Increase in fecal primary bile acids and dysbiosis in patients with diarrhea-predominant irritable bowel syndrome Original paper
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Irritable Bowel Syndrome (IBS)
Irritable Bowel Syndrome (IBS)
Irritable Bowel Syndrome (IBS) is a common gastrointestinal disorder characterized by symptoms such as abdominal pain, bloating, and altered bowel habits. Recent research has focused on the gut microbiota's role in IBS, aiming to identify specific microbial signatures associated with the condition.
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Kimberly Eyer
Kimberly Eyer, a Registered Nurse with 30 years of nursing experience across diverse settings, including Home Health, ICU, Operating Room Nursing, and Research. Her roles have encompassed Operating Room Nurse, RN First Assistant, and Acting Director of a Same Day Surgery Center. Her specialty areas include Adult Cardiac Surgery, Congenital Cardiac Surgery, Vascular Surgery, and Neurosurgery.
Microbiome Signatures identifies and validates condition-specific microbiome shifts and interventions to accelerate clinical translation. Our multidisciplinary team supports clinicians, researchers, and innovators in turning microbiome science into actionable medicine.
Karen Pendergrass
Location
France
Sample Site
Feces
Species
Homo sapiens
What was studied?
This study examined the alterations in fecal bile acid (BA) composition and gut microbiota dysbiosis in patients with diarrhea-predominant irritable bowel syndrome (IBS-D) compared to healthy subjects. The research aimed to identify how shifts in primary and secondary bile acid levels correlate with symptoms of diarrhea, stool frequency, and microbial changes that could influence bile acid metabolism
Who was studied?
The study included 14 patients diagnosed with diarrhea-predominant IBS (IBS-D) and 18 healthy subjects (HS) as controls. All participants were evaluated for clinical symptoms, and stool samples were collected for analysis of bile acid composition and gut microbiota profiling using quantitative PCR (qPCR) and high-performance liquid chromatography–tandem mass spectrometry (HPLC-MS/MS).
What were the most important findings?
The study uncovered a significant increase in primary bile acids (BA) in the feces of IBS-D patients compared to healthy subjects, with a corresponding decrease in secondary bile acids. Primary bile acids, particularly cholic acid (CA) and chenodeoxycholic acid (CDCA), were markedly elevated, contributing to looser stool consistency and higher stool frequency. These elevations in primary BA were positively correlated with the Bristol Stool Scale score and the frequency of bowel movements. In contrast, secondary bile acids such as deoxycholic acid (DCA) were significantly reduced in IBS-D patients, suggesting impaired microbial transformation. Dysbiosis within the gut microbiota was also evident, characterized by a significant increase in Escherichia coli and a marked decrease in Bifidobacterium and members of the Leptum group. These microbial shifts indicate a reduction in the bacteria responsible for bile acid dehydroxylation, further exacerbating the accumulation of primary BA. The study postulates that this microbial imbalance not only alters bile acid metabolism but may also promote mucosal permeability and colonic motility, contributing to the pathophysiology of diarrhea in IBS-D patients.
| Parameter | IBS-D Patients |
|---|---|
| Primary Bile Acids | Significantly elevated (CA, CDCA) |
| Secondary Bile Acids | Markedly reduced (DCA) |
| Gut Microbiota Imbalance | Increase in Escherichia coli |
| Microbial Reductions | Bifidobacterium and Leptum groups |
| Stool Frequency | Increased; correlated with primary BA levels |
| Stool Consistency | Looser; linked to higher primary BA levels |
| Microbial Transformation | Impaired conversion from primary to secondary BA |
| Inflammatory Implications | Suggestive of increased mucosal permeability and motility changes |
What are the greatest implications of this study?
This study underscores the critical role of bile acid dysbiosis in the pathogenesis of diarrhea-predominant IBS. The findings suggest that the elevated primary bile acids, linked to microbial dysbiosis, could serve as both biomarkers and therapeutic targets for IBS-D. The observed reduction in secondary bile acids, typically resulting from microbial transformation, highlights the importance of gut microbiota in maintaining bile acid homeostasis. This disruption in bile acid metabolism not only influences stool consistency and motility but may also contribute to chronic gut inflammation. Therapeutic interventions that aim to modulate bile acid levels or restore microbial balance may hold promise for symptom relief in IBS-D patients.
Irritable Bowel Syndrome (IBS)
Irritable Bowel Syndrome (IBS) is a common gastrointestinal disorder characterized by symptoms such as abdominal pain, bloating, and altered bowel habits. Recent research has focused on the gut microbiota's role in IBS, aiming to identify specific microbial signatures associated with the condition.