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Effects of dietary fibers or probiotics on functional constipation symptoms and roles of gut microbiota: a double-blinded randomized placebo trial.
Lai, H, Li, Y, He, Y, Chen, F, Mi, B, Li, J, Xie, J, Ma, G, Yang, J, Xu, K, et al
Gut microbes. 2023;15(1):2197837
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Functional constipation is characterised by continuously difficult, incomplete, or infrequent defecation, without an organic origin. Effective intervention strategies are required to relieve the functional constipation difficulties, particularly in rapidly aging populations, such as Chinese populations. The aim of this study was to evaluate the effectiveness of three dietary fibre formulas (polydextrose, psyllium husk, and wheat bran + psyllium husk) and one probiotic supplement on the improvement of constipation symptoms among Chinese adults with functional constipation. This study was a double-blinded randomised placebo-controlled trial which enrolled 250 participants who were randomly assigned to one of the five groups. Results showed: - that daily supplement of three prebiotic formulas with dietary fibres, or a probiotic formula effectively relieved hard stool in functional constipation patients after 4 weeks intervention. - the capacity of gut microbial genera in shaping the intervention responsiveness in the improvement of bowel movement frequency, Bristol stool scale score, and degree of defecation straining. Authors conclude that the pre or probiotic interventions may modulate gut microbiota, associated with intestinal health.
Abstract
Dietary fibers/probiotics may relieve constipation via optimizing gut microbiome, yet with limited trial-based evidences. We aimed to evaluate the effects of formulas with dietary fibers or probiotics on functional constipation symptoms, and to identify modulations of gut microbiota of relevance. We conducted a 4-week double-blinded randomized placebo-controlled trial in 250 adults with functional constipation. Intervention: A: polydextrose; B: psyllium husk; C: wheat bran + psyllium husk; D: Bifidobacterium animalis subsp. lactis HN019 + Lacticaseibacillus rhamnosus HN001; Placebo: maltodextrin. Oligosaccharides were also included in group A to D. 16S rRNA sequencing was used to assess the gut microbiota at weeks 0, 2, and 4. A total of 242 participants completed the study. No time-by-group effect was observed for bowel movement frequency (BMF), Bristol stool scale score (BSS), and degree of defecation straining (DDS), while BSS showed mean increases of 0.95-1.05 in group A to D (all P < 0.05), but not significantly changed in placebo (P = 0.170), and 4-week change of BSS showed similarly superior effects of the interventions as compared placebo. Group D showed a marginal reduction in plasma 5-hydroxytryptamine. Group A resulted in a higher Bifidobacterium abundance than placebo at week 2 and 4. Fourteen genera showed intervention-specific increasing or decreasing trends continuously, among which Anaerostipes showed increasing trends in groups B and C, associated with BMF increase. Random forest models identified specific baseline microbial genera panels predicting intervention responders. In conclusion, we found that the dietary fibers or probiotics may relieve hard stool, with intervention-specific changes in gut microbiota relevant to constipation relief. Baseline gut microbiota may predispose the intervention responsiveness. ClincialTrials.gov number, NCT04667884. What is the context?Supplementation of dietary fibers, such as psyllium husk or wheat bran (10 ~ 15 g/day) may relieve constipation symptoms, but bloating and flatulence are major concerns on a high fiber intake.Functional constipation patients had alternated gut microbiota profiles, while meta-analysis suggested that multispecies probiotics may increase bowel movement frequency and relieve hard stool in functional constipation.Dietary fibers or probiotics may lead to before-after changes of gut microbiota in patients with functional constipation, but time-series continued changes of gut microbiota during the intervention are unknown.Elevation of 5-hydroxytryptamine synthesis in enterochromaffin cells may affect bowel movement. And the elevated plasma 5-hydroxytryptamine was observed in functional constipation patients.What is new? Daily supplement of three prebiotic formulas with dietary fibers (polydextrose, psyllium husk, wheat bran, together with oligosaccharides), or a probiotic formula with Bifidobacterium animalis subsp. lactis HN019 + Lacticaseibacillus rhamnosus HN001 effectively relieved hard stool in functional constipation patients after 4 weeks intervention.We identified continued increasing or decreasing gut microbial genera over the intervention. Dietary fiber – gut microbiota (Anaerostipes)—constipation relieve (bowel movement frequency) evidence axis was identified in this human trial.Probiotic supplementation marginally reduced plasma 5-hydroxytryptamine, possibly associated with changes in BMF-related gut microbial genera.Intervention-specific baseline gut microbiota well predicted the responsiveness of constipation symptom relief.What is the impact? We provided references for the dosage and duration of dietary fiber/probiotics recommendations for adults with functional constipation, and advanced the microbial genera evidences of the fibers/probiotics-microbiota-laxation theory in humans.
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Wild blueberry (poly)phenols can improve vascular function and cognitive performance in healthy older individuals: a double-blind randomized controlled trial.
Wood, E, Hein, S, Mesnage, R, Fernandes, F, Abhayaratne, N, Xu, Y, Zhang, Z, Bell, L, Williams, C, Rodriguez-Mateos, A
The American journal of clinical nutrition. 2023;117(6):1306-1319
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The risk of developing both cardiovascular and neurodegenerative diseases increases with aging. Growing evidence from epidemiological and human intervention trials indicates that (poly)phenols may have cardioprotective properties as well as the ability to improve cognitive function. The aim of this study was to investigate the effects of daily wild blueberry (WBB) (poly)phenol consumption on vascular function and cognitive performance in healthy older individuals. This study was a randomised, double-blinded, placebo-controlled parallel design study. A total of 61 healthy older individuals were recruited and randomly assigned to one of the two arms; placebo intervention or blueberry intervention group. Results showed that long-term consumption of a dietary achievable amount of WBB enhanced vascular and cognitive function in older adults. Authors conclude that gut microbiota and vascular blood flow may play important roles in mediating the cognitive benefits shown by the consumption of (poly)phenol-rich foods.
Abstract
BACKGROUND Evidence suggests that the intake of blueberry (poly)phenols is associated with improvements in vascular function and cognitive performance. Whether these cognitive effects are linked to increases in cerebral and vascular blood flow or changes in the gut microbiota is currently unknown. METHODS A double-blind, parallel randomized controlled trial was conducted in 61 healthy older individuals aged 65-80 y. Participants received either 26 g of freeze-dried wild blueberry (WBB) powder (302 mg anthocyanins) or a matched placebo (0 mg anthocyanins). Endothelial function measured by flow-mediated dilation (FMD), cognitive function, arterial stiffness, blood pressure (BP), cerebral blood flow (CBF), gut microbiome, and blood parameters were measured at baseline and 12 wk following daily consumption. Plasma and urinary (poly)phenol metabolites were analyzed using microelution solid-phase extraction coupled with liquid chromatography-mass spectrometry. RESULTS A significant increase in FMD and reduction in 24 h ambulatory systolic BP were found in the WBB group compared with the placebo group (0.86%; 95% CI: 0.56, 1.17, P < 0.001; -3.59 mmHg; 95% CI: -6.95, -0.23, P = 0.037; respectively). Enhanced immediate recall on the auditory verbal learning task, alongside better accuracy on a task-switch task was also found following WBB treatment compared with placebo (P < 0.05). Total 24 h urinary (poly)phenol excretion increased significantly in the WBB group compared with placebo. No changes in the CBF or gut microbiota composition were found. CONCLUSIONS Daily intake of WBB powder, equivalent to 178 g fresh weight, improves vascular and cognitive function and decreases 24 h ambulatory systolic BP in healthy older individuals. This suggests that WBB (poly)phenols may reduce future CVD risk in an older population and may improve episodic memory processes and executive functioning in older adults at risk for cognitive decline. Clinical Trial Registration number in clinicaltrials.gov: NCT04084457.
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Probiotics fortify intestinal barrier function: a systematic review and meta-analysis of randomized trials.
Zheng, Y, Zhang, Z, Tang, P, Wu, Y, Zhang, A, Li, D, Wang, CZ, Wan, JY, Yao, H, Yuan, CS
Frontiers in immunology. 2023;14:1143548
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Intestinal barrier function is closely related to the pathogenesis of various immune and inflammatory diseases. The intestinal microbiota plays an essential role in maintaining gut homeostasis and functionality in the presence of pro-inflammatory and anti-inflammatory microbes. The aim of this study was to comprehensively evaluate the role of probiotics in contributing to intestinal barrier function, and the related immune function, inflammatory status, and gut microbiota composition. This study was a systematic review of 28 articles (qualitative synthesis), and a meta-analysis of 26 randomised controlled trials. Results showed that probiotics could significantly improve intestinal barrier function according to specific indicators. The meta-analysis also indicated that probiotic supplementation could reduce inflammatory factors. Furthermore, it also demonstrated that probiotics could modulate gut microbiota compositions by elevating the abundances of Bifidobacterium and Lactobacillus. Authors conclude that probiotics could improve intestinal barrier function to some extent, but more high-quality randomised controlled studies are needed to reach a solid conclusion.
Expert Review
Conflicts of interest:
None
Take Home Message:
The probiotics Bifidobacterium and Lactobacillus may be beneficial for health by addressing imbalances in gut bacteria (dysbiosis), reducing inflammation in the gut and improving the integrity and function of the gut barrier
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Introduction
Probiotics are microorganisms that are considered beneficial to health. The aim of this study was to assess the role of probiotics in protecting intestinal barrier function as well as their effects on the composition of gut microbiota, inflammatory status, and immune function for reducing the risk of related diseases.
Methods
26 randomised controlled trials (RCTs) published between 2005-2021 with a total population of n=1891 (n = 955 Intervention, n = 936 controls)) were included in the meta-analysis. Outcome measures were categorised under indicators relating to intestinal barrier function, inflammatory markers, immune function and microbiota composition. Studies were conducted worldwide with participants being healthcare patients or athletes. Study durations ranged from 3 days to 6 months. Different dosages and forms of probiotics were used. Data was pooled for Bifidobacterium, Lactobacillus, Enterobacteriaceae and Enterococcus species.
Results
Gut barrier function in the probiotic groups was improved as measured by transepithelial resistance (TER) mean difference (MD) 5.27 {95% CI, 3.82 to 6.72, p = < 0.00001], lipopolysaccharide (LPS) standardised mean difference (SMD) -0.47 (95% CI, -0.85 to -0.09, p = 0.02), serum zonulin SMD -1.58 (95% CI,-2.49 to -0.66, p = 0.0007), and endotoxin SMD -3.20 (95% CI, -5.41 to - 0.98, p = 0.005).
The inflammatory markers interleukin 6 (IL-6), C-reactive protein (CRP) and tumour necrosis factor-alpha (TNF-a) were also improved compared to control groups. Lactobacillus (95% CI p=0.02) and Bifidobacterium (95% CI, p=0.01) enhanced microbial composition, however, Enterobacteriaceae and Enterococcus species did not. Immune function as measured by Immunoglobulin A (IgA), Immunoglobulin G IgG and Immunoglobulin M (IgM) were not improved.
Conclusion
The findings of this study suggest that intestinal barrier function and microbial composition could be improved using probiotics. They were also found to help alleviate inflammation. Further studies of high quality are however needed to confirm these results.
No conflicts of interest were reported.
Clinical practice applications:
The use of the probiotics Bifidobacterium and Lactobacillus may be beneficial for:
- supporting the integrity of gut barrier function
- improving the composition of gut microbiota
- lowering inflammation
Considerations for future research:
High heterogeneity between studies may affect the applicability of the results. Future research development should focus on the following areas:
- testing methods
- study durations
- measuring indicators
- the type and dose of probiotics
Abstract
BACKGROUND Probiotics play a vital role in treating immune and inflammatory diseases by improving intestinal barrier function; however, a comprehensive evaluation is missing. The present study aimed to explore the impact of probiotics on the intestinal barrier and related immune function, inflammation, and microbiota composition. A systematic review and meta-analyses were conducted. METHODS Four major databases (PubMed, Science Citation Index Expanded, CENTRAL, and Embase) were thoroughly searched. Weighted mean differences were calculated for continuous outcomes with corresponding 95% confidence intervals (CIs), heterogeneity among studies was evaluated utilizing I2 statistic (Chi-Square test), and data were pooled using random effects meta-analyses. RESULTS Meta-analysis of data from a total of 26 RCTs (n = 1891) indicated that probiotics significantly improved gut barrier function measured by levels of TER (MD, 5.27, 95% CI, 3.82 to 6.72, P < 0.00001), serum zonulin (SMD, -1.58, 95% CI, -2.49 to -0.66, P = 0.0007), endotoxin (SMD, -3.20, 95% CI, -5.41 to -0.98, P = 0.005), and LPS (SMD, -0.47, 95% CI, -0.85 to -0.09, P = 0.02). Furthermore, probiotic groups demonstrated better efficacy over control groups in reducing inflammatory factors, including CRP, TNF-α, and IL-6. Probiotics can also modulate the gut microbiota structure by boosting the enrichment of Bifidobacterium and Lactobacillus. CONCLUSION The present work revealed that probiotics could improve intestinal barrier function, and alleviate inflammation and microbial dysbiosis. Further high-quality RCTs are warranted to achieve a more definitive conclusion. CLINICAL TRIAL REGISTRATION https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=281822, identifier CRD42021281822.
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Effect of synbiotic supplementation on immune parameters and gut microbiota in healthy adults: a double-blind randomized controlled trial.
Li, X, Hu, S, Yin, J, Peng, X, King, L, Li, L, Xu, Z, Zhou, L, Peng, Z, Ze, X, et al
Gut microbes. 2023;15(2):2247025
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The gut microbiota is involved in regulating immunity and synbiotics, that is combinations of pro- and prebiotics, may therefore modulate immunity via the gut microbiota. The aim of this randomised, double-blind, placebo-controlled trial was to evaluate the immune-modulatory effects of a synbiotic supplement (containing Bifidobacterium lactis HN019, Lactobacillus rhamnosus HN001 and fructo-oligosaccharide) in healthy adults. Outcome measures included C-reactive protein (CRP, an inflammatory marker), various pro- and anti-inflammatory cytokines, stool and salivary secretory IgA (sIgA), leukocytes, microbial stool analysis and occurrence, duration, and severity of upper respiratory tract infections (URTI). Compared to the control group, a significant reduction in the inflammatory markers CRP and interferon-gamma and an increase in the anti-inflammatory interleukin-10 and stool sIgA were observed in the supplementation group. There were no differences in types of leukocytes or URTIs between groups. Significant favourable changes in microbiome analysis were observed in the supplemented group which correlated with the observed improvements in inflammatory markers. These changes were dependent on the baseline composition of the microbiome. No adverse events were reported. The authors conclude that the data show that synbiotics are of benefit to healthy adults and support the concept of personalised supplementation.
Abstract
Synbiotics are increasingly used by the general population to boost immunity. However, there is limited evidence concerning the immunomodulatory effects of synbiotics in healthy individuals. Therefore, we conducted a double-blind, randomized, placebo-controlled study in 106 healthy adults. Participants were randomly assigned to receive either synbiotics (containing Bifidobacterium lactis HN019 1.5 × 108 CFU/d, Lactobacillus rhamnosus HN001 7.5 × 107 CFU/d, and fructooligosaccharide 500 mg/d) or placebo for 8 weeks. Immune parameters and gut microbiota composition were measured at baseline, mid, and end of the study. Compared to the placebo group, participants receiving synbiotic supplementation exhibited greater reductions in plasma C-reactive protein (P = 0.088) and interferon-gamma (P = 0.008), along with larger increases in plasma interleukin (IL)-10 (P = 0.008) and stool secretory IgA (sIgA) (P = 0.014). Additionally, synbiotic supplementation led to an enrichment of beneficial bacteria (Clostridium_sensu_stricto_1, Lactobacillus, Bifidobacterium, and Collinsella) and several functional pathways related to amino acids and short-chain fatty acids biosynthesis, whereas reduced potential pro-inflammatory Parabacteroides compared to baseline. Importantly, alternations in anti-inflammatory markers (IL-10 and sIgA) were significantly correlated with microbial variations triggered by synbiotic supplementation. Stratification of participants into two enterotypes based on pre-treatment Prevotella-to-Bacteroides (P/B) ratio revealed a more favorable effect of synbiotic supplements in individuals with a higher P/B ratio. In conclusion, this study suggested the beneficial effects of synbiotic supplementation on immune parameters, which were correlated with synbiotics-induced microbial changes and modified by microbial enterotypes. These findings provided direct evidence supporting the personalized supplementation of synbiotics for immunomodulation.
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The Impact of Synbiotic Treatment on the Levels of Gut-Derived Uremic Toxins, Inflammation, and Gut Microbiome of Chronic Kidney Disease Patients-A Randomized Trial.
Mitrović, M, Stanković-Popović, V, Tolinački, M, Golić, N, Soković Bajić, S, Veljović, K, Nastasijević, B, Soldatović, I, Svorcan, P, Dimković, N
Journal of renal nutrition : the official journal of the Council on Renal Nutrition of the National Kidney Foundation. 2023;33(2):278-288
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The gut microbiome consists of more than 100 trillion bacteria and plays an important role in normal body functioning. There is increasing evidence that gut microbiome alteration can affect multiple organ systems and also lead to numerous chronic diseases, such as chronic kidney disease (CKD). The aim of this study was to assess the efficacy and safety of synbiotic treatment in reducing the levels of gut-derived uremic toxins and serum inflammatory markers and its impact on gut microbiome, with controlled factors such as diet and antibiotic usage. This study was a single-centre, randomised, double-blind, placebo-controlled study. After a 2-week run-in period under prescribed diet, patients were randomised into 2 groups, one receiving synbiotic therapy and the other receiving placebo. Results showed that in comparison to placebo: - synbiotic treatment significantly altered levels of indoxyl sulfate [uremic toxin] and p-cresyl sulfate [uremic toxin] in the intervention arm, and - only the dynamic of total serum indoxyl sulfate was significant. Authors conclude that synbiotics are a safe and an effective therapeutic strategy that may help to decrease levels of uremic toxins and microinflammation in chronic kidney disease patients.
Abstract
OBJECTIVE Altering dysbiotic gut flora through synbiotic supplementation has recently been recognized as a potential treatment strategy to reduce the levels of gut-derived uremic toxins and decrease inflammation. Assessing its efficacy and safety has been the main goal of our randomized, double-blind, placebo-controlled study. METHODS A total of 34 nondialyzed chronic kidney disease patients, aged ≥18 years, with an estimated glomerular filtration rate between 15 and 45 mL/minute, were randomized either to an intervention group (n = 17), receiving synbiotic (Lactobacillus acidophilus, Lactobacillus casei, and Bifidobacterium lactis, 32 billion colony forming units per day plus 3.2 g of inulin), or control group (n = 17), receiving placebo during 12 weeks. The impact of treatment on the dynamic of serum levels of gut-derived uremic toxins, total serum indoxyl sulfate, p-cresyl sulfate, and trimethylamine N-oxide, was defined as the primary outcome of the study. Secondary outcomes included changes in the stool microbiome, serum interleukin-6 levels, high-sensitivity C-reactive protein, estimated glomerular filtration rate, albuminuria, diet, gastrointestinal symptom dynamics, and safety. Serum levels of uremic toxins were determined using ultraperformance liquid chromatography. The stool microbiome analysis was performed using the 16S ribosomal ribonucleic acid gene sequencing approach. RESULTS Synbiotic treatment significantly modified gut microbiome with Bifidobacteria, Lactobacillus, and Subdoligranulum genera enrichment and consequently reduced serum level of indoxyl sulfate (ΔIS -21.5% vs. 5.3%, P < .001), improved estimated glomerular filtration rate (ΔeGFR 12% vs. 8%, P = .029), and decreased level of high-sensitivity C-reactive protein (-39.5 vs. -8.5%, P < .001) in treated patients. Two patients of the intervention arm complained of increased flatulence. No other safety issues were noted. CONCLUSION Synbiotics could be available, safe, and an effective therapeutic strategy we could use in daily practice in order to decrease levels of uremic toxins and microinflammation in chronic kidney disease patients.
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Impact of dietary interventions on pre-diabetic oral and gut microbiome, metabolites and cytokines.
Shoer, S, Shilo, S, Godneva, A, Ben-Yacov, O, Rein, M, Wolf, BC, Lotan-Pompan, M, Bar, N, Weiss, EI, Houri-Haddad, Y, et al
Nature communications. 2023;14(1):5384
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Pre-diabetes, a condition characterized by elevated blood glucose levels but below diabetes thresholds, is a significant risk factor for the development of type 2 diabetes, as well as other comorbidities including cardiovascular and kidney diseases. Diet plays a critical role in the development of hyperglycaemia and the onset of pre-diabetes. The aim of this study was to assess the impact of a personalized postprandial glucose-targeting diet (PPT), as well as the standard of care Mediterranean diet (MED), on the oral and gut microbiome, metabolites and cytokines in 200 pre-diabetic individuals. This study was a biphasic, randomised, controlled, single-blind dietary intervention. Phase one included a six-month intervention that compared two diets targeting glycaemic control, while phase two included a six-month follow-up period. Participants (n = 225) were randomly assigned in a 1:1 ratio to a PPT (n = 113) or a MED (n = 112). Results showed that participants assigned to the PPT diet had significant changes in 19 gut microbial species, 14 gut and one oral microbial pathway, 86 serum metabolites and four cytokines. Participants assigned to the MED diet showed significant changes in five gut and one oral microbial species, 18 gut microbial pathways, 27 serum metabolites and four cytokines. Authors conclude that dietary interventions can affect the microbiome, cardiometabolic profile and immune response of the host. Thus, diets such as the PPT used in this study, which takes into account microbiome features, could be designed to affect the microbiome and inflict desired metabolic outcomes.
Abstract
Diabetes and associated comorbidities are a global health threat on the rise. We conducted a six-month dietary intervention in pre-diabetic individuals (NCT03222791), to mitigate the hyperglycemia and enhance metabolic health. The current work explores early diabetes markers in the 200 individuals who completed the trial. We find 166 of 2,803 measured features, including oral and gut microbial species and pathways, serum metabolites and cytokines, show significant change in response to a personalized postprandial glucose-targeting diet or the standard of care Mediterranean diet. These changes include established markers of hyperglycemia as well as novel features that can now be investigated as potential therapeutic targets. Our results indicate the microbiome mediates the effect of diet on glycemic, metabolic and immune measurements, with gut microbiome compositional change explaining 12.25% of serum metabolites variance. Although the gut microbiome displays greater compositional changes compared to the oral microbiome, the oral microbiome demonstrates more changes at the genetic level, with trends dependent on environmental richness and species prevalence in the population. In conclusion, our study shows dietary interventions can affect the microbiome, cardiometabolic profile and immune response of the host, and that these factors are well associated with each other, and can be harnessed for new therapeutic modalities.
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Gut microbiota in nonalcoholic fatty liver disease: a PREDIMED-Plus trial sub analysis.
Gómez-Pérez, AM, Ruiz-Limón, P, Salas-Salvadó, J, Vioque, J, Corella, D, Fitó, M, Vidal, J, Atzeni, A, Torres-Collado, L, Álvarez-Sala, A, et al
Gut microbes. 2023;15(1):2223339
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Nonalcoholic fatty liver disease (NAFLD) is the main cause of chronic liver disease. The aim of this study was to evaluate the changes in the microbiota associated with changes in biochemical markers of NAFLD/NASH after an intervention. This substudy was conducted in the frame of the PREDIMED-Plus study, a 6-year, multicentre, randomised clinical trial for primary prevention of cardiovascular disease (CVD) conducted in men aged 55–75 years and women aged 60–75 years with overweight or obesity and metabolic syndrome. Results showed a relationship between liver disease biochemical indexes changes and gut microbiota changes within a context of a Mediterranean lifestyle. In fact, two noninvasive scores for liver steatosis and liver fibrosis, usually used in clinical practice, could differentiate gut microbiota populations. Authors conclude that their findings highlight the importance of lifestyle intervention in the modulation of gut microbiota and the management of metabolic syndrome and its hepatic manifestations.
Abstract
To evaluate the changes in the gut microbiota associated with changes in the biochemical markers of nonalcoholic fatty liver disease (NAFLD) after a lifestyle intervention with the Mediterranean diet. Participants (n = 297) from two centers of PREDIMED-Plus trial (Prevención con Dieta Mediterránea) were divided into three different groups based on the change tertile in the Hepatic Steatosis Index (HSI) or the Fibrosis-4 score (FIB-4) between baseline and one year of intervention. One-year changes in HSI were: tertile 1 (T1) (-24.9 to -7.51), T2 (-7.5 to -1.86), T3 (-1.85 to 13.64). The most significant differences in gut microbiota within the year of intervention were observed in the T1 and T3. According to the FIB-4, participants were categorized in non-suspected fibrosis (NSF) and with indeterminate or suspected fibrosis (SF). NSF participants showed higher abundances of Alcaligenaceae, Bacteroidaceae, Bifidobacteriaceae, Clostridiaceae, Enterobacteriaceae, Peptostreptococcaceae, Verrucomicrobiaceae compared to those with SF. Then, participants were divided depending on the FIB-4 tertile of change: T1 (-89.60 to -5.57), T2 (-5.56 to 11.4), and T3 (11.41 to 206.24). FIB-4 T1 showed a decrease in Akkermansia and an increase in Desulfovibrio. T2 had an increase in Victivallaceae, Clostridiaceae, and Desulfovibrio. T3 showed a decrease in Enterobacteriaceae, and an increase in Sutterella, Faecalibacterium, and Blautia. A relation between biochemical index changes of NAFLD/NASH (HSI and FIB-4) and gut microbiota changes were found. These observations highlight the importance of lifestyle intervention in the modulation of gut microbiota and the management of metabolic syndrome and its hepatic manifestations. What You Need to KnowWhat is the context:Obesity and metabolic syndrome have been associated with nonalcoholic fatty liver disease (NAFLD). Gut microbiota and its interaction with the environment may play a key role in NAFLD.What is new:Mediterranean diet and physical activity can modify the scores for liver steatosis (HSI) and liver fibrosis (FIB−4) in only one year. A relation between the changes in these scores and gut microbiota changes was found.What is the impact:The discovery of microbiota-based biomarkers for NAFLD and the development of strategies to modulate gut microbiota in the treatment of NAFLD.
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Effects of a low FODMAP diet on gut microbiota in individuals with treated coeliac disease having persistent gastrointestinal symptoms - a randomised controlled trial.
Herfindal, AM, van Megen, F, Gilde, MKO, Valeur, J, Rudi, K, Skodje, GI, Lundin, KEA, Henriksen, C, Bøhn, SK
The British journal of nutrition. 2023;130(12):2061-2075
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Coeliac disease (CeD) is a common immune-mediated disease where intolerance to gluten can lead to severe health problems with a wide range of gastrointestinal (GI) and extra-intestinal symptoms. Research shows that a diet low in fermentable oligo-, di-, mono-saccharides and polyols (FODMAP) helps to reduce GI symptoms in irritable-bowel syndrome and gluten-free diet treated CeD. The aim of this study was to investigate whether a low FODMAP diet (LFD) in this patient group affects (i) the faecal microbiota, (ii) the concentrations of faecal short-chain fatty acids (SCFA) and (iii) the concentrations of faecal human neutrophil gelatinase-associated lipocalin (a biomarker of gut inflammation). This study is part of a clinical trial which followed a nonblinded, parallel randomised design. The participants were randomised to either an LFD group or a control group. Results showed that after four weeks, certain differences in gut microbiota were detected between the control and LFD group. The SCFA results indicated that the LFD resulted in lower concentrations of propionic and valeric acid in participants with initially high concentrations. Biomarker of gut inflammation was, however, unaffected by the LFD. Authors conclude that the LFD led to changes in overall community structure of the faecal microbiota, with a possible unfavourable low faecal abundance of Anaerostipes, and low concentrations of the faecal SCFA propionic and valeric acid in participants with high concentrations of these acids at baseline.
Abstract
Individuals with coeliac disease (CeD) often experience gastrointestinal symptoms despite adherence to a gluten-free diet (GFD). While we recently showed that a diet low in fermentable oligo-, di-, monosaccharides and polyols (FODMAP) successfully provided symptom relief in GFD-treated CeD patients, there have been concerns that the low FODMAP diet (LFD) could adversely affect the gut microbiota. Our main objective was therefore to investigate whether the LFD affects the faecal microbiota and related variables of gut health. In a randomised controlled trial GFD-treated CeD adults, having persistent gastrointestinal symptoms, were randomised to either consume a combined LFD and GFD (n 39) for 4 weeks or continue with GFD (controls, n 36). Compared with the control group, the LFD group displayed greater changes in the overall faecal microbiota profile (16S rRNA gene sequencing) from baseline to follow-up (within-subject β-diversity, P < 0·001), characterised by lower and higher follow-up abundances (%) of genus Anaerostipes (Pgroup < 0·001) and class Erysipelotrichia (Pgroup = 0·02), respectively. Compared with the control group, the LFD led to lower follow-up concentrations of faecal propionic and valeric acid (GC-FID) in participants with high concentrations at baseline (Pinteraction ≤ 0·009). No differences were found in faecal bacterial α-diversity (Pgroup ≥ 0·20) or in faecal neutrophil gelatinase-associated lipocalin (ELISA), a biomarker of gut integrity and inflammation (Pgroup = 0·74), between the groups at follow-up. The modest effects of the LFD on the gut microbiota and related variables in the CeD patients of the present study are encouraging given the beneficial effects of the LFD strategy to treat functional GI symptoms (Registered at clinicaltrials.gov as NCT03678935).
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Probio-X Relieves Symptoms of Hyperlipidemia by Regulating Patients' Gut Microbiome, Blood Lipid Metabolism, and Lifestyle Habits.
Wang, H, Ma, C, Li, Y, Zhang, L, A, L, Yang, C, Zhao, F, Han, H, Shang, D, Yang, F, et al
Microbiology spectrum. 2023;11(3):e0444022
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A long-term high-fat diet will not only disrupt the balance of lipid metabolism in the body and cause metabolic disorders but also lead to chronic diseases, such as hyperlipidaemia, type 2 diabetes, hypertension, and obesity. Hyperlipidaemia is also an important contributing factor in cardiovascular disease. The aim of this study was to analyse the effects of a mixed probiotic formulation on hyperlipidaemia, with focus on changes in patients’ gut microbiota and their metabolic potential. This study was a 3-month randomised controlled intervention trial. A total of 56 hyperlipidaemic patients were recruited and randomised into either the placebo or probiotic (receiving a mixed probiotic formulation) group. Results show that the intake of the probiotic mix effectively reduced the serum levels of total cholesterol and low-density lipoprotein cholesterol, while increasing serum high-density lipoprotein cholesterol levels, in patients with hyperlipidaemia. In fact, there was a strong association between the desirable changes in patients’ lifestyle habits and lowering of these indexes. Furthermore, although insignificant changes were observed in the lipid metabolome and gut microbiota structure, some interesting fecal bacteria and blood metabolites increased significantly after Probio-X intervention. Authors conclude that their findings show that probiotic administration is a promising approach in managing hyperlipidaemia and improving public health.
Abstract
Hyperlipidemia is a key risk factor for cardiovascular disease, and it is associated with lipid metabolic disorders and gut microbiota dysbiosis. Here, we aimed to investigate the beneficial effects of 3-month intake of a mixed probiotic formulation in hyperlipidemic patients (n = 27 and 29 in placebo and probiotic groups, respectively). The blood lipid indexes, lipid metabolome, and fecal microbiome before and after the intervention were monitored. Our results showed that probiotic intervention could significantly decrease the serum levels of total cholesterol, triglyceride, and low-density lipoprotein cholesterol (P < 0.05), while increasing the levels of high-density lipoprotein cholesterol (P < 0.05) in patients with hyperlipidemia. Probiotic recipients showing improved blood lipid profile also exhibited significant differences in their lifestyle habits after the 3-month intervention, with an increase in daily intake of vegetable and dairy products, as well as weekly exercise time (P < 0.05). Moreover, two blood lipid metabolites (namely, acetyl-carnitine and free carnitine) significantly increased after probiotic supplementation cholesterol (P < 0.05). In addition, probiotic-driven mitigation of hyperlipidemic symptoms were accompanied by increases in beneficial bacteria like Bifidobacterium animalis subsp. lactis and Lactiplantibacillus plantarum in patients' fecal microbiota. These results supported that mixed probiotic application could regulate host gut microbiota balance, lipid metabolism, and lifestyle habits, through which hyperlipidemic symptoms could be alleviated. The findings of this study urge further research and development of probiotics into nutraceuticals for managing hyperlipidemia. IMPORTANCE The human gut microbiota have a potential effect on the lipid metabolism and are closely related to the disease hyperlipidemia. Our trial has demonstrated that 3-month intake of a mixed probiotic formulation alleviates hyperlipidemic symptoms, possibly by modulation of gut microbes and host lipid metabolism. The findings of the present study provide new insights into the treatment of hyperlipidemia, mechanisms of novel therapeutic strategies, and application of probiotics-based therapy.
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Targeting the gut-lung axis by synbiotic feeding to infants in a randomized controlled trial.
Sjödin, KS, Sjödin, A, Ruszczyński, M, Kristensen, MB, Hernell, O, Szajewska, H, West, CE
BMC biology. 2023;21(1):38
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Infants are at increased risk of infections, and respiratory tract infections are a leading cause of morbidity and mortality globally. Although the respiratory and gastrointestinal tracts are separate, they share a mucosal immune system called the “gut-lung axis.” The aim of this study was to compare the impacts of feeding prebiotic infant formula with the same prebiotic infant formula supplemented with probiotic Lactobacillus F19 (synbiotics) until 6 months of age on infant gut microbiota development in the first year of life. This study was a multicentre, double-blind randomised controlled study. Infants were randomised to control group - prebiotic formula or experimental group - synbiotic formula. Results showed additional benefit of feeding specific synbiotics to formula-fed infants over prebiotics only. In fact, synbiotic feeding led to the underrepresentation of Klebsiella [bacteria], enrichment of bifidobacteria, and slight increases in microbial degradation metabolites. Authors concluded that their findings support future clinical evaluation of synbiotic formula in the prevention of infections and associated antibiotic treatment as a primary outcome when breastfeeding is not feasible.
Abstract
BACKGROUND Formula-fed infants are at increased risk of infections. Due to the cross-talk between the mucosal systems of the gastrointestinal and respiratory tracts, adding synbiotics (prebiotics and probiotics) to infant formula may prevent infections even at distant sites. Infants that were born full term and weaned from breast milk were randomized to prebiotic formula (fructo- and galactooligosaccharides) or the same prebiotic formula with Lactobacillus paracasei ssp. paracasei F19 (synbiotics) from 1 to 6 months of age. The objective was to examine the synbiotic effects on gut microbiota development. RESULTS Fecal samples collected at ages 1, 4, 6, and 12 months were analyzed using 16S rRNA gene sequencing and a combination of untargeted gas chromatography-mass spectrometry/liquid chromatography-mass spectrometry. These analyses revealed that the synbiotic group had a lower abundance of Klebsiella, a higher abundance of Bifidobacterium breve compared to the prebiotic group, and increases in the anti-microbial metabolite d-3-phenyllactic acid. We also analyzed the fecal metagenome and antibiotic resistome in the 11 infants that had been diagnosed with lower respiratory tract infection (cases) and 11 matched controls using deep metagenomic sequencing. Cases with lower respiratory tract infection had a higher abundance of Klebsiella species and antimicrobial resistance genes related to Klebsiella pneumoniae, compared to controls. The results obtained using 16S rRNA gene amplicon and metagenomic sequencing were confirmed in silico by successful recovery of the metagenome-assembled genomes of the bacteria of interest. CONCLUSIONS This study demonstrates the additional benefit of feeding specific synbiotics to formula-fed infants over prebiotics only. Synbiotic feeding led to the underrepresentation of Klebsiella, enrichment of bifidobacteria, and increases in microbial degradation metabolites implicated in immune signaling and in the gut-lung and gut-skin axes. Our findings support future clinical evaluation of synbiotic formula in the prevention of infections and associated antibiotic treatment as a primary outcome when breastfeeding is not feasible. TRIAL REGISTRATION ClinicalTrials.gov NCT01625273 . Retrospectively registered on 21 June 2012.