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Collinsella aerofaciens as a predictive marker of response to probiotic treatment in non-constipated irritable bowel syndrome.
Gargari, G, Mantegazza, G, Cremon, C, Taverniti, V, Valenza, A, Barbaro, MR, Marasco, G, Duncan, R, Fiore, W, Ferrari, R, et al
Gut microbes. 2024;16(1):2298246
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Irritable bowel syndrome (IBS) is a common disorder of gut-brain interaction in which recurrent abdominal pain is associated with defecation or a change in bowel habits. Various therapeutic options for IBS target the underlying pathophysiological aspects of the condition. Unfortunately, no single approach can effectively address this disorder’s diverse manifestations simultaneously. The aim of this study was to identify markers for recognising non-constipated (NC) IBS patients that may show significant clinical improvements upon treatment with the probiotic strain Lacticaseibacillus paracasei DG (LDG). This study is based on a multicentre, randomised, double-blind, parallel-group, placebo-controlled clinical trial. A total of 63 patients were included in this study who were randomised to receive a probiotic treatment or placebo capsules for 12 weeks. Results showed that the probiotic bacterium LDG can be clinically effective in a subgroup of non-constipated IBS patients characterised by an altered faecal microbiota which resembles that observed in metabolic syndrome-associated pathologic or pre-pathologic conditions. Furthermore, a bacterium reported to contribute to pro-inflammatory immune states, was positively associated with markers of increased endothelial permeability and liver functionality Authors concluded that an analysis of the faecal microbiota focused on particular bacteria could permit the identification of NC-IBS patients who can obtain a significant clinical benefit from the probiotic treatment.
Abstract
Probiotics are exploited for adjuvant treatment in IBS, but reliable guidance for selecting the appropriate probiotic to adopt for different forms of IBS is lacking. We aimed to identify markers for recognizing non-constipated (NC) IBS patients that may show significant clinical improvements upon treatment with the probiotic strain Lacticaseibacillus paracasei DG (LDG). To this purpose, we performed a post-hoc analysis of samples collected during a multicenter, double-blind, parallel-group, placebo-controlled trial in which NC-IBS patients were randomized to receive at least 24 billion CFU LDG or placebo capsules b.i.d. for 12 weeks. The primary clinical endpoint was the composite response based on improved abdominal pain and fecal type. The fecal microbiome and serum markers of intestinal (PV1 and zonulin), liver, and kidney functions were investigated. We found that responders (R) in the probiotic arm (25%) differed from non-responders (NR) based on the abundance of 18 bacterial taxa, including the families Coriobacteriaceae, Dorea spp. and Collinsella aerofaciens, which were overrepresented in R patients. These taxa also distinguished R (but not NR) patients from healthy controls. Probiotic intervention significantly reduced the abundance of these bacteria in R, but not in NR. Analogous results emerged for C. aerofaciens from the analysis of data from a previous trial on IBS with the same probiotic. Finally, C. aerofaciens was positively correlated with the plasmalemmal vesicle associated protein-1 (PV-1) and the markers of liver function. In conclusion, LDG is effective on NC-IBS patients with NC-IBS with a greater abundance of potential pathobionts. Among these, C. aerofaciens has emerged as a potential predictor of probiotic efficacy.
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Effects of FODMAPs and Gluten on Gut Microbiota and Their Association with the Metabolome in Irritable Bowel Syndrome: A Double-Blind, Randomized, Cross-Over Intervention Study.
Nordin, E, Hellström, PM, Dicksved, J, Pelve, E, Landberg, R, Brunius, C
Nutrients. 2023;15(13)
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Irritable bowel syndrome (IBS) is defined as recurring abdominal pain in relation to stool irregularities. The mechanisms behind IBS are poorly understood, but changes in gut microbiota composition, intestinal barrier function, enteroendocrine cell population, low-grade inflammation and gut–brain axis modulations are believed to play a role. The aim of this study was to investigate how fermentable oligo-, di-, mono-saccharides, and polyols (FODMAPs) and gluten affected gut microbiota and circulating metabolite profiles, as well as to investigate potential links between gut microbiota, metabolites, and IBS symptoms. This study was a double-blind, placebo-controlled three-way crossover study. Both the study personnel and participants were blinded. Results showed that consumption of high FODMAP foods, but not gluten, altered the gut microbiota composition, in particular causing changes to microbiota and metabolites, previously associated with improved metabolic health and reduced inflammation. There were also minor effects of FODMAPs and gluten on short-chain fatty acids. Authors conclude that the intake of FODMAP, but not gluten, over one week altered the gut microbiota composition, with only weak associations with IBS symptoms. Healthcare practitioners working with IBS should consider the impacts on the gut microbiome when advising the use of a low-FODMAP diet.
Abstract
BACKGROUND A mechanistic understanding of the effects of dietary treatment in irritable bowel syndrome (IBS) is lacking. Our aim was therefore to investigate how fermentable oligo- di-, monosaccharides, and polyols (FODMAPs) and gluten affected gut microbiota and circulating metabolite profiles, as well as to investigate potential links between gut microbiota, metabolites, and IBS symptoms. METHODS We used data from a double-blind, randomized, crossover study with week-long provocations of FODMAPs, gluten, and placebo in participants with IBS. To study the effects of the provocations on fecal microbiota, fecal and plasma short-chain fatty acids, the untargeted plasma metabolome, and IBS symptoms, we used Random Forest, linear mixed model and Spearman correlation analysis. RESULTS FODMAPs increased fecal saccharolytic bacteria, plasma phenolic-derived metabolites, 3-indolepropionate, and decreased isobutyrate and bile acids. Gluten decreased fecal isovalerate and altered carnitine derivatives, CoA, and fatty acids in plasma. For FODMAPs, modest correlations were observed between microbiota and phenolic-derived metabolites and 3-indolepropionate, previously associated with improved metabolic health, and reduced inflammation. Correlations between molecular data and IBS symptoms were weak. CONCLUSIONS FODMAPs, but not gluten, altered microbiota composition and correlated with phenolic-derived metabolites and 3-indolepropionate, with only weak associations with IBS symptoms. Thus, the minor effect of FODMAPs on IBS symptoms must be weighed against the effect on microbiota and metabolites related to positive health factors.
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Serum, Urine, and Fecal Metabolome Alterations in the Gut Microbiota in Response to Lifestyle Interventions in Pediatric Obesity: A Non-Randomized Clinical Trial.
Lee, Y, Cho, JY, Cho, KY
Nutrients. 2023;15(9)
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Paediatric obesity is linked to an increased risk of type 2 diabetes, hypertension, dyslipidaemia, and metabolic syndrome. Diverse evidence suggests that obesity is associated with alterations in the gut microbiota and its metabolites. The aim of this study was to understand the metabolic pathways underlying paediatric obesity and the effect of intervention, which could provide guidance for the treatment of obesity. This study was a non-randomised clinical trial which enrolled 50 children with obesity and 22 normal-weight children aged 7–18 years. Results showed that imbalances in microbiota and metabolites were associated with both obesity and response to the intervention. The most distinct metabolic alterations in the obese group were branched-chain amino acid and purine changes. Authors conclude that the findings of their study could be valuable for identifying novel targets and biomarkers for the treatment of obesity.
Abstract
Pediatric obesity is associated with alterations in the gut microbiota and its metabolites. However, how they influence obesity and the effect of lifestyle interventions remains unknown.. In this non-randomized clinical trial, we analyzed metabolomes and microbial features to understand the associated metabolic pathways and the effect of lifestyle interventions on pediatric obesity. Anthropometric/biochemical data and fasting serum, urine, and fecal samples were collected at baseline and after an eight-week, weight-reduction lifestyle modification program. Post-intervention, children with obesity were classified into responder and non-responder groups based on changes in total body fat. At baseline, serum L-isoleucine and uric acid levels were significantly higher in children with obesity compared with those in normal-weight children and were positively correlated with obesogenic genera. Taurodeoxycholic and tauromuricholic α + β acid levels decreased significantly with obesity and were negatively correlated with obesogenic genera. Branched-chain amino acid and purine metabolisms were distinguished metabolic pathways in the obese group. Post-intervention, urinary myristic acid levels decreased significantly in the responder group, showing a significant positive correlation with Bacteroides. Fatty acid biosynthesis decreased significantly in the responder group. Thus, lifestyle intervention with weight loss is associated with changes in fatty acid biosynthesis, and myristic acid is a possible therapeutic target for pediatric obesity.
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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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PRO-DEMET Randomized Controlled Trial on Probiotics in Depression-Pilot Study Results.
Gawlik-Kotelnicka, O, Margulska, A, Skowrońska, A, Strzelecki, D
Nutrients. 2023;15(6)
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Depression often coexists with metabolic abnormalities, and metabolic syndrome (MetS) is diagnosed in 30% of depressed subjects. Importantly, both obesity and MetS have been found to be independently associated with depressive symptoms and inflammation. The aim of this study was to investigate the effect of probiotics in the treatment of depressive disorders with possible comorbid MetS and its components. This study was an internal feasibility study based on the main randomised study - a single-centre, parallel-group, prospective, randomised, double-blind, placebo-controlled pilot trial. Adult patients (≥18 years) with depressive disorders were randomly assigned (1:1) into either the placebo or probiotic group. Results showed a positive association between probiotics supplementation and psychometric parameters together with the metabolic profile, serum inflammation markers, and biomarkers of metabolic-associated fatty liver disease in patients with depressive disorders. Authors conclude that the findings of their study would be suitable for determining the potential clinical use of probiotics and assessing certain key factors such as potential biomarkers of response.
Abstract
There is a pressing need to identify new treatment options for depression and its comorbidities. Depression often coexists with metabolic complications, and the two may share a pathophysiological overlap, including inflammation and microbiota changes. Microbiota interventions (e.g., probiotics) may represent a safe and easy-to-use treatment option as an adjunctive therapy in patients only partially responsive to pharmacologic treatment. (1) Objective: The paper presents the results of a feasibility and pilot study. The study is an internal part of a randomized controlled trail (RCT) of the effect of probiotic supplementation on psychometric, anthropometric, metabolic, and inflammatory parameters in adult patients with depressive disorders depending on the presence of metabolic syndrome. (2) Methods: The trial has a four-arm, parallel-group, prospective, randomized, double-blind, controlled design. Sixty participants received a probiotic preparation containing Lactobacillus helveticus Rosell®-52 and Bifidobacterium longum Rosell®-175 over 60 days. The feasibility of the study design was assessed, as well as the rates of recruitment, eligibility, consent, and study completion. The following were assessed: depressive, anxiety and stress symptoms, quality of life, blood pressure, body mass index and waist circumference, complete blood count with differential, serum levels of C-reactive protein, high-density lipoprotein cholesterol, triglycerides, fasting glucose, some secondary markers of inflammation and metabolic health, as well as noninvasive biomarkers of liver fibrosis (APRI and FIB-4). (3) Results: The study was found to be generally feasible. The eligibility rate was 52% of recruited participants with 80% completing the study protocol. No differences in sociodemographic or anthropometric factors or basic laboratory findings were found between the placebo and probiotic group at the start of the intervention period. Importantly, the proportion of recruited participants fulfilling the criteria of metabolic syndrome was too low. (4) Conclusions: Whilst the whole study protocol was feasible, some different timepoint procedures require modification. The major weakness of the recruitment methods was that the percentage of metabolic arms participants was insufficient. Overall, the full RCT design on probiotics in depression with vs. without metabolic syndrome was shown to be feasible with little modification.
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An insight into the functional alterations in the gut microbiome of healthy adults in response to a multi-strain probiotic intake: a single arm open label trial.
Rodenes-Gavidia, A, Lamelas, A, Bloor, S, Hobson, A, Treadway, S, Haworth, J, Vijayakumar, V, Naghibi, M, Day, R, Chenoll, E
Frontiers in cellular and infection microbiology. 2023;13:1240267
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The human gut microbiota is a key mediator of host health and is known to affect many physiological processes, such as digestion, metabolism, immune function and inhibition of pathogen colonisation. The gut microbiome can be impacted by many extrinsic factors. The aim of this study was to assess both compositional and functional changes in the microbiome of healthy individuals using shotgun metagenomics following 8-weeks of daily multi-strain probiotic intake. This study was a single-arm open-label study which enrolled a total of 41 healthy adult males and females between 18 to 40 years old. Results showed that alpha- and beta-diversity of the faecal microbiota structure was not significantly altered in response to probiotic intake. However, significant changes were observed when functional genes were assessed. Abundance of certain genes involved in several functional pathways were also significantly altered. Additionally, there were no significant changes in stool frequency or consistency, faecal biochemistry, or breath tests of methane and hydrogen observed. Authors conclude that the findings of their study have the potential to provide insights into the underlying mechanisms of action of the 14-strain probiotic blend in healthy adults.
Abstract
BACKGROUND Probiotic supplements, by definition, provide a benefit to the host, but few studies have investigated the effect of probiotic supplements in healthy adult populations. PURPOSE The present, single arm, open label clinical trial, evaluated compositional and functional changes in the fecal microbiome of healthy adults after supplementation with a 14-strain probiotic. METHODS We analysed the effect of a 14-strain probiotic blend (Bacillus subtilis NCIMB 30223, Bifidobacterium bifidum NCIMB 30179, B. breve NCIMB 30180, B. infantis NCIMB 30181, B. longum NCIMB 30182, Lactobacillus helveticus NCIMB 30184, L. delbrueckii subsp. bulgaricus NCIMB 30186, Lacticaseibacillus paracasei NCIMB 30185, Lactiplantibacillus plantarum NCIMB 30187, Lacticaseibacillus rhamnosus NCIMB 30188, L. helveticus NCIMB 30224, Lactobacillus salivarius NCIMB 30225, Lactococcus lactis subsp. lactis NCIMB 30222, and Streptococcus thermophilus NCIMB 30189), on the faecal microbiota of healthy young adults (n=41) in a single arm study. The adults consumed 4 capsules daily of the 14 strain blend(8 billion colony forming units/day) for 8 weeks. Compositional and functional changes in faecal microbiota before and after supplementation were assessed using shotgun metagenomic sequencing. Fasting breath analysis, faecal biochemistry and bowel habits were also assessed. RESULTS In healthy adult participants, no significant changes to the overall alpha- or beta-diversity was observed after 8 weeks of multi-strain probiotic supplementation. However, in a simplified model that considered only time and individual differences, significant decreases (p < 0.05) in family Odoribacteraceae and Bacteroidaceae abundance and a significant increase (p < 0.05) in genus Megamonas abundance were observed. At a functional level, there were significant changes in functional gene abundance related to several functional pathways, including phenylalanine metabolism, O-antigen nucleotide sugar biosynthesis, bacterial chemotaxis, and flagellar assembly. No significant changes in stool form or frequency, fecal biochemistry, or methane and hydrogen breath tests were observed. CONCLUSION In healthy young adults, overall alpha- and beta-diversity did not change in response to probiotic intake even though modest compositional changes at the family and genus level were observed. However, at functional level, results identified changes in gene abundance for several functional pathways.
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The Usefulness of the Low-FODMAP Diet with Limited Tryptophan Intake in the Treatment of Diarrhea-Predominant Irritable Bowel Syndrome.
Chojnacki, C, Poplawski, T, Blonska, A, Konrad, P, Chojnacki, J, Blasiak, J
Nutrients. 2023;15(8)
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Several pathogenic factors are responsible for the occurrence of irritable bowel syndrome (IBS-D), and food products are present among them. The human diet contains various nutrients, which may have beneficial or unfavourable effects. Numerous patients with IBS attribute their abdominal symptoms to food, and in fact, certain foods ingested can cause exaggerated gastrointestinal complaints. The aim of this study was to evaluate the effect of a low-fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (known as the low-FODMAP) diet with a limitation of Tryptophan (TRP) intake on the clinical symptoms of patients with IBS-D in relation to its metabolism along the serotonin and kynurenine pathways. This study enrolled 40 healthy people (controls) and 80 patients with IBS-D. The IBS-D patients were randomly divided into two groups of 40 each (Groups IIA and IIB). In Group IIA, the low-FODMAP diet was recommended, while in Group IIB, the same diet was recommended but with limited TRP intake for 8 weeks. Results showed that: - both groups did not differ in clinical parameters or daily TRP consumption. - all IBS-D patients in both subgroups showed similar severity of abdominal complaints as well as anxiety and depressive symptoms before nutritional intervention. - reducing the amount of TRP content in a low-FODMAP diet improves its effectiveness in the treatment of IBS-D patients. Authors concluded that lowering the tryptophan content of a low-FODMAP diet may be useful in treating diarrhoea-predominant irritable bowel syndrome.
Abstract
(1) Background: A low-FODMAP diet is often recommended in the treatment of irritable bowel syndrome, but it does not improve abdominal symptoms in all patients, and an alternative diet is desirable. The purpose of this study was to evaluate the efficacy of a low-FODMAP diet with a concomitant reduction in tryptophan (TRP) intake in irritable bowel syndrome with diarrhea predominance (IBS-D) in relation to its metabolism via the serotonin and kynurenine pathways. (2) Methods: 40 healthy people (Group I, Controls) and 80 patients with IBS-D were included in the study. IBS-D patients were randomly divided into two groups of 40 each (Groups IIA and IIB). In Group IIA, the low-FODMAP diet was recommended, while in Group IIB, the same diet was recommended but with limited TRP intake for 8 weeks. The TRP intake was analyzed with the use of the nutritional calculator. Abdominal complaints were assessed using the Gastrointestinal Symptom Rating Scale (GSRS-IBS), and psychological status was simultaneously determined using two scales: the Hamilton Anxiety Scale (HAM-A) and the Hamilton Depression Scale (HAM-D). TRP and its metabolites: 5-hydoxyindoleacetic acid (5-HIAA), kynurenine (KYN), kynurenic acid (KYNA), and quinolinic acid (QA) were measured in urine using liquid chromatography tandem mass spectrometry (LC-MS/MS). (3) Results: The consumption of TRP per mg/kg/b.w./24 h has decreased in Group IIA from 20.9 ± 2.39 to 17.45 ± 2.41 (16.5%) and in Group IIB from 21.3 ± 2.33 to 14.32 (34.4%). Significantly greater improvement was found after nutritional treatment in patients in Group IIB as compared to Group IIA (GSRS score: 38.1% vs. 49.8%; HAM-A: 38.7% vs. 49.9%; HAM-D: 13.8% vs. 35.0%; p < 0.01). Reducing TRP intake showed a negative correlation with the degree of improvement in the GSRS score. (4) Conclusions: Lowering the TRP content in a low-FODMAP diet may be useful in treating IBS-D.
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Blueberries Improve Abdominal Symptoms, Well-Being and Functioning in Patients with Functional Gastrointestinal Disorders.
Wilder-Smith, CH, Materna, A, Olesen, SS
Nutrients. 2023;15(10)
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Functional gastrointestinal disorders (FGID) are the most common cause of recurring, chronic digestive upsets. Irritable bowel syndrome (IBS) and functional dyspepsia (FD), or persistent indigestion, are the most prevalent types of those disorders. Typical symptoms include pain or discomfort in the abdomen, changes in stool patterns or bloating and may also manifest in symptoms not directly relating to the digestive tract. It remains uncertain what the exact mechanisms of those disorders are. However, scientists identified various factors involved, including immune system activation, sensitisation of the nervous system, dysregulated permeability of the gut walls, and changes in the microbiota, their composition and metabolic activity. Polyphenols are natural compounds found abundantly in plants and are most known for their antioxidant qualities. One frequently studied and rich-source of phenols is Blueberries (Vaccinium spp). Blueberries have antioxidant, anti-inflammatory, and neuroprotective properties, and are known to reverse the permeability of the gut membrane. Hence their use in the management of FGID appeared promising. This double-blind, randomized, cross-over study assessed the benefit of blueberries in 43 people with IBS or FD, between 18–60 years of age. The candidates were given 30g freeze-dried blueberries, the equivalent of 180g of fresh blueberries, or a sugar-based placebo of similar calorific value for 6-weeks each. When receiving the blueberries, greater symptom relief was observed when compared to the placebo group. Blueberry intake also positively reflected in experienced improvement in quality of life. No notable differences were observed between groups in stool patterns and fructose digestion. Blueberries and their beneficial compounds such as polyphenols and fiber appear to have a wide range of benefits that can help manage some of the FGID-associated symptoms. Further studies are needed to understand why, despite some notable benefits, some of the other GI markers remained unaffected. As blueberries are generally well tolerated, they can be a simple and helpful food intervention to complement other FGID management strategies.
Abstract
Blueberries beneficially modulate physiologic mechanisms relevant to the pathogenesis of functional gastrointestinal disorders (FGID). Forty-three patients with FGID received freeze-dried blueberries (equivalent to 180 g fresh blueberries) or sugar and energy-matched placebo in a double-blind, randomized, cross-over study. After 6 weeks of treatment, the differences in Gastrointestinal Clinical Rating Scale (GSRS) scores and abdominal symptom relief were compared as primary outcome measures. The quality of life and life functioning ratings (OQ45.2 questionnaire), Bristol stool scales, and fructose breath test results constituted secondary outcome measures. Blueberry treatment resulted in more patients with relevant abdominal symptom relief compared to placebo (53% vs. 30%, p = 0.03). Total and pain GSRS scores improved insignificantly (mean treatment differences [95% CI]: -3.4 [-7.4 to 0.6] (p = 0.09) and -1.0 [-2.2 to 0.1] (p = 0.08), respectively). OQ45.2 scores improved during blueberry treatment compared to placebo (treatment difference -3.2 [95% CI: -5.6 to -0], p = 0.01). Treatment effect differences for the further measures did not reach statistical significance. Blueberries relieved abdominal symptoms and improved general markers of well-being, quality of life, and life functioning more than placebo in patients with FGID. Consequently, the polyphenol and fiber components of blueberries exert broad beneficial effects separate from the sugars present in both treatments.
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Randomized controlled trial demonstrates response to a probiotic intervention for metabolic syndrome that may correspond to diet.
Wastyk, HC, Perelman, D, Topf, M, Fragiadakis, GK, Robinson, JL, Sonnenburg, JL, Gardner, CD, Sonnenburg, ED
Gut microbes. 2023;15(1):2178794
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Rates of metabolic syndrome are high throughout developed countries. Metabolic syndrome is a cluster of conditions that occur together and increase your risk for heart disease, stroke, and type 2 diabetes. Studies in animals and humans have shown that the composition of the gut microbiome may be linked to metabolic syndrome and that it is affected by diet. This randomised control trial of 39 individuals showed that the supplementation of a probiotic containing three different probiotic strains did not have a population wide effect but did influence a subset of individuals. These individuals had a different microbiome by the end of the trial and a decrease in blood pressure and blood lipids. Interestingly these individuals also had a higher dietary intake of sugar, yet a lower blood sugar level. It was concluded that the response to probiotic supplements may be dependent upon an individual’s diet. This study could be used by healthcare professionals to understand that diet may influence the success of probiotics, however more research is warranted before firm conclusions are made on the optimal diet during supplementation.
Abstract
An individual's immune and metabolic status is coupled to their microbiome. Probiotics offer a promising, safe route to influence host health, possibly via the microbiome. Here, we report an 18-week, randomized prospective study that explores the effects of a probiotic vs. placebo supplement on 39 adults with elevated parameters of metabolic syndrome. We performed longitudinal sampling of stool and blood to profile the human microbiome and immune system. While we did not see changes in metabolic syndrome markers in response to the probiotic across the entire cohort, there were significant improvements in triglycerides and diastolic blood pressure in a subset of probiotic arm participants. Conversely, the non-responders had increased blood glucose and insulin levels over time. The responders had a distinct microbiome profile at the end of the intervention relative to the non-responders and placebo arm. Importantly, diet was a key differentiating factor between responders and non-responders. Our results show participant-specific effects of a probiotic supplement on improving parameters of metabolic syndrome and suggest that dietary factors may enhance stability and efficacy of the supplement.
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Impact of Blueberry Consumption on the Human Fecal Bileacidome: A Pilot Study of Bile Acid Modulation by Freeze-Dried Blueberry.
Gagnon, W, Garneau, V, Trottier, J, Verreault, M, Couillard, C, Roy, D, Marette, A, Drouin-Chartier, JP, Vohl, MC, Barbier, O
Nutrients. 2022;14(18)
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Primary bile acids (BAs) are made in the liver from cholesterol. They are released into the small intestine, where they aid fat digestion and absorption. Most BAs are reabsorbed from the gut, yet a small amount gets modified by the gut bacteria, forming secondary BAs destined for faecal excretion. Excess secondary BAs have negative health consequences. The different types of primary BAs influence many physiological functions. Such as glucose regulation, fat metabolism and absorption, intestinal inflammation and immunity, as well as gut bacteria diversity. For optimal BA metabolism, they are tightly regulated by the body, as minimal changes in BA pool and composition can have a significant impact on overall health. The composition of the BA pool can be influenced by gut bacteria, metabolic disorders, pathologies of the liver and gut, and diet. Dietary polyphenols, a plant-based compound, have been of particular interest here. This study sought to investigate the impact of supplementary freeze-dried blueberry powder (BBP), a rich polyphenol source, on the faecal BA pool composition in people at risk of metabolic syndrome. For this 11 men and 13 women were supplemented for 8 weeks. When compared to the data before the intervention, no significant changes in total BAs were observed. However, the composition of the BA pool changed leading to the accumulation of particular BAs and a reduction in secondary BA levels. This suggested that the consumption of blueberries can be considered a potential clinical intervention to aid the elimination of toxic secondary BAs. As the mechanisms leading to such modifications and their consequences for human health are complex, the authors advocate for investigation in larger population groups and also alert that such changes may be subject to interindividual variability and health status.
Abstract
Cholesterol-derived bile acids (BAs) affect numerous physiological functions such as glucose homeostasis, lipid metabolism and absorption, intestinal inflammation and immunity, as well as intestinal microbiota diversity. Diet influences the composition of the BA pool. In the present study, we analyzed the impact of a dietary supplementation with a freeze-dried blueberry powder (BBP) on the fecal BA pool composition. The diet of 11 men and 13 women at risk of metabolic syndrome was supplemented with 50 g/day of BBP for 8 weeks, and feces were harvested before (pre) and after (post) BBP consumption. BAs were profiled using liquid chromatography coupled with tandem mass spectrometry. No significant changes in total BAs were detected when comparing pre- vs. post-BBP consumption samples. However, post-BBP consumption samples exhibited significant accumulations of glycine-conjugated BAs (p = 0.04), glycochenodeoxycholic (p = 0.01), and glycoursodeoxycholic (p = 0.01) acids, as well as a significant reduction (p = 0.03) in the secondary BA levels compared with pre-BBP feces. In conclusion, the fecal bileacidome is significantly altered after the consumption of BBP for 8 weeks. While additional studies are needed to fully understand the underlying mechanisms and physiological implications of these changes, our data suggest that the consumption of blueberries can modulate toxic BA elimination.