SIBO

Gut problems, such as constipation, can have an important impact on quality of life of people who have them, and have been associated with higher risk of developing neurological diseases such as Parkinson's or Alzheimer's disease. Recent studies suggest that gut problems may also have implications for the progression of these diseases, as constipation is a risk factor for faster Parkinson's and Alzheimer's progression. However, how constipation and brain diseases are linked is unknown. Previous research has suggested that gut changes may lead to inflammation, which could play a role in accelerating the progression of both movement and memory problems in Parkinson's and memory and thinking problems in people with cognitive impairment. Methane is a gas that is naturally produced by microorganisms in the gut. Levels of methane can be measured using a simple breath test. Higher methane levels in the breath are thought to be more common in people with Parkinson's disease (PwP) when compared to people without Parkinson's (healthy controls) and have been associated with gut symptoms, particularly constipation, as well as worse movement problems in PwP, although they are less understood in conditions that affect memory and thinking (like dementia or mild cognitive impairment). The investigators want to better understand the changes in the gut of PwP and people with cognitive impairment (e.g. mild cognitive impairment or dementia). They will compare breath methane levels in PwP, people with cognitive impairment, people with REM Sleep Behaviour Disorder (a sleep condition linked to a higher risk of developing Parkinson's) and healthy participants. Participants will be followed-up over time to assess how methane levels are linked to changes in the blood and the stools, gut function, and clinical symptoms. This study has 2 components: Component 1: observational study, where the study investigators will follow 200 participants over 2 visits, 18 months apart. The study will recruit 4 groups of people: 50 people with Parkinson's disease, 50 people at high risk of developing Parkinson's disease (people with REM Sleep behaviour disorder), 50 people with other conditions affecting cognition (e.g. dementia, mild cognitive impairment), and 50 healthy controls. Component 2: study with 15 people with Parkinson's, who produce high methane levels, to test whether a probiotic (Lactobacillus reuteri) affects how much methane is produced.

Pancreatic exocrine insufficiency (PEI) results from reduced pancreatic enzyme secretion, leading to malabsorption, malnutrition, and impaired quality of life. Although pancreatic enzyme replacement therapy (PERT) is the standard treatment, some patients remain symptomatic despite apparently adequate therapy. Possible causes include suboptimal dosing or concomitant conditions such as small intestinal bacterial overgrowth (SIBO). This study aims to determine the prevalence of SIBO in symptomatic PEI patients despite adequate PERT and to identify treatable causes of persistent symptoms using non-invasive diagnostic tests, with the goal of improving nutritional status and quality of life.

The small intestine is an understudied frontier of microbiome research. While aspiration during endoscopy is considered the gold standard to assess small bowel bacteria, the tools for sterile retrieval are primitive and poorly validated. Endoscopic aspiration is time-consuming and prone to contamination. Inspired by plants' ability to draw water by capillary action, a novel multi-capillary sterile system was designed which is a modified version of the conventional aspiration catheter. The purpose of this study is to examine the time and volume capabilities of this catheter in suctioning various liquids compared to conventional aspiration catheter, in two groups, each includes 23 patients that going under endoscopy at GI lab at Cedars Sinai Medical Center. The investigator will collect up to 2 ml fluid from Duodenum- in first group by using the conventional catheter and in second group by using the capillary catheter. The time collection and the volume of samples in 2 groups will be compared.

Abdominal bloating is a common clinical symptom in the digestive system, with obscure origins and complex mechanisms. Its etiology can be attributed to organic diseases and various Functional Gastrointestinal Disorders (FGIDs). In recent years, the roles of Small Intestinal Bacterial Overgrowth (SIBO), Oral-Cecal Transit Time (OCTT), and gut microbiota dysbiosis in Functional Abdominal Bloating/Distention (FAB/D) have garnered increasing attention. Currently, there is a lack of diagnostic tests and effective treatment measures for patients with bloating. The hydrogen/methane breath test is a safe, economical, and non-invasive examination recommended for diagnosing SIBO. Rifaximin, an antibiotic that acts exclusively in the intestines, has been widely validated for its efficacy in SIBO and in patients with SIBO co-occurring with Irritable Bowel Syndrome (IBS). However, research on the role of SIBO in the production of bloating symptoms and the extent to which rifaximin treatment of SIBO alleviates symptoms in clinical bloating patients is still lacking. This study aims to investigate the efficacy of rifaximin in patients with SIBO who primarily present with bloating. Exploring clinical treatment options for bloating provides a reference for its management. Furthermore, questionnaires on psychiatric symptoms and fecal microbiota analysis for patients with bloating-type SIBO can help clarify the etiology of bloating, offering a basis for the etiological treatment of bloating patients in the next steps.