disorder. Lipopolysaccharide (LPS) can trigger the inflammation burden of various tissues. Whether PSNPs deteriorate LPS-induced intestinal damage via ROS drived-NF-κB/NLRP3 pathway is remains unknown. In this study, PSNPs exposure/PSNPs and LPS co-exposure mice model were duplicated by intraperitoneal injection. The results showed that exposure to PSNPs/LPS caused duodenal inflammation and increased permeability. We evaluated the change of duodenum structure, oxidative stress parameters, inflammatory factors, and tight junction protein in the duodenum. We found that PSNPs/LPS could aggravate the production of ROS and oxidative stress in cells, activate NF-κB/NLRP3 pathway, decrease the expression tight junction proteins (ZO-1, Claudin 1, and Occludin) levels, promote inflammatory factors (TNF-α, IL-6, and IFN-γ) expressions. Duodenal oxidative stress and inflammation in PS + LPS group were more serious than those in single exposure group, which could be alleviated by NF-kB inhibitor QNZ. Collectively, the results verified that PSNPs deteriorated LPS-induced inflammation and increasing permeability in mice duodenum via ROS drived-NF-κB/NLRP3 pathway. The current study indicated the relationship and molecular mechanism between PSNPs and intestinal injury, providing novel insights into the adverse effects of PSNPs exposure on mammals and humans.

Lifestyle, behaviour, and environmental modification for the management of patients with inflammatory bowel diseases: an International Organization for Study of Inflammatory Bowel Diseases consensus

Environmental and lifestyle factors play an important role in the natural history of Crohn's disease and ulcerative colitis. A group of international experts from the International Organization for the Study of Inflammatory Bowel Diseases voted on a series of consensus statements to inform the management of inflammatory bowel disease (IBD). The recommendations include avoiding traditional cigarette smoking in patients with Crohn's disease or ulcerative colitis, screening for symptoms of depression, anxiety, and psychosocial stressors at diagnosis and during flares (with referral to mental health professionals when appropriate), and encouraging regular physical activity as tolerated. Patients using dietary approaches for treatment of their IBD should be encouraged to adopt diets that are best supported by evidence and involve monitoring for the objective resolution of inflammation. We recommend formal assessment for obesity and nutritional deficiencies, and patients should be encouraged to maintain a normal body-mass index. A shared decision-making approach to contraception should include the consideration of IBD-related factors, and risk factors for venous thromboembolism. Long-term or frequent use of high-dose non-steroidal anti-inflammatory drugs should be avoided. For primary prevention of disease in the offspring of patients with IBD, we recommend avoiding passive exposure to tobacco, using antibiotics judiciously, and considering breastfeeding when able.

Risk of respiratory, gastrointestinal, and constitutional health symptoms: A cross-sectional study of Texas adolescent and young adult nicotine and marijuana vapers

Observational studies investigating the health consequences of vaping among youth and young adults are limited. This study aimed to describe and examine the risk for health symptoms by vape user category (never users, marijuana only, nicotine only, and dual users). Health symptoms included adverse respiratory, gastrointestinal, and constitutional problems. This cross-sectional study analyzed data from Fall 2020, Wave 12 (n = 2389) of the Texas Adolescent Tobacco and Marketing Surveillance System. Chi-square, one-way analysis of variance (ANOVA), and multivariable logistic regression analyses examined the associations between past 30-day vape user category and 15 health symptoms (e.g., coughing, nausea, vomiting, fever). For total symptoms, dual vapers reported the highest mean (2.76[standard deviation = 3.17]), followed by nicotine-only vapers (2.47[2.89]), marijuana-only vapers (1.94[2.60]), and never users (1.56[2.31]), p < .001. Dual vapers and nicotine-only vapers had significantly higher odds of experiencing respiratory symptoms as compared with never users (adjusted odds ratios [AORs] = 2.35, 95% confidence interval [CI]: 1.30, 4.25; AOR = 1.86, 95% CI: 1.22, 2.81, respectively). Marijuana-only (AOR = 2.41, 95% CI: 1.53, 3.79), nicotine-only (AOR = 2.03, 95% CI: 1.38, 2.99), and dual vapers (AOR = 2.03, 95% CI: 1.15, 3.57) had significantly higher odds of gastrointestinal symptoms compared with never users. Dual vapers had significantly higher odds of experiencing constitutional symptoms as compared to never users (AOR = 1.92, 95% CI: 1.10, 3.34). This study uniquely highlights the risk for gastrointestinal symptoms from vaping. Future research and clinical practice should monitor the occurrence of these symptoms and explore potential mechanisms, such as specific flavorings or chemicals, for the link between vaping and health symptoms.

Electronic Cigarettes: Are They Smoking Cessation Aids or Health Hazards?

The US Food and Drug Administration (FDA) recently approved the marketing of an electronic cigarette (e-cig) brand called Vuse (RJ Reynolds Vapor Company, US) to help aid in smoking cessation for adult smokers. It was believed that the consumption of traditional cigarettes and their harmful effects would be reduced given the availability of newer e-cigarettes. However, adolescent use of tobacco and nicotine products rather increased with the availability of the same e-cigarettes, and the FDA-approved market boom only worsened this problem. Although the FDA underlines the importance of marketing e-cigarettes as a possible solution for adult traditional smoking, its consequences on adolescents' health raise many concerns, which we narrated in this review article.

Impulsivity-Related Personality Traits as Predictors of E-Cigarette Use among Young Adults over Time

Introduction: There has been rising concern about e-cigarette usage among teenagers and young adults. As knowledge about the adverse health effects of e-cigarettes accumulates, it is critical to identify factors that may increase risk of vaping initiation and frequency of use. One potential risk factor known to increase risk for other substance use is impulsivity. This study tested the hypothesis that impulsivity prospectively predicts vaping over time. Methods: Active e-cigarette users (n = 137; 51.8% male; Mean age 20 years at baseline) completed 8 waves of assessment over 21 months (2017-2020). The S-UPPS-P impulse behavior scale was used at baseline to measure impulsivity, and frequency of e-cigarette, cigarette, marijuana and alcohol use was calculated at each wave thereafter. Results: Vaping frequency declined over time [Incidence Rate Ratio (IRR) = 0.92]. There were significant, stable, positive associations between e-cigarette use and lack of premeditation (IRR = 1.06) and sensation seeking (IRR = 1.09). Vaping frequency was inversely associated with negative urgency (IRR = 0.95). Positive urgency and lack of perseverance were not associated with frequency of vaping. Conclusion: These findings suggest that young adults who have higher impulsivity of certain types may use e-cigarettes more frequently. Thus, vaping interventions for young adults should address these factors to ensure the greatest impact on public health.

Cigarette Smoking and Human Gut Microbiota in Healthy Adults: A Systematic Review

The intestinal microbiota is a crucial regulator of human health and disease because of its interactions with the immune system. Tobacco smoke also influences the human ecosystem with implications for disease development. This systematic review aims to analyze the available evidence, until June 2021, on the relationship between traditional and/or electronic cigarette smoking and intestinal microbiota in healthy human adults. Of the 2645 articles published in PubMed, Scopus, and Web of Science, 13 were included in the review. Despite differences in design, quality, and participants’ characteristics, most of the studies reported a reduction in bacterial species diversity, and decreased variability indices in smokers’ fecal samples. At the phylum or genus level, the results are very mixed on bacterial abundance both in smokers and non-smokers with two exceptions. Prevotella spp. appears significantly increased in smokers and former smokers but not in electronic cigarette users, while Proteobacteria showed a progressive increase in Desulfovibrio with the number of pack-years of cigarette (p = 0.001) and an increase in Alphaproteobacteria (p = 0.04) in current versus never smokers. This attempt to systematically characterize the effects of tobacco smoking on the composition of gut microbiota gives new perspectives on future research in smoking cessation and on a new possible use of probiotics to contrast smoke-related dysbiosis.

Impact of e-cigarettes on colonic mucosa and the role of recovery: involvement of oxidative and inflammatory pathway

Electronic cigarettes (e-cigarettes) (EC) are often advertised as a safer alternative to conventional cigarettes. Its widespread use has led to increased interest in its adverse health effects, thanks to few restrictions and a lack of regulatory guidelines. The study aimed to evaluate the influence of exposure to e-cigarette aerosol inhalation in rat colon model and conduct a follow-up after cessation of exposure. The experiment included 30 male adult Albino rats. The animals were divided into three groups: group I (control), non-exposed animals; group II (exposed), was exposed to electronic cigarette liquid vapor for four consecutive weeks; and group III (recovery), was followed up for another 4 weeks after exposure to an e-cigarette as exposed group and for the same duration. In the exposed group, malondialdehyde (MDA) and total nitric oxide (NO) increased significantly in colonic tissue, while superoxide dismutase (SOD) decreased. On histological examination, colonic mucosa showed distortion and loss of its epithelial lining with heavy inflammatory cell infiltration. Also, there was a significant decrease in periodic acid-Schiff-positive goblet cells and area percent of proliferating cell nuclear antigen expression. Tumor necrosis factor-alpha (TNFα) expression significantly increased in colonic mucosa. After 4 weeks of EC cessation, the colonic mucosal histological structure showed recovery with downregulated TNFα immunoexpression and restored oxidant/antioxidant balance. In conclusion, the usage of electronic cigarettes resulted in marked pathological alterations in the colonic mucosa, which could be attributed to oxidative and inflammatory stresses. In contrast, the cessation of exposure led to recovery.

Quantification and cytotoxicity of degradation products (chloropropanols) in sucralose containing e-liquids with propylene glycol and glycerol as base

Electronic cigarettes (e-cigarettes) have gained increasing popularity in recent years, mostly because they are supposed to be less harmful than regular cigarettes. Therefore, it is highly imperative to investigate possible noxious effects to protect the consumers. E-liquids consist of propylene glycol, glycerol, aroma compounds and sweeteners. One of these sweeteners is a chlorinated version of sucrose, namely sucralose. The aim of this work was to investigate degradation products of sucralose in the presence of propylene glycol and glycerol at different temperatures of commercially available e-cigarettes. Chemical analysis and biological tests were simultaneously performed on e-liquid aerosol condensates. The results of the chemical analysis, which was executed by employing GC-MS/GC-FID, demonstrated high amounts of various chloropropanols. The most abundant one is extremely toxic, namely 3-chloropropane-1,2-diol, which can be detected at concentrations ranging up to 10,000 mg/kg. Furthermore, a cytotoxicity investigation of the condensates was performed on HUVEC/Tert2 cells in which metabolic activity was determined by means of resazurin assay. The cellular metabolic activity significantly decreased by treatment with e-liquid aerosol condensate. Due to the results of this study, we advise against the use of sucralose as sweetener in e-liquids.

Inflammatory phenotype modulation in the respiratory tract and systemic circulation of e-cigarette users: a pilot study

Over 40 million people use e-cigarettes worldwide, but the impact of chronic e-cigarette use on health has not been adequately defined. In particular, effects of e-cigarette aerosol inhalation on inflammation and host defenses across the body are not fully understood. We conducted a longitudinal cohort pilot study to explore changes in the inflammatory state and monocyte function of e-cigarette users (n=20) versus healthy controls (n=13), and to evaluate effects of e-cigarette use reduction on the same. Saliva, sputum, and blood were obtained from e-cigarette users at baseline and after a 2-week intervention of decreased e-cigarette use. Overall, across 38 proteins quantified by multiplex, airway samples from e-cigarette users tended to have decreased levels of immunomodulatory proteins relative to healthy controls, while levels of cytokines, chemokines and growth factors in the circulation tended to be elevated. Specifically, e-cigarette users had lower levels of IL-1 receptor antagonist (IL-1Ra) in saliva (p<0.0001), with higher IL-1Ra and GRO levels in sputum (p<0.01 and p<0.05, respectively), and higher levels of both TNFβ (p<0.0001) and VEGF (p<0.0001) in plasma. Circulating monocytes from e-cigarette users had alterations in their inflammatory phenotype in response to reduced e-cigarette use, with blunted IL-8 and IL-6 release upon challenge with bacterial lipopolysaccharide (p<0.001 and p<0.05, respectively), suggesting a decreased ability to appropriately respond to bacterial infection. Based on these findings, chronic inhalation of e-cigarette aerosols alters the inflammatory state of the airways and systemic circulation, raising concern for the development of both inflammatory and infectious diseases in chronic users of e-cigarettes.

Digital Surveillance to Identify California Alternative and Emerging Tobacco Industry Policy Influence and Mobilization on Facebook

Growing popularity of electronic nicotine-delivery systems (ENDS) has coincided with a need to strengthen tobacco-control policy. In response, the ENDS industry has taken actions to mobilize against public health measures, including coordination on social media platforms. To explore this phenomenon, data mining was used to collect public posts on two Facebook public group pages: the California Consumer Advocates for Smoke Free Alternatives Association (CCASAA) and the community page of the Northern California Chapter of SFATA (NC-SFATA). Posts were manually annotated to characterize themes associated with industry political interference and user interaction. We collected 288 posts from the NC-SFATA and 411 posts from CCASAA. A total of 522 (74.7%) posts were categorized as a form of political interference, with 339 posts (64.9%) from CCASAA and 183 posts (35.1%) from NC-SFATA. We identified three different categories of policy interference-related posts: (1) providing updates on ENDS-related policy at the federal, state, and local levels; (2) sharing opinions about ENDS-related policies; (3) posts related to scientific information related to vaping; and (4) calls to action to mobilize against tobacco/ENDS policies. Our findings indicate that pro-tobacco social media communities on Facebook, driven by strategic activities of trade associations and their members, may act as focal points for anti-policy information dissemination, grass-roots mobilization, and industry coordination that needs further research.

SPT6 loss permits the transdifferentiation of keratinocytes into an intestinal fate that resembles Barrett's metaplasia

Transient depletion of the transcription elongation factor SPT6 in the keratinocyte has been recently shown to inhibit epidermal differentiation and stratification; instead, they transdifferentiate into a gut-like lineage. We show here that this phenomenon of transdifferentiation recapitulates Barrett's metaplasia, the only human pathophysiologic condition in which a stratified squamous epithelium that is injured due to chronic acid reflux is trans-committed into an intestinal fate. The evidence we present here not only lend support to the notion that the keratinocytes are potentially the cell of origin of Barrett's metaplasia but also provide mechanistic insights linking transient acid exposure, downregulation of SPT6, stalled transcription of the master regulator of epidermal fate TP63, loss of epidermal fate, and metaplastic progression. Because Barrett's metaplasia in the esophagus is a pre-neoplastic condition with no preclinical human models, these findings have a profound impact on the modeling Barrett's metaplasia-in-a-dish.

Functional assays with human patient-derived enteroid monolayers to assess the human gut barrier

Here, we describe the use of polarized patient enteroid-derived monolayers (EDMs) to assess the impact of e-cigarettes on the human gut barrier. These EDMs can be adapted to culture in a 96-well plate for high-throughput screening. We model the effect of e-cigarettes by combining pathogens, enteroids, and e-cigarette vapor-infused media and assess gut barrier integrity, bacterial internalization, and inflammatory response of the gut epithelium. This protocol can be used to assess the effects of e-cigarette components on gut functions. For complete details on the use and execution of this protocol, please refer to Sharma et al. (2021).

Machine Learning-Based Nicotine Addiction Prediction Models for Youth E-Cigarette and Waterpipe (Hookah) Users

Despite the harmful effect on health, e-cigarette and hookah smoking in youth in the U.S. has increased. Developing tailored e-cigarette and hookah cessation programs for youth is imperative. The aim of this study was to identify predictor variables such as social, mental, and environmental determinants that cause nicotine addiction in youth e-cigarette or hookah users and build nicotine addiction prediction models using machine learning algorithms. A total of 6511 participants were identified as ever having used e-cigarettes or hookah from the National Youth Tobacco Survey (2019) datasets. Prediction models were built by Random Forest with ReliefF and Least Absolute Shrinkage and Selection Operator (LASSO). ReliefF identified important predictor variables, and the Davies–Bouldin clustering evaluation index selected the optimal number of predictors for Random Forest. A total of 193 predictor variables were included in the final analysis. Performance of prediction models was measured by Root Mean Square Error (RMSE) and Confusion Matrix. The results suggested high performance of prediction. Identified predictor variables were aligned with previous research. The noble predictors found, such as ‘witnessed e-cigarette use in their household’ and ‘perception of their tobacco use’, could be used in public awareness or targeted e-cigarette and hookah youth education and for policymakers.