Anti-obesity properties of probiotics; a considerable medical nutrition intervention: Findings from an umbrella meta-analysis

The effects of probiotic supplementation and exercise training on liver enzymes and cardiometabolic markers in patients with non-alcoholic fatty liver disease: a systematic review and meta-analysis of randomized clinical trials

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver ailment worldwide, in which nonpharmacological strategies have a considerable role in the treatment. Probiotic supplementation as well as physical exercise can improve cardiometabolic parameters, but further research is needed to determine the effects of combined treatment versus exercise alone in managing NAFLD-associated biomarkers, primarily liver enzymes, lipid markers, and insulin resistance.

OBJECTIVES

This systematic review and meta-analysis aimed to evaluate the effects of probiotic supplementation, combined with exercise versus exercise alone, on liver enzymes and cardiometabolic markers in patients with NAFLD.

METHODS

A systematic review and meta-analysis of randomized clinical trials was performed by searching PubMed, Scopus, and Web of Science databases up to April 2024. The search was restricted to articles published in the English language and human studies. Random effects models were used to calculate weighted mean differences (WMD).

RESULTS

Pooled estimates (9 studies, 615 patients, intervention durations ranging from 8 to 48 weeks) revealed that probiotics plus exercise decreased aspartate transaminase (AST) [WMD=-5.64 U/L, p = 0.02], gamma-glutamyl transferase (GGT) [WMD=-7.09 U/L, p = 0.004], low-density lipoprotein (LDL) [WMD=-8.98 mg/dL, p = 0.03], total cholesterol (TC) [WMD=-16.97 mg/dL, p = 0.01], and homeostatic model assessment for insulin resistance (HOMA-IR) [WMD=-0.94, p = 0.005] significantly more than exercise only. However, probiotics plus exercise did not significantly change high-density lipoprotein (HDL) [WMD = 0.07 mg/dL, p = 0.9], fasting insulin [WMD=-1.47 µIU/mL, p = 0.4] or fasting blood glucose (FBG) [WMD=-1.57 mg/dL, p = 0.3] compared with exercise only. While not statistically significant, there were clinically relevant reductions in alanine aminotransferase (ALT) [WMD=-6.78 U/L, p = 0.1], triglycerides (TG) [WMD=-21.84 mg/dL, p = 0.1], and body weight (BW) [WMD=-1.45 kg, p = 0.5] for probiotics plus exercise compared with exercise only. The included studies exhibited significant heterogeneity for AST (I2 = 78.99%, p = 0.001), GGT (I2 = 73.87%, p = 0.004), LDL (I2 = 62.78%, p = 0.02), TC (I2 = 72.41%, p = 0.003), HOMA-IR (I2 = 93.86%, p = 0.001), HDL (I2 = 0.00%, p = 0.9), FBG (I2 = 66.30%, p = 0.01), ALT (I2 = 88.08%, p = 0.001), and TG (I2 = 85.46%, p = 0.001). There was no significant heterogeneity among the included studies for BW (I2 = 0.00%, p = 0.9).

CONCLUSION

Probiotic supplementation combined with exercise training elicited better results compared to exercise alone on liver enzymes, lipid profile, and insulin resistance in patients with NAFLD.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42023424290.

Effect of probiotics at different intervention time on glycemic control in patients with type 2 diabetes mellitus: a systematic review and meta-analysis

Background

Type 2 diabetes mellitus(T2DM) is characterized by hyperglycemia. Gut microbiome adjustment plays a positive part in glucose regulation, which has become a hotspot. Probiotics have been studied for their potential to control the gut flora and to treat T2DM. However, the conclusion of its glucose-lowering effect is inconsistent based on different probiotic intervention times.

Objectives

To comprehensively evaluate how various probiotic intervention times affect glycemic control in people with T2DM.

Methods

We retrieved PubMed, Embase, Web of Science, and Cochrane Library on randomized controlled trials(RCTs)regarding the impact of probiotics on glycemic control in patients with T2DM from the inception to November 16, 2023. Separately, two researchers conducted a literature analysis, data extraction, and bias risk assessment of the involved studies. We followed the PRISMA guidelines, used RevMan 5.4 software for meta-analysis, and assessed the risk of bias by applying the Cochrane Handbook for Systematic Reviews 5.1.0.

Results

We included eight RCTs with 507 patients. Meta-analysis revealed that the use of probiotics might considerably reduce levels of glycosylated hemoglobin (HbA1c) {mean deviation (MD) = -0.33, 95% confidence interval (CI) (-0.59, -0.07), p = 0.01}, Insulin {standard mean deviation (SMD) = -0.48, 95% CI (-0.74, -0.22), p = 0.0003} and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR){SMD = -1.36, 95% CI (-2.30, -0.41), p = 0.005} than placebo group. No statistically significant differences were found regarding fasting blood glucose (FBG) and body mass index (BMI) {SMD = -0.39, 95% CI (-0.83, 0.05), p = 0.08}, {SMD = -0.40, 95% CI (-1.07, 0.27), p = 0.25}, respectively. Subgroup analyses, grouped by intervention times, showed that six to eight weeks of intervention improved HbA1c compared to the control group (p < 0.05), both six to eight weeks and 12-24 weeks had a better intervention effect on Insulin, and HOMA-IR (p < 0.05).In contrast, there was no statistically significant variation in the length between FBG and BMI regarding duration.

Conclusion

This meta-analysis found probiotics at different intervention times play a positive role in modulating glucose in T2DM, specifically for HbA1c in six to eight weeks, Insulin and HOMA-IR in six to eight weeks, and 12-24 weeks. To confirm our findings, further excellent large-sample research is still required.

Systematic review registration

https://www.crd.york.ac.uk/prospero, identifier CRD42023483325.

Is There Evidence to Support Probiotic Use for Healthy People?

Probiotics are typically marketed as foods and dietary supplements, categories for products intended to maintain health in generally healthy populations and which, unlike drugs, cannot claim to treat or cure disease. This review addresses the existing evidence that probiotics are beneficial to healthy people. Our approach was to perform a descriptive review of efficacy evidence that probiotics can prevent urinary, vaginal, gastrointestinal, and respiratory infections, and improve risk factors associated with cardiovascular health or reduce antibiotic use. Other endpoints such as mental, dental, or immune health were not specifically addressed. We concluded that there is sufficient evidence of efficacy and safety for clinicians and consumers to consider using specific probiotics for some indications - such as the use of probiotics to support gut function during antibiotic use or to reduce the risk of respiratory tract infections - for certain people. However, we did not find a sufficiently high level of evidence to support unconditional, population-wide recommendations for other preventive endpoints we reviewed for healthy people. Although evidence for some indications is suggestive of the preventive benefits of probiotics, additional research is needed.

Sex differences in clinical risk factors in obese ischemic stroke patients with a history of smoking

Clinical risk factors associated obesity and smoking, as well as their combined effect, are not fully understood. This study aims to determine sex differences in risk factors in a population of acute ischemic stroke (AIS) patients who are obese and with a history of previous or current smoking.

METHODS

A retrospective analysis of risk factors in male and female AIS patients with baseline data of obesity and current or previous history of smoking, smoking, and obesity alone was determined. The primary predictor and outcome are risk factors associated with male and female AIS patients. Baseline risk factors were analyzed using a multivariate regression analysis to determine specific risk factors linked with the combined effect of obesity and current or previous history of smoking''.

RESULTS

Male obese AIS patients who are current or previous smokers were more likely to be older patients(OR = 1.024, 95% CI, 1.022-1.047, P = 0.033) that present with coronary artery disease (OR = 1.806, 95% CI, 1.028-3.174, P = 0.040), a history of alcohol use (OR = 2.873, 95% CI, 1.349-6.166, P = 0.006), elevated serum creatinine (OR = 4.724, 95% CI, 2.171-10.281, P < 0.001) and systolic blood pressure (OR = 1.029, 95% CI, 1.011-1.047, P < 0.002). Females were more associated with depression (OR = 0.432, 95% CI, 0.244-0.764, P = 0.004), previous TIA (OR = 0.319, 95% CI, 0.142-0.714, P < 0.005), and higher levels of HDL (OR = 0.938, 95% CI, 0.915-0.962, P < 0.001).

CONCLUSION

Our results reveal sex differences in risk factors in obese AIS patients with a current or past history of smoking. This finding emphasizes the need to develop management strategies to improve the care of obese AIS patients who are either current or former smokers.

The effects of prebiotic, probiotic or synbiotic supplementation on overweight/obesity indicators: an umbrella review of the trials' meta-analyses

Background

There is controversial data on the effects of prebiotic, probiotic, or synbiotic supplementations on overweight/obesity indicators. Thus, we aimed to clarify this role of biotics through an umbrella review of the trials' meta-analyses.

Methods

All meta-analyses of the clinical trials conducted on the impact of biotics on overweight/obesity indicators in general populations, pregnant women, and infants published until June 2023 in PubMed, Web of Sciences, Scopus, Embase, and Cochrane Library web databases included. The meta-analysis of observational and systematic review studies without meta-analysis were excluded. We reported the results by implementing the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) flowchart. The Assessment of Multiple Systematic Reviews-2 (AMSTAR2) and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) systems were used to assess the methodological quality and quality of evidence.

Results

Overall, 97 meta-analysis studies were included. Most studies were conducted on the effect of probiotics in both genders. Consumption of prebiotic: 8-66 g/day, probiotic: 104 -1.35×1015 colony-forming unit (CFU)/day, and synbiotic: 106-1.5×1011 CFU/day and 0.5-300 g/day for 2 to 104 weeks showed a favorable effect on the overweight/obesity indicators. Moreover, an inverse association was observed between biotics consumption and overweight/obesity risk in adults in most of the studies. Biotics did not show any beneficial effect on weight and body mass index (BMI) in pregnant women by 6.6×105-1010 CFU/day of probiotics during 1-25 weeks and 1×109-112.5×109 CFU/capsule of synbiotics during 4-8 weeks. The effect of biotics on weight and BMI in infants is predominantly non-significant. Prebiotics and probiotics used in infancy were from 0.15 to 0.8 g/dL and 2×106-6×109 CFU/day for 2-24 weeks, respectively.

Conclusion

It seems biotics consumption can result in favorable impacts on some anthropometric indices of overweight/obesity (body weight, BMI, waist circumference) in the general population, without any significant effects on birth weight or weight gain during pregnancy and infancy. So, it is recommended to intake the biotics as complementary medications for reducing anthropometric indices of overweight/obese adults. However, more well-designed trials are needed to elucidate the anti-obesity effects of specific strains of probiotics.

Gut microbiota in patients with prostate cancer: a systematic review and meta-analysis

BACKGROUND

Increasing evidence indicates that gut microbiota are closely related to prostate cancer. This study aims to assess the gut microbiota composition in patients with prostate cancer compared to healthy participants, thereby advancing understanding of gut microbiota's role in prostate cancer.

METHODS

A systematic search was conducted across PubMed, Web of Science, and Embase databases, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The methodological quality of included studies was evaluated using the Newcastle-Ottawa Scale (NOS), and pertinent data were analyzed. The kappa score assessed interrater agreement.

RESULTS

This study encompassed seven research papers, involving 250 prostate cancer patients and 192 controls. The kappa was 0.93. Meta-analysis results showed that alpha-diversity of gut microbiota in prostate cancer patients was significantly lower than in the control group. In terms of gut microbiota abundance, the ratio of Proteobacteria, Bacteroidia, Clostridia, Bacteroidales, Clostridiales, Prevotellaceae, Lachnospiraceae, Prevotella, Escherichia-Shigella, Faecalibacterium, and Bacteroides was higher in prostate cancer patients. Conversely, the abundance ratio of Actinobacteria, Bacteroidetes, Firmicutes, Selenomonadales, Veillonella, and Megasphaera was higher in the control group.

CONCLUSION

Our study reveals differences in alpha-diversity and abundance of gut microbiota between patients with prostate cancer and controls, indicating gut microbiota dysbiosis in those with prostate cancer. However, given the limited quality and quantity of selected studies, further research is necessary to validate these findings.

The Effect of Berberine Supplementation on Glycemic Control and Inflammatory Biomarkers in Metabolic Disorders: An Umbrella Meta-analysis of Randomized Controlled Trials

PURPOSE

Several meta-analyses reported berberine (BBR) supplementation improves glycemic parameters and inflammatory marker, but findings remain inconsistent. Therefore, this study was conducted.

METHODS

We systematically searched PubMed, Embase, Web of Science, Scopus, and Google Scholar to identify the relevant meta-analyses up to April 2023.

FINDINGS

BBR supplementation was effective in reducing fasting blood glucose (FBG) (ESWMD: -0.77; 95% CI: -0.90 to -0.63, and ESSMD: -0.65; 95% CI: -0.83 to -0.47), hemoglobin A1C (HbA1C) (ESWMD: -0.57; 95% CI: -0.68 to -0.46), homeostasis model assessment for insulin resistance (HOMA-IR) (ESWMD: -1.04; 95% CI: -1.66 to -0.42, and ESSMD: -0.71; 95% CI: -0.97 to -0.46), insulin (ESWMD: -1.00; 95% CI: -1.70 to -0.30, and ESSMD: -0.63; 95% CI: -0.94 to -0.32), interleukin (IL)-6 (ESSMD: -1.23; 95% CI: -1.61 to -0.85), tumor necrosis factor-α (TNF-α) (ESSMD: -1.04; 95% CI: -1.28 to -0.79), and C-reactive protein (CRP) (ESWMD: -0.62; 95% CI: -0.74 to -0.50, and ESSMD: -1.70; 95% CI: -2.21 to -1.19).

IMPLICATIONS

The finding of our umbrella showed that the supplementation of BBR could be effective in improving glycemic parameters and inflammatory marker in adults.

The gut microbiome in the fight against obesity: The potential of dietary factors

Obesity as a global public health burden has experienced a drastic growing trend recently. The management of obesity is challenging because of its complex etiology, and various factors are involved in its development, such as genetic and environmental factors. Different approaches are available to treat and/or manage obesity, including diet, physical activity, lifestyle changes, medications, and surgery. However, some of these approaches have inherent limitations and are closely associated with adverse effects. Therefore, probing into a novel/safe approach to treat and/or manage obesity is of fundamental importance. One such approach gaining renewed interest is the potential role of gut microbiota in obesity and its effectiveness in treating this condition. However, there is a dearth of comprehensive compilation of data on the potential role of the gut microbiome in obesity, particularly regarding dietary factors as a therapeutic approach. Therefore, this review aims to provide an updated overview of the role of gut microbiota in obesity, further highlighting the importance of dietary factors, particularly diet, prebiotics, and probiotics, as potential complementary and/or alternative therapeutic options. Moreover, the association of gut microbiota with obese or lean individuals has also been discussed.

Effects of probiotics in rats with experimental metabolic syndrome and periodontitis: An investigation of the intestine-adipose tissue axis

BACKGROUND

This study evaluated the systemic (intestine and adipose tissue) and local (periodontal tissues) impact of probiotic therapy in rats with metabolic syndrome (MS) associated or not with periodontitis (PE).

METHODS

Forty-eight rats received a high-fat diet for induction of MS for 16 weeks. They were subdivided into groups with (+) and without (-) PE, receiving (*) or not (**) receiving probiotics (PROB): MS (-**), MSP (-*), MSPE (+**), and MSPEP (+*). PROB administration (Bifidobacterium animalis subsp. lactis HN019) started on the 8th week of the study and PE was induced on the 14th week by placing ligature on the animals' lower first molars. Euthanasia occurred in the 16th week. Biomolecular, immunoenzymatic assays, and histomorphometric analyses were performed. The data obtained were statistically analyzed (ANOVA, Tukey, p < 0.05).

RESULTS

The MSPEP group exhibited reduced alveolar bone loss when compared with the MSPE group, as well as lower levels of hepatic steatosis and proteinuria (p < 0.05). In the intestinal environment, the MSPE group exhibited significantly lower villus height and crypt depth, as well as a greater increase in Bacillota when compared with the MSPEP group (p < 0.05). The MSPEP group showed lower adipokine gene expression (LEPR, NAMPT, and FABP4) in adipose tissue than the MSPE group (p < 0.05).

CONCLUSION

The probiotic B. lactis HN019 reduced the severity of experimental periodontitis and modulated the expression of lipogenic genes and intestinal morphological and microbiological parameters in rats with MS.

An In Vitro Study of the Impacts of Sweet Potato Chips with Potentially Probiotic Levilactobacillus brevis and Lactiplantibacillus plantarum on Human Intestinal Microbiota : Impacts of potato chips with probiotics on intestinal microbiota

This study formulated sweet potato chips with powdered potentially probiotic Levilactobacillus brevis (SPLB) and Lactiplantibacillus plantarum (SPLP) and evaluated their impacts on human intestinal microbiota during 48 h of in vitro colonic fermentation. L. brevis and L. plantarum kept high viable cell counts (> 6 log CFU/g) on sweet potato chips after freeze-drying and during 60 days of storage. SPLB and SPLP had satisfactory quality parameters during 60 days of storage. SPLB and SPLP increased the relative abundance of Lactobacillus ssp./Enterococcus spp. (3.84-10.22%) and Bifidobacterium spp. (3.25-12.45%) and decreased the relative abundance of Bacteroides spp./Prevotella spp. (8.56-2.16%), Clostridium histolyticum (8.23-2.33%), and Eubacterium rectale/Clostridium coccoides (8.07-1.33%) during 48 h of in vitro colonic fermentation. SPLB and SPLP achieved high positive prebiotic indexes (> 8.24), decreased pH values and sugar contents, and increased lactic acid and short-chain fatty acid production, proving selective stimulatory effects on beneficial bacterial groups forming the intestinal microbiota. The results showed that SPLB and SPLP have good stability and high viable cell counts of L. brevis and L. plantarum when stored under room temperature and caused positive impacts on human intestinal microbiota, making them potentially probiotic non-dairy snack options.

Bifidobacterium animalis subspecies lactis HN019 can reduce the sequelae of experimental periodontitis in rats modulating intestinal parameters, expression of lipogenic genes, and levels of hepatic steatosis

OBJECTIVE

To determine whether Bifidobacterium animalis subspecies lactis HN019 (B. lactis HN019) can reduce the sequelae of experimental periodontitis (EP) in rats modulating systemic parameters.

BACKGROUND

This study evaluated the effects of probiotic therapy (PROB) in the prevention of local and systemic damage resulting from EP.

METHODS

Forty-eight rats were allocated into four groups: C (control), PROB, EP, and EP-PROB. PROB (1 × 1010  CFU/mL) administration lasted 8 weeks and PE was induced on the 7th week by placing ligature on the animals' lower first molars. All animals were euthanized in the 9th week of the experiment. Biomolecular analyses, RT-PCR, and histomorphometric analyses were performed. The data obtained were analyzed statistically (ANOVA, Tukey, p < .05).

RESULTS

The EP group had higher dyslipidemia when compared to the C group, as well as higher levels of insulin resistance, proteinuria levels, percentages of systolic blood pressure, percentage of fatty hepatocytes in the liver, and expression of adipokines was up-regulated (LEPR, NAMPT, and FABP4). All these parameters (except insulin resistance, systolic blood pressure, LEPR and FABP4 gene expression) were reduced in the EP-PROB group when compared to the EP group. The EP group had lower villus height and crypt depth, as well as a greater reduction in Bacteroidetes and a greater increase in Firmicutes when compared to the EP-PROB group. Greater alveolar bone loss was observed in the EP group when compared to the EP-PROB group.

CONCLUSION

Bifidobacterium lactis HN019 can reduce the sequelae of EP in rats modulating intestinal parameters, attenuating expression of lipogenic genes and hepatic steatosis.

Effect of probiotic supplementation on gastrointestinal motility, inflammation, motor, non-motor symptoms and mental health in Parkinson's disease: a meta-analysis of randomized controlled trials

BACKGROUND

Parkinson's disease (PD) is the second most common neurodegenerative disease worldwide. Gut dysbiosis is hypothesized to cause PD; therefore, whether probiotics can be used as adjuvants in the treatment of PD is being actively investigated.

AIMS

We performed a systematic review and meta-analysis to evaluate the effectiveness of probiotic therapy in PD patients.

METHODS

PUBMED/MEDLINE, EMBASE, Cochrane, Scopus, PsycINFO and Web of Science databases were searched till February 20, 2023. The meta-analysis used a random effects model and the effect size was calculated as mean difference or standardized mean difference. We assessed the quality of the evidence using the Grade of Recommendations Assessment, Development and Evaluation (GRADE) approach.

RESULTS

Eleven studies involving 840 participants were included in the final analysis. This meta-analysis showed high-quality evidence of improvement in Unified PD Rating Scale Part III motor scale (standardized mean difference [95% confidence interval]) (- 0.65 [- 1.11 to - 0.19]), non-motor symptom (- 0.81 [- 1.12 to - 0.51]), and depression scale (- 0.70 [- 0.93 to -0.46]). Moderate to low quality evidence of significant improvement was observed in gastrointestinal motility (0.83 [0.45-1.10]), quality of life (- 1.02 [- 1.66 to - 0.37]), anxiety scale (- 0.72 [- 1.10 to - 0.35]), serum inflammatory markers (- 5.98 [- 9.20 to - 2.75]), and diabetes risk (- 3.46 [- 4.72 to - 2.20]). However, there were no significant improvements in Bristol Stool Scale scores, constipation, antioxidant capacity, and risk of dyslipidemia. In a subgroup analysis, probiotic capsules improved gastrointestinal motility compared to fermented milk.

CONCLUSION

Probiotic supplements may be suitable for improving the motor and non-motor symptoms of PD and reducing depression. Further research is warranted to determine the mechanism of action of probiotics and to determine the optimal treatment protocol.

Immune mechanism of gut microbiota and its metabolites in the occurrence and development of cardiovascular diseases

The risk of cardiovascular disease (CVD) is associated with unusual changes in the human gut microbiota, most commonly coronary atherosclerotic heart disease, hypertension, and heart failure. Immune mechanisms maintain a dynamic balance between the gut microbiota and the host immune system. When one side changes and the balance is disrupted, different degrees of damage are inflicted on the host and a diseased state gradually develops over time. This review summarizes the immune mechanism of the gut microbiota and its metabolites in the occurrence of common CVDs, discusses the relationship between gut-heart axis dysfunction and the progression of CVD, and lists the currently effective methods of regulating the gut microbiota for the treatment of CVDs.

Probiotic therapy, a novel and efficient adjuvant approach to improve glycemic status: An umbrella meta-analysis

BACKGROUND

Probiotics exert several promoting effects on the glycemic status, however, the results of meta-analyses are inconsistent. we conducted an umbrella meta-analysis, across existing systematic reviews and meta-analyses of clinical trials to determine the definite effects of supplementation with probiotics on glycemic indices.

METHODS

A comprehensive systematic search of PubMed/Medline, Scopus, EMBASE, and Web of Science was carried out till August 2021. The random-effects model was employed to conduct meta-analysis. Meta-analysis studies of randomized clinical trials examining the impacts of probiotics supplementation on glycemic indices were qualified in the current umbrella meta-analysis.

RESULTS

48 articles out of 693 in the literature search qualified for inclusion in the umbrella meta-analysis. Pooled effects of probiotics on fasting plasma glucose (FPG), hemoglobin A1C (HbA1c), homeostatic model assessment for insulin resistance (HOMA-IR), and insulin levels were reported in articles 45, 21, 35, and 33, respectively. The analysis indicated a significant decrease of FPG (ES= -0.51 mg/dL; 95% CI: -0.63, -0.38, p < 0.001), HbA1c (ES = -0.32 mg/dL; 95% CI: -0.44, -0.20, p < 0.001), HOMA-IR (ES= -0.56; 95% CI: -0.66, -0.47, p < 0.001), and insulin levels (ES= -1.09 IU/mL; 95% CI: -1.37, -0.81, p = 0.006) by probiotics supplementation.

CONCLUSION

Probiotics have amending effects on FPG, HbA1c, HOMA-IR, and insulin levels. A < 8-week period of probiotic supplementation in the moderate dosages (10⁸ or 10⁹ CFU) is an efficacious approach in improving glycemic parameters. Overall, probiotics could be recommended as an adjuvant anti-hyperglycemic agent.