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Effects of Wholegrain Compared to Refined Grain Intake on Cardiometabolic Risk Markers, Gut Microbiota, and Gastrointestinal Symptoms in Children: A Randomized Crossover Trial.
Madsen, MTB, Landberg, R, Nielsen, DS, Zhang, Y, Anneberg, OMR, Lauritzen, L, Damsgaard, CT
The American journal of clinical nutrition. 2024;119(1):18-28
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High consumption of wholegrain foods has been linked to a lower risk of cardiovascular disease (CVD) and type 2 diabetes. Some trials have shown benefits to body weight, blood lipids and glucose homeostasis but most of these studies are with adults. Cardiometabolic disease begins in childhood therefore data is needed for this age group to back up dietary recommendations in order to prevent later development of cardiometabolic disease. The aim of this randomized crossover trial was to look at the effects of wholegrain oats and rye intake on serum low-density lipoprotein (LDL), cholesterol and plasma insulin, other cardiometabolic markers, body composition, the composition of the gut microbiome and gastrointestinal symptoms in children with high body mass index (BMI). 55 healthy Danish children (aged 8 – 13) took part. They ate wholegrain oats and rye (WG) or refined grain products (RG) ad libtum for 8 weeks in random order. Measurements were taken at 0, 8 and 16 weeks. Compared with RG, WG reduced LDL cholesterol as well as total:high-density lipoprotein cholesterol and triacylglycerol. WG also modulated the abundance of specific types of gut bacteria, increased plasma acetate, propionate, and butyrate and fecal butyrate and reduced fatigue with no other effects on gut symptoms. This study supports the recommendation to swap refined grain for wholegrain oats and rye in children. Further studies are needed.
Abstract
BACKGROUND Wholegrain intake is associated with lower risk of cardiometabolic diseases in adults, potentially via changes in the gut microbiota. Although cardiometabolic prevention should start early, we lack evidence on the effects in children. OBJECTIVES This study investigated the effects of wholegrain oats and rye intake on serum low-density lipoprotein (LDL) cholesterol and plasma insulin (coprimary outcomes), other cardiometabolic markers, body composition, gut microbiota composition and metabolites, and gastrointestinal symptoms in children with high body mass index (BMI). METHODS In a randomized crossover trial, 55 healthy Danish 8- to 13-y-olds received wholegrain oats and rye ("WG") or refined grain ("RG") products ad libitum for 8 wk in random order. At 0, 8, and 16 wk, we measured anthropometry, body composition by dual-energy absorptiometry, and blood pressure. Fasting blood and fecal samples were collected for analysis of blood lipids, glucose homeostasis markers, gut microbiota, and short-chain fatty acids. Gut symptoms and stool characteristics were determined by questionnaires. Diet was assessed by 4-d dietary records and compliance by plasma alkylresorcinols (ARs). RESULTS Fifty-two children (95%) with a BMI z-score of 1.5 ± 0.6 (mean ± standard deviation) completed the study. They consumed 108 ± 38 and 3 ± 2 g/d wholegrain in the WG and RG period, which was verified by a profound difference in ARs (P < 0.001). Compared with RG, WG reduced LDL cholesterol by 0.14 (95% confidence interval: -0.24, -0.04) mmol/L (P = 0.009) and reduced total:high-density lipoprotein cholesterol (P < 0.001) and triacylglycerol (P = 0.048) without altering body composition or other cardiometabolic markers. WG also modulated the abundance of specific bacterial taxa, increased plasma acetate, propionate, and butyrate and fecal butyrate and reduced fatigue with no other effects on gut symptoms. CONCLUSION High intake of wholegrain oats and rye reduced LDL cholesterol and triacylglycerol, modulated bacterial taxa, and increased beneficial metabolites in children. This supports recommendations of exchanging refined grain with wholegrain oats and rye among children. This trial was registered at clinicaltrials.gov as NCT04430465.
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Efficacy of probiotic treatment as post-exposure prophylaxis for COVID-19: A double-blind, Placebo-Controlled Randomized trial.
Wischmeyer, PE, Tang, H, Ren, Y, Bohannon, L, Jiang, D, Bergens, M, Ramirez, ZE, Andermann, TM, Messina, JA, Sung, JA, et al
Clinical nutrition (Edinburgh, Scotland). 2024;43(1):259-267
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The Coronavirus Disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus infection, continues to pose a unique and novel challenge to global health. Ongoing research is showing a potentially significant role of the microbiome and dysbiosis in COVID-19 disease severity and development of Long-Covid. The aim of this study was to investigate the efficacy of the probiotic Lacticaseibacillus rhamnosus GG (LGG) as post-exposure prophylaxis against COVID-19. This study was a randomised, double-blind, placebo-controlled trial. Participants were randomised to receive LGG or placebo in a 1:1 ratio. Results showed that the participants randomised to LGG had fewer symptoms and prolonged time to development of COVID-19 compared to those receiving placebo. Additionally, probiotic supplementation also reduced symptomatic disease, and changed the gut microbiome structure. Authors conclude that their findings lend credence to the notion that symbiotic microbes may be valuable partners in the fight against COVID-19 and potentially other future pandemic diseases.
Abstract
BACKGROUND & AIMS The COVID-19 pandemic continues to pose unprecedented challenges to worldwide health. While vaccines are effective, additional strategies to mitigate the spread/severity of COVID-19 continue to be needed. Emerging evidence suggests susceptibility to respiratory tract infections in healthy subjects can be reduced by probiotic interventions; thus, probiotics may be a low-risk, low-cost, and easily implementable modality to reduce risk of COVID-19. METHODS In this initial study, we conducted a randomized, double-blind, placebo-controlled trial across the United States testing probiotic Lacticaseibacillus rhamnosus GG (LGG) as postexposure prophylaxis for COVID-19 in 182 participants who had household exposure to someone with confirmed COVID-19 diagnosed within ≤7 days. Participants were randomized to receive oral LGG or placebo for 28 days. The primary outcome was development of illness symptoms within 28 days of COVID-19 exposure. Stool was collected to evaluate microbiome changes. RESULTS Intention-to-treat analysis showed LGG treatment led to a lower likelihood of developing illness symptoms versus placebo (26.4 % vs. 42.9 %, p = 0.02). Further, LGG was associated with a statistically significant reduction in COVID-19 diagnosis (log rank, p = 0.049) via time-to-event analysis. Overall incidence of COVID-19 diagnosis did not significantly differ between LGG and placebo groups (8.8 % vs. 15.4 %, p = 0.17). CONCLUSIONS This data suggests LGG is associated with prolonged time to COVID-19 infection, reduced incidence of illness symptoms, and gut microbiome changes when used as prophylaxis ≤7 days post-COVID-19 exposure, but not overall incidence. This initial work may inform future COVID-19 prevention studies worldwide, particularly in developing nations where Lacticaseibacillus probiotics have previously been utilized to reduce other non-COVID infectious-morbidity. TRIAL REGISTRATION ClinicalTrials.gov, NCT04399252, Date: 22/05/2020. https://clinicaltrials.gov/ct2/show/NCT04399252.
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Synbiotic as an ameliorating factor in the health-related quality of life in women with polycystic ovary syndrome. A randomized, triple-blind, placebo-controlled trial.
Hariri, Z, Yari, Z, Hoseini, S, Abhari, K, Sohrab, G
BMC women's health. 2024;24(1):19
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Polycystic ovary syndrome (PCOS), as a chronic endocrine disorder, can affect many aspects of young women’s lives. Apart from physical complications, women with polycystic ovary syndrome are more likely to suffer from mental and behavioural disorders. The aim of this study was to examine whether synbiotic supplementation could improve the health quality of life of women with PCOS. This study was a triple-blind, randomised clinical trial which recruited women with polycystic ovary syndrome. Participants were randomly divided into synbiotic or placebo groups for 12 weeks. Results showed that synbiotic supplementation improved the scores of emotional, body hair, weight and infertility domains of PCOSQ-26 compared to placebo group. Authors concluded that 12-week supplementation with synbiotics could noticeably improve the emotional, body hair, weight, infertility and general physical health status of women with polycystic ovary syndrome.
Abstract
BACKGROUND There are complicated mechanisms that link the disruption of the gut microbiome to the symptoms and complications of polycystic ovary syndrome (PCOS). In this study, an attempt was made to assess the effects of synbiotics on the health-related quality of life (HRQoL) in women with PCOS . METHODS Fifty-six women with PCOS were enrolled in a triple-blind controlled trial for 12 weeks. They were randomly assigned to receive a daily 2-gram synbiotic sachets (containing Bacillus coagulans (GBI-30), Lactobacillus rhamnosus, Lactobacillus helveticus, and fructooligosaccharide) (n = 28) or placebo (n = 28). To evaluate the impact on the HRQoL, participants were required to fill 26-Item Polycystic Ovary Syndrome Health-Related Quality of Life Questionnaire (PCOSQ-26), 12-Item Short-Form Health Survey (SF-12) and Perceived Stress Scale (PSS-10) pre and post the intervention. RESULTS Finally, statistical analyses were performed on 52 participants who finished the trial. Synbiotic supplementation improved the scores of emotional (P = 0.044), body hair (P = 0.016), weight (P = 0.033) and infertility domains (P = 0.027) of PCOSQ-26 compared to placebo group. The physical score within SF-12 also had a significant enhancement (P = 0.035). No significant improvement was seen in the PSS-10 score at the end of the trial. CONCLUSION This study illustrated the advantageous effects of synbiotics on the health-related quality of life in women with PCOS. Further studies are required to confirm our findings. TRIAL REGISTRATION http://www.irct.ir : IRCT20211108053007N1; date of registration: 14/02/2023.
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A starch- and sucrose-reduced diet may lead to improvement of intestinal and extraintestinal symptoms in more conditions than irritable bowel syndrome and congenital sucrase-isomaltase deficiency.
Roth, B, Ohlsson, B
Nutrition (Burbank, Los Angeles County, Calif.). 2024;117:112254
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Studies have shown that a starch and sucrose-reduced diet (SSRD) leads to considerable improvements of gastrointestinal and extraintestinal symptoms in patients with irritable bowel syndrome (IBS). The purpose of this pilot study was to see if a SSRD would be beneficial in other conditions with similar symptoms. Two people took part in the study. A man with functional diarrhoea and a woman with microscopic colitis. The SSRD consists of low intakes of sugar-rich products, but continued or increased intakes of all meats and fish, fat, natural dairy products, eggs, berries, fruits, nuts, seeds, and vegetables low in starch. Fiber-rich bread and pasta and raw or wild rice were recommended instead of white bread and more processed rice and pasta. During the 4-week intervention, the participants lost weight and waist circumference reduced. The degree of satiety after a meal was increased and the sweet cravings were strongly reduced. The gastrointestinal symptoms improved in the participant with diarrhoea but was unaffected in the participant with microscopic colitis. Reductions of diarrhoea and of bloating and flatulence were most pronounced in both patients. The psychological well-being was improved during the intervention. Extraintestinal symptoms were also reduced during the SSRD, especially urinary urgency and belching. This is a small intervention study and therefore not possible to make generalised claims or recommendations. However, healthcare practitioners could look at SSRD when working with IBS patients as a therapeutic dietary option.
Abstract
OBJECTIVES A starch- and sucrose-reduced diet has been found to improve gastrointestinal and extraintestinal symptoms in irritable bowel syndrome, as well as reduce weight and improve psychological well-being. Our hypothesis was that a starch- and sucrose-reduced diet would also be beneficial in other conditions with similar symptoms. The aim of the present research letter was to describe the role of a starch- and sucrose-reduced diet in a pilot project in patients with diarrhea having varying causes. METHODS One man, age 36 y, suffering from functional diarrhea and one woman, 56 y, suffering from microscopic colitis, were randomized to a starch- and sucrose-reduced diet for 4 wk. At baseline, dietary information was given, and blood samples collected. Weight and waist circumference were measured. The participants completed the irritable bowel syndrome severity scoring system for evaluating specific gastrointestinal and extraintestinal symptoms and visual analog scale for irritable bowel syndrome for evaluation of specific gastrointestinal symptoms and psychological well-being. The degrees of satiety and sweet craving were measured on visual analog scales. After 4 wk, all procedures were repeated. RESULTS Weight, body mass index, and waist circumference were decreased during the intervention. The total amount of gastrointestinal symptoms was decreased in the participants with functional diarrhea, and diarrhea and bloating were decreased in both participants. Both had reduced extraintestinal symptoms and improved psychological well-being. Blood levels had mainly unchanged or slightly increased values of measurements reflecting nutrient intake. CONCLUSIONS A starch- and sucrose-reduced diet may lead to weight reduction, reduced symptoms, and improved well-being in several patient categories, not only in patients suffering from irritable bowel syndrome. Future randomized trials should be done.
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Daily skin-to-skin contact alters microbiota development in healthy full-term infants.
Eckermann, HA, Meijer, J, Cooijmans, K, Lahti, L, de Weerth, C
Gut microbes. 2024;16(1):2295403
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The gut microbiome develops in early life and is influenced by several different factors. Skin-to-skin contact (SSC), whereby an infant and mother have bare skin contact, has been shown to be associated with improved brain and heart development, decreased anxiety and stress, and longer breast-feeding duration. In animals, SSC has also been shown to alter the infants gut microbiota, but this has not been investigated in humans. This study of 116 infant-mother pairs aimed to determine the effect of SSC compared to normal care on the infant gut microbiome and the gut-brain connection. The results showed that there was an overall difference in microbiota diversity between SSC and normal care infants in early but not late infancy. The development of the gut microbiota was also affected in early and late infancy. In SSC infants there was a lower abundance of Faecalibacterium, Eubacterium hallii, and Rothia and higher abundance of Flavonifractor, Lacticaseibacillus, Bacteroides and Megasphaera compared to the normal care infants. Some gut-brain communication pathways differed between the two groups including those associated with anxiety and stress. It was concluded that SSC may influence gut microbiota development. This study could be used by healthcare professionals to understand that SSC can alter the infants gut microbiome, however further studies are required to determine the significance of this.
Abstract
The gut microbiota is vital for human body development and function. Its development in early life is influenced by various environmental factors. In this randomized controlled trial, the gut microbiota was obtained as a secondary outcome measure in a study on the effects of one hour of daily skin-to-skin contact (SSC) for five weeks in healthy full-term infants. Specifically, we studied the effects on alpha/beta diversity, volatility, microbiota maturation, and bacterial and gut-brain-axis-related functional abundances in microbiota assessed thrice in the first year. Pregnant Dutch women (n = 116) were randomly assigned to the SSC or care-as-usual groups. The SSC group participants engaged in one hour of daily SSC from birth to five weeks of age. Stool samples were collected at two, five, and 52 weeks and the V4 region was sequenced. We observed significant differences in the microbiota composition, bacterial abundances, and predicted functional pathways between the groups. The SSC group exhibited lower microbiota volatility during early infancy. Microbiota maturation was slower in the SSC group during the first year and our results suggested that breastfeeding duration may have partially mediated this relation. Our findings provide evidence that postpartum SSC may influence microbiota development. Replication is necessary to validate and generalize these results. Future studies should include direct stress measurements and extend microbiota sampling beyond the first year to investigate stress as a mechanism and research SSC's impact on long-term microbiota maturation trajectories.
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Exploration of differential responses to FODMAPs and gluten in people with irritable bowel syndrome- a double-blind randomized cross-over challenge study.
Nordin, E, Landberg, R, Hellström, PM, Brunius, C
Metabolomics : Official journal of the Metabolomic Society. 2024;20(2):21
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Irritable bowel syndrome (IBS) is a complex condition characterized by recurrent abdominal pain associated with abnormal bowel habits. Diet is considered a main cause of symptoms in IBS, and fermentable oligo-, di-, monosaccharides, and polyols (FODMAPs) are of major concern. The aim of this study was to unravel determinants of differential IBS responses to FODMAP and gluten provocation interventions from molecular data. This study was a randomised, double-blind, placebo-controlled three-way crossover study. Participants were randomised in blocks of 12 into the sequences CBA, ACB, and BAC (A=FODMAPs, B=Gluten, and C=Placebo). Results showed that despite a comprehensive set of methods applied to explore IBS responses, including both regression and classification, predictors of differential response could not be established. Authors concluded by encouraging the application of molecular subtyping methodologies in future studies due to the differential responses to treatment.
Abstract
INTRODUCTION There is large variation in response to diet in irritable bowel syndrome (IBS) and determinants for differential response are poorly understood. OBJECTIVES Our aim was to investigate differential clinical and molecular responses to provocation with fermentable oligo-, di-, monosaccharides, and polyols (FODMAPs) and gluten in individuals with IBS. METHODS Data were used from a crossover study with week-long interventions with either FODMAPs, gluten or placebo. The study also included a rapid provocation test. Molecular data consisted of fecal microbiota, short chain fatty acids, and untargeted plasma metabolomics. IBS symptoms were evaluated with the IBS severity scoring system. IBS symptoms were modelled against molecular and baseline questionnaire data, using Random Forest (RF; regression and clustering), Parallel Factor Analysis (PARAFAC), and univariate methods. RESULTS Regression and classification RF models were in general of low predictive power (Q2 ≤ 0.22, classification rate < 0.73). Out of 864 clustering models, only 2 had significant associations to clusters (0.69 < CR < 0.73, p < 0.05), but with no associations to baseline clinical measures. Similarly, PARAFAC revealed no clear association between metabolome data and IBS symptoms. CONCLUSION Differential IBS responses to FODMAPs or gluten exposures could not be explained from clinical and molecular data despite extensive exploration with different data analytical approaches. The trial is registered at www. CLINICALTRIALS gov as NCT03653689 31/08/2018.
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Almond Consumption for 8 Weeks Altered Host and Microbial Metabolism in Comparison to a Control Snack in Young Adults.
Dhillon, J, Newman, JW, Fiehn, O, Ortiz, RM
Journal of the American Nutrition Association. 2023;42(3):242-254
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The consumption of almonds can improve cardiometabolic (CM) health. This study explored the effects of consuming a snack of almonds vs. crackers for 8 weeks on changes in cardiometabolic, microbiome and metabolomics markers in young adults. 73 (41 women and 32 men) young adults took part in this 8-week randomized controlled, parallel-arm intervention study. Blood samples were taken at the beginning, at 4 weeks and then at 8 weeks. The results looked at alternations in many serum metabolites involved in metabolic pathways. They therefore provide a deeper understanding of host carbohydrate, lipid and tocopherol metabolism. The findings also show the interconnections between circulating metabolites and microbial metabolism. This provides further evidence for the impacts of dietary changes on host metabolism and associated changes in gut microbe metabolism.
Abstract
Almond consumption can improve cardiometabolic (CM) health. However, the mechanisms underlying those benefits are not well characterized. This study explored the effects of consuming a snack of almonds vs. crackers for 8 weeks on changes in metabolomic profiles in young adults (clinicaltrials.gov ID: NCT03084003). Participants (n = 73, age: 18-19 years, BMI: 18-41 kg/m2) were randomly assigned to consume either almonds (2 oz/d, n = 38) or an isocaloric control snack of graham crackers (325 kcal/d, n = 35) daily for 8 weeks. Blood samples were collected at baseline prior to and at 4 and 8 weeks after the intervention. Metabolite abundances in the serum were quantified by hydrophilic interaction chromatography quadrupole (Q) time-of-flight (TOF) mass spectrometry (MS/MS), gas chromatography (GC) TOF MS, CSH-ESI (electrospray) QTOF MS/MS, and targeted analyses for free PUFAs, total fatty acids, oxylipins and endocannabinoids. Linear mixed model analyses with baseline-adjustment were conducted, and those results were used for enrichment and network analyses. Microbial community pathway predictions from 16S rRNA sequencing of fecal samples was done using PICRUST2. Almond consumption enriched unsaturated triglycerides, unsaturated phosphatidylcholines, saturated and unsaturated lysophosphatidylcholines, tricarboxylic acids, and tocopherol clusters (p < 0.05). Targeted analyses reveal lower levels of omega-3 total fatty acids (TFAs) overall in the almond group compared to the cracker group (p < 0.05). Microbial amino acid biosynthesis, and amino sugar and nucleotide sugar metabolism pathways were also differentially enriched at the end of the intervention (p < 0.05). The study demonstrates the differential effects of almonds on host tocopherol, lipid, and TCA cycle metabolism with potential changes in microbial metabolism, which may interact with host metabolism to facilitate the CM benefits.
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L-Arginine is a feasible supplement to heal chronic anal fissure via reducing internal anal sphincter pressure: a randomized clinical trial study.
Khalighi Sikaroudi, M, Sedaghat, M, Shidfar, F, Talebi, S, Hosseini-Baharanchi, FS, Masoodi, M, Farahani, SV
Amino acids. 2023;55(2):193-202
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An anal fissure is a condition resulting from a superficial open wound or tear in the anus mucosa with a sharp pain that can extend from the anal canal to the periphery. The aim of this study was to evaluate the effect of oral L-arginine as a safer method with better performance on clinical symptoms, quality of life, and internal anal sphincter pressure in patients with chronic anal fissure. This study is a randomised, double-blind, placebo-controlled trial with parallel design conducted in the 4-week intervention and the 8-week follow-up. The study recruited 76 adult men and women who were aged between 18 and 65 years of age and were diagnosed with chronic fissures. Participants were assigned to two groups: 3000 mg l-arginine, or a placebo filled with Maltodextrin. Results show that supplementation with l-arginine may relieve clinical symptoms, especially pain and bleeding, and improve the quality of life of patients with chronic anal fissure. In addition, analysis of anal internal sphincter pressures evaluated by manometry and balloon showed the significant reduction of sphincter pressure in these patients. Authors conclude that l-arginine supplementation may relieve clinical symptoms and improve the quality of life, anxiety, and depression in patients with chronic anal fissures.
Abstract
The hypertonicity of internal anal sphincter resting pressure is one of the main causes of chronic anal fissure. Therefore, the aim of this study was to assess the effect of oral administration of L-arginine on the improvement of the anal fissures by relaxing the internal anal sphincter. Seventy-six chronic anal fissure patients (aged 18-65 years) who were referred to Rasoul-e-Akram Hospital, Tehran, Iran from February 2019 to October 2020 participated in this randomized, double-blind, placebo-controlled trial. Participants were allocated into treatment (L-arginine) and placebo groups. They took a 1000 mg capsule three times a day for 1 month, and then we followed them at the end of the first and third months after the intervention. Clinical symptoms, anal sphincter resting pressure, and quality of life (QoL) were completed at baseline and the end of the study. The analysis of data showed a significant decrease in bleeding, fissure size, and pain for each group; however, in the L-arginine group was more than the control group at the end of the study (P values < 0.001). Following that, a significant increase in QoL was seen just in patients treated with L-arginine (P value = 0.006). In addition, the comparison of anal pressures at baseline and, between groups at the end of the study showed a significant reduction in sphincter pressure in patients treated with L-arginine (P value < 0.001, = 0.049; respectively). The oral administration of 3000 mg L-arginine can heal chronic anal fissures by reducing internal anal sphincter pressure with more negligible side effects. However, we recommend long-term study with more extended follow-up.Clinical trial registry: IRCT20190712044182N1 at Iranian clinical trials, date: 2019-08-27.
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Impact of probiotics on muscle mass, muscle strength and lean mass: a systematic review and meta-analysis of randomized controlled trials.
Prokopidis, K, Giannos, P, Kirwan, R, Ispoglou, T, Galli, F, Witard, OC, Triantafyllidis, KK, Kechagias, KS, Morwani-Mangnani, J, Ticinesi, A, et al
Journal of cachexia, sarcopenia and muscle. 2023;14(1):30-44
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Sarcopenia is a progressive skeletal muscle disorder involving accelerated loss of muscle mass, strength and function. It generally occurs in older age groups but can also be seen in younger people. Multiple factors contribute to the development of the condition. Besides nutritional management strategies, probiotics have recently caught the interest of researchers. As probiotics promote metabolic building activity, aid digestion and absorption and reduce muscle breakdown by favourably managing inflammation, they present great potential for the management of sarcopenia. This systematic review and meta-analysis explored the impact of probiotic supplementation on muscle mass, total lean mass and muscle strength in human adults. The review included 24 studies, with probiotics mainly from the Bifidobacteria or Lactobacilli family. The analysis concluded that probiotic supplementation improved muscle mass in comparison to placebos. It also significantly increased overall muscle strength in 6 randomized controlled trials, which was most obvious in age groups of 50 and above. However, no changes were seen concerning total lean mass. It appeared that longer studies, of >12 weeks or more, showed better outcomes in this review. Furthermore, Bifidobacteria species seemed to exhibit more favourable effects, and the authors also noted the beneficial results were more significant in Asian populations. Further research is needed to understand more about the underlying mechanism, best probiotics strains and the specifics of different demographic groups. This article yields a concise overview of sarcopenia, the nutritional aspects of the disease and how probiotics may be beneficial in disease management, strengthened with data from the review.
Expert Review
Conflicts of interest:
None
Take Home Message:
- This was a well-conducted meta-analysis based on its methodological approach that demonstrated that Lactobacillus and Bifidobacterium probiotic supplementation may contribute to improved muscle mass in younger adults and improved muscle strength in older adults.
- Bifidobacterium probiotic supplementation was associated with enhanced muscle mass in younger adults, a potential focus for those considering probiotic supplements.
- The duration of probiotic therapy matters, with longer-term (12 weeks or more) supplementation showing improvements in muscle mass and strength..
Evidence Category:
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X
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
This systematic review and meta-analysis evaluated the effect of probiotics on muscle mass, total lean mass and muscle strength in both young and older adults.
Methods
- The search encompassed PubMed, Scopus, Web of Science, and Cochrane Library databases, from inception up to June 2022; studies included spanned a period from 2013 to June 2022.
- The study adhered to Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines and included the Risk-of-Bias tool to assess study quality.
- The study focused on changes in muscle mass, total lean mass, and muscle strength.
- Inclusion criteria: randomised controlled trials (RCTs) with adult participants (>18 years); interventions involving any probiotics, and a control group receiving either no treatment or a placebo.
Results
- 24 RCTs were included (709 participants), with studies conducted in Europe, USA, and Asia. Intervention durations: ranged from 3 weeks to 12 months.
- Participants included overweight, untrained healthy and resistance-trained individuals, and those with specific conditions like metabolic syndrome and frailty.
- Body composition assessments were conducted using bioelectrical impedance (BIA) and/or dual-energy X-ray absorptiometry (DXA).
- Probiotic strains employed in the included studies varied, with Lactobacillus the most common, followed by Bifidobacterium; some combined both. 5 of 24 studies also used additional strains.
- Dosages: ranged from 2 × 10^9 to 11.2 × 10^10 colony-forming units (CFU).
- 4 out of 24 studies used fermented food products like cheese and noodles as sources of probiotics.
- 22 RCTs measured muscle mass and total lean mass; 6 RCTs measured global muscle strength.
- Probiotic supplementation (≥12 weeks) moderately increased muscle mass, with a standardised mean difference (SMD) of 0.42. This significant effect (95% CI: 0.10–0.74, P=0.009) was observed only in younger Asian adults (<50 years) after Bifidobacterium supplementation, based on a meta-analysis of 10 studies.
- Probiotic supplementation (≥12 weeks) significantly increased global muscle strength in older adults (>50 years; SMD: 0.69, 95% CI: 0.33–1.06, P = 0.0002).
- Probiotic supplementation showed no significant impact on lean mass (SMD: -0.03, 95% CI: 0.19 – 0.13, P = 0.69).
Conclusion
Probiotic supplementation, especially Lactobacillus and Bifidobacterium may have a positive impact on muscle mass and global strength
Clinical practice applications:
- Consumption of probiotics, mainly Lactobacillus and Bifidobacterium may contribute to improved muscle strength in older individuals (>50y).
- Consumption of Bifidobacterium strains was associated with improved muscle mass in younger individuals (<50y) in Asian countries, in a low number of studies (k=2).
- Bifidobacterium breve B-3 was associated with an improvement in muscle mass in older overweight individuals, although a causal relationship was not established.
- Probiotics may enhance muscle mass or strength by enhancing protein digestion and amino acid absorption for muscle synthesis and function.
- Considering an individual’s goals, a practitioner could consider probiotic supplementation as a complementary intervention when aiming to enhance muscle mass or strength .
Considerations for future research:
- Future research could focus on pinpointing which specific probiotic strains are most effective for muscle strength or muscle mass to tailor more precise interventions.
- Most studies did not exceed 12 weeks, highlighting the need for long-term research on probiotics sustained muscle impact.
- Future research could investigate the effects of probiotics across diverse demographic groups including different ages, sexes, and ethnic backgrounds to understand the impact in different populations.
- Delving deeper into the mechanisms by which probiotics influence muscle health could lead to targeted probiotic therapies that address specific physiological pathways.
- Finally, future research could explore how probiotics can be combined with other interventions, such as exercise or nutritional modifications, to synergistically improve muscle health and function.
Abstract
Probiotics have shown potential to counteract sarcopenia, although the extent to which they can influence domains of sarcopenia such as muscle mass and strength in humans is unclear. The aim of this systematic review and meta-analysis was to explore the impact of probiotic supplementation on muscle mass, total lean mass and muscle strength in human adults. A literature search of randomized controlled trials (RCTs) was conducted through PubMed, Scopus, Web of Science and Cochrane Library from inception until June 2022. Eligible RCTs compared the effect of probiotic supplementation versus placebo on muscle and total lean mass and global muscle strength (composite score of all muscle strength outcomes) in adults (>18 years). To evaluate the differences between groups, a meta-analysis was conducted using the random effects inverse-variance model by utilizing standardized mean differences. Twenty-four studies were included in the systematic review and meta-analysis exploring the effects of probiotics on muscle mass, total lean mass and global muscle strength. Our main analysis (k = 10) revealed that muscle mass was improved following probiotics compared with placebo (SMD: 0.42, 95% CI: 0.10-0.74, I2 = 57%, P = 0.009), although no changes were revealed in relation to total lean mass (k = 12; SMD: -0.03, 95% CI: -0.19 - 0.13, I2 = 0%, P = 0.69). Interestingly, a significant increase in global muscle strength was also observed among six RCTs (SMD: 0.69, 95% CI: 0.33-1.06, I2 = 64%, P = 0.0002). Probiotic supplementation enhances both muscle mass and global muscle strength; however, no beneficial effects were observed in total lean mass. Investigating the physiological mechanisms underpinning different ageing groups and elucidating appropriate probiotic strains for optimal gains in muscle mass and strength are warranted.
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The efficacy of fermented foods in the treatment and management of diarrhoeal diseases: A systematic review and meta-analysis.
Olayanju, A, Mellor, D, Khatri, Y, Pickles, N
Nutrition and health. 2023;29(1):71-83
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Plain language summary
According to World Health Organisation (WHO), diarrhoeal disease is the second leading cause of death among children under the age of 5 in the world. The WHO’s recommendation for the treatment of diarrhoea is oral rehydration solution (ORS), consisting of a solution of clean water, sugar and salt along with a 10-14 day supplemental treatment course of dispersible 20 mg zinc tablets. The aim of this study was to evaluate the available evidence with respect to the efficacy of fermented foods and beverages in comparison with unfermented or heat-treated products, including dairy and cereal products, focussing on the treatment of diarrhoea in infants. This study is a systematic review and meta-analysis of seven randomised controlled trials. Results show that administering fermented foods during an episode of diarrhoea in infants under five years of age, may reduce the duration of the disease in comparison to the control groups. There was no clear effect on daily stool frequency, but duration of hospitalisation was reduced following administration of fermented foods. Authors conclude that fermented foods may be helpful in the treatment of diarrhoea in infants up to the age of five. Thus, more good quality trials are required to investigate the complex matrix of fermented food products, other than dairy foods, in the management, particularly treatment of gastrointestinal diseases such as diarrhoea.
Abstract
Background: Diarrhoeal disease is a major cause of global infant mortality, and compromises the ability of many countries with respect to achieving sustainable development goals. The WHO's recommendation of Oral Rehydration Solution (ORS) and zinc in the management of this disease, may not be readily available. Consideration and assessment of cultural practices in its management has been an area of increased interest over the last decade. Aim: This study aims to systematically evaluate efficacy of the consumption of traditional fermented foods as functional products for the treatment and management of diarrhoea. Methods: Following PRISMA guidelines, a systematic review was conducted of electronic databases (Cochrane Library, Ovid Medline and Pubmed) databases with no restrictions on language and publication date for RCTs that investigated the effect of consumption of fermented foods on the treatment of diarrhoea in children under five years of age. Results: Seven RCTs were included. Meta-analysis showed that compared to control, consumption of fermented foods significantly reduced mean duration of diarrhoea, -0.61 days; (95% CI, -1.04, -0.18); length of hospitalization, -0.35 days (95% CI, -0.69, -0.02); but not mean daily frequency of stool -2.00 (95% CI,-7.03, 3.04). Conclusion: Limited available evidence suggests that consumption of fermented foods may help reduce duration and severity of symptoms as a treatment of diarrhoea. More high quality research needs to be undertaken to investigate the efficacy of fermented food as an effective alternative to ORS as a potential WHO recommendation for management of diarrhoeal disease.