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Environment International May 2024Potential effect of greenspace exposure on human microbiota have been explored by a number of observational and interventional studies, but the results remained mixed....
BACKGROUND
Potential effect of greenspace exposure on human microbiota have been explored by a number of observational and interventional studies, but the results remained mixed. We comprehensively synthesized these studies by performing a systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.
METHODS
Comprehensive literature searches in three international databases (PubMed, Embase, and Web of Science) and three Chinese databases (China National Knowledge Infrastructure, Wanfang, and China Biology Medicine disc) were conducted from inception to November 1, 2023. Observational and interventional studies that evaluated associations between greenspace exposure and human microbiota at different anatomical sites were included. Studies were assessed using the National Toxicology Program's office of Health Assessment and Translation risk of bias tool and certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation framework. Two authors independently performed study selection, data extraction, and risk of bias assessment, and evidence grading. Study results were synthesized descriptively.
RESULTS
Twenty studies, including 11 observational studies and 9 interventional studies, were finally included into the systematic review. The microbiota of the included studies was from gut (n = 13), skin (n = 10), oral cavity (n = 5), nasal cavity (n = 5) and eyes (n = 1). The majority of studies reported the associations of greenspace exposure with increased diversity (e.g., richness and Shannon index) and/or altered overall composition of human gut (n = 12) and skin microbiota (n = 8), with increases in the relative abundance of probiotics (e.g., Ruminococcaceae) and decreases in the relative abundance of pathogens (e.g., Streptococcus and Escherichia/Shigella). Due to limited number of studies, evidence concerning greenspace and oral, nasal, and ocular microbiota were still inconclusive.
CONCLUSION
The current evidence suggests that greenspace exposure may diversify gut and skin microbiota and alter their composition to healthier profiles. These findings would be helpful in uncovering the potential mechanisms underlying greenspace and human health and in promoting a healthier profile of human microbiota.
Topics: Humans; Microbiota; Environmental Exposure
PubMed: 38653130
DOI: 10.1016/j.envint.2024.108662 -
Nutrients Jan 2024Over recent decades, a growing body of evidence has emerged linking the composition of the gut microbiota to sleep regulation. Interestingly, the prevalence of sleep... (Review)
Review
BACKGROUND
Over recent decades, a growing body of evidence has emerged linking the composition of the gut microbiota to sleep regulation. Interestingly, the prevalence of sleep disorders is commonly related to cardiometabolic comorbidities such as diabetes, impaired lipid metabolism, and metabolic syndrome (MetS). In this complex scenario, the role of the gut-brain axis as the main communicating pathway between gut microbiota and sleep regulation pathways in the brain reveals some common host-microbial biomarkers in both sleep disturbances and MetS. As the biological mechanisms behind this complex interacting network of neuroendocrine, immune, and metabolic pathways are not fully understood yet, the present systematic review aims to describe common microbial features between these two unrelated chronic conditions.
RESULTS
This systematic review highlights a total of 36 articles associating the gut microbial signature with MetS or sleep disorders. Specific emphasis is given to studies evaluating the effect of dietary patterns, dietary supplementation, and probiotics on MetS or sleep disturbances.
CONCLUSIONS
Dietary choices promote microbial composition and metabolites, causing both the amelioration and impairment of MetS and sleep homeostasis.
Topics: Humans; Metabolic Syndrome; Brain-Gut Axis; Probiotics; Diet; Gastrointestinal Microbiome; Dysbiosis
PubMed: 38337675
DOI: 10.3390/nu16030390 -
American Journal of Obstetrics &... Apr 2024This study aimed to synthesize the available evidence on probiotic administration during pregnancy for the prevention of preeclampsia and its effects on related... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
This study aimed to synthesize the available evidence on probiotic administration during pregnancy for the prevention of preeclampsia and its effects on related maternal, fetal, and newborn outcomes.
DATA SOURCES
Six databases were systematically searched for eligible studies, namely Ovid MEDLINE, Embase, CINAHL, Cochrane, Global Index Medicus, and the Maternity and Infant Care Database, from inception to August 2, 2023.
STUDY ELIGIBILITY CRITERIA
Randomized controlled trials that evaluated the effects of probiotic administration on women during any stage of pregnancy were eligible for inclusion.
METHODS
The protocol was registered with the International Prospective Register of Systematic Reviews under identifier CRD42023421613. Evaluating study eligibility, extracting data, assessing risk of bias (ROB-2 tool), and rating certainty (Grading of Recommendations, Assessment, Development and Evaluations) were conducted independently by 2 authors. The primary outcomes were incidence of preeclampsia, eclampsia, and maternal mortality. A meta-analysis was performed, and the results were reported as risk ratios with 95% confidence intervals.
RESULTS
A total of 29 trials (7735 pregnant women) met the eligibility criteria. There was heterogeneity across the trials in the population of enrolled women and the type of probiotic tested (20 different strains), although most used oral administration. Probiotics may make no difference to the risk of preeclampsia (risk ratio, 1.14; 95% confidence interval, 0.84-1.53; 11 trials; 2401 women; low certainty evidence), preterm birth at <37 weeks' gestation (risk ratio, 0.93; 95% confidence interval, 0.66-1.30; 18 trials, 4016 women; low certainty evidence), or gestational age at delivery (mean difference, -0.03 weeks [≈0.2 days]; 95% confidence interval, -0.16 to 0.10 weeks [≈ -1.1 to 0.7 days]; 13 trials, 2194 women; low certainty evidence). It is difficult to assess the effects of probiotics on other secondary outcomes because the evidence was of very low certainty, however, no benefits or harms were observed.
CONCLUSION
Limited evidence suggests that probiotic supplementation does not affect the risk for preeclampsia. Further high-quality trials are needed to definitively assess the benefits and possible harms of probiotic supplementation during pregnancy. There is also a lack of data from trials that included women who were undernourished or who experienced microbial dysbiosis and for whom probiotic supplementation might be useful.
Topics: Humans; Probiotics; Pregnancy; Pre-Eclampsia; Female; Infant, Newborn; Pregnancy Outcome; Randomized Controlled Trials as Topic; Maternal Mortality; Premature Birth
PubMed: 38447676
DOI: 10.1016/j.ajogmf.2024.101322 -
Diseases (Basel, Switzerland) Oct 2023Probiotics have been widely used in gastroenteritis due to acute and chronic illnesses. However, evidence supporting the effectiveness of probiotics in different health... (Review)
Review
Probiotics have been widely used in gastroenteritis due to acute and chronic illnesses. However, evidence supporting the effectiveness of probiotics in different health conditions is inconclusive and conflicting. The aim of this study was to review the existing literature on the effects of probiotics on gastroenteritis among adults. Only original articles on clinical trials that demonstrated the effects of probiotics in adults with gastroenteritis were used for this analysis. Multiple databases, such as PubMed, Google Scholar, MEDLINE and Scopus databases, were searched for the data. The study followed standard procedures for data extraction using a PRISMA flow chart. A quality appraisal of the selected studies was conducted using CADIMA. Finally, a meta-analysis was performed. Thirty-five articles met the selection criteria; of them, probiotics were found effective in the treatment and/or prevention of chronic inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease in 17 (49%), and the treatment of in 4 (11.4%), antibiotic-induced diarrhea in 3 (8.6%), infection in 2 (5.7%) and diverticulitis in 1 (2.9%), while the remaining 7 (20%) were ineffective, and 1 study's results were inconclusive. The meta-analysis did not demonstrate any significant protective effects of probiotics. Having a τ value of zero and I of 6%, the studies were homogeneous and had minimum variances. Further studies are suggested to evaluate the beneficial effects of probiotics in IBDs and other chronic bowel diseases.
PubMed: 37873782
DOI: 10.3390/diseases11040138 -
Advances in Nutrition (Bethesda, Md.) Jan 2024Probiotic supplementation is a potential therapeutic for metabolic diseases, including obesity, metabolic syndrome (MetS), and type 2 diabetes (T2D), but most studies... (Meta-Analysis)
Meta-Analysis Review
Probiotic supplementation is a potential therapeutic for metabolic diseases, including obesity, metabolic syndrome (MetS), and type 2 diabetes (T2D), but most studies deliver multiple species of bacteria in addition to prebiotics or oral pharmaceuticals. This may contribute to conflicting evidence in existing meta-analyses of probiotics in these populations and warrants a systematic review of the literature to assess the contribution of a single probiotic genus to better understand the contribution of individual probiotics to modulate blood glucose. We conducted a systematic review and meta-analysis of animal studies and human randomized controlled trials (RCTs) to assess the effects of Bifidobacterium (BF) probiotic supplementation on markers of glycemia. In a meta-analysis of 6 RCTs, BF supplementation had no effect on fasting blood glucose {FBG; mean difference [MD] = -1.99 mg/dL [95% confidence interval (CI): -4.84, 0.86], P = 0.13}, and there were no subgroup differences between subjects with elevated FBG concentrations and normoglycemia. However, BF supplementation reduced FBG concentrations in a meta-analysis comprised of studies utilizing animal models of obesity, MetS, or T2D [n = 16; MD = -36.11 mg/dL (CI: -49.04, -23.18), P < 0.0001]. Translational gaps from animal to human trials include paucity of research in female animals, BF supplementation in subjects that were normoglycemic, and lack of methodologic reporting regarding probiotic viability and stability. More research is necessary to assess the effects of BF supplementation in human subjects with elevated FBG concentrations. Overall, there was consistent evidence of the efficacy of BF probiotics to reduce elevated FBG concentrations in animal models but not clinical trials, suggesting that BF alone may have minimal effects on glycemic control, may be more effective when combined with multiple probiotic species, or may be more effective in conditions of hyperglycemia rather than elevated FBG concentrations.
Topics: Female; Humans; Animals; Blood Glucose; Bifidobacterium; Probiotics; Metabolic Syndrome; Obesity; Diabetes Mellitus, Type 2; Models, Animal
PubMed: 37923223
DOI: 10.1016/j.advnut.2023.10.009 -
Frontiers in Neuroscience 2024Critical phases of neurodevelopment and gut microbiota diversification occur in early life and both processes are impacted by genetic and environmental factors. Recent...
Functional contribution of the intestinal microbiome in autism spectrum disorder, attention deficit hyperactivity disorder, and Rett syndrome: a systematic review of pediatric and adult studies.
INTRODUCTION
Critical phases of neurodevelopment and gut microbiota diversification occur in early life and both processes are impacted by genetic and environmental factors. Recent studies have shown the presence of gut microbiota alterations in neurodevelopmental disorders. Here we performed a systematic review of alterations of the intestinal microbiota composition and function in pediatric and adult patients affected by autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), and Rett syndrome (RETT).
METHODS
We searched selected keywords in the online databases of PubMed, Cochrane, and OVID (January 1980 to December 2021) with secondary review of references of eligible articles. Two reviewers independently performed critical appraisals on the included articles using the Critical Appraisal Skills Program for each study design.
RESULTS
Our systematic review identified 18, 7, and 3 original articles describing intestinal microbiota profiles in ASD, ADHD, and RETT, respectively. Decreased Firmicutes and increased Bacteroidetes were observed in the gut microbiota of individuals affected by ASD and ADHD. Proinflammatory cytokines, short-chain fatty acids and neurotransmitter levels were altered in ASD and RETT. Constipation and visceral pain were related to changes in the gut microbiota in patients affected by ASD and RETT. Hyperactivity and impulsivity were negatively correlated with (phylum Firmicutes) and positively correlated with sp. (phylum Bacteroidetes) in ADHD subjects. Five studies explored microbiota-or diet-targeted interventions in ASD and ADHD. Probiotic treatments with sp. and fecal microbiota transplantation from healthy donors reduced constipation and ameliorated ASD symptoms in affected children. Perinatal administration of sp. prevented the onset of Asperger and ADHD symptoms in adolescence. Micronutrient supplementation improved disease symptomatology in ADHD without causing significant changes in microbiota communities' composition.
DISCUSSION
Several discrepancies were found among the included studies, primarily due to sample size, variations in dietary practices, and a high prevalence of functional gastrointestinal symptoms. Further studies employing longitudinal study designs, larger sample sizes and multi-omics technologies are warranted to identify the functional contribution of the intestinal microbiota in developmental trajectories of the human brain and neurobehavior.
SYSTEMATIC REVIEW REGISTRATION
https://clinicaltrials.gov/, CRD42020158734.
PubMed: 38516317
DOI: 10.3389/fnins.2024.1341656 -
Clinical and Experimental Dermatology Dec 2023Atopic dermatitis (AD) is one of the most common chronic inflammatory skin diseases. The effect of probiotic administration on the severity of AD in adults has shown... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Atopic dermatitis (AD) is one of the most common chronic inflammatory skin diseases. The effect of probiotic administration on the severity of AD in adults has shown inconsistent results.
OBJECTIVES
To determine the effectiveness of probiotic supplementation as a therapeutic tool for adult AD.
METHODS
PubMed, Scopus and Embase were systematically searched to collect data from studies in which probiotics were administered to treat adult AD.
RESULTS
Out of 413 publications, 9 papers were included in the meta-analysis. Significant differences in the ScORing Atopic Dermatitis tool favouring probiotics were observed [relative risk (RR) -5.93, 95% confidence interval (CI) -8.43 to -3.43]. Lactobacillus salivarius presented with largest effect size (RR -9.79, 95% CI -13.04 to -6.54), followed by L. acidophilus (RR -5.77, 95% CI -10.82 to -0.72) and L. plantarum (RR -3.76, 95% CI -6.36 to -1.16). No benefit was observed with L. fermentum. Based on the severity of AD, probiotics showed better results in people with moderate-to-severe AD (RR -9.12, 95% CI -12.17 to -6.08) than in individuals with mild disease (RR -2.67, 95% CI -4.67 to -0.66). Serum levels of IgE and eosinophil count remained significantly unchanged after the probiotic intervention (RR 0.25, 95% CI -0.10 to 0.60; RR -0.27, 95% CI -0.68 to 0.13, respectively).
CONCLUSIONS
Current evidence supports a role for some probiotics as a therapeutic tool for the treatment of adult AD, particularly in patients with severe AD. The efficacy of probiotics is strain specific, with L. salivarius and L. acidophilus having the largest clinical benefit. Such benefit is apparently independent of IgE levels and eosinophil count. Despite these encouraging results, the decrease in AD severity did not translate into a clinically meaningful better quality of life as assessed by the Dermatology Life Quality Index. There currently is not enough reliable data to reach conclusions about the optimal dose and duration for probiotic treatment.
Topics: Adult; Humans; Dermatitis, Atopic; Quality of Life; Skin; Probiotics; Immunoglobulin E
PubMed: 37706436
DOI: 10.1093/ced/llad318 -
Nutritional Neuroscience Sep 2023Available evidence indicates that junk foods, defined as unhealthy foods with high-calorie and low-nutrient value, negatively affect mental and metabolic health of... (Meta-Analysis)
Meta-Analysis
Available evidence indicates that junk foods, defined as unhealthy foods with high-calorie and low-nutrient value, negatively affect mental and metabolic health of children. This study aimed to conduct a meta-analysis to clarify the association between junk food consumption and psychological distress in children and adolescents. A systematic literature search of relevant documents published in PubMed, Web of Science, and SCOPUS was conducted up to 2022. All observation studies which assessed association of junk foods and psychological distress in children and adolescents were included. Random-effect model was used to pool odds ratio (OR) and 95% confidence interval (CI) from individual studies. Subgroup meta-analysis was performed based on junk foods categories (sweet drinks, sweet snacks and snacks). Data of 17 included articles on junk foods consumption in relation to depression, stress, anxiety, sleep dissatisfaction and happiness in children and adolescents were included in this systematic review. According to random effect model, the pooled OR in the highest vs. the lowest category of junk foods was 1.62 (95% CI: 1.35-1.95) for depression, 1.34 (95% CI: 1.16-1.54) for stress, 1.24 (95% CI: 1.03-1.50) for anxiety, 1.17 (95% CI: 1.05-1.30) for sleep dissatisfaction and 0.83 (95% CI: 0.75-0.92) for happiness. In subgroup meta-analysis, there were significant associations between different types of junk foods and psychological distress ( < 0.05). This meta-analysis showed that junk foods consumption was associated with increased odds of psychological distress in children and adolescents. These findings support the current recommendation of decreasing junk foods intake.
Topics: Humans; Child; Adolescent; Energy Intake; Anxiety; Anxiety Disorders; Emotions; Psychological Distress
PubMed: 35816403
DOI: 10.1080/1028415X.2022.2094856 -
International Journal of Molecular... Dec 2023The objective of this review is to systematically analyze the potential correlation between gut microbiota and osteoarthritis (OA) as well as to evaluate the feasibility... (Review)
Review
The objective of this review is to systematically analyze the potential correlation between gut microbiota and osteoarthritis (OA) as well as to evaluate the feasibility of microbiota-targeted therapies for treating OA. Studies conducted from October 2013 to October 2023 were identified via a search on electronic databases such as PubMed, Web of Science, and Scopus, following established PRISMA statement standards. Two reviewers independently screened, assessed, and extracted relevant data, and then they graded the studies using the ROBINS I tool for non-randomized interventions studies and SYRCLE's risk-of-bias tool for animal studies. A search through 370 studies yielded 38 studies (24 preclinical and 14 clinical) that were included. In vivo research has predominantly concentrated on modifying the gut microbiota microenvironment, using dietary supplements, probiotics, and prebiotics to modify the OA status. are the most thoroughly examined with found to effectively reduce cartilage damage, inflammatory factors, and pain. Additionally, inhibits the development of OA by preventing high-fat diet (HFD)-induced obesity and protecting cartilage from damage. Although there are limited clinical studies, certain compositions of intestinal microbiota may be associated with onset and progression of OA, while others are linked to pain reduction in OA patients. Based on preclinical studies, there is evidence to suggest that the gut microbiota could play a significant role in the development and progression of OA. However, due to the scarcity of clinical studies, the exact mechanism linking the gut microbiota and OA remains unclear. Further research is necessary to evaluate specific gut microbiota compositions, potential pathogens, and their corresponding signaling pathways that contribute to the onset and progression of OA. This will help to validate the potential of targeting gut microbiota for treating OA patients.
Topics: Animals; Humans; Gastrointestinal Microbiome; Osteoarthritis; Microbiota; Databases, Factual; Lactobacillus; Pain
PubMed: 38203314
DOI: 10.3390/ijms25010143 -
Clinical Nutrition (Edinburgh, Scotland) Aug 2023Autism spectrum disorders (ASDs) are associated with specific dietary habits, including limited food selection and gastrointestinal problems, resulting in an altered gut... (Review)
Review
Autism spectrum disorders (ASDs) are associated with specific dietary habits, including limited food selection and gastrointestinal problems, resulting in an altered gut microbiota. Autistic patients have an elevated abundance of certain gut bacteria associated with increased oxidative stress in the gastrointestinal tract. Probiotic supplementation has been shown to decrease oxidative stress in a simulated gut model, but the antioxidant effects of probiotics on the oxidative stress of the gut in autistic patients have not been directly studied. However, it is speculated that probiotic supplementation may help decrease oxidative stress in the gastrointestinal tract of autistic patients due to their specific dietary habits altering the microbiota. PubMed, Scopus and Web of Science databases and Google Scholar were searched up to May 2023. This systematic-narrative review aims to present the latest evidence regarding the changes in eating habits of autistic children which may further increase the gut microbiota induced oxidative stress. Additionally, this review will assess the available literature on the effects of probiotic supplementation on oxidative stress parameters.
Topics: Child; Humans; Autistic Disorder; Probiotics; Gastrointestinal Tract; Microbiota; Oxidative Stress
PubMed: 37418842
DOI: 10.1016/j.clnu.2023.06.014