Clinical Research Directory

Modulation of Gut Microbiota Composition and Gut Permeability Profiles by Multispecies Synbiotic Supplementation in Hemodialysis Patients

Chronic kidney disease (CKD) patients undergoing maintenance hemodialysis experience profound alterations in their gut microbiota, leading to dysbiosis and increased gut permeability. This disruption facilitates the translocation of endotoxins and gut-derived uremic toxins such as indoxyl sulfate and p-cresyl sulfate into the systemic circulation, contributing to heightened systemic inflammation, cardiovascular disease risk, and accelerated CKD progression. Synbiotic supplementation, particularly multispecies formulations, has emerged as a promising therapeutic strategy to restore gut microbial balance, enhance intestinal barrier integrity, and reduce the systemic burden of deleterious microbial metabolites. These probiotics potentially improve clinical outcomes by modulating inflammatory pathways and decreasing circulating levels of uremic toxins. Despite these insights, few clinical trials have comprehensively assessed the effects of multispecies synbiotic on fecal microbiome composition, gut permeability and uremic toxin profiles in hemodialysis patients. This pilot study aims to fill this gap by evaluating the modulatory effects of a 12-week multispecies synbiotic intervention.

Alterations of Gut Derived Uremic Toxins and Microbiome Metabolites by Multispecies Synbiotic

Patients with chronic kidney disease (CKD) undergoing maintenance hemodialysis frequently exhibit significant gut microbiota dysbiosis and increased intestinal permeability. These alterations enable the translocation of endotoxins and gut-derived uremic toxins-such as indoxyl sulfate and p-cresyl sulfate-into the systemic circulation, exacerbating systemic inflammation, elevating cardiovascular risk, and accelerating disease progression. Multispecies synbiotic supplementation has emerged as a promising intervention to restore gut microbial equilibrium, strengthen intestinal barrier function, and reduce the systemic load of harmful microbial metabolites. Through modulation of inflammatory pathways and reduction of circulating uremic toxins, synbiotic hold potential to improve clinical outcomes in this vulnerable population. Although preclinical and some clinical evidence suggests benefits of probiotic therapy, comprehensive clinical trials specifically examining multispecies synbiotic effects on gut inflammatory markers, gut derived metabolite profiles, and uremic toxin levels in hemodialysis patients remain limited. This pilot study aims to address this gap by investigating the biological and clinical effects of a 12-week multispecies regimen in adult maintenance hemodialysis patients.

Impact of a Cricket and Black Soldier Fly Larvae-Fortified Cracker on the Gut Microbiome and Iron Status in Malagasy Schoolchildren

The purpose of this study is to determine the health impacts of consistent consumption of insect-fortified crackers among school-aged children in Madagascar. Specifically, in this RCT, the investigators will assess whether the insect-fortified crackers can improve the health status of Malagasy school children. The investigators' objectives are to: (1) Assess changes in gut microbiome composition that occur after 6 and 14 weeks of cracker consumption through 16S rRNA sequencing. (2) Assess changes in intestinal and systemic inflammation after 6 and 14 weeks of cracker consumption through quantification of fecal calprotectin, lactoferrin, myeloperoxidase (MPO), and alpha-1-antitrypsin (AAT) and circulating pro-inflammatory cytokines. (3) Assess changes in iron status after 14 weeks of cracker consumption through quantification of hemoglobin (Hb), inflammation-adjusted serum ferritin, and soluble transferrin receptor (sTfR).

Dietary Wild Blueberries and Joint Health

The goal of this proposed study is to examine the effects of dietary wild blueberries on gut microbiome, serum markers of inflammation, and joint function in adults. Each participant will consume 25g freeze-dried blueberries or matched placebo powder for 12 weeks, with a 2-week washout phase between.

Infant Microbiota Restoration With Maternal Microbes

The goal of this clinical trial is to test the ability of different bacterial products in restoring natural gut microbiota in C-section born infants. The main question it aims to answer is: Do maternally derived strains of bacteria perform better than commercially available probiotic strains in restoring the gut microbiota of C-section born infants? Researchers will compare the gut microbiota of treated infants to that of untreated C-section born infants and untreated vaginally born infants to see if the bacterial treatments cause the microbiota to resemble that of vaginally born infants. Participants will be given a bacterial product orally once daily for either one or four weeks and be asked to collect faecal, urine and saliva samples.

Walnuts as an Infant Solid Food for Health

The objective is to investigate the effect of walnuts on gut microbiota, inflammatory markers, atopic dermatitis status, and indices of allergy outcomes in breastfed infants during early complementary feeding. The three primary aims include: Aim 1: Evaluate the effect of walnut consumption on gut microbiota structure and function, inflammation, atopic dermatitis, and allergy outcomes. Aim 2: Evaluate the impact of walnut consumption on infant growth trajectories and risk of overweight. Aim 3 (exploratory): Identify walnut-specific food signatures that are associated with gut microbiota and immunity biomarkers using a novel nutri-metabolomics technique.

Probiotics and Active Aging: Enhancing Gut Health

The general objective of this clinical trial is to assess the physical fitness and gut microbiota of older adults, thereby highlighting the importance of focusing on health maintenance. By making use of available resources and fostering collaboration among the elements involved in the study, more specific objectives can be defined: 1. To determine the state of the gut flora in older adults through the analysis of the intestinal microbiota. 2. To identify changes in the intestinal microbiota resulting from the intake of probiotics in older adults. 3. To evaluate the effects of the intestinal microbiota in older adults participating in a training programme. 4. To assess the physical fitness and perceived quality of life in older adults who engage in sport activities supported by technology. Participants will: * Perform physical tests such as the 6-Minute Walk Test (6MWT), the Timed Up and Go (TUG), and the Sit-to-Stand test. * Complete wellbeing questionnaires to assess their perceived quality of life and health status. * Complete dietary habit questionnaires. * Provide stool samples for microbiota analysis. * Take part in exercise interventions or placebo exercise sessions, depending on their assigned group.

How a Plant-Based Diet Affects Blood Pressure and Gut Health in Kidney Transplant Patient

Kidney transplant improves the quality of life (QoL) and survival of appropriate patients with advanced chronic kidney disease (CKD) and end-stage kidney disease (ESKD). However, these patients still have higher mortality compared to the general population and cardiovascular disease (CVD) is the leading cause of mortality. Among several metabolic complications post-transplantation, hypertension is one of the common risk factors for CVD. In addition to cardiometabolic alteration post-transplant, there is often observed gut microbial dysbiosis, marked by a decrease in microbial diversity and an increase in the relative abundance of Proteobacteria compared to individuals in a healthy state. Different dietary patterns can lead to distinct gut microbiota compositions. Diets rich in plant-based foods, whole grains, fruits, and vegetables tend to promote a more diverse and beneficial gut microbiota characterized by a higher abundance of fiber-degrading bacteria. On the other hand, diets high in saturated fats, refined sugars, and processed foods have been associated with dysbiosis, characterized by a reduction in beneficial bacteria and an overgrowth of potentially harmful microbes. While there is data in the normal population suggesting that a healthy diet can alter gut microbiota composition, the impact of a plant-based diet on gut microbiota-associated hypertension in kidney transplant recipients remains understudied. To address this gap, the investigators propose a single-center, single-blinded, 1:1 parallel randomized controlled trial to examine the effect of consuming a plant-based diet (intervention group) for 12 weeks on the change in blood pressure, gut microbiota, and patient report outcomes compared to the habitual diet (control group) in kidney transplant recipients with stable kidney allograft function at least 6 months post-transplantation. The investigators hypothesize that the adoption of a plant-based diet decreases in blood pressure, induces significant changes in gut microbiota composition and does not change in QoL.

Associations Between Dietary Intake and Cardiometabolic and Gut Microbiota Outcomes

This cross-sectional study aims to investigate the associations between dietary intake, cardiometabolic health markers, and gut microbiota composition in Singapore adults.