Harnessing the potential of probiotics in the treatment of alcoholic liver disorders

Exploring the alleviating effects of Bifidobacterium metabolite lactic acid on non-alcoholic steatohepatitis through the gut-liver axis

Objective

This study investigates the protective effects of lactic acid, a metabolite of Bifidobacterium, on non-alcoholic fatty liver disease (NAFLD) induced by a high-sugar, high-fat diet (HFD) in mice, in the context of the gut-liver axis.

Methods

A NAFLD mouse model was established using a HFD, and different intervention groups were set up to study the protective effects of Bifidobacterium and its metabolite lactic acid. The groups included a control group, NAFLD group, Bifidobacterium treatment group, Glyceraldehyde-3-P (G-3P) co-treatment group, and NOD-like receptor family pyrin domain containing 3 (NLRP3) overexpression group. The evaluation of liver function and lipid metabolism was conducted using the liver-to-body weight ratio, histological staining, and biochemical assays. Enzyme-linked immunosorbent assay (ELISA) was performed to measure inflammatory cytokines, and western blotting was used to analyze the expression of NLRP3 inflammasome and autophagy-related molecules. In vitro, an NAFLD cell model was established using oleic acid, with cells treated with lactic acid and NLRP3 overexpression to assess lipid droplet accumulation and inflammation.

Results

In vivo findings indicated that, in comparison to CBX group (Control group without antibiotic treatment), NAFLD/CBX group (NAFLD group without antibiotic administration) and NAFLD/ABX group (NAFLD group with antibiotic administration) exhibited increased liver-to-body weight ratio, higher lipid droplet accumulation, aggravated liver histopathological damage, and elevated levels of AST (Aspartate Aminotransferase), ALT (Alanine Aminotransferase), TC (Total Cholesterol), TG (Triglycerides), LDL-C (Low-Density Lipoprotein Cholesterol), IL-6 (Interleukin-6), TNF-α (Tumor Necrosis Factor-alpha), IL-1β (Interleukin-1 beta), and NLRP3-related molecules, while HDL-C (High-Density Lipoprotein Cholesterol) levels significantly decreased. Intervention with Bifidobacterium significantly reversed these adverse changes. Further addition of G-3P led to more pronounced improvement in NAFLD symptoms, while overexpression of NLRP3 weakened the protective effects of Bifidobacterium. In vitro results indicated that Ole group exhibited heightened lipid droplet accumulation and expression of NLRP3 inflammasome-related molecules relative to the control group. Treatment with lactic acid effectively reversed these changes; however, the protective effect of lactic acid was significantly weakened with NLRP3 overexpression.

Conclusion

Lactic acid can alleviate lipid metabolism disorders in NAFLD induced by diet through the inhibition of inflammation mediated by the NLRP3 inflammasome and the regulation of the autophagy process.

Effects of Probiotics on Liver Diseases: Current In Vitro and In Vivo Studies

Various types of liver or hepatic diseases cause the death of about 2 million people worldwide every year, of which 1 million die from the complications of cirrhosis and another million from hepatocellular carcinoma and viral hepatitis. Currently, the second most common solid organ transplant is the liver, and the current rate represents less than 10% of global transplant requests. Hence, finding new approaches to treat and prevent liver diseases is essential. In liver diseases, the interaction between the liver, gut, and immune system is crucial, and probiotics positively affect the human microbiota. Probiotics are a non-toxic and biosafe alternative to synthetic chemical compounds. Health promotion by lowering cholesterol levels, stimulating host immunity, the natural gut microbiota, and other functions are some of the activities of probiotics, and their metabolites, including bacteriocins, can exert antimicrobial effects against a broad range of pathogenic bacteria. The present review discusses the available data on the results of preclinical and clinical studies on the effects of probiotic administration on different types of liver diseases.

Gut Bacteria in Alcohol-Associated Liver Disease

Alcohol-associated liver disease (ALD) poses a significant global public health challenge, with high patient mortality rates and economic burden. The gut microbiome plays an important role in the onset and progression of alcohol-associated liver disease. Excessive alcohol consumption disrupts the intestinal barrier, facilitating the entry of harmful microbes and their products into the liver, exacerbating liver damage. Dysbiosis, marked by imbalance in gut bacteria, correlates with ALD severity. Promising microbiota-centered therapies include probiotics, phages, and fecal microbiota transplantation. Clinical trials demonstrate the potential of these interventions to improve liver function and patient outcomes, offering a new frontier in ALD treatment.

Efficacy and Safety of Wilac L Probiotic Complex Isolated from Kimchi on the Regulation of Alcohol and Acetaldehyde Metabolism in Humans

Alcohol-related hangovers impact both physical and mental wellness, largely due to acetaldehyde levels produced through alcohol metabolism. The present study investigated the efficacy and safety of the Wilac L probiotic complex (Levilactobacillus brevis WiKim0168 and Leuconostoc mesenteroides WiKim0172 isolated from kimchi) in improving hangovers post-alcohol consumption. This study was conducted as a randomized, double-blind, crossover placebo-controlled clinical trial from August 2023 to February 2024. Subjects (n = 26) were randomized into six test groups consuming three products, the Wilac L probiotic complex, Wilac L35 (Wilac L probiotic complex with Pyrus pyrifolia Nakai), or placebo, in different orders with crossover after a wash-out interval of 7-10 days. Blood alcohol and acetaldehyde concentrations were measured 0, 0.25, 0.5, 1, 2, 4, 6, and 15 h after alcohol consumption. The blood acetaldehyde levels measured with Wilac L probiotic complex supplementation were significantly lower than the control at 0.25 (p = 0.0381), 0.5 (p = 0.0498), and 1 h (p = 0.0260) post-consumption. The blood acetaldehyde levels after Wilac L35 consumption compared to the control are significant at 0.25 (p = 0.0115), 0.5 (p = 0.0054), 1 (p = 0.0285), 2 (p = 0.0113), and 6 h (p = 0.0287) post-consumption. No significant adverse events were reported. The Wilac L probiotic complex is associated with decreased blood acetaldehyde levels and improved subjective hangover symptoms.

Therapeutic Role of Probiotics Against Environmental-Induced Hepatotoxicity: Mechanisms, Clinical Perspectives, Limitations, and Future

Hepatotoxicity is one of the biggest health challenges, particularly in the context of liver diseases, often aggravated by gut microbiota dysbiosis. The gut-liver axis has been regarded as a key idea in liver health. It indicates that changes in gut flora caused by various hepatotoxicants, including alcoholism, acetaminophen, carbon tetrachloride, and thioacetamide, can affect the balance of the gut's microflora, which may lead to increased dysbiosis and intestinal permeability. As a result, bacterial endotoxins would eventually enter the bloodstream and liver, causing hepatotoxicity and inducing inflammatory reactions. Many treatments, including liver transplantation and modern drugs, can be used to address these issues. However, because of the many side effects of these approaches, scientists and medical experts are still hoping for a therapeutic approach with fewer side effects and more positive results. Thus, probiotics have become well-known as an adjunctive strategy for managing, preventing, or reducing hepatotoxicity in treating liver injury. By altering the gut microbiota, probiotics offer a secure, non-invasive, and economical way to improve liver health in the treatment of hepatotoxicity. Through various mechanisms such as regulation of gut microbiota, reduction of pathogenic overgrowth, suppression of inflammatory mediators, modification of hepatic lipid metabolism, improvement in the performance of the epithelial barrier of the gut, antioxidative effects, and modulation of mucosal immunity, probiotics play their role in the treatment and prevention of hepatotoxicity. This review highlights the mechanistic effects of probiotics in environmental toxicants-induced hepatotoxicity and current findings on this therapeutic approach's experimental and clinical trials.

Probiotics-role in alleviating the impact of alcohol liver disease and alcohol deaddiction: a systematic review

Background

There are few efficient treatment options for alcohol addiction, which continues to be a serious public health concern. The possible contribution of gut microbiota to the onset and progression of alcohol addiction has been brought to light by recent studies. Probiotics have become a cutting-edge intervention in the treatment of alcohol consumption disorder because of its favorable effects on gut health. The purpose of this systematic review is to assess the body of research on the advantages of probiotics in treating alcoholism and associated neuroinflammatory conditions.

Methods

To find pertinent research published from January 2012 to 2023, a thorough search of electronic databases, including PubMed, Scopus, Google Scholar and Web of Science, was carried out. Included were studies looking at how probiotics affect neuroinflammation, gut- brain axis regulation, alcohol addiction, and related behaviors.

Findings

Several investigations have shown how beneficial probiotics are in reducing systemic inflammation and alcoholic liver disease (ALD). Probiotic treatments successfully corrected the imbalance of microbiota, decreased intestinal permeability, and stopped the passage of bacterial constituents such lipopolysaccharides (LPS) into the bloodstream. Additionally, probiotics helped to regulate neurotransmitter pathways, especially those connected to GABA, glutamate, and dopamine, which are intimately linked to behaviors related to addiction. Furthermore, it was shown that probiotics altered the expression of neurotransmitter signaling and dopamine receptors.

Conclusion

There is strong evidence from this systematic study that probiotics have potential advantages in treating alcohol addiction. The potential of probiotic therapies is demonstrated by the way they modulate important neurotransmitter pathways implicated in addiction, decrease neuroinflammation, and restore the balance of gut flora. To fully investigate the therapeutic potential of probiotics in treating alcohol addiction and enhancing the general wellbeing of those afflicted by this condition, more research is necessary.

Inflammation, oxidative stress and gut microbiome perturbation: A narrative review of mechanisms and treatment of the alcohol hangover

Alcohol is the most widely abused substance in the world, the leading source of mortality in 15-49-year-olds, and a major risk factor for heart disease, liver disease, diabetes, and cancer. Despite this, alcohol is regularly misused in wider society. Consumers of excess alcohol often note a constellation of negative symptoms, known as the alcohol hangover. However, the alcohol hangover is not considered to have long-term clinical significance by clinicians or consumers. We undertook a critical review of the literature to demonstrate the pathophysiological mechanisms of the alcohol hangover. Hereafter, the alcohol hangover is re-defined as a manifestation of sickness behavior secondary to alcohol-induced inflammation, using the Bradford-Hill criteria to demonstrate causation above correlation. Alcohol causes inflammation through oxidative stress and endotoxemia. Alcohol metabolism is oxidative and increased intake causes relative tissue hypoxia and increased free radical generation. Tissue damage ensues through lipid peroxidation and the formation of DNA/protein adducts. Byproducts of alcohol metabolism such as acetaldehyde and congeners, sleep deprivation, and the activation of nonspecific inducible CYP2E1 in alcohol-exposed tissues exacerbate free radical generation. Tissue damage and cell death lead to inflammation, but in the intestine loss of epithelial cells leads to intestinal permeability, allowing the translocation of pathogenic bacteria to the systemic circulation (endotoxemia). This leads to a well-characterized cascade of systemic inflammation, additionally activating toll-like receptor 4 to induce sickness behavior. Considering the evidence, it is suggested that hangover frequency and severity may be predictors of the development of later alcohol-related diseases, meriting formal confirmation in prospective studies. In light of the mechanisms of alcohol-mediated inflammation, research into gut permeability and the gut microbiome may be an exciting future therapeutic avenue to prevent alcohol hangover and other alcohol-related diseases.

Bruceine A alleviates alcoholic liver disease by inhibiting AIM2 inflammasome activation via activating FXR

BACKGROUND

Alcoholic liver disease (ALD), a public health challenge worldwide caused by long-term persistent drinking, is life-threatening with minimal approved therapies. Hepatic steatosis accompanied by inflammation is an initial and inevitable stage in the complex progression of simple alcoholic liver injury to more severe liver diseases such as hepatitis, liver fibrosis, cirrhosis and liver cancer.

PURPOSE

We aimed to identify the therapeutic role of Bruceine A (BA) in ALD whilst attempting to explore whether its protective effects depend specifically on the farnesoid X receptor (FXR).

METHODS

Autodock was applied to detect the affinity between BA and FXR. Lieber-DeCarli liquid diet with 5 % ethanol (v/v) was adopted to establish the mouse ALD model. The lentivirus mediating FXR (LV-FXR) was injected into mice via the tail vein to establish FXR-overexpressed mice. FXR silencing or overexpression plasmids were transfected into AML-12 cells prior to ethanol stimulation. Quantitative real-time PCR, Western blotting and immunofluorescence assays were employed to determine the expression of related genes. We subjected liver sections to H&E and Oil Red O staining to evaluate the liver histological injury and the deposition of lipid droplets.

RESULTS

BA significantly reduced body weight and liver-to-body weight ratios as well as biochemical indexes in mice. Ethanol-induced liver damage and lipid accumulation could be alleviated by BA treatment. BA bound to FXR by two hydrogen bonds. There was a positive correlation between BA administration and FXR expression. BA inhibited the expression of lipid synthesis genes and enhanced the expression of lipid metabolism genes by activating FXR, thus alleviating steatosis in ALD. Moreover, BA exerted an ameliorative effect against inflammation by inhibiting the activation of absent in melanoma 2 (AIM2) inflammasome by activating FXR. FXR overexpression possessed the ability to counter the accumulation of lipid and the activation of AIM2 inflammasome caused by ethanol. FXR deficiency exacerbated ethanol-induced liver steatosis and inflammation. The hepatoprotective effect of BA could be disrupted by FXR antagonist guggulsterone (GS) in vivo and FXR siRNA in vitro.

CONCLUSION

BA alleviated alcoholic liver disease by inhibiting AIM2 inflammasome activation through an FXR-dependent mechanism. This study may potentially represent a new therapeutic approach for ALD.

Therapeutic benefit of probiotic in alcohol dependence syndrome: Evidence from a tertiary care centre of India

Probiotic adjuvant has promising effects in treating alcohol induced hepatitis, depression, and anxiety. This study aimed to assess the effectiveness of adjuvant probiotic use in improving the liver functions, anxiety, and depression among patients with alcohol dependence syndrome (ADS) in a tertiary care hospital in Andhra Pradesh, India. In this prospective observational design, ADS patients with or without probiotics were followed-up at one and three months after initiation of treatment. They were assessed for liver function test (LFT), anxiety by HAM-A and depression by HAM-D scale. A total of 120 patients complied with the treatment, 60 in each group, mean age being 35.0 years (SD 9.5 years). The baseline socio-demographic and clinical characteristics were similar in both the groups. Significant reduction was noted in the probiotic group for total bilirubin (Mean difference (MD) 0.18; 95 % CI: 0.04, 0.31), AST (MD 5.0; 95 % CI: 0.5, 9.5), and ALT (MD 8.6; 95 % CI: 1.4, 15.7) at one month after treatment. Both the groups showed a considerable change in anxiety and depression scores (HAM-A and HAM-D) till three months. At three months of treatment initiation, proportional improvement of severity grade to mild form in anxiety was more in the probiotic group (35 %) than the non-probiotic group (13.3 %) (p < 0.05). Hence, probiotic supplementation can significantly reduce the hepatic enzymes and depression severity in patients with alcohol dependence syndrome but demands additional robust evidence on the causal inference.

Oral Administration of Alcohol-Tolerant Lactic Acid Bacteria Alleviates Blood Alcohol Concentration and Ethanol-Induced Liver Damage in Rodents

Excessive alcohol consumption can have serious negative consequences on health, including addiction, liver damage, and other long-term effects. The causes of hangovers include dehydration, alcohol and alcohol metabolite toxicity, and nutrient deficiency due to absorption disorders. Additionally, alcohol consumption can slow reaction times, making it more difficult to rapidly respond to situations that require quick thinking. Exposure to a large amount of ethanol can also negatively affect a person's righting reflex and balance. In this study, we evaluated the potential of lactic acid bacteria (LAB) to alleviate alcohol-induced effects and behavioral responses. Two LAB strains isolated from kimchi, Levilactobacillus brevis WiKim0168 and Leuconostoc mesenteroides WiKim0172, were selected for their ethanol tolerance and potential to alleviate hangover symptoms. Enzyme activity assays for alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) were then conducted to evaluate the role of these bacteria in alcohol metabolism. Through in vitro and in vivo studies, these strains were assessed for their ability to reduce blood alcohol concentrations and protect against alcohol-induced liver damage. The results indicated that these LAB strains possess significant ethanol tolerance and elevate ADH and ALDH activities. LAB administration remarkably reduced blood alcohol levels in rats after excessive alcohol consumption. Moreover, the LAB strains showed hepatoprotective effects and enhanced behavioral outcomes, highlighting their potential as probiotics for counteracting the adverse effects of alcohol consumption. These findings support the development of functional foods incorporating LAB strains that can mediate behavioral improvements following alcohol intake.

Clinical efficacy of probiotics in the treatment of alcoholic liver disease: a systematic review and meta-analysis

Objective

Alcoholic liver disease (ALD) is a liver damage disease caused by long-term heavy drinking. Currently, there is no targeted pharmaceutical intervention available for the treatment of this disease. To address this, this paper evaluates the efficacy and safety of probiotic preparation in treating ALD through conducting a meta-analysis, and provides a valuable insight for clinical decision-making.

Methods

A systematic search was conducted across databases, including PubMed, Embase, Web of Science, Cochrane Library, CNKI, VIP, Wanfang, and CBM from the inception dates to October 15, 2023, to identify clinical randomized controlled trials on probiotic preparations in the treatment of ALD. After the literature underwent screening, data extraction, and quality assessment, RevMan 5.3 and Stata 14.2 were employed for data analysis and processing.

Results

A total of 9 randomized controlled trials fulfilled the inclusion criteria. The results of the meta-analysis showed that probiotic preparation could significantly improve the liver function of patients with alcoholic liver disease compared with the control group. Probiotic intervention led to a significant reduction in the levels of alanine aminotransferase (MD=-13.36,95%CI:-15.80,-10.91;P<0.00001),aspartate aminotransferase (MD=-16.99,95%CI:-20.38,-13.59;P<0.00001),γ-glutamyl transpeptidase (MD=-18.79,95% CI:-28.23,-9.34; P<0.0001). Concurrently, the level of serum albumin (MD=0.19,95% CI:0.02,0.36;P=0.03) was increased. Furthermore, probiotic intervention could also modulate the composition of intestinal flora in patients with alcoholic liver disease, leading to an augmentation in Bifidobacteria and a reduction in Escherichia coli. However, in patients with alcoholic liver disease, probiotic intervention showed no significant effects on total bilirubin (MD=-0.01,95% CI:-0.17,0.15;P=0.91), tumor necrosis factor-α (MD=0.03,95% CI:-0.86,0.92;P=0.94) and interleukin-6 (MD=-5.3,95% CI:-16.04,5.45;P=0.33).

Conclusion

The meta-analysis indicates that probiotics can improve liver function in alcoholic liver disease, reduce inflammatory responses, regulate intestinal flora, which have potential value in the treatment of alcoholic liver disease.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023472527.

Red Rice Seed Coat Targeting SPHK2 Ameliorated Alcoholic Liver Disease via Restored Intestinal Barrier and Improved Gut Microbiota in Mice

Alcoholic liver disease (ALD), leading to the most common chronic liver diseases, is increasingly emerging as a global health problem, which is intensifying the need to develop novel treatments. Herein, our work aimed to estimate the therapeutic efficacy of red rice (Oryza sativa L.) seed coat on ALD and further uncover the underlying mechanisms. Red rice seed coat extract (RRA) was obtained with citric acid-ethanol and analyzed via a widely targeted components approach. The potential targets of RRA to ALD were predicted by bioinformatics analysis. Drunken behavior, histopathological examination, liver function, gut microbiota composition and intestinal barrier integrity were used to assess the effects of RRA (RRAH, 600 mg/kg·body weight; RRAL, 200 mg/kg·body weight) on ALD. Oxidative stress, inflammation, apoptosis associated factors and signaling pathways were measured by corresponding kits, Western blot and immunofluorescence staining. In ALD model mice, RRA treatment increased sphingosine kinase 2 (SPHK2) and sphingosine-1-phosphate (S1P) levels, improved gut microbiota composition, restored intestinal barrier, decreased lipopolysaccharide (LPS) levels in plasma and the liver, cut down Toll-like receptor 4 (TLR4)/Nuclear factor kappa B (NF-κB) pathways, alleviated liver pathological injury and oxidative stress, attenuated inflammation and apoptosis and enhanced liver function. To sum up, RRA targeting SPHK2 can ameliorate ALD by repairing intestinal barrier damage and reducing liver LPS level via the TLR4/NF-κB pathway and intestinal microbiota, revealing that red rice seed coat holds potential as a functional food for the prevention and treatment of ALD.