Bifidobacterium adolescentis CGMCC 15058 alleviates liver injury, enhances the intestinal barrier and modifies the gut microbiota in D-galactosamine-treated rats

Management of hepatic encephalopathy following transjugular intrahepatic portosystemic shunts: Current strategies and future directions

Transjugular intrahepatic portosystemic shunts (TIPSs) are generally used for the management of complications of portal hypertension in patients with decompensated cirrhosis. However, hepatic encephalopathy (HE), which impairs neuropsychiatric function and motor control, remains the primary adverse effect of TIPS, limiting its utility. Prompt prevention and treatment of post-TIPS HE are critical, as they are strongly associated with readmission rates and poor quality of life. This review focuses on the main pathophysiological mechanisms underlying post-TIPS HE, explores advanced biomarkers and predictive tools, and discusses current management strategies and future directions to prevent or reverse HE following TIPS. These strategies include preoperative patient assessment, individualized shunt diameter optimization, spontaneous portosystemic shunt embolization during the TIPS procedure, postoperative preventive and therapeutic measures such as nutrition management, medical therapy, fecal microbiota transplantation, and stent reduction.

Protective Effect of Enterococcus faecium Against Alcohol-Induced Acute Liver Injury Via Extracellular Vesicles in Rats

The beneficial effects of probiotics on alcohol-induced liver injury have been studied, but the mechanisms by which Enterococcus regulates liver function are still under investigation. In this study, we examined Enterococcus faecium (Efm) and E. faecium-derived extracellular vesicles (EfmEVs) to provide a protective effect against ethanol-induced liver injury in rats. We evaluated the impact of EfmEVs on liver histological lesions, antioxidative function, alanine aminotransferase (ALT), aspartate aminotransferase (AST) activities, and serum ALT, AST, blood alcohol concentration. The results demonstrated that pretreatment with Efm significantly ameliorated ethanol-induced liver injury. Efm pretreatment mitigated the decline in ethanol-induced liver antioxidant indicators (malondialdehyde, superoxide dismutase, and glutathione peroxidase. Additionally, Efm pretreatment significantly reduced ethanol-induced ALT activities in the liver and serum, potentially by lowering blood ethanol concentration. Further, functional studies on three bioactive components (inactivated Efm, EfmEVs, and EVs-free supernatants) from the bacterial culture revealed that EVs were primarily responsible for the liver-protective effect. Moreover, EVs secretion contributed to the overall liver-protective effect of Efm. In summary, EfmEVs mediated the protective effect of Efm against ethanol-induced liver injury, potentially by improving antioxidative function and lowering blood ethanol concentration. These findings suggest that EfmEVs could serve as a potential antioxidative strategy to alleviate alcohol-induced acute liver injury.

Supplementation with Akkermansia muciniphila improved intestinal barrier and immunity in zebrafish (Danio rerio)

Akkermansia muciniphila (Akk), a second-generation probiotic known for its ability to regulate intestinal function in mammals, is not yet fully understood in the context of aquaculture. This study aims to investigate the effects of different forms of Akk on intestinal barrier function and immune response in zebrafish (Danio rerio) under high-fat diet conditions. The experimental groups included a control group, a high-fat diet group, an Akk group, and a group receiving various concentrations of pasteurized Akkermansia muciniphila (P-Akk) along with a high-fat diet. Evaluation methods included histological examination with hematoxylin and eosin staining, ultrastructural analysis using transmission electron microscopy, real-time fluorescence quantitative analysis, and transcriptome sequencing technology. The results showed that both the Akk and P-Akk groups exhibited a significant increase in villi number and length compared to the high-fat group. Furthermore the expression levels of claudin, claudin-2, occludin A, occludin B, and other genes were significantly upregulated, while the expression levels of intestinal proinflammatory factors genes and proteins were significantly downregulated. Compared to the high-fat group, the Akk group showed a more complete and well-preserved nucleus, mitochondria, and tight junction structures. Additionally, the morphology of intestinal epithelial microvilli in the medium and high concentration Akk group was complete and dense. The expressions of tlr2 and nf-κb were upregulated, while the expressions of myd88 and nod2 were downregulated in the medium- and high-concentration Akk groups. Akk may improve immune dysfunction in high-fat fed zebrafish through the TLR2/NF-κB signaling pathway, which requires further study. Transcriptome analysis revealed significant upregulation of the immune-related gene pigr, significant downregulation of stat3, and significant upregulation of the intercellular adhesion molecule f11r. In conclusion, dietary Akk supplementation alleviated intestinal barrier damage and immune dysfunction in high-fat zebrafish. This study provides important insights into the potential use of Akk in fish and lays the foundation for further studies on its role in fish immunity.

Current progress on the microbial therapies for acute liver failure

Acute liver failure (ALF), associated with a clinical fatality rate exceeding 80%, is characterized by severe liver damage resulting from various factors in the absence of pre-existing liver disease. The role of microbiota in the progression of diverse liver diseases, including ALF, has been increasingly recognized, with the interactions between the microbiota and the host significantly influencing both disease onset and progression. Despite growing interest in the microbiological aspects of ALF, comprehensive reviews remain limited. This review critically examines the mechanisms and efficacy of microbiota-based treatments for ALF, focusing on their role in prevention, treatment, and prognosis over the past decade.

Bifidobacterium adolescentis-derived hypaphorine alleviates acetaminophen hepatotoxicity by promoting hepatic Cry1 expression

Acetaminophen (APAP)-induced liver injury (AILI) is a pressing public health concern. Although evidence suggests that Bifidobacterium adolescentis (B. adolescentis) can be used to treat liver disease, it is unclear if it can prevent AILI. In this report, we prove that B. adolescentis significantly attenuated AILI in mice, as demonstrated through biochemical analysis, histopathology, and enzyme-linked immunosorbent assays. Based on untargeted metabolomics and in vitro cultures, we found that B. adolescentis generates microbial metabolite hypaphorine. Functionally, hypaphorine inhibits the inflammatory response and hepatic oxidative stress to alleviate AILI in mice. Transcriptomic analysis indicates that Cry1 expression is increased in APAP-treated mice after hypaphorine treatment. Overexpression of Cry1 by its stabilizer KL001 effectively mitigates liver damage arising from oxidative stress in APAP-treated mice. Using the gene expression omnibus (GEO) database, we verified that Cry1 gene expression was also decreased in patients with APAP-induced acute liver failure. In conclusion, this study demonstrates that B. adolescentis inhibits APAP-induced liver injury by generating hypaphorine, which subsequently upregulates Cry1 to decrease inflammation and oxidative stress.

The Potential Mechanism of the Anti-Liver Fibrotic Effect of Curcumin in the Gut-Liver Axis

This study aimed to explore the curative effect of curcumin on liver fibrosis and its correlation with the gut-liver axis in animal models. Histological staining was utilized to conduct histological analysis of the liver and intestine. An automatic biochemical analyzer or enzyme-linked immunosorbent assay system was utilized for analyzing the biochemical indexes in mice. Western blotting was employed to examine the level of relevant proteins. Furthermore, 16S rRNA high-throughput sequencing was performed to explore the impact of curcumin on intestinal microorganisms in rats with liver fibrosis. Ultrahigh-performance liquid chromatography with quadrupole-orbitrap mass spectrometry was utilized to analyze the effect of curcumin on rat feces metabolites. Our results showed that curcumin reduced the formation of collagen fibers caused by carbon tetrachloride in a dose-dependent manner. In addition, curcumin was able to restore intestinal permeability in rats with liver fibrosis. By adopting α diversity analysis (Chao 1 index, Shannon index, and Simpson index), we observed that both the diversity and the abundance of intestinal flora in rats with liver fibrosis were increased. The principal component analysis diagram demonstrated that curcumin could enhance the abundance and diversity of intestinal flora, and also restore the composition of model rat flora, which was similar to that in normal rats, thereby correcting the imbalance of flora in rats with liver fibrosis. In addition, curcumin regulated feces metabolites and their signaling pathways, including glycerophospholipid metabolism, pantothenate and CoA biosynthesis. Our findings suggest that curcumin exhibits antiliver fibrosis effects, and its antiliver fibrosis effects might correlate with gut-liver axis.

Border Control: The Role of the Microbiome in Regulating Epithelial Barrier Function

The gut mucosal epithelium is one of the largest organs in the body and plays a critical role in regulating the crosstalk between the resident microbiome and the host. To this effect, the tight control of what is permitted through this barrier is of high importance. There should be restricted passage of harmful microorganisms and antigens while at the same time allowing the absorption of nutrients and water. An increased gut permeability, or "leaky gut", has been associated with a variety of diseases ranging from infections, metabolic diseases, and inflammatory and autoimmune diseases to neurological conditions. Several factors can affect gut permeability, including cytokines, dietary components, and the gut microbiome. Here, we discuss how the gut microbiome impacts the permeability of the gut epithelial barrier and how this can be harnessed for therapeutic purposes.

The oral administration of Lacticaseibacillus casei Shirota alleviates acetaminophen-induced liver injury through accelerated acetaminophen metabolism via the liver-gut axis in mice

Acetaminophen is a widely used antipyretic and analgesic drug, and its overdose is the leading cause of drug-induced acute liver failure. This study aimed to investigate the effect and mechanism of Lacticaseibacillus casei Shirota (LcS), an extensively used and highly studied probiotic, on acetaminophen-induced acute liver injury. C57BL/6 mice were gavaged with LcS suspension or saline once daily for 7 days before acute liver injury was induced via intraperitoneal injection of 300 mg/kg acetaminophen. The results showed that LcS significantly decreased acetaminophen-induced liver and ileum injury, as demonstrated by reductions in the increases in aspartate aminotransferase, total bile acids, total bilirubin, indirect bilirubin, and hepatic cell necrosis. Moreover, LcS alleviated acetaminophen-induced intestinal mucosal permeability, decreased serum IL-1α and lipopolysaccharide levels, and elevated serum eosinophil chemokine (eotaxin) and hepatic glutathione levels. Furthermore, analysis of the gut microbiota and metabolome showed that LcS reduced the acetaminophen-enriched levels of Cyanobacteria, Oxyphotobacteria, long-chain fatty acids, cholesterol, and sugars in the gut. Additionally, the transcriptomic and proteomic results showed that LcS mitigated the decrease in metabolic and immune pathways as well as glutathione formation during acetaminophen-induced acute liver injury. This is the first study showing that pretreatment with LcS alleviates acetaminophen-enriched acute liver injury, and it provides a reference for the application of LcS.IMPORTANCEAcetaminophen is the most frequently used antipyretic analgesic worldwide. As a result, overdoses easily occur and lead to drug-induced acute liver injury, which quickly progresses to liver failure with a mortality of 60%-80% if not corrected in time. The current emergency treatment for overused acetaminophen needs to be administered within 8 hours to avoid liver injury or even liver failure. Therefore, developing preventive strategies for liver injury during planned acetaminophen medication is particularly important, preferably nonpharmacological methods. Lacticaseibacillus casei Shirota (LcS) is a famous probiotic that has been used for many years. Our study found that LcS significantly alleviated acetaminophen-induced acute liver injury, especially acetaminophen-induced liver injury toward fulminant hepatic failure. Here, we elucidated the function and potential mechanisms of LcS in alleviating acetaminophen-induced acute liver injury, hoping it will provide preventive strategies to people during acetaminophen treatment.

Role of fecal microbiota transplant in management of hepatic encephalopathy: Current trends and future directions

Fecal microbiota transplantation (FMT) offers a potential treatment avenue for hepatic encephalopathy (HE) by leveraging beneficial bacterial displacement to restore a balanced gut microbiome. The prevalence of HE varies with liver disease severity and comorbidities. HE pathogenesis involves ammonia toxicity, gut-brain communication disruption, and inflammation. FMT aims to restore gut microbiota balance, addressing these factors. FMT's efficacy has been explored in various conditions, including HE. Studies suggest that FMT can modulate gut microbiota, reduce ammonia levels, and alleviate inflammation. FMT has shown promise in alcohol-associated, hepatitis B and C-associated, and non-alcoholic fatty liver disease. Benefits include improved liver function, cognitive function, and the slowing of disease progression. However, larger, controlled studies are needed to validate its effectiveness in these contexts. Studies have shown cognitive improvements through FMT, with potential benefits in cirrhotic patients. Notably, trials have demonstrated reduced serious adverse events and cognitive enhancements in FMT arms compared to the standard of care. Although evidence is promising, challenges remain: Limited patient numbers, varied dosages, administration routes, and donor profiles. Further large-scale, controlled trials are essential to establish standardized guidelines and ensure FMT's clinical applications and efficacy. While FMT holds potential for HE management, ongoing research is needed to address these challenges, optimize protocols, and expand its availability as a therapeutic option for diverse hepatic conditions.

Negative Lifestyle Factors Specific to Aging Persons Living with HIV and Multimorbidity

The primary goal of medical care during the pre-antiretroviral therapy (ART) era was to keep persons living with human immunodeficiency virus (HIV) alive, whereas since the advent of ART, the treatment objective has shifted to decreasing viral loads and infectiousness while increasing CD4+ T-cell counts and longevity. The health crisis, however, is in preventing and managing multimorbidity (ie, type 2 diabetes), which develops at a more accelerated or accentuated pace among aging persons living with HIV. Relative to the general population and age-matched uninfected adults, it may be more difficult for aging HIV-positive persons who also suffer from multimorbidity to improve negative lifestyle factors to the extent that their behaviors could support the prevention and management of diseases. With recommendations and a viable solution, this article explores the impact of negative lifestyle factors (ie, poor mental health, suboptimal nutrition, physical inactivity, alcohol use) on the health of aging individuals living with HIV.

Emerging role of the crosstalk between gut microbiota and liver metabolome of subterranean herbivores in response to toxic plants

Plant secondary metabolites (PSMs) are a defense mechanism against herbivores, which in turn use detoxification metabolism to process ingested and absorbed PSMs. The feeding environment can cause changes in liver metabolism patterns and the gut microbiota. Here, we compared gut microbiota and liver metabolome to investigate the response mechanism of plateau zokors (Eospalax baileyi) to toxic plant Stellera chamaejasme (SC) in non-SC and SC grassland (-SCG and +SCG). Our results indicated that exposure to SC in the -SCG population increased liver inflammatory markers including prostaglandin (PG) in the Arachidonic acid pathway, while exposure to SC in the +SCG population exhibited a significant downregulation of PGs. Secondary bile acids were significantly downregulated in +SCG plateau zokors after SC treatment. Of note, the microbial taxa Veillonella in the -SCG group was significantly correlated with liver inflammation markers, while Clostridium innocum in the +SCG group had a significant positive correlation with secondary bile acids. The increase in bile acids and PGs can lead to liver inflammatory reactions, suggesting that +SCG plateau zokors may mitigate the toxicity of SC plants by reducing liver inflammatory markers including PGs and secondary bile acids, thereby avoiding liver damage. This provides new insight into mechanisms of toxicity by PSMs and counter-mechanisms for toxin tolerance by herbivores.

Immunomodulatory functions of microorganisms in tissue regenerative healing

External pathogenic microorganisms and commensal microorganisms in the body have either harmful or beneficial impacts on the regenerative repair of tissues, and the immune system plays a crucial regulatory role in this process. This review summarises our current understanding of microorganism-immune system interactions, with a focus on how these interactions impact the renewal and repair ability of tissues, including skin, bone, gut, liver, and nerves. This review concludes with a discussion of the mechanisms by which microbes act on various types of immune cells to affect tissue regeneration, offers potential strategies for using microbial therapies to enhance the regenerative repair function of tissues, and suggest novel therapeutic approaches for regenerative medicine. STATEMENT OF SIGNIFICANCE: Microbiological communities have crucial impacts on human health and illness by participating in energy collection and storage and performing various metabolic processes. External pathogenic microorganisms and commensal microorganisms in the body have either harmful or beneficial impacts on the regenerative repair of tissues, and the immune system plays a critical regulatory role in this process. This study reviews the important correlation between microorganisms and the immune system and investigates the mechanism of various microorganism that participate in the regeneration and repair of tissues and organs by modulating immune system.

Prenatal Lead Exposure Is Associated with Reduced Abundance of Beneficial Gut Microbial Cliques in Late Childhood: An Investigation Using Microbial Co-Occurrence Analysis (MiCA)

Many analytical methods used in gut microbiome research focus on either single bacterial taxa or the whole microbiome, ignoring multibacteria relationships (microbial cliques). We present a novel analytical approach to identify microbial cliques within the gut microbiome of children at 9-11 years associated with prenatal lead (Pb) exposure. Data came from a subset of participants (n = 123) in the Programming Research in Obesity, Growth, Environment and Social Stressors cohort. Pb concentrations were measured in maternal whole blood from the second and third trimesters of pregnancy. Stool samples collected at 9-11 years old underwent metagenomic sequencing to assess the gut microbiome. Using a novel analytical approach, Microbial Co-occurrence Analysis (MiCA), we paired a machine learning algorithm with randomization-based inference to first identify microbial cliques that were predictive of prenatal Pb exposure and then estimate the association between prenatal Pb exposure and microbial clique abundance. With second-trimester Pb exposure, we identified a two-taxa microbial clique that included Bifidobacterium adolescentis and Ruminococcus callidus and a three-taxa clique that also included Prevotella clara. Increasing second-trimester Pb exposure was associated with significantly increased odds of having the two-taxa microbial clique below the median relative abundance (odds ratio (OR) = 1.03, 95% confidence interval (CI) [1.01-1.05]). Using a novel combination of machine learning and causal inference, MiCA identified a significant association between second-trimester Pb exposure and the reduced abundance of a probiotic microbial clique within the gut microbiome in late childhood.

Gut microbiota modulate distal symmetric polyneuropathy in patients with diabetes

The pathogenic mechanisms underlying distal symmetric polyneuropathy (DSPN), a common neuropathy in patients with diabetes mellitus (DM), are not fully understood. Here, we discover that the gut microbiota from patients with DSPN can induce a phenotype exhibiting more severe peripheral neuropathy in db/db mice. In a randomized, double-blind, and placebo-controlled trial (ChiCTR1800017257), compared to 10 patients who received placebo, DSPN was significantly alleviated in the 22 patients who received fecal microbiota transplants from healthy donors, independent of glycemic control. The gut bacterial genomes that correlated with the Toronto Clinical Scoring System (TCSS) score were organized in two competing guilds. Increased guild 1, which had higher capacity in butyrate production, and decreased guild 2, which harbored more genes in synthetic pathway of endotoxin, were associated with improved gut barrier integrity and decreased proinflammatory cytokine levels. Moreover, matched enterotype between transplants and recipients showed better therapeutic efficacy with more enriched guild 1 and suppressed guild 2. Thus, changes in these two competing guilds may play a causative role in DSPN and have the potential for therapeutic targeting.

Prenatal Pb exposure is associated with reduced abundance of beneficial gut microbial cliques in late childhood: an investigation using Microbial Co-occurrence Analysis (MiCA)

Background

Many analytical methods used in gut microbiome research focus on either single bacterial taxa or the whole microbiome, ignoring multi-bacteria relationships (microbial cliques). We present a novel analytical approach to identify multiple bacterial taxa within the gut microbiome of children at 9-11 years associated with prenatal Pb exposure.

Methods

Data came from a subset of participants (n=123) in the Programming Research in Obesity, Growth, Environment and Social Stressors (PROGRESS) cohort. Pb concentrations were measured in maternal whole blood from the second and third trimesters of pregnancy. Stool samples collected at 9-11 years old underwent metagenomic sequencing to assess the gut microbiome. Using a novel analytical approach, Microbial Co-occurrence Analysis (MiCA), we paired a machine-learning algorithm with randomization-based inference to first identify microbial cliques that were predictive of prenatal Pb exposure and then estimate the association between prenatal Pb exposure and microbial clique abundance.

Results

With second-trimester Pb exposure, we identified a 2-taxa microbial clique that included Bifidobacterium adolescentis and Ruminococcus callidus, and a 3-taxa clique that added Prevotella clara. Increasing second-trimester Pb exposure was associated with significantly increased odds of having the 2-taxa microbial clique below the 50th percentile relative abundance (OR=1.03,95%CI[1.01-1.05]). In an analysis of Pb concentration at or above vs. below the United States and Mexico guidelines for child Pb exposure, odds of the 2-taxa clique in low abundance were 3.36(95%CI[1.32-8.51]) and 6.11(95%CI[1.87-19.93]), respectively. Trends were similar with the 3-taxa clique but not statistically significant.

Discussion

Using a novel combination of machine-learning and causal-inference, MiCA identified a significant association between second-trimester Pb exposure and reduced abundance of a probiotic microbial clique within the gut microbiome in late childhood. Pb exposure levels at the guidelines for child Pb poisoning in the United States, and Mexico are not sufficient to protect against the potential loss of probiotic benefits.

Gut Dysbiosis and Blood-Brain Barrier Alteration in Hepatic Encephalopathy: From Gut to Brain

A common neuropsychiatric complication of advanced liver disease, hepatic encephalopathy (HE), impacts the quality of life and length of hospital stays. There is new evidence that gut microbiota plays a significant role in brain development and cerebral homeostasis. Microbiota metabolites are providing a new avenue of therapeutic options for several neurological-related disorders. For instance, the gut microbiota composition and blood-brain barrier (BBB) integrity are altered in HE in a variety of clinical and experimental studies. Furthermore, probiotics, prebiotics, antibiotics, and fecal microbiota transplantation have been shown to positively affect BBB integrity in disease models that are potentially extendable to HE by targeting gut microbiota. However, the mechanisms that underlie microbiota dysbiosis and its effects on the BBB are still unclear in HE. To this end, the aim of this review was to summarize the clinical and experimental evidence of gut dysbiosis and BBB disruption in HE and a possible mechanism.

Gut microbiota affects sensitivity to immune-mediated isoniazid-induced liver injury

Isoniazid (INH) is a highly effective single and/or combined first-line anti-tuberculosis (anti-TB) therapy drug, and the hepatotoxicity greatly limits its clinical application. INH-induced liver injury (INH-DILI) is a typical immune-mediated idiosyncratic drug-induced liver injury. Existing mechanisms including genetic variations in drug metabolism and immune responses cannot fully explain the differences in susceptibility and sensitivity to INH-DILI, suggesting that other factors may be involved. Accumulating evidence indicates that the development and severity of immune-mediated liver injury is related to gut microbiota. In this study, INH exposure caused liver damage, immune disregulation and microbiota profile alteration. Depletion of gut microbiota ameliorated INH-DILI, and improved INH-DILI-associated immune disorder and inflammatory response. Moreover, hepatotoxicity of INH was ameliorated by fecal microbiota transplantation (FMT) from INH-treated mice. Notably, Bifidobacterium abundance was significantly associated with transaminase levels. In conclusion, our results suggested that the effect of gut microbiota on INH-DILI was related to immunity, and the difference in INH-DILI sensitivity was related to the structure of gut microbiota. Changes in the structure of gut microbiota by continuous exposure of INH resulted in the tolerance to liver injury, and probiotics such as Bifidobacterium might play an important role in INH-DILI and its "adaptation" phenomenon. This work provides novel evidence for elucidating the underlying mechanism of difference in individual's response to INH-DILI and potential approach for intervening anti-TB drug liver injury by modulating gut microbiota.

Gut microbiome therapeutic modulation to alleviate drug-induced hepatic damage in COVID-19 patients

Coronavirus disease 2019 (COVID-19) infection caused by the severe acute respiratory syndrome coronavirus 2 virus, its symptoms, treatment, and post-COVID-19 effects have been a major focus of research since 2020. In addition to respiratory symptoms, different clinical variants of the virus have been associated with dynamic symptoms and multiorgan diseases, including liver abnormalities. The release of cytokines by the activation of innate immune cells during viral infection and the high doses of drugs used for COVID-19 treatment are considered major drivers of liver injury in COVID-19 patients. The degree of hepatic inflammation in patients suffering from chronic liver disease and having COVID-19 could be severe and can be estimated through different liver chemistry abnormality markers. Gut microbiota influences liver chemistry through its metabolites. Gut dysbiosis during COVID-19 treatment can promote liver inflammation. Here, we highlighted the bidirectional association of liver physiology and gut microbiota (gut-liver axis) and its potential to manipulate drug-induced chemical abnormalities in the livers of COVID-19 patients.

Systemic inflammatory regulators and risk of acute-on-chronic liver failure: A bidirectional mendelian-randomization study

Inflammation plays a role in the pathogenesis of acute-on-chronic liver failure (ACLF), however, whether there is a causal relationship between inflammation and ACLF remains unclear. A two-sample Mendelian randomization (MR) approach was used to investigate the causal relationship between systemic inflammatory regulators and ACLF. The study analyzed 41 cytokines and growth factors from 8,293 individuals extracted from a genome-wide association study (GWAS) meta-analysis database involving 253 ACLF cases and 456,095 controls. Our results showed that lower stem cell factor (SCF) levels, lower basic fibroblast growth factor (bFGF) levels and higher Interleukin-13 (IL-13) levels were associated with an increased risk of ACLF (OR = 0.486, 95% CI = 0.264-0.892, p = 0.020; OR = 0.323, 95% CI = 0.107-0.972, p = 0.044; OR = 1.492, 95% CI = 1.111-2.004, p = 0.008, respectively). In addition, genetically predicted ACLF did not affect the expression of systemic inflammatory regulators. Our results indicate that cytokines play a crucial role in the pathogenesis of ACLF. Further studies are needed to determine whether these biomarkers can be used to prevent and treat ACLF.

Lactobacillus acidophilus (LA) Fermenting Astragalus Polysaccharides (APS) Improves Calcium Absorption and Osteoporosis by Altering Gut Microbiota

Lactobacillus acidophilus (LA) and Astragalus polysaccharides (APS) have each been shown to have anti-osteoporotic activity, and the aim of this study was to further investigate whether the LA fermenting APS was more effective in improving calcium absorption and osteoporosis than the unfermented mixed solution (MS). We found that the fermentation solution (FS) intervention improved the calcium absorption, BMD, and bone microarchitecture in osteoporotic rats and resulted in better inhibition of osteoclast differentiation markers ACP-5 and pro-inflammatory cytokines TNF-α and IL-6 and promotion of osteoblast differentiation marker OCN. This better performance may be due to the improved restoration of the relative abundance of specific bacteria associated with improved calcium absorption and osteoporosis such as Lactobacillus, Allobaculum, and UCG-005. Several key metabolites, including indicaxanthin, chlorogenic acid, and 3-hydroxymelatonin, may also be the key to the better improvement. In conclusion, the LA fermenting APS can better improve calcium absorption and osteoporosis by increasing active metabolites and altering gut microbiota. This finding should become a solid foundation for the development of LA fermenting APS in functional foods.

Amelioration of alcohol-induced acute liver injury in C57BL/6 mice by a mixture of TCM phytochemicals and probiotics with antioxidative and anti-inflammatory effects

Background

There are many causes of acute liver injury (ALI), such as alcohol, drugs, infection, and toxic materials, which have caused major health problems around the world. Among these causes, alcohol consumption induced liver injury is a common alcoholic liver disease, which can further lead to liver failure even liver cancer. A number of traditional Chinese medicine (TCM) and TCM derived compounds have been used in treating the liver-associated diseases and combination use of probiotics with TCM phytochemicals has attracted interests for enhanced biological effects.

Methods

This study investigated the hepatoprotective effect of TCM-probiotics complex (TCMPC) and its underlying mechanism for the treatment of ALI in mice. The TCMPC is composed of TCM phytochemicals puerarin, curcumin, ginsenosides, and 5 lactobacteria strains. We first established a mouse model of alcohol-induced ALI, then the therapeutic effects of TCMPC on alcohol-induced ALI were monitored. A series of measurements have been performed on antioxidation, anti-inflammation, and lipid metabolism regulation.

Results

The results showed that TCMPC can reduce the level of liver injury biomarkers and regulate oxidative stress. Histopathological results indicated that TCMPC could ameliorate ALI in mice. In addition, it can also significantly reduce the production of inflammatory cytokines caused by ALI.

Conclusion

Our research has proved the therapeutic effect of TCMPC on alcohol-induced ALI. The potential mechanism of hepatoprotective effects of TCMPC may be related to its antioxidative and anti-inflammatory effects. Our research might provide a new way for liver disease treatment.

Lactobacillus gasseri JM1 Isolated from Infant Feces Alleviates Colitis in Mice via Protecting the Intestinal Barrier

Ulcerative colitis (UC) is a chronic and recurrent inflammatory bowel disease, and the intestinal barrier is an important line of defense against intestinal disease. Herein, we investigated the effect of Lactobacillus gasseri JM1 at different doses (1 × 10⁶, 1 × 10⁷, 1 × 10⁸ CFU/day) on colitis mice and explored the possible mechanism. The results showed that L. gasseri JM1 alleviated DSS-induced colitis in mice, with reductions in disease activity index (DAI), histological scores and myeloperoxidase activity as well as alleviation of colonic shortening. Furthermore, L. gasseri JM1 regulated the levels of inflammatory cytokines TNF-α, IL-6, IL-1β, and IL-10; restored the expression of Claudin-3, Occludin, ZO-1, and MUC2; and increased the number of goblet cells and acidic mucin. The 16S rDNA sequencing results indicated that intervention with L. gasseri JM1 balanced the gut microbiota structure by elevating the abundance of beneficial bacteria (Oscillospira, Clostridium and Ruminococcus) and decreasing that of harmful bacteria (Shigella and Turicibacter). Meanwhile, the contents of short-chain fatty acids (SCFAs) increased. In conclusion, L. gasseri JM1 could alleviate intestinal barrier damage in colitis mice by modulating the tight junction structures, intestinal mucus layer, inflammatory cytokines, gut microbiota, and SCFAs. It can be considered a potential preventive strategy to alleviate colitis injury.

Cyanidin Alleviated CCl4-Induced Acute Liver Injury by Regulating the Nrf2 and NF-κB Signaling Pathways

Acute liver injury has multiple causes and can result in liver failure. In this study, we evaluated the hepatoprotective ability of cyanidin (Cy) and investigated its associated mechanisms. Cy administration significantly and dose-dependently ameliorated acute liver injury induced by carbon tetrachloride (CCl₄). High-dose Cy showed effects comparable to those achieved by the positive control (silymarin). Severe oxidative stress and inflammatory responses in the liver tissue induced by CCl₄ were significantly mitigated by Cy supplementation. The total antioxidant capacity and the activity of superoxide dismutase, catalase, and glutathione peroxidase were increased and the content of malondialdehyde, lipid peroxide, tumor necrosis factor α, interleukin-1β, and interleukin-6 were decreased. Additionally, the Nrf2 and NF-κB signaling pathways, which regulate antioxidative and inflammatory responses, were analyzed using quantitative real-time polymerase chain reaction and western blot assay. Cy treatment not only increased Nrf2 transcription and expression but also decreased NF-κB signaling. Moreover, molecular docking simulation indicated that Cy had high affinity for Keap1 and NF-κB/p65, which may promote nuclear translocation of Nrf2 and inhibit that of NF-κB. In summary, Cy treatment exerted antioxidative and anti-inflammatory effects and ameliorated liver injury by increasing Nrf2 and inhibiting the NF-κB pathway, demonstrating the potential of Cy as a therapeutic agent in liver injury.

Nutritional Support in Acute Liver Failure

Acute liver failure (ALF) presents with an acute abnormality of liver blood tests in an individual without underlying chronic liver disease. The clinical course leads to the development of coagulopathy and hepatic encephalopathy. The role of nutrition in its prevention and treatment remains uncertain. We aimed to review literature data on the concept of ALF and the role of nutrition in its treatment and prevention, considering the impact of gut microbiota dysbiosis and eubiosis. We conducted a review of the literature on the main medical databases using the following keywords and acronyms and their associations: liver failure, nutrition, branched-chain amino acids, gut microbiota, dysbiosis, and probiotics. Upon their arrival at the emergency department, an early, accurate nutritional assessment is crucial for individuals with ALF. Branched-chain amino acids (BCAAs), stable euglycemia maintenance, and moderate caloric support are crucial for this subset of patients. An excessive protein load must be avoided because it worsens hepatic encephalopathy. Preclinical evidence supports future probiotics use for ALF treatment/prevention. Nutritional support and treatment for ALF are crucial steps against patient morbidity and mortality. BCAAs and euglycemia remain the mainstay of nutritional treatment of ALF. Gut dysbiosis re-modulation has an emerging and natural-history changing impact on ALF.

Prospects of Probiotic Adjuvant Drugs in Clinical Treatment

In modern society, where new diseases and viruses are constantly emerging, drugs are still the most important means of resistance. However, adverse effects and diminished efficacy remain the leading cause of treatment failure and a major determinant of impaired health-related quality of life for patients. Clinical studies have shown that the disturbance of the gut microbial structure plays a crucial role in the toxic and side effects of drugs. It is well known that probiotics have the ability to maintain the balance of intestinal microecology, which implies their potential as an adjunct to prevent and alleviate the adverse reactions of drugs and to make medicines play a better role. In addition, in the past decade, probiotics have been found to have excellent prevention and alleviation effects in drug toxicity side effects, such as liver injury. In this review, we summarize the development history of probiotics, discuss the impact on drug side effects of probiotics, and propose the underlying mechanisms. Probiotics will be a new star in the world of complementary medicine.

Fecal microbiota transplant improves cognition in hepatic encephalopathy and its effect varies by donor and recipient

Early data suggest fecal microbiota transplant (FMT) may treat hepatic encephalopathy (HE). Optimal FMT donor and recipient characteristics are unknown. We assessed the safety and efficacy of FMT in patients with prior overt HE, comparing five FMT donors. We performed an open-label study of FMT capsules, administered 5 times over 3 weeks. Primary outcomes were change in psychometric HE score (PHES) and serious adverse events (SAEs). Serial stool samples underwent shallow shotgun metagenomic sequencing. Ten patients completed FMT administration and 6-month follow-up. Model for End-Stage Liver Disease (MELD) score did not change after FMT (14 versus 14, p = 0.51). Thirteen minor adverse events and three serious adverse events (two unrelated to FMT) were reported. One SAE was extended-spectrum beta-lactamase Escherichia coli bacteremia. The PHES improved after three doses of FMT (+2.1, p < 0.05), after five doses of FMT (+2.9, p = 0.007), and 4 weeks after the fifth dose of FMT (+3.1, p = 0.02). Mean change in the PHES ranged from -1 to +6 by donor. Two taxa were identified by random forest analysis and confirmed by linear regression to predict the PHES- Bifidobacterium adolescentis (adjusted R² = 0.27) and B. angulatum (adjusted R² = 0.25)-both short-chain fatty acid (SCFA) producers. Patients who responded to FMT had higher levels of Bifidobacterium as well as other known beneficial taxa at baseline and throughout the study. The FMT donor with poorest cognitive outcomes in recipients had the lowest fecal SCFA levels. Conclusion: FMT capsules improved cognition in HE, with an effect varying by donor and recipient factors (NCT03420482).

Effect and Mechanism of Bifidobacterium animalis B94 in the Prevention and Treatment of Liver Injury in Rats

Objective

To investigate the effect of Bifidobacterium animalis B94 on the prevention and treatment of liver injury in rats and to elucidate the underlying mechanism of this relationship.

Methods

Specific pathogen-free (SPF) rats were selected as the healthy control group, liver injury group and B94 treatment group, with 6 rats in each group. After the model was established, the experimental animals were tested for serum liver function indicators, gut microbiota composition, metabolite composition, and histopathology.

Results

The albumin/globulin ratio and serum TBA, alanine aminotransferase, aspartate aminotransferase, and indirect bilirubin levels in the B94 treatment group were significantly lower than those in the liver injury group. 16S rRNA analysis showed that the gut microbiota of the three groups of rats were significantly different. Metabolic profile analysis showed that there were significant differences in the gut metabolomes of the three groups. Haematoxylin–eosin staining of the intestinal mucosa and liver tissues showed that the degree of liver and intestinal tissue damage in the B94 treatment group was significantly lower than that in the liver injury group.

Conclusion

Bifidobacterium animalis B94 can affect the process of liver injury in rats by improving liver function, reducing intestinal damage, and regulating gut microbiota and metabolite production.

Characterising the Intestinal Bacterial and Fungal Microbiome Associated With Different Cytokine Profiles in Two Bifidobacterium strains Pre-Treated Rats With D-Galactosamine-Induced Liver Injury

Multiple probiotics have protective effects against different types of liver injury. Different intestinal microbes could be beneficial to the protective effects of the probiotics on the treated cohorts in different aspects. The current study was designed to determine the intestinal bacterial and fungal microbiome associated with different cytokine profiles in the Bifidobacterium pseudocatenulatum LI09 and Bifidobacterium catenulatum LI10 pretreated rats with D-galactosamine-induced liver injury. In this study, partition around medoids clustering analysis determined two distinct cytokine profiles (i.e., CP1 and CP2) comprising the same 11 cytokines but with different levels among the LI09, LI10, positive control (PC), and negative control (NC) cohorts. All rats in PC and NC cohorts were determined with CP1 and CP2, respectively, while the rats with CP1 in LI09 and LI10 cohorts had more severe liver injury than those with CP2, suggesting that CP2 represented better immune status and was the “better cytokine profile” in this study. PERMANOVA analyses showed that the compositions of both bacterial and fungal microbiome were different in the LI10 cohorts with different cytokine profiles, while the same compositions were similar between LI09 cohorts with different cytokine profiles. The phylotype abundances of both bacteria and fungi were different in the rats with different cytokine profiles in LI09 or LI10 cohorts according to similarity percentage (SIMPER) analyses results. At the composition level, multiple microbes were associated with different cytokine profiles in LI09 or LI10 cohorts, among which Flavonifractor and Penicillium were the bacterium and fungus most associated with LI09 cohort with CP2, while Parabacteroides and Aspergillus were the bacterium and fungus most associated with LI10 cohort with CP2. These microbes were determined to influence the cytokine profiles of the corresponding cohorts. At the structure level, Corynebacterium and Cephalotrichiella were determined as the two most powerful gatekeepers in the microbiome networks of LI09 cohort CP2, while Pseudoflavonifractor was the most powerful gatekeeper in LI10 cohort with CP2. These identified intestinal microbes were likely to be beneficial to the effect of probiotic Bifidobacterium on the immunity improvement of the treated cohorts, and they could be potential microbial biomarkers assisting with the evaluation of immune status of probiotics-treated cohorts.

The Gut-Liver Axis in Health and Disease: The Role of Gut Microbiota-Derived Signals in Liver Injury and Regeneration

Diverse liver diseases undergo a similar pathophysiological process in which liver regeneration follows a liver injury. Given the important role of the gut-liver axis in health and diseases, the role of gut microbiota-derived signals in liver injury and regeneration has attracted much attention. It has been observed that the composition of gut microbiota dynamically changes in the process of liver regeneration after partial hepatectomy, and gut microbiota modulation by antibiotics or probiotics affects both liver injury and regeneration. Mechanically, through the portal vein, the liver is constantly exposed to gut microbial components and metabolites, which have immense effects on the immunity and metabolism of the host. Emerging data demonstrate that gut-derived lipopolysaccharide, gut microbiota-associated bile acids, and other bacterial metabolites, such as short-chain fatty acids and tryptophan metabolites, may play multifaceted roles in liver injury and regeneration. In this perspective, we provide an overview of the possible molecular mechanisms by which gut microbiota-derived signals modulate liver injury and regeneration, highlighting the potential roles of gut microbiota in the development of gut microbiota-based therapies to alleviate liver injury and promote liver regeneration.

The synergy of dietary supplements Lactobacillus salivarius LI01 and Bifidobacterium longum TC01 in alleviating liver failure in rats treated with D-galactosamine

Lactobacillus salivarius (L. salivarius) has been widely used in dietary supplements and clinical treatments. Previous studies demonstrated the protective effect of L. salivarius LI01 on liver injury induced by D-galactosamine (D-GaIN) in rats. Accumulating evidence indicates that Lactobacillus and Bifidobacterium are highly coordinated; so in this study, we focus on the synergistic effect of L. salivarius LI01 and B. longum TC01 on the alleviation of liver injury caused by D-GaIN in rats and aim to find out the underlying interaction between the two strains. We observed reduced hepatic damage in the D-GaIN-treated rats with probiotic pre-administration, characterized by lower levels of AST and ALT (p < 0.05) and decreased HAI (Histological Activity Index) scores. Moreover, cotreatment with LI01 and TC01 more effectively decreases proinflammatory cytokines TNF-α, MCP-1 and M-CSF (p < 0.05) so as to inhibit systemic inflammation. Gut barrier dysfunction was ameliorated with compound probiotic pretreatment, as evidenced by the ultrastructure integrity, decreased histological score and elevated TJP-1 expression. What's more, supplementation with LI01 and TC01 markedly alleviates gut dysbiosis in the G-DaIN-treated rats, with enrichment of short chain fatty acid (SCFA) producers Faecalibaculum and Eubacterium_xylanophilum_group, a decreased Firmicutes/Bacteroidetes (F/B) ratio and depletion of proinflammatory microbes, such as Peptococcaeae and Ruminococcaceae_UCG-005. This study highlights the synergistic effect of dietary supplements LI01 and TC01 on the protection against liver failure, which is probably via altering gut microbiota.

Effectiveness of Probiotics and Prebiotics Against Acute Liver Injury: A Meta-Analysis

Background and Aims: Acute liver injury (ALI) is a clinical syndrome characterized by rapid loss of liver function, which may progress to life-threatening liver failure. We conducted this meta-analysis to examine the evidence on the effects of probiotics or prebiotics on ALI.

Methods and Results: Several databases, including PubMed, EMBASE, and Cochrane Library, were scrutinized from the inception through February 2021 by combining key search terms, yielding 26 eligible studies, which concluded that modulation of gut microbiota significantly decreased aspartate transaminase [standardized mean difference (SMD): −1.51, 95% confidence interval (CI): −2.03 to −1.00], alanine aminotransferase (SMD: −1.42, 95% CI: −1.85 to −0.98), and bilirubin (SMD: −0.91, 95% CI: −1.33 to −0.49). In addition, administration of probiotics or prebiotics also promoted proliferation of Bifidobacterium (SMD: 1.21, 95% CI: −0.18 to 2.60) and inhibited Enterococcus (SMD: −1.00, 95% CI: −1.39 to −0.61), contributing to lower levels of endotoxin (SMD: −2.14, 95% CI: −2.91 to −1.37). Tight junction protein ZO-1 (SMD: 1.95, 95% CI: 0.14 to 3.76) was upregulated after intervention, thereby reducing bacterial translocation to the liver [odds ratio (OR) = 0.23, 95% CI: 0.13–0.44] and mesenteric lymph node (OR = 0.14, 95% CI: 0.08 to 0.26), with decreased tumor necrosis factor-α (SMD: −2.84, 95% CI: −3.76 to −1.93) and interleukin-6 (SMD: −2.62, 95% CI: −4.14 to −1.10). Oxidative stress was also relieved by reducing malondialdehyde (SMD: −1.83, 95% CI: −2.55 to −1.10) while elevating superoxide dismutase (SMD: 1.78, 95% CI: 1.00–2.55) and glutathione (SMD: 1.83, 95% CI: 0.76–2.91).

Conclusion: Our findings suggest that probiotics and prebiotics could be a promising therapeutic strategy in ALI and possess a potential for clinical applications.

Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=255888, CRD42021255888.

Lactobacillus acidophilus LA14 Alleviates Liver Injury

Although the probiotic Lactobacillus acidophilus LA14 is used worldwide, its effect on liver diseases remains unelucidated. Here, 32 rats were divided into four groups, gavaged with L. acidophilus LA14 (3 × 10⁹ CFU) or phosphate-buffered saline for 7 days, and then intraperitoneally injected with d-galactosamine or saline. After 24 h, blood, liver, ileum, and feces samples were collected for liver injury, inflammation, intestinal barrier, gut microbiota, metabolome, and transcriptome analyses. Pretreatment with L. acidophilus LA14 alleviated the d-galactosamine-induced elevation of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and bile acids; mitigated the histological injury to the liver and gut; and suppressed the inflammatory cytokines macrophage inflammatory protein 1α (MIP-1α), MIP-3α, and MCP-1. L. acidophilus LA14 also ameliorated the d-galactosamine-induced dysbiosis of the gut microbiota and metabolism, such as the enrichment of Bacteroides sp. strain dnLKV3 and the depletion of Streptococcus, butanoic acid, and N-acetyl-d-glucosamine. The underlying mechanism of L. acidophilus LA14 included prevention of not only the d-galactosamine-induced upregulation of infection- and tumor-related pathways but also the d-galactosamine-induced downregulation of antioxidation-related pathways during this process, as reflected by the liver transcriptome and proteome analyses. Furthermore, the administration of L. acidophilus LA14 to healthy rats did not alter the tested liver indicators but significantly enriched the beneficial Lactobacillus and Bifidobacterium species, promoted metabolism and regulated pathways to improve immunity. The ability of L. acidophilus LA14 to alleviate liver injury was further confirmed with an acetaminophen-induced mouse model. These results might provide a reference for future studies on the application of L. acidophilus LA14 for the prevention of liver injury.

IMPORTANCE The probiotic Lactobacillus acidophilus LA14 is widely used, but its effect on liver diseases has not been elucidated. We explored the protective effect of L. acidophilus LA14 on the liver using rats with d-galactosamine-induced liver injury. Pretreatment with L. acidophilus LA14 alleviated the d-galactosamine-induced elevation of serum ALT, AST, ALP, and bile acids, mitigated the histological injury to the liver and gut, and suppressed the inflammatory cytokines MIP-1α, MIP-3α, and MCP-1. These effects were correlated with the modulations of the gut microbiome, metabolome, and hepatic gene expression induced by L. acidophilus LA14. Moreover, the ability of L. acidophilus LA14 to alleviate liver injury was further confirmed with an acetaminophen-induced mouse model. These results might provide a reference for future studies on the application of L. acidophilus LA14 for the prevention of liver injury.

Gut Microbiota and Chemical-Induced Acute Liver Injury

Background: Drug overdose or chemical exposures are the main causes of acute liver injury (ALI). Severe liver injury can develop into liver failure that is an important cause of liver-related mortality in intensive care units in most countries. Pharmacological studies have utilized a variety of comprehensive chemical induction models that recapitulate the natural pathogenesis of acute liver injury. Their mechanism is always based on redox imbalance-induced direct hepatotoxicity and massive hepatocyte cell death, which can trigger immune cell activation and recruitment to the liver. However, the pathogenesis of these models has not been fully stated. Many studies showed that gut microbiota plays a crucial role in chemical-induced liver injury. Hepatotoxicity is likely induced by imbalanced microbiota homeostasis, gut mucosal barrier damage, systemic immune activation, microbial-associated molecular patterns, and bacterial metabolites. Meanwhile, many preclinical studies have shown that supplementation with probiotics can improve chemical-induced liver injury. In this review, we highlight the pathogenesis of gut microorganisms in chemical-induced acute liver injury animal models and explore the protective mechanism of exogenous microbial supplements on acute liver injury.

Systems Analysis of Gut Microbiome Influence on Metabolic Disease in HIV-Positive and High-Risk Populations

Poor metabolic health, characterized by insulin resistance and dyslipidemia, is higher in people living with HIV and has been linked with inflammation, antiretroviral therapy (ART) drugs, and ART-associated lipodystrophy (LD). Metabolic disease is associated with gut microbiome composition outside the context of HIV but has not been deeply explored in HIV infection or in high-risk men who have sex with men (HR-MSM), who have a highly altered gut microbiome composition. Furthermore, the contribution of increased bacterial translocation and associated systemic inflammation that has been described in HIV-positive and HR-MSM individuals has not been explored. We used a multiomic approach to explore relationships between impaired metabolic health, defined using fasting blood markers, gut microbes, immune phenotypes, and diet. Our cohort included ART-treated HIV-positive MSM with or without LD, untreated HIV-positive MSM, and HR-MSM. For HIV-positive MSM on ART, we further explored associations with the plasma metabolome. We found that elevated plasma lipopolysaccharide binding protein (LBP) was the most important predictor of impaired metabolic health and network analysis showed that LBP formed a hub joining correlated microbial and immune predictors of metabolic disease. Taken together, our results suggest the role of inflammatory processes linked with bacterial translocation and interaction with the gut microbiome in metabolic disease among HIV-positive and -negative MSM.IMPORTANCE The gut microbiome in people living with HIV (PLWH) is of interest since chronic infection often results in long-term comorbidities. Metabolic disease is prevalent in PLWH even in well-controlled infection and has been linked with the gut microbiome in previous studies, but little attention has been given to PLWH. Furthermore, integrated analyses that consider gut microbiome, together with diet, systemic immune activation, metabolites, and demographics, have been lacking. In a systems-level analysis of predictors of metabolic disease in PLWH and men who are at high risk of acquiring HIV, we found that increased lipopolysaccharide-binding protein, an inflammatory marker indicative of compromised intestinal barrier function, was associated with worse metabolic health. We also found impaired metabolic health associated with specific dietary components, gut microbes, and host and microbial metabolites. This study lays the framework for mechanistic studies aimed at targeting the microbiome to prevent or treat metabolic endotoxemia in HIV-infected individuals.

Polychlorinated biphenyls altered gut microbiome in CAR and PXR knockout mice exhibiting toxicant-associated steatohepatitis

Polychlorinated biphenyls (PCBs) are persistent organic pollutants associated with non-alcoholic fatty liver disease (NAFLD). Previously, we demonstrated that the PCB mixture, Aroclor1260, exacerbated NAFLD, reflective of toxicant-associated steatohepatitis, in diet-induced obese mice, in part through pregnane-xenobiotic receptor (PXR) and constitutive androstane receptor (CAR) activation. Recent studies have also reported PCB-induced changes in the gut microbiome that consequently impact NAFLD. Therefore, the objective of this study is to examine PCB effects on the gut-liver axis and characterize the role of CAR and PXR in microbiome alterations. C57Bl/6 (wildtype, WT), CAR and PXR knockout mice were fed a high fat diet and exposed to Aroclor1260 (20 mg/kg, oral gavage, 12 weeks). Metagenomics analysis of cecal samples revealed that CAR and/or PXR ablation increased bacterial alpha diversity regardless of exposure status. CAR and PXR ablation also increased bacterial composition (beta diversity) versus WT; Aroclor1260 altered beta diversity only in WT and CAR knockouts. Distinct changes in bacterial abundance at different taxonomic levels were observed between WT and knockout groups; however Aroclor1260 had modest effects on bacterial abundance within each genotype. Notably, both knockout groups displayed increased Actinobacteria and Verrucomicrobia abundance. In spite of improved bacterial diversity, the knockout groups however failed to show protection from PCB-induced hepato- and intestinal- toxicity including decreased mRNA levels of ileal permeability markers (occludin, claudin3). In summary, CAR and PXR ablation significantly altered gut microbiome in diet-induced obesity while Aroclor1260 compromised intestinal integrity in knockout mice, implicating interactions between PCBs and CAR, PXR on the gut-liver axis.

Betaine inhibits Toll-like receptor 4 responses and restores intestinal microbiota in acute liver failure mice

Previous research has revealed that the gut microbiome has a marked impact on acute liver failure (ALF). Here, we evaluated the impact of betaine on the gut microbiota composition in an ALF animal model. The potential protective effect of betaine by regulating Toll-like receptor 4 (TLR4) responses was explored as well. Both mouse and cell experiments included normal, model, and betaine groups. The rat small intestinal cell line IEC-18 was used for in vitro experiments. Betaine ameliorated the small intestine tissue and IEC-18 cell damage in the model group by reducing the high expression of TLR4 and MyD88. Furthermore, the intestinal permeability in the model group was improved by enhancing the expression of the (ZO)-1 and occludin tight junction proteins. There were 509 operational taxonomic units (OTUs) that were identified in mouse fecal samples, including 156 core microbiome taxa. Betaine significantly improved the microbial communities, depleted the gut microbiota constituents Coriobacteriaceae, Lachnospiraceae, Enterorhabdus and Coriobacteriales and markedly enriched the taxa Bacteroidaceae, Bacteroides, Parabacteroides and Prevotella in the model group. Betaine effectively improved intestinal injury in ALF by inhibiting the TLR4/MyD88 signaling pathway, improving the intestinal mucosal barrier and maintaining the gut microbiota composition.

The Herbal Medicine Scutellaria-Coptis Alleviates Intestinal Mucosal Barrier Damage in Diabetic Rats by Inhibiting Inflammation and Modulating the Gut Microbiota

Recent studies have confirmed that increased intestinal permeability and gut-origin lipopolysaccharide (LPS) translocation are important causes of metabolic inflammation in type 2 diabetes (T2D), but there are no recognized therapies for targeting this pathological state. Scutellaria baicalensis and Coptis chinensis are a classic herbal pair often used to treat diabetes and various intestinal diseases, and repair of intestinal barrier damage may be at the core of their therapeutic mechanism. This study investigated the effects of oral administration of Scutellaria-Coptis (SC) on the intestinal mucosal barrier in diabetic rats and explored the underlying mechanism from the perspective of anti-inflammatory and gut microbiota-modulatory effects. The main results showed that, in addition to regulating glycolipid metabolism disorders and inhibiting serum inflammatory factors, SC could also upregulate the expression levels of the tight junction proteins claudin-1, occludin, and zonula occludens (ZO-1), significantly improve intestinal epithelial damage, and inhibit excessive LPS translocation into the blood circulation. Furthermore, it was found that SC could reduce the levels of the inflammatory factors interleukin-1β (IL-1β), IL-6, and tumour necrosis factor-α (TNF-α) in intestinal tissue and that the anti-inflammatory effects involved the TLR-4/TRIF and TNFR-1/NF-κB signalling pathways. Moreover, SC had a strong inhibitory effect on some potential enteropathogenic bacteria and LPS-producing bacteria, such as Proteobacteria, Enterobacteriaceae, Enterobacter, Escherichia-Shigella, and Enterococcus, and could also promote the proliferation of butyrate-producing bacteria, such as Lachnospiraceae and Prevotellaceae. Taken together, the hypoglycaemic effects of SC were related to the protection of the intestinal mucosal barrier, and the mechanisms might be related to the inhibition of intestinal inflammation and the regulation of the gut microbiota.

Lactobacillus salivarius LI01 encapsulated in alginate-pectin microgels ameliorates D-galactosamine-induced acute liver injury in rats

Acute liver failure is a clinical emergency associated with high mortality. Accumulating evidence indicates that gut microbiota participates in the progression of liver injury, and preventive therapies based on altering gut microbiota are of great interest. Previous studies demonstrated that Lactobacillus salivarius LI01 attenuates hepatic injury, though efficiency in curtailed in the harsh environment in the gastrointestinal tract. In this study, a system to encapsulate LI01 in alginate-pectin (AP) microgels was investigated. Encapsulation significantly enhances probiotic viability for long-term storage and heat treatment, and in simulated gastrointestinal fluids (SGF or SIF) and bile salt solutions. Acute liver injury was induced in Sprague-Dawley (SD) rats by D-galactosamine (D-GaIN) injection following pretreatment with probiotics. Liver and gut barrier function, cytokines, liver and gut histology, bacterial translocation, and gut microbiota were assessed. Administration of encapsulated LI01 more effectively upregulates hepatic anti-inflammatory cytokine IL-10 and TLR-3, restores expressions of gut barrier biomarkers Claudin-1 and MUC2 and attenuates destruction of mucosal ultrastructure compared with unencapsulated probiotics pretreatment. Pretreatment with AP-LI01 microgels altered the microbial community, decreasing the abundance of pathogenic taxa Ruminiclostridium, Dorea and Ruminococcaceae_UCG-004 and enriching beneficial taxa Ruminococcaceae_UCG-014, Eubacterium, and Prevotella_1 that produce short-chain fatty acids. These results suggest that AP encapsulation of LI01 boosts viability and attenuates liver injury by reducing inflammation and restoring intestinal barrier function. These beneficial effects are probably due to alternation of gut flora. These findings provide new insight into encapsulation technology and prevention of liver failure. KEY POINTS: • Alginate-pectin encapsulation enhances the viability of Lactobacillus salivarius LI01 under simulated commercial conditions and simulated gastrointestinal environment. • AP-LI01 microgel attenuates hepatic and intestinal inflammation and restores gut barrier function. • AP-LI01 microgel alters gut microbial community with increased SCFAs producers and decreased pathogenic microbes. • Beneficial improvements after administration of probiotics are highly associated with alternation of gut microbial community.

Gut Microbiota and Liver Injury (I)-Acute Liver Injury

Over the last few decades, intestinal microbial communities have been considered to play a vital role in host liver health. Acute liver injury (ALI) is the manifestation of sudden hepatic injury and arises from a variety of causes. The studies of dysbiosis in gut microbiota provide new insight into the pathogenesis of ALI. However, the relationship of gut microbiota and ALI is not well understood, and the contribution of gut microbiota to ALI has not been well characterized. In this chapter, we integrate several major pathogenic factors in ALI with the role of gut microbiota to stress the significance of gut microbiota in prevention and treatment of ALI.

A disease-specific decline of the relative abundance of Bifidobacterium in patients with autoimmune hepatitis

BACKGROUND

The pathogenesis of autoimmune hepatitis (AIH) is poorly understood and little is known about enteric microbiota in AIH.

AIM

To investigate disease-specific microbiome alterations in AIH.

METHODS

The V1-V2 variable regions of the 16S rRNA gene were sequenced in faecal samples from 347 patients with AIH and controls (AIH n = 72, healthy controls (HC) n = 95, primary biliary cholangitis (PBC) n = 99 and ulcerative colitis (UC) n = 81).

RESULTS

Biodiversity (Shannon entropy) was decreased in AIH patients compared to HC (P = 0.016), which was partially reversed by azathioprine (P = 0.011). Regarding between-sample diversity, AIH patients separated from HC, PBC and UC individuals (all P = 0.001). Compared to HC, decreased relative abundance of anaerobic genera such as Faecalibacterium and an increase of Veillonella and the facultative anaerobic genera Streptococcus and Lactobacillus were detected. Importantly, a disease-specific decline of relative abundance of Bifidobacterium was observed in AIH patients. Lack of Bifidobacterium was associated with failure to achieve remission of AIH (P < 0.001). Of potential therapeutic implication, Bifidobacterium abundance correlated with average protein intake (P < 0.001). Random forests classification between AIH and PBC on the microbiome signature yielded an area under receiver operating characteristic curve (AUC) of 0.787 in the training cohort, and an AUC of 0.849 in an external validation cohort.

CONCLUSION

Disease-specific faecal microbial alterations were identified in patients with AIH. Intestinal dysbiosis in AIH was characterised by a decline of Bifidobacterium, which was associated with increased disease activity. These results point to the contribution of intestinal microbiota to AIH pathogenesis and to novel therapeutic targets.

Lactobacillus helveticus R0052 alleviates liver injury by modulating gut microbiome and metabolome in D-galactosamine-treated rats

The liver is an important digestive gland, and acute liver failure results in high mortality. Probiotics are considered potential adjuvant therapies for liver disease. This study aimed to investigate the beneficial effects of Lactobacillus helveticus R0052 on acute liver injury and the underlying mechanisms. Sprague-Dawley rats were gavaged with L. helveticus R0052 suspensions (3 × 10⁹ CFU) for 1 week. Subsequently, acute liver injury was induced by intraperitoneal D-galactosamine injection on the eighth day. After 24 h, samples (blood, liver, ileum, faeces) were collected and assessed for histological injury, inflammation, intestinal barrier, gut microbiome and metabolome. L. helveticus R0052 alleviated aminotransferase, bilirubin and total bile acid elevation and histological hepatic injuries. Additionally, L. helveticus R0052 exhibited anti-inflammatory properties by downregulating Toll-like receptors, tumour necrosis factor-α and nuclear factor-κb transcription in liver samples and decreasing proinflammatory cytokine plasma concentrations. Additionally, L. helveticus R0052 ameliorated intestinal abnormalities and regulated Toll-like receptors, claudin2 and mucin3 gene transcription in the intestine. These effects were associated with gut microbiome and metabolome modulation by L. helveticus R0052. Probiotic pretreatment enriched Lactobacillus and Bacteroides and depleted Flavonifractor and Acetatifactor in the gut microbiome. Meanwhile, L. helveticus R0052 improved carbohydrate and fatty acid metabolism and reduced lithocholic acid levels. These results indicate that L. helveticus R0052 is promising for alleviating acute liver injury and provide new insights regarding the correlations among the microbiome, the metabolome, the intestinal barrier and liver disease.

Administration of Akkermansia muciniphila Ameliorates Dextran Sulfate Sodium-Induced Ulcerative Colitis in Mice

Inflammatory bowel diseases (IBDs) develop as a result of complex interactions among genes, innate immunity and environmental factors, which are related to the gut microbiota. Multiple clinical and animal data have shown that Akkermansia muciniphila is associated with a healthy mucosa. However, its precise role in colitis is currently unknown. Our study aimed to determine its protective effects and underlying mechanisms in a dextran sulfate sodium (DSS)-induced colitis mouse model. Twenty-four C57BL/6 male mice were administered A. muciniphila Muc^T or phosphate-buffered saline (PBS) once daily by oral gavage for 14 days. Colitis was induced by drinking 2% DSS from days 0 to 6, followed by 2 days of drinking normal water. Mice were weighed daily and then sacrificed on day 8. We found that A. muciniphila improved DSS-induced colitis, which was evidenced by reduced weight loss, colon length shortening and histopathology scores and enhanced barrier function. Serum and tissue levels of inflammatory cytokines and chemokines (TNF-α, IL1α, IL6, IL12A, MIP-1A, G-CSF, and KC) decreased as a result of A. muciniphila administration. Analysis of 16S rDNA sequences showed that A. muciniphila induced significant gut microbiota alterations. Furthermore, correlation analysis indicated that pro-inflammatory cytokines and other injury factors were negatively associated with Verrucomicrobia, Akkermansia, Ruminococcaceae, and Rikenellaceae, which were prominently abundant in A. muciniphila-treated mice. We confirmed that A. muciniphila treatment could ameliorate mucosal inflammation either via microbe-host interactions, which protect the gut barrier function and reduce the levels of inflammatory cytokines, or by improving the microbial community. Our findings suggest that A. muciniphila may be a potential probiotic agent for ameliorating colitis.

Dietary fat intake and age modulate the composition of the gut microbiota and colonic inflammation in C57BL/6J mice

Background

More than half of the adult population worldwide is overweight or obese, while excess adiposity has been linked to chronic low-grade inflammation, contributing to the development of chronic diseases. Recent studies have showed that diet-induced alterations to the gut microbiota composition play a pivotal role in the development of obesity. However, the cause-effect relationship between obesity and gut microbiota composition is not yet fully understood. In this study, we investigated the short-term responses of gut microbiota composition to diets with different fat contents and their associations with inflammatory biomarkers.

Results

Sixty male C57BL/6 J mice were fed a normal diet (ND; 15% fat) or a high-fat diet (HFD; 45% fat) for 10 or 20 weeks. The relative proportion of the phylum Actinobacteria was elevated by the HFD and was positively associated with body weight and proinflammatory cytokines including TNF-α, IL-1β, and IL-6. The proportion of the phylum Firmicutes increased with aging and was also positively correlated with proinflammatory cytokines. The proportions of Actinobacteria and Firmicutes were inversely associated with tight junction proteins claudin-1 and E-cadherin, respectively. The proportions of the class Clostridia and the family Ruminococcaceae within the phylum Firmicutes were affected by both diet and age. In addition, the proportions of the phylum Bacteroidetes, the family Bacteroidaceae, and the genus Bacteroides decreased with aging and were inversely correlated with colonic proinflammatory cytokines representing a positive association with tight junction proteins.

Conclusions

Host age and dietary fat intake are important elements that induce proportional changes in gut microbiota, and these changes are also associated with systemic inflammation. This study provides evidence that diet affects the gut microbiota composition within a short period of time.