Randomised Double-Blind Placebo-Controlled Trial of Inulin with Metronidazole in Non-Alcoholic Fatty Liver Disease (NAFLD)

A very-low-calorie diet (VLCD) intervention for the management of prediabetes and early Type 2 diabetes mellitus in a multi-ethnic cohort in Aotearoa New Zealand: The PROGRESS NZ feasibility study

BACKGROUND AND OBJECTIVES

Very-low calorie diets (VLCD) achieve weight loss and remission of Type 2 diabetes (T2DM), but efficacy and acceptability in non-European populations is less clear. This feasibility study examines the impact of 10% weight loss through VLCD on metabolic and body composition outcomes in a multi-ethnic cohort of Aotearoa New Zealand (AoNZ) men with prediabetes/early T2DM, and VLCD tolerability/cultural acceptability.

METHODS AND STUDY DESIGN

Participants followed a VLCD intervention (mean energy 3033kJ/day) until achievement of 10% weight loss. An oral glucose tolerance test (OGTT), hyperinsulinaemic isoglycaemic clamp with stable isotopes, hood calorimetry and dual-energy Xray absorptiometry (DXA) were undertaken before and after intervention. Qualitative data on VLCD tolerability/cultural acceptability were collected.

RESULTS

Fifteen participants were enrolled; nine achieved 10% weight loss. In this group, mean HbA1c reduced by 4.8mmol/mol (2.4-7.1) and reverted to normoglycaemia in n=5/9; mean body weight reduced by 12.0 kg (11.0-13.1) and whole-body glucose disposal improved by 1.5 mg kgFFM-1 min-1 (0.7-2.2). Blood pressure and fasting triglycerides improved significantly. No changes in hepatic glu-cose metabolism were found. In all participants who attended completion testing, HbA1c reduced by 3.4mmol/mol (SD 3.5) and total weight by 9.0kg (SD 5.7). The intervention was highly tolerable/culturally acceptable however challenges with fulfilment of cultural obligations were described.

CONCLUSIONS

Results support VLCD use in AoNZ however further work to investigate ethnic differences in physiological response to VLCDs and to optimise protocols for multi-ethnic populations are required.

Role of Probiotics in Gut Microbiome and Metabolome in Non-Alcoholic Fatty Liver Disease Mouse Model: A Comparative Study

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver condition worldwide. Numerous studies conducted recently have demonstrated a connection between the dysbiosis of the development of NAFLD and gut microbiota. Rebuilding a healthy gut ecology has been proposed as a strategy involving the use of probiotics. The purpose of this work is to investigate and compare the function of probiotics Akkermansia muciniphila (A. muciniphila) and VSL#3 in NAFLD mice. Rodent NAFLD was modeled using a methionine choline-deficient diet (MCD) with/without oral probiotic delivery. Subsequently, qPCR, histological staining, and liver function tests were conducted. Mass spectrometry-based analysis and 16S rDNA gene sequencing were used to investigate the liver metabolome and gut microbiota. We found that while both A. muciniphila and VSL#3 reduced hepatic fat content, A. muciniphila outperformed VSL#3. Furthermore, probiotic treatment restored the β diversity of the gut flora and A. muciniphila decreased the abundance of pathogenic bacteria such as Ileibacterium valens. These probiotics altered the metabolism in MCD mice, especially the glycerophospholipid metabolism. In conclusion, our findings distinguished the role of A. muciniphila and VSL#3 in NAFLD and indicated that oral-gavage probiotics remodel gut microbiota and improve metabolism, raising the possibility of using probiotics in the cure of NAFLD.

Gut microbiota in MAFLD: therapeutic and diagnostic implications

Metabolic dysfunction-associated fatty liver disease (MAFLD), formerly known as nonalcoholic fatty liver disease, is becoming a significant contributor to chronic liver disease globally, surpassing other etiologies, such as viral hepatitis. Prevention and early treatment strategies to curb its growing prevalence are urgently required. Recent evidence suggests that targeting the gut microbiota may help treat and alleviate disease progression in patients with MAFLD. This review aims to explore the complex relationship between MAFLD and the gut microbiota in relation to disease pathogenesis. Additionally, it delves into the therapeutic strategies targeting the gut microbiota, such as diet, exercise, antibiotics, probiotics, synbiotics, glucagon-like peptide-1 receptor agonists, and fecal microbiota transplantation, and discusses novel biomarkers, such as microbiota-derived testing and liquid biopsy, for their diagnostic and staging potential. Overall, the review emphasizes the urgent need for preventive and therapeutic strategies to address the devastating consequences of MAFLD at both individual and societal levels and recognizes that further exploration of the gut microbiota may open avenues for managing MAFLD effectively in the future.

Effects of Prebiotic Therapy on Gastrointestinal Microbiome of Individuals with Different Inflammatory Conditions: A Systematic Review of Randomized Controlled Trials

Prebiotics are substrates selectively utilized by host microorganisms conferring a health benefit. The effects of prebiotics on the gut microbiome of individuals with inflammatory processes need further investigations. The purpose of this study was to evaluate the effects of prebiotics on the gastrointestinal microbiome of individuals with some types of inflammatory conditions. Randomized controlled clinical trials (RCTs) evaluating the effects of different prebiotics on the gut microbiome were included. A systematic review of the literature including searches in PubMed/MEDLINE, EMBASE, Cochrane Library, Web of Science, and Scopus databases was performed until 23 March 2023. The risk of bias was assessed using the Cochrane Collaboration's criteria. Qualitative data was tabulated to facilitate comparisons and represented in the form of descriptive statistics and summary tables. Thirty trials, ranging from 12 to 135 patients, were included. The most commonly used prebiotic type was inulin-type fructans, and the treatment duration ranged from 1 to 36 weeks. The majority of the trials investigated the gut microbiome using 16 s rRNA gene sequencing on the Illumina Miseq platform. In general, prebiotic therapy exerted positive effects on inflammatory conditions. An increase in Bifidobacterium genus was the most common shift in bacterial composition observed. Within the limits of this systematic review, it can be suggested that prebiotic therapy presents the potential to favorably modulate the gastrointestinal microbiome of individuals with different types of inflammatory conditions.

Inulin: Unveiling its potential as a multifaceted biopolymer in prebiotics, drug delivery, and therapeutics

In recent years, inulin has gained much attention as a promising multifunctional natural biopolymer with numerous applications in drug delivery, prebiotics, and therapeutics. It reveals a multifaceted biopolymer with transformative implications by elucidating the intricate interplay between inulin and the host, microbiome, and therapeutic agents. Their flexible structure, exceptional targetability, biocompatibility, inherent ability to control release behavior, tunable degradation kinetics, and protective ability make them outstanding carriers in healthcare and biomedicine. USFDA has approved Inulin as a nutritional dietary supplement for infants. The possible applications of inulin in biomedicine research inspired by nature are presented. The therapeutic potential of inulin goes beyond its role in prebiotics and drug delivery. Recently, significant research efforts have been made towards inulin's anti-inflammatory, antioxidant, and immunomodulatory properties for their potential applications in treating various chronic diseases. Moreover, its ability to reduce inflammation and modulate immune responses opens new avenues for treating conditions such as autoimmune disorders and gastrointestinal ailments. This review will attempt to illustrate the inulin's numerous and interconnected roles, shedding light on its critical contributions to the advancement of healthcare and biomedicine and its recent advancement in therapeutics, and conclude by taking valuable insights into the prospects and opportunities of inulin.

Non-alcoholic fatty liver disease and gut microbial dysbiosis- underlying mechanisms and gut microbiota mediated treatment strategies

Non-alcoholic fatty liver disease (NAFLD) is by far the most prevalent form of liver disease worldwide. It's also the leading cause of liver-related hospitalizations and deaths. Furthermore, there is a link between obesity and NAFLD risk. A projected 25% of the world's population grieves from NAFLD, making it the most common chronic liver disorder. Several factors, such as obesity, oxidative stress, and insulin resistance, typically accompany NAFLD. Weight loss, lipid-lowering agents, thiazolidinediones, and metformin help prominently control NAFLD. Interestingly, pre-clinical studies demonstrate gut microbiota's potential causal role in NAFLD. Increased intestinal permeability and unhindered transport of microbial metabolites into the liver are the major disruptions due to gut microbiome dysbiosis, contributing to the development of NAFLD by dysregulating the gut-liver axis. Hence, altering the pathogenic bacterial population using probiotics, prebiotics, synbiotics, and fecal microbiota transplantation (FMT) could benefit patients with NAFLD. Therefore, it is crucial to acknowledge the importance of microbiota-mediated therapeutic approaches for NAFLD and comprehend the underlying mechanisms that establish a connection between NAFLD and gut microbiota. This review provides a comprehensive overview of the affiliation between dysbiosis of gut microbiota and the progress of NAFLD, as well as the potential benefits of prebiotic, probiotic, synbiotic supplementation, and FMT in obese individuals with NAFLD.

Gut Microbiota and Bacterial Translocation in the Pathogenesis of Liver Fibrosis

Cirrhosis is the end result of liver fibrosis in chronic liver diseases. Studying the mechanisms of its development and developing measures to slow down and regress it based on this knowledge seem to be important tasks for medicine. Currently, disorders of the gut-liver axis have great importance in the pathogenesis of cirrhosis. However, gut dysbiosis, which manifests as increased proportions in the gut microbiota of Bacilli and Proteobacteria that are capable of bacterial translocation and a decreased proportion of Clostridia that strengthen the intestinal barrier, occurs even at the pre-cirrhotic stage of chronic liver disease. This leads to the development of bacterial translocation, a process by which those microbes enter the blood of the portal vein and then the liver tissue, where they activate Kupffer cells through Toll-like receptor 4. In response, the Kupffer cells produce profibrogenic cytokines, which activate hepatic stellate cells, stimulating their transformation into myofibroblasts that produce collagen and other elements of the extracellular matrix. Blocking bacterial translocation with antibiotics, probiotics, synbiotics, and other methods could slow down the progression of liver fibrosis. This was shown in a number of animal models but requires further verification in long-term randomized controlled trials with humans.

Prebiotics and Probiotics: Therapeutic Tools for Nonalcoholic Fatty Liver Disease

Alterations in the gut-liver axis and changes in the gut microbiome are among the risk factors for the pathogenesis of non-alcoholic fatty liver disease (NAFLD). These patients show increased bacterial overgrowth in the small intestine and impaired intestinal permeability. Therefore, therapeutic options such as probiotics or prebiotics have been investigated to modulate intestinal microbiota composition to improve NAFLD. Most in vivo and in vitro probiotic studies have focused on reducing hepatic fat accumulation. The beneficial effects of probiotics on NAFLD have been demonstrated in animal models, and the most widely used microorganisms are those of the Lactobacillus and Bifidobacterium genera. In animal models, probiotics help restore the intestinal microbiota and improve the integrity of the intestinal barrier. This narrative review summarizes published evidence and the likely benefits of probiotics and prebiotics as a therapeutic option for patients with NAFLD.

Gut microbiome and nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) has become the most prevalent chronic liver disease globally and imposed a heavy economic burden on society and individuals. To date, the pathological process of NAFLD is not yet fully elucidated. Compelling evidences have demonstrated the pivotal role of gut microbiota in the pathogenesis of NAFLD, and gut dysbiosis has been commonly observed in patients with NAFLD. Gut dysbiosis impairs gut permeability, allowing the translocation of bacterial products such as lipopolysaccharides (LPS), short-chain fatty acids (SCFAs), and ethanol to the liver via portal blood flow. This review aimed to shed light on the underlying mechanisms by which gut microbiota influences the development and progression of NAFLD. In addition, the potential application of gut microbiome as a non-invasive diagnostic tool and a novel therapeutical target was reviewed.

Use of probiotics, prebiotics, and synbiotics in non-alcoholic fatty liver disease: A systematic review and meta-analysis

BACKGROUND AND AIM

Patients with non-alcoholic fatty liver disease (NAFLD) exhibit compositional changes in their gut microbiome, which represents a potential therapeutic target. Probiotics, prebiotics, and synbiotics are microbiome-targeted therapies that have been proposed as treatment for NAFLD. We aim to systematically review the effects of these therapies in liver-related outcomes of NAFLD patients.

METHODS

We conducted a systematic search in Embase (Ovid), Medline (Ovid), Scopus, Cochrane, and EBSCOhost from inception to August 19, 2022. We included randomized controlled trials (RCTs) that treated NAFLD patients with prebiotics and/or probiotics. We meta-analyzed the outcomes using standardized mean difference (SMD) and assessed study heterogeneity using Cochran's Q test and I2 statistics. Risk of bias was assessed using the Cochrane Risk-of-Bias 2 tool.

RESULTS

A total of 41 (18 probiotics, 17 synbiotics, and 6 prebiotics) RCTs were included. Pooled data demonstrated that the intervention had significantly improved liver steatosis (measured by ultrasound grading) (SMD: 4.87; 95% confidence interval [CI]: 3.27, 7.25), fibrosis (SMD: -0.61 kPa; 95% CI: -1.12, -0.09 kPa), and liver enzymes including alanine transaminase (SMD: -0.86 U/L; 95% CI: -1.16, -0.56 U/L), aspartate transaminase (SMD: -0.87 U/L; 95% CI: -1.22, -0.52 U/L), and gamma-glutamyl transferase (SMD: -0.77 U/L; 95% CI: -1.26, -0.29 U/L).

CONCLUSIONS

Microbiome-targeted therapies were associated with significant improvements in liver-related outcomes in NAFLD patients. Nevertheless, limitations in existing literature like heterogeneity in probiotic strains, dosage, and formulation undermine our findings. This study was registered with PROSPERO (CRD42022354562) and supported by the Nanyang Technological University Start-up Grant and Wang Lee Wah Memorial Fund.

Vive la resistant starch: A potential treatment for metabolic dysfunction-associated steatohepatitis

Metabolic dysfunction-associated steatotic liver disease is a prevalent chronic liver disease that affects nearly a third of the global adult population. Here, we preview a randomized controlled clinical trial on the potential benefits and underlying mechanisms of using resistant starch, a prebiotic, for treating this common liver condition.

Exploring the Impact of Nutrition on Non-Alcoholic Fatty Liver Disease Management: Unveiling the Roles of Various Foods, Food Components, and Compounds

There is a need to introduce standardized treatment options for non-alcoholic fatty liver disease (NAFLD) due to its global prevalence and the complications of this disease. Many studies have revealed that food-derived substances may be beneficial in dealing with this disease. Therefore, this review aims to evaluate the recently published studies on the food-derived treatment options for NAFLD. A comprehensive search of the PubMed database using keywords such as "NAFLD", "nutrition", "food", "derived", "therapy", and "guidelines" yielded 219 relevant papers for our analysis, published from 2004 to 2023. The results show the significant benefits of food-derived treatment in NAFLD therapy, including improvements in liver histology, hepatic fat amounts, anthropometric measures, lipid profile, and other metabolic measures. The availability of the substances discussed makes them a significant adjuvant in the treatment of this disease. The usefulness of Viusid as additional therapy to diet and physical activity should be emphasized due to improvements in liver histology; however, many other substances lead to a decrease in liver fat amounts including, e.g., berberine or omega-3 fatty acids. In addition, the synbiotic Protexin seems to be useful in terms of NAFLD treatment, especially because it is effective in both obese and lean subjects. Based on the latest research results, we suggest revising the therapeutic recommendations for patients suffering from NAFLD.

The effect of synbiotics in patients with NAFLD: a systematic review and meta-analysis

Background

Nonalcoholic fatty liver disease (NAFLD) is the highest incidence of chronic liver disease worldwide, seriously endangering human health, and its pathogenesis is still unclear. In the recent years, increasing evidence has shown that intestinal flora plays an important role in the occurrence and development of NAFLD. Synbiotics can alter gut microbiota and may be a treatment option for NAFLD in the future.

Objectives

To systematically investigate the therapeutic effect of synbiotic supplementation on NAFLD patients.

Design

A systematic review and meta-analysis were conducted.

Data sources and methods

We conducted a search on four databases (PubMed, Embase, Cochrane Library, and Web of Science) to identify relevant studies. Eligible studies were then screened, and data from the included studies were extracted, combined, and analyzed.

Result

This study analyzed 10 randomized controlled trials involving 634 patients with NAFLD. The results showed that synbiotic supplementation could significantly reduce the level of alanine aminotransferase (mean difference (MD) = -8.80; (95% CI [-13.06, -4.53]), p < 0.0001), aspartate aminotransferase (MD = -9.48; 95% CI [-12.54, -6.43], p < 0.0001), and γ-glutamyl transferase (MD = -12.55; 95% CI [-19.40, -5.69], p = 0.0003) in NAFLD patients. In the field of metabolism, synbiotic supplementation could significantly reduce the level of total cholesterol (MD = -11.93; 95% CI [-20.43, -3.42], p = 0.006) and low-density lipoprotein cholesterol (MD = -16.2; 95% CI [-19.79, -12.60], p < 0.0001) and increase the level of high-density lipoprotein cholesterol (MD = 1.56; 95% CI [0.43, 2.68], p = 0.007) in NAFLD patients. In addition, synbiotic supplementation could significantly reduce liver stiffness measurement indicator (MD = -1.09; 95% CI [-1.87, -0.30], p = 0.006) and controlled attenuation parameter indicator (MD = -37.04; 95% CI [-56.78, -17.30], p = 0.0002) in NAFLD patients.

Conclusion

Based on the current evidence, synbiotic supplementation can improve liver function, adjust lipid metabolism, and reduce the degree of liver fibrosis in patients with NAFLD, but these effects need to be confirmed by further studies.

Exploration of Maternal and Fetal Toxicity Risks for Metronidazole-Related Teratogenicity and Hepatotoxicity through an Assessment in Albino Rats

Metronidazole is the primary antimicrobial drug for treating acute and chronic vaginal pathogens during pregnancy; however, there has been insufficient research on placental disorders, early pregnancy loss, and preterm birth. Here, the potential activity of metronidazole on pregnancy outcomes was investigated. 130 mg/kg body weight of metronidazole was orally given individually to pregnant rats on gestation days 0-7, 7-14, and 0-20. Pregnancy outcome evaluations were carried out on gestation day 20. It was demonstrated that metronidazole could induce maternal and fetal hepatotoxicity. There is a significant increase in the activities of maternal hepatic enzymes (ALT, AST, and ALP), total cholesterol, and triglycerides compared with the control. These biochemical findings were evidenced by maternal and fetal liver histopathological alterations. Furthermore, metronidazole caused a significant decrease in the number of implantation sites and fetal viability, whereas it caused an increase in fetal lethality and the number of fetal resorptions. In addition, a significant decrease in fetal weight, placental weight, and placental diameter was estimated. Macroscopical examination revealed placental discoloration and hypotrophy in the labyrinth zone and the degeneration of the basal zone. The fetal defects are related to exencephaly, visceral hernias, and tail defects. These findings suggest that the administration of metroniazole during gestation interferes with embryonic implantation and fetal organogenesis and enhances placental pathology. We can also conclude that metronidazole has potential maternal and fetal risks and is unsafe during pregnancy. Additionally, it should be strictly advised and prescribed, and further consideration should be given to the associated health risks.

Impact of caloric restriction on the gut microbiota

Caloric restriction (CR) and related time-restricted diets have been popularized as means of preventing metabolic disease while improving general well-being. However, evidence as to their long-term efficacy, adverse effects, and mechanisms of activity remains incompletely understood. The gut microbiota is modulated by such dietary approaches, yet causal evidence to its possible downstream impacts on host metabolism remains elusive. Herein, we discuss the positive and adverse influences of restrictive dietary interventions on gut microbiota composition and function, and their collective impacts on host health and disease risk. We highlight known mechanisms of microbiota influences on the host, such as modulation of bioactive metabolites, while discussing challenges in achieving mechanistic dietary-microbiota insights, including interindividual variability in dietary responses as well as other methodological and conceptual challenges. In all, causally understanding the impact of CR approaches on the gut microbiota may enable to better decode their overall influences on human physiology and disease.

Gut microbiota therapy for nonalcoholic fatty liver disease: Evidence from randomized clinical trials

Nonalcoholic fatty liver disease (NAFLD) has a high prevalence worldwide, but there are no medications approved for treatment. Gut microbiota would be a novel and promising therapeutic target based on the concept of the gut-liver axis in liver disease. We reviewed randomized controlled trials on gut microbiota therapy in NAFLD in this study to evaluate its efficacy and plausibility in NAFLD.

Global publication trends and research hotspots of the gut-liver axis in NAFLD: A bibliometric analysis

BACKGROUND

Nonalcoholic Fatty Liver Disease(NAFLD)refers to a spectrum of diseases ranging from simple liver steatosis to nonalcoholic steatohepatitis (NASH) and cirrhosis. Bidirectional cross-talk between the gut-liver axis plays an important role in the pathogenesis of NAFLD. To learn more about the gut-liver axis in NAFLD, this study aims to provide a comprehensive analysis from a bibliometric perspective.

METHOD

Literature related to the gut-liver axis in NAFLD from 1989 to 2022 was extracted from the Web of Science Core Collection. Based on Microsoft Excel, CiteSpace and Vosviewer, we conducted to analyze the number of publications, countries/regions, institutions, authors, journals, references, and keywords.

RESULTS

A total of 1,891 literature since 2004 was included, with the rapid growth of the number of papers on the gut-liver axis in NAFLD annually. These publications were mainly from 66 countries and 442 institutions. Of the 638 authors analyzed, Bernd Schnabl was the one with the most publications, and Patrice D. Cani was the one with the most co-citations. International Journal of Molecular Sciences is the journal with the most articles published, and Hepatology is the journal with the most citations. The most common keywords are gut microbiota, inflammation, and insulin instance, which are current research hotspots. Short-chain fatty acid, in vitro, randomized controlled trial in clinical, and diabetes mellitus represent the research frontiers in this field and are in a stage of rapid development.

CONCLUSION

This is the first study to conduct a comprehensive bibliometric analysis of publications related to the gut-liver axis in NAFLD. This study reveals that gut microbiota, inflammation, insulin resistance, short-chain fatty acids, and randomized controlled trial will be the hotspots and new trends in the gut-liver axis in NAFLD research, which could provide researchers with key research information in this field and is helpful for further exploration of new research directions.

Multi-Time-Point Fecal Sampling in Human and Mouse Reveals the Formation of New Homeostasis in Gut Microbiota after Bowel Cleansing

Polyethylene glycol (PEG) is one of the most commonly used bowel cleansing methods. Although the safety of PEG for bowel cleansing has been proven, its impact on intestinal microbiota has not been clearly explained, especially in terms of the dynamic changes in intestinal microbiota after PEG bowel cleansing, and there are no consistent results. In this study, stool samples were collected from 12 participants at six time points before and after bowel cleansing. We obtained data on the microbiota of these samples using 16S rRNA gene sequencing and analysis. The data revealed that the structure and composition of the microbiota changed greatly approximately 7 d after intestinal cleansing. The analysis of the dynamic changes in the microbiota showed that the change was most significant at day 3, but the internal structure of the microbiota was similar to that before bowel cleansing. A comparison of the most significantly changed microbiota at different time points before and after bowel cleansing revealed four bacteria: Bacteroides, Roseburia, Eubacterium, and Bifidobacterium. We also established a humanized mouse model to simulate human bowel cleansing using PEG. The results showed that the mouse model achieved similar effects to human bowel cleansing, but its recovery speed was one stage earlier than that of humans. These findings suggest that the intestinal microbiota after bowel cleansing initially underwent a short-term change and then actively returned to its initial status. The results on key bacteria and establishment of mouse models can provide a reference for subsequent research on bowel cleansing.

Dietary Polysaccharides as Modulators of the Gut Microbiota Ecosystem: An Update on Their Impact on Health

A polysaccharide is a macromolecule composed of more than ten monosaccharides with a wide distribution and high structural diversity and complexity in nature. Certain polysaccharides are immunomodulators and play key roles in the regulation of immune responses during the progression of some diseases. In addition to stimulating the growth of certain intestinal bacteria, polysaccharides may also promote health benefits by modulating the gut microbiota. In the last years, studies about the triad gut microbiota–polysaccharides–health have increased exponentially. In consequence, in the present review, we aim to summarize recent knowledge about the function of dietary polysaccharides on gut microbiota composition and how these effects affect host health.

High fat diet-induced hyperlipidemia and tissue steatosis in rabbits through modulating ileal microbiota

High-fat diet (HFD) and overnutrition are important starting factors that may alter intestinal microbiota, lipid metabolism, and systemic inflammation. However, there were few studies on how intestinal microbiota contributes to tissue steatosis and hyperlipidemia. Here, we investigated the effect of lipid metabolism disorder-induced inflammation via toll-like receptor 2 (TLR-2), toll-like receptor 4 (TLR-4), and nuclear factor-κB (NF-κB) pathways at the intestinal level in response to HFD. Twenty 80-day-old male New Zealand White rabbits were randomly divided into the normal diet group (NDG) and the high-fat diet group (HDG) for 80 days. Growth performance, blood biochemical parameters, lipid metabolism, inflammation, degree of tissue steatosis, and intestinal microbial composition were measured. HFD increased the relative abundance of Christensenellaceae_R_7_group, Marvinbryantia, Akkermansia etc., with a reduced relative abundance of Enterorhabdus and Lactobacillus. Moreover, HFD caused steatosis in the liver and abdominal fat and abnormal expression of some genes related to lipid metabolism and tight junction proteins. The TLR-2, TLR-4, NF-κB, TNF-α, and IL-6 were confirmed by overexpression with downregulation of IL-10. Serum biochemical indices (TG, TCHO, LDL-C, and HDL-C) were also increased, indicating evidence for the development of the hyperlipidemia model. Correlation analysis showed that this microbial dysbiosis was correlated with lipid metabolism and inflammation, which were associated with the intestinal tract's barrier function and hyperlipidemia. These results provide an insight into the relationship between HFD, the intestinal microbiota, intestinal barrier, tissue inflammation, lipid metabolism, and hyperlipidemia. KEY POINTS: • High-fat diet leads to ileal microbiota disorders • Ileal microbiota mediates local and systemic lipid metabolism disorders and inflammation • There is a specific link between ileal microbiota, histopathology, and hyperlipidemia.

The Effects of Probiotics, Prebiotics and Synbiotics in Non-Alcoholic Fat Liver Disease (NAFLD) and Non-Alcoholic Steatohepatitis (NASH): A Systematic Review

Modifications in the microbiota caused by environmental and genetic reasons can unbalance the intestinal homeostasis, deregulating the host’s metabolism and immune system, intensifying the risk factors for the development and aggravation of non-alcoholic fat liver disease (NAFLD). The use of probiotics, prebiotics and synbiotics have been considered a potential and promising strategy to regulate the gut microbiota and produce beneficial effects in patients with liver conditions. For this reason, this review aimed to evaluate the effectiveness of probiotics, prebiotics, and symbiotics in patients with NAFLD and NASH. Pubmed, Embase, and Cochrane databases were consulted, and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines were followed. The clinical trials used in this study demonstrated that gut microbiota interventions could improve a wide range of markers of inflammation, glycemia, insulin resistance, dyslipidemia, obesity, liver injury (decrease of hepatic enzymes and steatosis and fibrosis). Although microbiota modulators do not play a healing role, they can work as an important adjunct therapy in pathological processes involving NAFLD and its spectrums, either by improving the intestinal barrier or by preventing the formation of toxic metabolites for the liver or by acting on the immune system.

The use of very low-calorie diets in subjects with obesity complicated with nonalcoholic fatty liver disease: A scoping review

This scoping review synthesizes the existing research on the use of very low-calorie diets (VLCDs) in subjects with nonalcoholic fatty liver disease (NAFLD) and end-stage liver disease (ESLD). 19 studies were included, of which 5 were clinical trials, 11 were cohort studies, 1 was a case-control study, and 2 were case series totaling 968 subjects. About 17 studies were focused on patients with NAFLD while the two case series described in patients with ESLD on the transplant list or post-liver transplant. Six studies included subjects managed with VLCDs prior bariatric surgery. Most studies were short term and demonstrated acute improvement of diverse liver biomarkers including liver function tests, indices of hepatosteatosis and reduction in liver size. Adherence rates in these studies were between 69% and 93%. Eight studies did not report any adverse events and four subjects were reported to have discontinued VLCD due to adverse effects in two different studies. Aggregated adverse events were mild. Treatments based on VLCD in subjects with NAFLD seem to be safe and tolerable but can result in mild adverse effects. The findings of this scoping review suggest that the use of VLCD in patients with obesity complicated with NAFLD and potentially in ESLD appear to be effective to induce weight loss and to acutely reduce hepatosteatosis.

Gut microbiota predicts body fat change following a low-energy diet: a PREVIEW intervention study

Background

Low-energy diets (LEDs) comprise commercially formulated food products that provide between 800 and 1200 kcal/day (3.3–5 MJ/day) to aid body weight loss. Recent small-scale studies suggest that LEDs are associated with marked changes in the gut microbiota that may modify the effect of the LED on host metabolism and weight loss. We investigated how the gut microbiota changed during 8 weeks of total meal replacement LED and determined their associations with host response in a sub-analysis of 211 overweight adults with pre-diabetes participating in the large multicentre PREVIEW (PREVention of diabetes through lifestyle intervention and population studies In Europe and around the World) clinical trial.

Methods

Microbial community composition was analysed by Illumina sequencing of the hypervariable V3-V4 regions of the 16S ribosomal RNA (rRNA) gene. Butyrate production capacity was estimated by qPCR targeting the butyryl-CoA:acetate CoA-transferase gene. Bioinformatics and statistical analyses, such as comparison of alpha and beta diversity measures, correlative and differential abundances analysis, were undertaken on the 16S rRNA gene sequences of 211 paired (pre- and post-LED) samples as well as their integration with the clinical, biomedical and dietary datasets for predictive modelling.

Results

The overall composition of the gut microbiota changed markedly and consistently from pre- to post-LED (P = 0.001), along with increased richness and diversity (both P < 0.001). Following the intervention, the relative abundance of several genera previously associated with metabolic improvements (e.g., Akkermansia and Christensenellaceae R-7 group) was significantly increased (P < 0.001), while flagellated Pseudobutyrivibrio, acetogenic Blautia and Bifidobacterium spp. were decreased (all P < 0.001). Butyrate production capacity was reduced (P < 0.001). The changes in microbiota composition and predicted functions were significantly associated with body weight loss (P < 0.05). Baseline gut microbiota features were able to explain ~25% of variation in total body fat change (post–pre-LED).

Conclusions

The gut microbiota and individual taxa were significantly influenced by the LED intervention and correlated with changes in total body fat and body weight in individuals with overweight and pre-diabetes. Despite inter-individual variation, the baseline gut microbiota was a strong predictor of total body fat change during the energy restriction period.

Trial registration

The PREVIEW trial was prospectively registered at ClinicalTrials.gov (NCT01777893) on January 29, 2013.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13073-022-01053-7.

Triclosan targeting of gut microbiome ameliorates hepatic steatosis in high fat diet-fed mice

Antibiotic use provides a promising strategy for the treatment of non-alcoholic fatty liver disease (NAFLD) by regulating the gut microbiota composition. Triclosan, a widely used antibiotic, may improve gut microbiome dysbiosis associated with NAFLD through the suppression of pathogenic gram-negative bacteria. However, the effects of triclosan on gut microbiota and hepatic steatosis and have not been explored in NAFLD mouse model. In this study, C57BL/6J mice were fed with high fat diet (HFD) for continuous 20 weeks and treated with triclosan at 400 mg/kg/d for 8 weeks from week 13. We explored the effects of triclosan on hepatic lipid accumulation and gut microbiome in HFD-fed mice by histological examination and 16 S ribosomal RNA sequencing, respectively. Analysis on the composition of gut microbiota indicated that triclosan suppressed pathogenic gram-negative bacteria, including Helicobacter, Erysipelatoclostridium and Citrobacter, and increased the ratio of Bacteroidetes/Firmicutes in HFD-fed mice. Meanwhile, triclosan increased the relative abundance of beneficial gut microbiomes including Lactobacillus, Bifidobacterium and Lachnospiraceae, which protected against metabolic abnormality. The results of alpha-diversity and beta-diversity also showed the improvement of triclosan on bacterial diversity and richness in HFD-fed mice. Pathway analysis further confirmed that triclosan can regulate nutrient and energy metabolism through the elimination of deleterious bacteria. As a result, triclosan intervention significantly reduced lipid accumulation and alleviated hepatic steatosis in HFD-fed mice. In conclusion, our results suggest that triclosan can alleviate liver steatosis in HFD-fed mice by targeting the gut microbiome.

Probiotics and Prebiotics as a Strategy for Non-Alcoholic Fatty Liver Disease, a Narrative Review

Non-alcoholic fatty liver disease (NAFLD) is a chronic non-communicable disease, with a prevalence of 25% worldwide. This pathology is a multifactorial illness, and is associated with different risks factors, including hypertension, hyperglycemia, dyslipidemia, and obesity. Beside these predisposing features, NAFLD has been related to changes in the microbiota, which favor the disease progression. In this context, the modulation of the gut microbiota has emerged as a new therapeutic target for the prophylaxis and treatment of NAFLD. This review describes the changes in the gut microbiota associated with NAFLD and the effect of probiotics, prebiotics, and synbiotics on the gut microbiota, liver damage, anthropometric parameters, blood lipids, inflammation markers and insulin resistance in these patients.

Gut Microbiome and Nonalcoholic Fatty Liver Disease (NAFLD): Implications for Nursing Care of Individuals Living With Chronic Metabolic Diseases

At present, the incidence of nonalcoholic fatty liver disease (NAFLD) in adults is increasing year by year and at a younger age. Evidence-based healthcare has confirmed that NAFLD is closely related to obesity, cardiovascular disease, type 2 diabetes, metabolic syndrome, and other chronic metabolic diseases. Despite the growing prevalence of NAFLD, little is known about symptoms for patients at risk of NAFLD progression, thus preventing healthcare providers from intervening at an early stage. In addition, these symptoms usually cause problems for patients to cope with other chronic metabolic diseases. Symptoms may have a biological basis; especially as the changes of gut microbes may affect the symptoms of metabolic diseases. This article aims to describe the new role of gut microbes in the development of NAFLD, focusing on the potential relationship between gut microbes and symptoms of NAFLD, as well as the mechanism of action of the "gut-liver-brain" axis. This information can be useful in developing precise nursing interventions for NAFLD patients, restoring the "health" of gut microbes, and alleviating the symptom burden of chronic metabolic disease in NAFLD.

Gut microbiome, liver immunology, and liver diseases

The gut microbiota is a complex and plastic consortium of microorganisms that are intricately connected with human physiology. The liver is a central immunological organ that is particularly enriched in innate immune cells and constantly exposed to circulating nutrients and endotoxins derived from the gut microbiota. The delicate interaction between the gut and liver prevents accidental immune activation against otherwise harmless antigens. Work on the interplay between the gut microbiota and liver has assisted in understanding the pathophysiology of various liver diseases. Of immense importance is the step from high-throughput sequencing (correlation) to mechanistic studies (causality) and therapeutic intervention. Here, we review the gut microbiota, liver immunology, and the interaction between the gut and liver. In addition, the impairment in the gut-liver axis found in various liver diseases is reviewed here, with an emphasis on alcohol-associated liver disease (ALD), nonalcoholic fatty liver disease (NAFLD), and autoimmune liver disease (AILD). On the basis of growing evidence from these preclinical studies, we propose that the gut-liver axis paves the way for targeted therapeutic modalities for liver diseases.

Microbial Metabolites: Critical Regulators in NAFLD

Non-alcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease throughout the world. The relationship between gut microbiota and NAFLD has been extensively investigated. The gut microbiota is involved in the regulation of NAFLD by participating in the fermentation of indigestible food, interacting with the intestinal mucosal immune system, and influencing the intestinal barrier function, leading to signaling alteration. Meanwhile, the microbial metabolites not only affect the signal transduction pathway in the gut but also reach the liver far away from gut. In this review, we focus on the effects of certain key microbial metabolites such as short-chain fatty acids, trimethylamine-N-oxide, bile acids, and endogenous ethanol and indole in NAFLD, and also summarize several potential therapies targeting the gut-liver axis and modulation of gut microbiota metabolites including antibiotics, prebiotics, probiotics, bile acid regulation, and fecal microbiota transplantation. Understanding the complex interactions between microbial metabolites and NAFLD may provide crucial insight into the pathogenesis and treatment of NAFLD.

Gut Microbiota Metabolites in NAFLD Pathogenesis and Therapeutic Implications

Gut microbiota dysregulation plays a key role in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) through its metabolites. Therefore, the restoration of the gut microbiota and supplementation with commensal bacterial metabolites can be of therapeutic benefit against the disease. In this review, we summarize the roles of various bacterial metabolites in the pathogenesis of NAFLD and their therapeutic implications. The gut microbiota dysregulation is a feature of NAFLD, and the signatures of gut microbiota are associated with the severity of the disease through altered bacterial metabolites. Disturbance of bile acid metabolism leads to underactivation of bile acid receptors FXR and TGR5, causal for decreased energy expenditure, increased lipogenesis, increased bile acid synthesis and increased macrophage activity. Decreased production of butyrate results in increased intestinal inflammation, increased gut permeability, endotoxemia and systemic inflammation. Dysregulation of amino acids and choline also contributes to lipid accumulation and to a chronic inflammatory status. In some NAFLD patients, overproduction of ethanol produced by bacteria is responsible for hepatic inflammation. Many approaches including probiotics, prebiotics, synbiotics, faecal microbiome transplantation and a fasting-mimicking diet have been applied to restore the gut microbiota for the improvement of NAFLD.

Nutrition, Microbiota and Noncommunicable Diseases

The advent of new sequencing technologies has inspired the foundation of novel research to ascertain the connections between the microbial communities that reside in our gut and some physiological and pathological conditions [...].