Tag: stool sample

A Potential Stool Test for Endometriosis also Suggests an IBD Link

Photo by Sora Shimazaki on Pexels

Promising findings by researchers at Baylor College of Medicine and collaborating institutions could lead to the development of a non-invasive stool test and a new therapy for endometriosis, a painful condition that affects nearly 200 million women worldwide. The study appeared in the journal Med.

“Endometriosis develops when lining inside the womb grows outside its normal location, for instance attached to surrounding intestine or the membrane lining the abdominal cavity. This typically causes bleeding, pain, inflammation and infertility,” said corresponding author Dr Rama Kommagani, associate professor in the Department of Pathology and Immunology at Baylor. “Generally, it takes approximately seven years to detect endometriosis and is often diagnosed incorrectly as a bowel condition. Thus, delayed diagnosis, together with the current use of invasive diagnostic procedures and ineffective treatments underscore the need for improvements in the management of endometriosis.”

“Our previous studies in mice have shown that the microbiome, the communities of bacteria living in the body, or their metabolites, the products they produce, can contribute to endometriosis progression,” Kommagani said. “In the current study, we took a closer look at the role of the microbiome in endometriosis by comparing the bacteria and metabolites present in stools of women with the condition with those of healthy women. We discovered significant differences between them.”

The findings suggested that stool metabolites found in women with endometriosis could be the basis for a non-invasive diagnostic test as well as a potential strategy to reduce disease progression.

The researchers discovered a combination of bacterial metabolites that is unique to endometriosis. Among them is the metabolite called 4-hydroxyindole. “This compound is produced by ‘good bacteria,’ but there is less of it in women with endometriosis than in women without the condition,” said first author Dr Chandni Talwar, postdoctoral associate in Kommagani’s lab.

“These findings are very exciting,” Talwar said. “There are studies in animal models of the disease that have shown specific bacterial metabolite signatures associated with endometriosis. Our study is the first to discover a unique metabolite profile linked to human endometriosis, which brings us closer to better understanding the human condition and potentially identifying better ways to manage it.”

Furthermore, extensive studies also showed that administering 4-hydroxyindole to animal models of the disease prevented the initiation and progression of endometriosis-associated inflammation and pain. 

“Interestingly, our findings also may have implications for another condition. The metabolite profile we identified in endometriosis is similar to that observed in inflammatory bowel disease (IBD), revealing intriguing connections between these two conditions,” Kommagani said. “Our findings support a role for the microbiome in endometriosis and IBD.”

The researchers are continuing their work toward the development of a non-invasive stool test for endometriosis. They are also conducting the necessary studies to evaluate the safety and efficacy of 4-hydroxyindole as a potential treatment for this condition.

Source: Baylor College of Medicine

A Stool Sample Could Detect Some Parkinson’s Cases Early

Old man with magnifying glass
Image by Mar Lezhava on Unsplash

One early indicator of Parkinson’s disease (PD) is isolated REM-sleep behaviour disorder. Researchers have shown that a greater concentration of α-synuclein aggregates can be detected in the stool samples of patients. In the scientific journal npj Parkinson’s Disease, they now present a method for detecting these aggregates.

There are two forms of PD. In 70% of cases, it originates in the central nervous system. However, in around 30% of cases it originates in the nervous system of the intestine (“enteric nervous system”). The latter form is referred to as “body-first Parkinson’s disease” (for short: body-first PD) and the characteristic deposits of aggregates of the body’s own α-synuclein protein are formed in the neurons in the intestine.

A preliminary form of body-first PD is the so-called isolated REM-sleep behaviour disorder (for short: iBRD). It causes in part complex movements during REM-sleep insofar as the patient experiences vivid and disturbing dreams. These movements can endanger the sufferer themselves or others.

A research team headed by Professor Erdem Gültekin Tamgüney from the Institute of Physical Biology at HHU now reports that it is possible to detect an elevated level of α-synuclein aggregates in the stool samples of patients. To achieve this, the team used a new surface-based fluorescence intensity distribution analysis (sFIDA) to detect and quantify individual particles of α-synuclein aggregates.

Professor Tamgüney: “We are the first to prove the presence of α-synuclein aggregates in stool samples. Our results show a significantly higher level of α-synuclein aggregates in iRBD patients compared with healthy individuals or patients with Parkinson’s. These findings could lead to a non-invasive diagnostic tool for prodromal synucleinopathies — including Parkinson’s — which could in turn enable therapies to be initiated at an early stage before symptoms occur.” However, more research is required before the process can find its way into clinical practice, for example investigation into why the level is lower in Parkinson’s patients.

The study was conducted in a collaboration to establish a biobank with stool samples from patients and control subjects, and to develop the test procedure and conduct the tests on the samples, and to eventually commercialise the technique.

Background

In body-first PD, the deposits of fibrils of the body’s own α-synuclein protein, which are characteristic of Parkinson’s, are first formed in the neurons of the enteric nervous system, which serves the gastrointestinal tract. The aggregates then spread to the central nervous system in a way similar to prions, i.e. an existing aggregate combines individual α-synuclein proteins in its vicinity into further aggregates in a nucleation process; these aggregates then spread further through the body.

The influence of what happens in the gastrointestinal tract on the brain is referred to as the “gut-brain axis.” The gastrointestinal tract is exposed to the environment and it is possible that harmful substances such as chemicals, bacteria or viruses ingested directly with food or via interaction with the microbiome of the gastrointestinal tract may trigger the pathological formation of α-synuclein aggregates.

Source: Heinrich-Heine University Duesseldorf