The promising role of probiotics/prebiotics/synbiotics in energy metabolism biomarkers in patients with NAFLD: A systematic review and meta-analysis

Effect of synbiotics on the cardiovascular risk factors in patients with non-alcoholic fatty liver: a GRADE assessed systematic review and meta-analysis

INTRODUCTION

Several studies revealed that synbiotics have been beneficial in managing non-alcoholic fatty liver disease (NAFLD), but the findings are conflicting. We aimed to assess the effect of synbiotic supplementation on cardiovascular risk factors in patients with NAFLD.

METHODS

A thorough literature search was conducted to identify relevant studies up to July 2024, including publications from Pubmed, Embase, Cochrane, Scopus, and the Web of Science. Standardized mean difference (SMD) was used, and data with a 95% confidence interval (CI) were presented.

RESULTS

Sixteen RCTs were included, involving NAFLD patients and synbiotic supplementation. No significant effects were found on blood pressure (SBP: SMD - 6.68, p = 0.234; DBP: SMD - 4.31, p = 0.391), anthropometric measures (weight: SMD - 0.78, p = 0.126; BMI: SMD - 0.21, p = 0.182; waist circumference: SMD - 0.53, p = 0.095), or lipid profile (triglycerides: SMD - 3.67, p = 0.266; total cholesterol: SMD - 0.61, p = 0.059; low-density lipoprotein: SMD - 3.09, p = 0.215; high-density lipoprotein: SMD 0.49, p = 0.219). Synbiotics significantly reduced CRP levels (SMD - 1.83, p = 0.019) but had no significant effect on TNF-α (SMD - 1.95, p = 0.087). Synbiotic led to a significant reduction in weight following adjustment of publication bias (SMD - 1.16, p < 0.05).

CONCLUSION

Overall, synbiotic supplementation does not significantly impact blood pressure, anthropometric indices, or lipid profile parameters in patients with NAFLD, except for a significant reduction in weight after adjusting for publication bias. Synbiotic supplementation significantly reduces CRP levels but has no effect on TNF-α.

Nutraceutical Strategies for Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD): A Path to Liver Health

MASLD (Metabolic Dysfunction-Associated Steatotic Liver Disease) is a growing global concern. Nutraceuticals offer an appealing approach by targeting key mechanisms, such as oxidative stress, inflammation, lipid metabolism, and insulin resistance. This narrative review examines the role of various nutraceuticals in MASLD treatment, including silymarin, vitamin E, omega-3, curcumin, berberine, and coenzyme Q10. Some of them show promising biochemical and metabolic changes, while others produce conflicting results due to relevant studies' design and endpoints. To bridge the gap between research and reality, we summarize the data, create an interpretation heatmap, and develop a practical supplement guide. Regardless of their potential, nutraceuticals should be viewed as add-ons to lifestyle interventions rather than standalone treatments. Future research should focus on well-designed, long-term studies to prove efficacy, dosing, and combination strategies for personalized MASLD management.

Polysaccharides: The Sweet and Bitter Impacts on Cardiovascular Risk

Cardiovascular risk is a clinical factor that represents the probability of developing cardiovascular diseases (CVDs). This risk is shaped by non-modifiable and modifiable factors, including dietary patterns, which are the main lifestyle factor influencing CVD. Dietary polysaccharides, integral to nutrition, have varying effects on cardiovascular health depending on their type and source. They include starches, non-starch polysaccharides, and prebiotic fibers, categorized further into soluble and insoluble fibers. Soluble fibers, found in oats, legumes, and fruits, dissolve in water, forming gels that help lower serum cholesterol and modulate blood glucose levels. Insoluble fibers, present in whole grains and vegetables, aid in bowel regularity. The cardiovascular benefits of polysaccharides are linked to their ability to bind bile acids, reducing cholesterol levels, and the production of short-chain fatty acids by gut microbiota, which have anti-inflammatory properties. However, not all polysaccharides are beneficial; refined starches can lead to adverse metabolic effects, and chitosan to mixed effects on gut microbiota. This review examines the dualistic nature of polysaccharides, highlighting their beneficial roles in reducing cardiovascular risk factors and the potential adverse effects of specific types.

Meta-analysis of randomized controlled trials of the effects of synbiotics, probiotics, or prebiotics in controlling glucose homeostasis in non-alcoholic fatty liver disease patients

Background: Probiotics, prebiotics, and synbiotics have been suggested as a possible therapy for non-alcoholic fatty liver disease (NAFLD). However, their efficacy in improving blood glucose levels in NAFLD patients remains uncertain. Objective: The aim of this study was to assess the effects of supplementation with probiotics, prebiotics, or synbiotics on fasting blood glucose (FBG) levels in NAFLD patients. Methods: We searched PubMed, Web of Science, and Google Scholar for relevant trials published up to March 2024. Out of 3369 identified studies, 24 randomized controlled trials (RCTs) were included. Results: Probiotic, prebiotic, or synbiotic supplementation substantially reduced FBG (n = 23; standard mean difference (SMD) = -0.17; 95% confidence interval (CI): -0.30, -0.03; P = 0.02), fasting insulin levels (n = 12; SMD = -0.28; 95% CI: -0.49, -0.07; P = 0.01), and homeostatic model assessment for insulin resistance (HOMA-IR; n = 14; SMD = -0.28; 95% CI: -0.47, -0.09; P = 0.004). However, glycosylated hemoglobin (HbA1c; n = 3; SMD = -0.17; 95% CI: -0.48, 0.13; P = 0.27) was not significantly affected. The FBG-decreasing effect diminished as the body mass index (BMI) of volunteers increased in the baseline. Additionally, the number of probiotic strains and geographic region were shown to significantly affect FBG levels. Conclusion: This meta-analysis indicates that supplementation with probiotics, prebiotics, or synbiotics may aid in controlling glucose homeostasis in patients with NAFLD.

Comparative analysis of pectin and prebiotics on human microbiota modulation in early life stages and adults

The gut microbiota is essential in human health, influencing various physiological processes ranging from digestion and metabolism to immune function and mental health. Dietary fiber pectins and prebiotics have emerged as key modulators of gut microbiota composition and function, offering potential therapeutic implications for promoting gut health and preventing intestinal inflammatory diseases. In this review, we explore the modulation of gut microbiota by dietary fiber pectins and prebiotics in infants and adults. We begin with an overview of the gut microbiota composition and function in different age groups, highlighting the factors in shaping microbial communities in both age groups, especially the effect of diet. We then delve into the impact of dietary fiber pectins and prebiotics on gut microbiota composition and function, examining their effects on digestive health, intestinal barrier integrity, immune function, metabolic health, and mental health across different life stages. We further compare how aging affects the gut function and immune system, and we discuss the main health outcomes associated with dietary fiber intake and prebiotics, including the impact on digestive health, improvement in immune function, improvement in cholesterol and glucose metabolism, weight management, mental health, and prevention of diseases. Finally, we highlight the challenges and future directions for research. By advancing the understanding of gut microbiota dynamics and translating scientific insights into clinical practice, it could harness the full potential of dietary fiber pectins and prebiotics to optimize gut health, improve overall well-being across the lifespan, and increase longevity.

Lactitol properties in the treatment of patients with lifestyle-related diseases

Russia and most countries of the world are currently facing pressures on their health services because of the growing number of diseases associated with unhealthy lifestyles: type 2 diabetes, obesity, non-alcoholic fatty liver disease, etc. Lifestyle modification is the first prerequisite in the treatment of non-alcoholic fatty liver disease and other diseases associated with unhealthy lifestyle. The use of lactitol provides the opportunity to make this process more effective, as it is able to increase the production of butyrate, reduce the damage to the intestine barrier structure, and interact with sweet-taste receptors. Lactitol has a low glycaemic index, it is not absorbed in the intestine and is fermented like dietary fibres. The results of the studies showed that the metabolic response to this drug corresponds to a lower increase in plasma glucose, insulin and C-peptide levels compared to the use of glucose in healthy, non-obese men. It has been shown through various experiments in animals and in humans that lactitol also reduces the plasma triglyceride levels, probably due to reduced triglyceride absorption as a result of accelerated transit of intestinal contents. An important property of the drug is its ability to increase the glucagon-like peptide-1 (GLP-1) and PYY levels, which is accompanied by delayed gastric emptying and reduced hunger, which is essential in the treatment of obesity, type 2 diabetes mellitus and non-alcoholic fatty liver disease. A 120-day randomized controlled trial was conducted to assess the efficacy, safety, and tolerability of lactitol in 139 patients with nonalcoholic fatty liver disease. Twice-daily administration of lactitol 6 g in addition to lifestyle modification events has been shown to increase their efficacy expressed as a significant decrease in ALT levels and an increase in the AST/ALT ratio compared to control subjects. Lactitol can be considered as a metabolic corrector and used in the treatment of diseases associated with an unhealthy lifestyle.

The interaction between gut microbiome and bone health

PURPOSE OF REVIEW

This review critically examines interconnected health domains like gut microbiome, bone health, interleukins, chronic periodontitis, and coronavirus disease 2019 (COVID-19), offering insights into fundamental mechanisms and clinical implications, contributing significantly to healthcare and biomedical research.

RECENT FINDINGS

This review explores the relationship between gut microbiome and bone health, a growing area of study. It provides insights into skeletal integrity and potential therapeutic avenues. The review also examines interleukins, chronic periodontitis, and COVID-19, highlighting the complexity of viral susceptibility and immune responses. It highlights the importance of understanding genetic predispositions and immune dynamics in the context of disease outcomes. The review emphasizes experimental evidence and therapeutic strategies, aligning with evidence-based medicine and personalized interventions. This approach offers actionable insights for healthcare practitioners and researchers, paving the way for targeted therapeutic approaches and improved patient outcomes.

SUMMARY

The implications of these findings for clinical practice and research underscore the importance of a multidisciplinary approach to healthcare that considers the complex interactions between genetics, immune responses, oral health, and systemic diseases. By leveraging advances in biomedical research, clinicians can optimize patient care and improve health outcomes across diverse patient populations.

Prebiotic Treatment in Patients with Nonalcoholic Fatty Liver Disease (NAFLD)-A Randomized Pilot Trial

Several studies show that gut microbiotas in patients with nonalcoholic fatty liver disease (NAFLD) differ from those in a healthy population, suggesting that this alteration plays a role in NAFLD pathogenesis. We investigated whether prebiotic administration affects liver fat content and/or liver-related and metabolic parameters. Patients with NAFLD and metabolic syndrome (age: 50 ± 11; 79% men) were randomized to receive either 16 g/day of prebiotic (ITFs-inulin-type fructans) (n = 8) or placebo (maltodextrin) (n = 11) for 12 weeks. Patients were instructed to maintain a stable weight throughout the study. Liver fat content (measured by H1MRS), fecal microbiota, and metabolic, inflammatory, and liver parameters were determined before and after intervention. Fecal samples from patients who received the prebiotic had an increased content of Bifidobacterium (p = 0.025), which was not observed with the placebo. However, the baseline and end-of-study liver fat contents did not change significantly in the prebiotic and placebo groups, neither did the liver function tests' metabolic and inflammatory mediators, including fibroblast growth factor-19 and lipopolysaccharide-binding protein. Body weight remained stable in both groups. These findings suggest that prebiotic treatment without weight reduction is insufficient to improve NAFLD.

The effects of gut microbiome manipulation on glycemic indices in patients with non-alcoholic fatty liver disease: a comprehensive umbrella review

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a significant risk factor for non-alcoholic fatty liver disease (NAFLD). Increased fasting blood sugar (FBS), fasting insulin (FI), and insulin resistance (HOMA-IR) are observed in patients with NAFLD. Gut microbial modulation using prebiotics, probiotics, and synbiotics has shown promise in NAFLD treatment. This meta-umbrella study aimed to investigate the effects of gut microbial modulation on glycemic indices in patients with NAFLD and discuss potential mechanisms of action.

METHODS

A systematic search was conducted in PubMed, Web of Science, Scopus, and Cochrane Library until March 2023 for meta-analyses evaluating the effects of probiotics, prebiotics, and synbiotics on patients with NAFLD. Random-effect models, sensitivity analysis, and subgroup analysis were employed.

RESULTS

Gut microbial therapy significantly decreased HOMA-IR (ES: -0.41; 95%CI: -0.52, -0.31; P < 0.001) and FI (ES: -0.59; 95%CI: -0.77, -0.41; P < 0.001). However, no significant effect was observed on FBS (ES: -0.17; 95%CI: -0.36, 0.02; P = 0.082). Subgroup analysis revealed prebiotics had the most potent effect on HOMA-IR, followed by probiotics and synbiotics. For FI, synbiotics had the most substantial effect, followed by prebiotics and probiotics.

CONCLUSION

Probiotics, prebiotics, and synbiotics administration significantly reduced FI and HOMA-IR, but no significant effect was observed on FBS.

NAFLD in the 21st Century: Current Knowledge Regarding Its Pathogenesis, Diagnosis and Therapeutics

Non-alcoholic fatty liver disease (NAFLD) is a major public health issue worldwide. It is the most common liver disease in Western countries, andits global prevalence is estimated to be up to 35%. However, its diagnosis may be elusive, because liver biopsy is relatively rarely performed and usually only in advanced stages of the disease. Therefore, several non-invasive scores may be applied to more easily diagnose and monitor NAFLD. In this review, we discuss the various biomarkers and imaging scores that could be useful in diagnosing and managing NAFLD. Despite the fact that general measures, such as abstinence from alcohol and modulation of other cardiovascular disease risk factors, should be applied, the mainstay of prevention and management is weight loss. Bariatric surgery may be suggested as a means to confront NAFLD. In addition, pharmacological treatment with GLP-1 analogues or the GIP agonist tirzepatide may be advisable. In this review, we focus on the utility of GLP-1 analogues and GIP agonists in lowering body weight, their pharmaceutical potential, and their safety profile, as already evidenced inanimal and human studies. We also elaborate on other options, such as the use of vitamin E, probiotics, especially next-generation probiotics, and prebiotics in this context. Finally, we explore future perspectives regarding the administration of GLP-1 analogues, GIP agonists, and probiotics/prebiotics as a means to prevent and combat NAFLD. The newest drugs pegozafermin and resmetiron, which seem to be very promising, arealso discussed.

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.

Thioredoxin/Glutaredoxin Systems and Gut Microbiota in NAFLD: Interplay, Mechanism, and Therapeutical Potential

Non-alcoholic fatty liver disease (NAFLD) is a common clinical disease, and its pathogenesis is closely linked to oxidative stress and gut microbiota dysbiosis. Recently accumulating evidence indicates that the thioredoxin and glutaredoxin systems, the two thiol-redox dependent antioxidant systems, are the key players in the NAFLD's development and progression. However, the effects of gut microbiota dysbiosis on the liver thiol-redox systems are not well clarified. This review explores the role and mechanisms of oxidative stress induced by bacteria in NAFLD while emphasizing the crucial interplay between gut microbiota dysbiosis and Trx mediated-redox regulation. The paper explores how dysbiosis affects the production of specific gut microbiota metabolites, such as trimethylamine N-oxide (TMAO), lipopolysaccharides (LPS), short-chain fatty acids (SCFAs), amino acids, bile acid, and alcohol. These metabolites, in turn, significantly impact liver inflammation, lipid metabolism, insulin resistance, and cellular damage through thiol-dependent redox signaling. It suggests that comprehensive approaches targeting both gut microbiota dysbiosis and the thiol-redox antioxidant system are essential for effectively preventing and treating NAFLD. Overall, comprehending the intricate relationship between gut microbiota dysbiosis and thiol-redox systems in NAFLD holds significant promise in enhancing patient outcomes and fostering the development of innovative therapeutic interventions.

Effects of gut microbial therapy on lipid profile in individuals with non-alcoholic fatty liver disease: an umbrella meta-analysis study

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD), the most common liver disease, is closely associated with metabolic conditions such as obesity and diabetes mellitus, which significantly impact human health outcomes. The impaired lipid profiles observed in NAFLD individuals can further contribute to cardiovascular events. Despite the high prevalence of NAFLD, there is currently no confirmed intervention approved for its treatment. This study aimed to summarize the results of meta-analysis studies of randomized control trials assessing the impact of gut microbial therapy (probiotics, synbiotics, and prebiotics) on the lipid profile of individuals with NAFLD.

METHODS

A systematic search was conducted on PubMed, Scopus, Web of Science, and Cochrane Library up to November 1, 2022. Meta-analyses surveying the impact of microbial therapy on lipid profile parameters (triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and total cholesterol (TC)) in the NAFLD population were included in our umbrella review. The final effect size (ES) was estimated, and sensitivity and subgroup analyses were performed to explore heterogeneity.

RESULTS

Fifteen studies were included in this umbrella review. Microbial therapy significantly reduced TG (ES - 0.31, 95% CI - 0.51, - 0.11, P < 0.01), TC (ES - 1.04, 95% CI - 1.46, - 0.61, P < 0.01), and LDL (ES - 0.77, 95% CI - 1.15, - 0.39, P < 0.01) in individuals with NAFLD. However, the effect on HDL was not statistically significant (ES - 0.06; 95% CI - 0.19, 0.07, P = 0.39).

CONCLUSION

Considering the absence of approved treatments for NAFLD and the promising role of microbial therapies in improving the three lipid profiles components in individuals with NAFLD, the use of these agents as alternative treatment options could be recommended. The findings underscore the potential of gut microbial therapy, including probiotics, synbiotics, and prebiotics, in managing NAFLD and its associated metabolic complications.

TRIAL REGISTRATION

PROSPERO ( CRD42022346998 ).

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.