View clinical trials related to Microbiota.
Filter by:Many studies describe the relationship between microbiota alteration and the occurrence of metabolic, alcoholic or inflammatory liver diseases. Nevertheless, the modifications of microbiota during liver transplantation (LT) as well as its implication are poorly studied. Similarly, only the intestinal microbiota is studied in this context, and no data are available on the biliary microbiota, even if it is known that bile microbiota can interfere with hepatobiliary diseases. This study proposes a clinical and biological in-depth follow-up with multiple sampling of liver transplanted patients to study biliary and intestinal microbiota alterations along LT, as well as bile acids metabolism in corresponding fluids. Indeed, in recipient samples as saliva, blood, urine, and feces can be taken before LT, and surgeons can easily perform bile sampling during LT. In donors all samples can be taken during liver removal. This offers the opportunity to have a microbiotic landscape of individuals without liver disease (donor), and patients suffering from a chronic liver disease or a liver cancer before and after transplantation. Also, in Grenoble University hospital, in case of biliary anastomotic incongruence, a biliary stent is placed during LT in 60% of recipients. This stent is removed by endoscopic retrograde cholangiopancreatography (ERCP) within 6 months after LT, offering a second opportunity to obtain bile samples in transplanted patients, after the early post-LT period. Patients who do not require a biliary stent will also be included for the study of secondary objectives, as intestinal microbiota is very poorly characterized in liver transplanted patients too. A portion of the patients without biliary stent, may also develop an anastomotic biliary stricture requiring an ERCP. If this ERCP is realized within the follow-up period of the study, the patient will also be included in the primary objective of the study. These multiple and sequential samples will allow a complete analysis of microbiota changes in LT patients and aim to answer to 3 questions: 1. What are the modifications of intestinal and biliary microbiomes during LT? 2. What is the influence of bile acids' composition on intestinal and biliary microbiota? 3. What are the relationships between microbiome alterations and the emergence of LT complications?
The study is based on the hypothesis that patients with postoperative anastomotic leakage have a different bacterial profile contributing to poor tissue healing, and that patients operated for colon cancer presumably have a different preoperative microbiota than healthy patients. This different composition is probably induced by the high heme level in the light intestinal tract that tumor spoliation generates. The objective of the study is to evaluate the feasibility of a larger study to evaluate the difference between microbiota composition of patients with and without colorectal cancer, with inflammatory bowel disease and those with and without anastomotic leakage postoperatively of a colonic resection. Stool samples will be taken from 20 patients, including 5 without intestinal pathology, 5 with colorectal cancer undergoing colorectal surgery, 5 with inflammatory bowel disease and 5 with anastomotic leakage after colectomy for colorectal cancer or inflammatory bowel disease. The stool samples will be analyzed at CRCHUM to draw up a profile of the bacteria that make up the microbiota of each patient.
In this study the investigators aim to investigate the changes of the intestinal microbiome in three different cohorts (IBD, IBS, healthy) after applying the uniform disruptive factor of osmotic diarrhea induced by macrogol. The investigators hypothesis is that ill people will show more severe changes of the microbiome than healthy people and that these changes persist longer.
The aim of this study is to investigate changes in nutrient intake, the human gut microbiota and pesticide excretion in urine when shifting from conventional food habits to sustainable food habits.
A prospective observational study. Enrolled participants admitted to ICU due to pneumonia and respiratory failure need mechanical ventilator support. Investigators collected the residual specimens, such as sputum from endotrachea aspiration, bronchoalveolar lavage fluid in those participants as the usual care in the ICU. Those residual samples were sent to extract RNA and sequence by using high-throughput sequencing (next-generation sequencing) method. Investigators will compared the microbiome feature between lower respiratory tract and stool specimens in those participants diagnosed as pneumonia with respiratory failure.
The objective of this study is to evaluate the impact of antimicrobial (antibiotic) exposures on the microbiome in healthy adults, specifically during and after usual courses of the antimicrobials used to treat community acquired pneumonia (CAP). Pneumonia is a lung infection, and community-acquired pneumonia is pneumonia that develops outside of a healthcare facility (i.e., in the community). A microbiome is a the community of microorganisms living in a particular location, such as the gut or the mouth. Disruptions to a person's microbiome may reduce his/her "colonization resistance" (resistance to colonization with pathogenic microorganisms) and make him/her more susceptible to multidrug resistant organism (MDRO) colonization and infection. To study changes in the microbiome, the investigators will recruit 20 healthy adult volunteers and obtain fecal, salivary, skin, and urine specimens at multiple time points before, during, and after administration of antimicrobials. Participants will be randomized to one of 4 antimicrobial regimens, all of which are FDA-approved for treatment of community-acquired pneumonia. Stool specimens will be analyzed via stool culture and genetic sequencing, and all remaining specimens will be frozen and used to create a biospecimen repository for future analysis. The rationale for using healthy volunteers (instead of patients already prescribed antibiotics by their physicians) is because the human microbiome is very complex and can be affected by a variety of medical conditions and other medications. In addition, the presence or absence of patient-specific factors means people with infections may not be prescribed the specific courses of antibiotics the investigators are trying to study. Studying the effect of antibiotics on healthy volunteers will provide baseline data that are more applicable to the population at large.
caries-free (CF) individuals caries-active (CA) individuals (DMFT ≥ 6) will be recruited. Subjects will be instructed to brush their teeth twice daily for 3 min using Colgate® Sensitive Pro-Relief® toothpaste (containing 8% arginine and 1450 ppm NaF) for 2 weeks. Supra- and subgingival plaque, saliva, and in situ plaque samples will be collected before and after the treatment for laboratory analyses.
The primary purpose of this study is to evaluate the effect of an IMO nutritional supplement on gut microbiome, gut health, and body weight. Two formulations of the supplement will be evaluated; thus, there will be three study arms: Supplement A, Supplement B, and placebo. Stool samples will be analyzed for bacterial DNA. The gut bacterial DNA, body weight, and gut health data will be compared across supplement and placebo groups. Primary Aim 1: To evaluate the effect of the IMO supplement on gut bacterial abundance, diversity, and gene function across intervention and placebo groups, and across two doses of the intervention. Secondary Aim 1: To evaluate the effect of the IMO supplement on gut health across intervention and placebo groups, and across two doses of the intervention. Secondary Aim 2: To evaluate the effect of the IMO supplement on body weight across intervention and placebo groups, and across two doses of the intervention. 60 subjects, randomized to three arms (20 each: Supplement formula A, Supplement formula B or placebo) will take a daily dose of Supplement A, Supplement B, or placebo for 8 weeks. The supplement is a light syrup liquid. Ingredients that are in the supplement are: isomalto-oligosaccharide, water, mannitol, maltose, glucose, and glycerol. Ingredients that are in the placebo are: high maltose corn syrup (Satin Sweet™), water, and mannitol. Dose will be 500 mg during the first 4 weeks and then 1000 mg for second 4 weeks. Subjects will be instructed to take 500 mg/day of the supplement or placebo the first four weeks and 1000 mg/day of the supplement or placebo for the second four weeks. Subjects will be blinded as to whether they are receiving placebo or supplement. After screening and once enrolled, subject involvement includes visits to George Mason University, being weighed, dropping off stool samples, and completing a survey on gut health. Stool samples will be analyzed for bacterial DNA. The gut bacterial DNA, weight, and gut health data will be compared across supplement and placebo groups.
The colonization of the neonatal gastro-intestinal (GI) tract begins at birth and is influenced by several factors, such as mode of delivery, gestational age, maternal intestinal and vaginal microbiota, type of feeding, hospitalization after birth and use of antibiotics and probiotics. Gut microbiota of term infants, vaginally delivered and exclusively breastfed, shows a low count of C. difficile and E. coli and a high number of Bifidobacteria and Lactobacilli, which positively influence the host's immunity processes; hence, is considered to be ideally healthy. Group B Streptococcus (GBS) represents one of the most important causes of neonatal infections and sepsis. Infants vaginally delivered may acquire GBS during the birth process from maternal vagina, cervix or rectum, where it resides in 10-20% of pregnant women. In the last decade, the incidence of early-onset GBS sepsis is significantly reduced, due to the introduction of GBS universal screening during late pregnancy and consequent intrapartum antibiotic prophylaxis (IAP) in GBS-positive women. The use of antibiotics in early life is shown to alter the commensal gut microbiota, thereby impairing the balance between health and disease later in life. The effect of IAP on bacterial colonization of the infant's gut, however, has not been largely investigated. The investigators have previously evaluated the effect of IAP in a relatively small sample of exclusively breast-fed term infants vaginally delivered by means of molecular techniques; at 7 days of life there were several differences in microbiota composition between infants IAP-exposed and not exposed. This observational prospective study thus aims to evaluate these differences in further detail, expanding the initial sample to formula-fed term infants and following up infants until one month of age. By including formula-fed infants, the investigators additionally aim to evaluate the influence of feeding type on the neonatal microbiota composition.
Background: - Normal bacteria and other tiny organisms are found in healthy human mouths. These are called oral microbiota. It is unclear exactly how the oral microbiota may affect health. For example, if the microbial composition is abnormal, it may lead to mouth conditions like periodontitis. Researchers want to study how the microbiota changes over time. This can help them plan future disease studies. Objectives: - To see if and how oral microbiota change over time. Eligibility: - Forty adult employees of the National Cancer Institute Shady Grove. Design: - For 12 hours before the first visit, participants will not eat or drink (except water). They will not brush, floss, use mouthwash, chew gum, eat lozenges or candies, smoke cigarettes, or chew tobacco. - At the first visit, participants will: - Be given a saliva collector. They will spit 2 mL of saliva into it. - Fill out an online questionnaire. - Every 2 months, participants will visit the clinic and repeat visit 1. - The study ends after 1 year. Sponsoring Institute: National Cancer Institute