Excessive alcohol consumption induces methane production in humans and rats.
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ABSTRACT:
SUBMITTER: Tuboly E
PROVIDER: S-EPMC5544731 | biostudies-literature | 2017 Aug
REPOSITORIES: biostudies-literature
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Excessive alcohol consumption induces methane production in humans and rats.
Tuboly E E Molnár R R Tőkés T T Turányi R N RN Hartmann P P Mészáros A T AT Strifler G G Földesi I I Siska A A Szabó A A Mohácsi Á Á Szabó G G Boros M M
Scientific reports 20170804 1
Various studies have established the possibility of non-bacterial methane (CH<sub>4</sub>) generation in oxido-reductive stress conditions in plants and animals. Increased ethanol input is leading to oxido-reductive imbalance in eukaryotes, thus our aim was to provide evidence for the possibility of ethanol-induced methanogenesis in non-CH<sub>4</sub> producer humans, and to corroborate the in vivo relevance of this pathway in rodents. Healthy volunteers consumed 1.15 g/kg/day alcohol for 4 days ...[more]
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Project description:BACKGROUND:We have used a genetical genomic approach, in conjunction with phenotypic analysis of alcohol consumption, to identify candidate genes that predispose to varying levels of alcohol intake by HXB/BXH recombinant inbred rat strains. In addition, in two populations of humans, we assessed genetic polymorphisms associated with alcohol consumption using a custom genotyping array for 1,350 single nucleotide polymorphisms (SNPs). Our goal was to ascertain whether our approach, which relies on statistical and informatics techniques, and non-human animal models of alcohol drinking behavior, could inform interpretation of genetic association studies with human populations. RESULTS:In the HXB/BXH recombinant inbred (RI) rats, correlation analysis of brain gene expression levels with alcohol consumption in a two-bottle choice paradigm, and filtering based on behavioral and gene expression quantitative trait locus (QTL) analyses, generated a list of candidate genes. A literature-based, functional analysis of the interactions of the products of these candidate genes defined pathways linked to presynaptic GABA release, activation of dopamine neurons, and postsynaptic GABA receptor trafficking, in brain regions including the hypothalamus, ventral tegmentum and amygdala. The analysis also implicated energy metabolism and caloric intake control as potential influences on alcohol consumption by the recombinant inbred rats. In the human populations, polymorphisms in genes associated with GABA synthesis and GABA receptors, as well as genes related to dopaminergic transmission, were associated with alcohol consumption. CONCLUSION:Our results emphasize the importance of the signaling pathways identified using the non-human animal models, rather than single gene products, in identifying factors responsible for complex traits such as alcohol consumption. The results suggest cross-species similarities in pathways that influence predisposition to consume alcohol by rats and humans. The importance of a well-defined phenotype is also illustrated. Our results also suggest that different genetic factors predispose alcohol dependence versus the phenotype of alcohol consumption.
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Project description:ImportanceAlthough the detrimental effects of alcohol on the brain are widely acknowledged, observed structural changes are highly heterogeneous, and diagnostic markers for characterizing alcohol-induced brain damage, especially in early abstinence, are lacking. This heterogeneity, likely contributed to by comorbidity factors in patients with alcohol use disorder (AUD), challenges a direct link of brain alterations to the pathophysiology of alcohol misuse. Translational studies in animal models may help bridge this causal gap.ObjectiveTo compare microstructural properties extracted using advanced diffusion tensor imaging (DTI) in the brains of patients with AUD and a well-controlled rat model of excessive alcohol consumption and monitor the progression of these properties during early abstinence.Design, setting, and participantsThis prospective observational study included 2 cohorts of hospitalized patients with AUD (n = 91) and Marchigian Sardinian alcohol-preferring (msP) rats (n = 27). In humans cross-sectional comparison were performed with control participants (healthy men [n = 36]) and longitudinal comparisons between different points after alcohol withdrawal. In rats, longitudinal comparisons were performed in alcohol-exposed (n = 27) and alcohol-naive msP rats (n = 9). Human data were collected from March 7, 2013, to August 3, 2016, and analyzed from June 14, 2017, to May 31, 2018; rat data were collected from January 15, 2017, to May 12, 2017, and analyzed from October 11, 2017, to May 28, 2018.Main outcomes and measuresFractional anisotropy and other DTI measures of white matter properties after long-term alcohol exposure and during early abstinence in both species and clinical and demographic variables and time of abstinence after discharge from hospital in patients.ResultsThe analysis included 91 men with AUD (mean [SD] age, 46.1 [9.6] years) and 27 male rats in the AUD groups and 36 male controls (mean [SD] age, 41.7 [9.3] years) and 9 male control rats. Comparable DTI alterations were found between alcohol and control groups in both species, with a preferential involvement of the corpus callosum (fractional anisotropy Cohen d = -0.84 [P < .01] corrected in humans and Cohen d = -1.17 [P < .001] corrected in rats) and the fornix/fimbria (fractional anisotropy Cohen d = -0.92 [P < .001] corrected in humans and d = -1.24 [P < .001] corrected in rats). Changes in DTI were associated with preadmission consumption patterns in patients and progress in humans and rats during 6 weeks of abstinence. Mathematical modeling shows this process to be compatible with a sustained demyelination and/or a glial reaction.Conclusions and relevanceUsing a translational DTI approach, comparable white matter alterations were found in patients with AUD and rats with long-term alcohol consumption. In humans and rats, a progression of DTI alterations into early abstinence (2-6 weeks) suggests an underlying process that evolves soon after cessation of alcohol use.
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Project description:BackgroundBinge drinking (BD) refers to a pattern of alcohol consumption characterized by the consumption of large amounts of alcohol in a short period of time followed by periods of abstinence. This drinking pattern is prevalent worldwide, mainly among young people. Excessive alcohol consumption is the spectrum of consumption patterns that may have or have had health consequences, and includes the concepts of risky alcohol use, harmful alcohol use and alcohol dependence according to Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV), the latter two are currently grouped into alcohol use disorder (AUD) according to the fifth edition of the DSM (DSM-5). Due to the high prevalence of BD among young people, especially university students, as well as the important consequences of its practice, a study was conducted to evaluate excessive alcohol consumption and its relationship with the practice of BD in university students.MethodsA cross-sectional study was conducted among students (aged 18-30 years) enrolled in the academic year 2018-2019 at the Faculty of Nursing at a university in northern Spain. Data collection included sociodemographic information, and alcohol use information, collected using a semi-structured questionnaire. To measure the excessive alcohol consumption, this study used the Alcohol Use Disorders Identification Test (AUDIT).ResultsA total of 142 participants were included, of which 88.03% were women. Up to 38.03% were classified as BD. Up to 14.77% of non-BD participants and 66.67% of BD participants were classified as risky drinkers (AUDIT Total geq 8 in men or geq 6 in women) (p < 0.001). Up to 3.41% of the non-BD and 24.07% of the BD were drinkers with harmful alcohol use and probable alcohol dependence (AUDIT Total geq 13) (p < 0.001). A total of 5.68% of non-BD and 42.59% of BD were AUD drinkers (AUDIT Total geq 9 in males or geq 8 in females) (p < 0.001). In addition, statistically significant differences were found between the BD and non-BD groups in the responses to each of the AUDIT items, as well as in the total score and also in the scores of the three domains of the questionnaire.ConclusionsExcessive alcohol consumption is frequent among university students, especially among those who practice BD.
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Project description:BackgroundMore than one-quarter of the US population qualify as excessive alcohol consumers. Alcohol use impacts several lung diseases, and heavy consumption has been associated with poor clinical outcomes. The fractional excretion of exhaled nitric oxide (Feno) has clinical implications in multiple airways diseases. We hypothesized that excessive alcohol intake is associated with lower Feno levels.MethodsTo test this hypothesis, we examined a sample consisting of 12,059 participants, aged 21 to 79 years, interviewed between 2007 and 2012 from the National Health and Examination Survey. Two valid Feno measurements that were reproducible were recorded. Alcohol questionnaire data were used to define the following alcohol groups: never drinkers, nonexcessive drinkers, excessive drinkers, and former excessive drinkers. The natural logarithm of Feno values [ln(Feno)] as well as blood eosinophil count and C-reactive protein were used as dependent variables to test the association with alcohol groups including multivariable linear regression models with adjustment for predictors of Feno.ResultsExcessive alcohol consumption comprised 3,693 (26.9%) of the US sample population. Controlling for all other factors, excessive alcohol consumption had a negative association and was an independent predictor for ln(Feno) levels in comparison with the never-drinker group (-0.11; 95% CI, -0.17 to -0.06; P < .001). ln(Feno) levels decreased across categories of increasing alcohol use (P < .001).ConclusionsAccounting for alcohol use in the interpretation of Feno levels should be an additional consideration, and further investigations are warranted to explore the complex interaction between alcohol and nitric oxide in the airways.
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Project description:Heavy alcohol consumption has detrimental neurologic effects, inducing widespread neuronal loss in both fetuses and adults. One proposed mechanism of ethanol-induced cell loss with sufficient exposure is an elevation in concentrations of bioactive lipids that mediate apoptosis, including the membrane sphingolipid metabolites ceramide and sphingosine. While these naturally-occurring lipids serve as important modulators of normal neuronal development, elevated levels resulting from various extracellular insults have been implicated in pathological apoptosis of neurons and oligodendrocytes in several neuroinflammatory and neurodegenerative disorders. Prior work has shown that acute administration of ethanol to developing mice increases levels of ceramide in multiple brain regions, hypothesized to be a mediator of fetal alcohol-induced neuronal loss. Elevated ceramide levels have also been implicated in ethanol-mediated neurodegeneration in adult animals and humans. Here, we determined the effect of chronic voluntary ethanol consumption on lipid profiles in brain and peripheral tissues from adult alcohol-preferring (P) rats to further examine alterations in lipid composition as a potential contributor to ethanol-induced cellular damage. P rats were exposed for 13 weeks to a 20% ethanol intermittent-access drinking paradigm (45 ethanol sessions total) or were given access only to water (control). Following the final session, tissues were collected for subsequent chromatographic analysis of lipid content and enzymatic gene expression. Contrary to expectations, ethanol-exposed rats displayed substantial reductions in concentrations of ceramides in forebrain and heart relative to non-exposed controls, and modest but significant decreases in liver cholesterol. qRT-PCR analysis showed a reduction in the expression of sphingolipid delta(4)-desaturase (Degs2), an enzyme involved in de novo ceramide synthesis. These findings indicate that ethanol intake levels achieved by alcohol-preferring P rats as a result of chronic voluntary exposure may have favorable vs. detrimental effects on lipid profiles in this genetic line, consistent with data supporting beneficial cardioprotective and neuroprotective effects of moderate ethanol consumption.
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