Clinical Research Directory

Impact of Ambulatory Physiological Stimulation of the Efferent Limb Prior to Ileostomy Closure on Colorectal Microbiota Composition and Histopathological Findings

BACKGROUND Loop ileostomies are a type of stoma frequently used to protect high-risk colorectal anastomoses (surgical reconnection of the intestines), for example following rectal cancer resection. Temporary diversion of intestinal transit does not reduce the risk of anastomotic failure, but it does lower the morbidity and mortality associated with potential pelvic sepsis. Unfortunately, a second surgical procedure is required to restore intestinal continuity, and this carries its own risk of complications, the most common being postoperative ileus (temporary paralysis of bowel motility associated with abdominal distension, absence of bowel movements, nausea, and vomiting), which occurs in up to 20% of cases. Several strategies have been proposed to reduce this problem, including stimulation of the efferent limb of the ileostomy (the part that is connected to the unused colon). This intervention consists of instilling a substance through the efferent limb of the ileostomy into the colon, simulating natural intestinal transit. It emerged as a harmless alternative aimed at reversing changes in the excluded colon in preparation for restoration of intestinal continuity. Several Spanish studies have investigated this technique, concluding that it is safe and significantly reduces the rate of postoperative ileus, thereby shortening hospital stay. Regarding the mechanism by which this intervention may be effective, there are studies investigating the changes that occur during diversion of intestinal transit: 1. Histopathology: reduced muscular contractility and the presence of intestinal villi in the efferent intestinal limb and excluded colon, which improve once intestinal flow is restored. 2. Microbiome: significant loss of microbiota in the defunctionalized colon, which progressively recovers with natural intestinal transit and reintroduction of a fiber-rich diet. Structural and microbiota-related changes favor the development of diversion colitis, a condition associated with erratic bowel habits once intestinal transit is restored. In an attempt to reverse this condition, several products have been tested for stimulation of the efferent limb of the ileostomy: probiotics, short chain fatty acids, saline solution with a thickening agent, and the patient's own intestinal contents, a well-tolerated and effective technique, in some cases superior to saline-based alternatives. Overall, the available evidence is of low quality due to the limited number of patients studied and protocol variability. For this reason, we propose the implementation of a protocol for stimulation of the distal ileostomy limb prior to ileostomy closure, either with saline solution and thickening agent (the most widely described technique in the literature) or physiological stimulation using the patient's own intestinal contents. The protocol consists of several sessions in which the instilled volume is progressively increased. This intervention will be performed on an outpatient basis, once daily, during the two weeks prior to surgery. This process promotes the onset of bowel movements through the anus, which progressively become more formed and less frequent, approaching a more normal bowel habit. Only minor adverse effects have been described with this technique, including cramp-like abdominal pain in 27.6% of sessions. Recently, a nationwide study confirmed the favorable clinical outcomes following distal ileostomy limb stimulation before ileostomy closure. However, to our knowledge, no studies have evaluated its effect on intestinal microbiota. HYPOTHESIS Distal limb stimulation of the ileostomy before its closure helps in the recovery of the colorectal microbiome and tissue. This associates with lower postoperative complications, specially postoperative ileus. OBJECTIVES To gain knowledge regarding changes in intestinal microbiota composition before and after stimulation, in order to better understand recovery of intestinal function following this procedure. We will also analyze outcomes after ileostomy closure following efferent limb stimulation, determining the incidence of postoperative complications, particularly postoperative ileus. METHODOLOGY Patients will be randomly assigned to one of three groups: 1. Control (no intervention other than the usual preoperative protocol) 2. Stimulation with serum and thickener 3. Stimulation with own stoma output Samples will be collected in all patients: 1. Stoma output 2. Stool, before stimulation, if performed 3. Stool, after stimulation, if performed 4. Stool, a month after surgery For a group of patients, the ones recruited at Hospital Clínic, rectal biopsies will also be collected before and after stimulation, to compare the effect of the treatment in the colonic tissue. We will collect clinical data during the whole process regarding postoperative complications.

Influence of the Gut Microbiome on Blueberry Polyphenol Metabolites

The objective of this study is to determine whether inter-individual differences in the gut microbiome influence exposure to blueberry polyphenol metabolites. We will use pharmacokinetics of blueberry polyphenols after an acute blueberry exposure to group individuals into "metabotypes", groups of individuals based on similarity in their metabolite profiles. We will then use multi-omic approaches to determine whether the gut microbiome predicts an individual's metabotype.

New Strategies to Evaluate the Reproductive Tract Microbiome

The goal of this observational study is to evaluate alternative less invasive sampling methods for the analysis of the endometrial microbiome. For that, vaginal swab and endometrial fluid samples will be assessed in comparison with the standard sampling method (an endometrial biopsy), in women aged 18-50 years on an oocyte donation program and/or who attend the clinic for routine gynecological controls, and whose samples will be collected during the secretory phase of a natural menstrual cycle. The study aims to: * Evaluate the pontential of the less invasive techniques to assess the endometrial microbiome, compared to the endometrial biopsy, as well as their safety. * Evaluate the microbiome's stability in a period of 1 to 3 months. Participants will undergo a sampling round (of the 3 sampling methods), and then a second round 1, 2 or 3 months later, as assigned by the investigator.

Effect of the Consumption of Cookies Enriched With Plant Proteins and of a Vitamin D Supplement on the Progression of Sarcopenia in the Elderly

The ageing population makes it necessary to find effective strategies for the prevention of sarcopenia (the progressive loss of muscle mass and strength and a decline in physical performance) that can be counteracted with foods containing protein and adequate intake of vitamin D. This study will evaluate the effectiveness of consuming a food based on plant proteins and vitamin D supplementation. Intervention studies in humans conducted to date have mostly focused on the effect of animal proteins (mainly from whey) on disease progression. A study on the effect of pea proteins has not yet been conducted and will provide information on the effectiveness of these proteins in modulating markers linked to the disease. The effect on the gut microbiota will also be considered, as the existence of a gut-muscle axis has been suggested, in which microbial genera producing short-chain fatty acids have been linked to a positive effect on muscle mass through anabolic stimulation. Thus, the analysis of the modulation of the intestinal microbiota, through the dietary intervention proposed in this study, may represent a further step in research related to the prevention of this disease. Sarcopenic volunteers aged between 65 and 80 will be recruited to consume either a shortbread biscuit made with wheat flour enriched with hydrolysed pea protein and a vitamin D supplement in extra virgin olive oil, or a control biscuit and a placebo (extra virgin olive oil) for 12 weeks. The study will be randomised, parallel, single-blind. The effect of consuming the experimental biscuit and vitamin D supplementation compared to that of a traditional control biscuit and a placebo oil solution will be evaluated on certain markers related to sarcopenia. In particular, the following will be considered: muscle strength, measuring grip strength and leg strength (chair stand test); muscle mass through the measurement of appendicular muscle mass, and the calculation of the appendicular muscle mass index; physical performance using the Short Physical Performance Battery; the inflammatory response and other blood biomarkers related to sarcopenia. In addition, the following will be assessed: dietary habits through a food diary and quality of life through the SarQoL questionnaire. Finally, the effect of nutritional intervention on the modulation of the gut microbiota will be evaluated through 16S rRNA sequencing and bioinformatic analysis of the data.

Probiotic Research: Open-label Functional Intervention and Longitudinal Evaluation in Healthy Adults

This study is a pre-post, open-label cohort study designed to investigate how a food-grade probiotic supplement affects biological measurements and wellbeing in healthy adults. Participants will take one capsule daily for either 1 month or 6 months. During the study, participants will complete online cognitive tasks and provide blood and stool samples collected during home visits by trained staff. The samples will be analysed to explore changes in gut bacteria and other biological markers. This study aims to understand whether the supplement is well tolerated and whether measurable biological changes occur. The study does not involve any experimental drugs or invasive procedures beyond blood sampling and stool collection, and participants will not be asked to change any current prescribed medications or treatments; with eligibility exclusions applying for recent antibiotics or immunosuppressants. The supplement is being studied for research purposes only and is not intended to diagnose, treat, or prevent disease. Participants will be invited to participate in a follow-up visit to assess long-term effects.

Alcohol and Cannabis Use Among Pregnant Slovenian Women

The aim of the study is to determine the prevalence of alcohol and drug use among Slovenian pregnant women. Alcohol and drug use during pregnancy has significant effects on the foetus and has short- and long-term health consequences. One of the most serious consequences is foetal alcohol syndrome, which is characterised by congenital anomalies, cognitive impairment and growth deficits. The prevalence of alcohol and drug use during pregnancy will be investigated in collaboration with the National Institute of Public Health, the Institute of Forensic Medicine of the Faculty of Medicine, University of Ljubljana, Institute Jozef Stefan and the Clinical Department of Neonatology of the Paediatric Clinic, University Clinical Centre Ljubljana, using two different methods. A cross-sectional study will be conducted on a nationally representative sample of meconium samples. Meconium samples will be collected from maternity hospitals in Slovenia. Biomarkers for alcohol and illicit drugs will be determined in the meconium samples.Meconium samples will be collected anonymously. National survey on the lifestyle will be conducted in Slovenian maternity hospitals, including questions on alcohol and drug use during pregnancy. The survey will be anonymous and not related to meconium sampling; participation in the survey will be voluntary. Data linkage between questionnaire responses and meconium analysis will be performed only within the additional subgroup of participants who provided informed consent. Meconium samples that will test positive for either alcohol of canabis will be analysed for microbiome. For every poisitve meconium sample, two negative samples will be analysed.

Microbiome Characterization in Fatty Pancreas

There has been a growing interest in evaluating the role of gut and intra-lesional microbiome in the pathogenesis of various benign and malignant conditions of the GI tract, liver and pancreas. In addition, the feasibility of using microbiome signature as non-invasive biomarker for benign and malignant disease conditions of the GI tract has also been studied. While research on the impact of microbiome and genomics has been conducted in some pancreatic disorders such as acute pancreatitis, pre-malignant mucinous pancreatic cystic neoplasms (eg, IPMN) and pancreatic cancer, very little data is available regarding the microbiome signature and genomics associated with FP. As such, it would be clinically important to conduct a pilot study to investigate the microbiome and genomics associated in patients with or without FP defined by MRI-PDFF pancreatic fat fraction measurement.

Comparison of Microbiome Changes in Healthy Adults Following Ketone Ester Consumption

The goal of this observational study is to learn if a ketone ester can improve the content of the gut microbiome. The main questions it aims to answer are: * Does a ketone ester reduce age-related signatures in the gut microbiome? * What changes occur in the gut microbiome after consuming a ketone ester? Participants will: * Take a ketone ester every day for seven (7) days * Collect and ship stool samples within seven (7) days before, during, and within seven (7) days after the study period * Measure their ketone levels with a urine strip every day after having the drink * Answer questions about their typical diet on a normal day * Record their symptoms, if any arise

Effect of Agricultural Practices on Crops, Gut Microbiome, and Human Health

The human gut microbiome plays a regulatory role in host health, and is involved in metabolic, immune, and neurological processes. Diet shapes the gut microbiome; by providing essential nutrients, which sustain the existing microorganisms and by introducing foodborne microbes that modulate its composition. Notably, the impact of microbes from fruit and vegetables on the gut microbiome is relatively unexplored. Differences in agricultural practices, organic vs conventional strategies, can lead to variations in nutritional content and associated microbial communities in and on crops, underscoring the potential for variations in cultivated crops to influence the human gut microbiome's composition and function. This study aims to explore how crop cultivation practices affect the composition and function of the human gut microbiome, ultimately influencing overall health.

Augmented Response of Volatile Biomarkers in Assessment of Oesophagogastric Cancer (AROMA 1 / BIORESOURCE)

Cancer of the stomach and oesophagus is among the world's top five cancers. Survival rates are very poor as the disease presents late and early symptoms are non-specific. The study team has developed a non-invasive test for cancers of the stomach and oesophagus based on the detection of volatile organic compounds in exhaled breath. These compounds are known to be produced by both cancers as well as cancer associated bacteria within the gut. The proposed innovation is to improve the accuracy of this test by investigating whether simple metabolic substrates can increase the production of these volatile organic compounds by both the tumour and its associated bacteria.

A Randomized, Double-Blind Study to Assess the Effect of a Postbiotic on Oxidative Stress and Exercise Performance

This is a prospective, randomized, placebo controlled, double-blind study to assess the effects of a postbiotic blend on exercise induced oxidative stress markers and exercise performance in healthy adult.

Impact of Probiotics on Gut Microbiome During Antibiotic Prophylaxis in Elective Orthopedic Surgery

This study aims to evaluate whether probiotics can help maintain a healthy gut microbiome in patients receiving prophylactic antibiotics during elective orthopedic surgery. Antibiotics, while effective in preventing infections, can disrupt the balance of gut bacteria, leading to dysbiosis. The study hypothesizes that the use of probiotics during the perioperative period can prevent or reduce this disruption, supporting gut health and overall well-being. The research seeks to answer whether combining probiotics with routine antibiotic prophylaxis can preserve gut microbiome balance and improve patient outcomes.