Alterations in composition and diversity of the intestinal microbiota 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
United States of America
Sample Site
Feces
Species
Homo sapiens
What was studied?
The study examined the composition and diversity of the gut microbiota in patients with diarrhea-predominant irritable bowel syndrome (D-IBS) compared to healthy controls. Using 16S rRNA gene sequencing, the researchers evaluated microbial populations, community structure, and specific taxonomic shifts associated with D-IBS, aiming to understand the microbial dysbiosis that may underlie the pathophysiology of this condition.
Who was studied?
The study included 23 patients diagnosed with diarrhea-predominant irritable bowel syndrome (D-IBS) and 23 healthy controls (HC). All participants were recruited from the University of North Carolina at Chapel Hill and were screened to exclude other gastrointestinal conditions.
What were the most important findings?
The analysis revealed significant dysbiosis in the gut microbiota of D-IBS patients compared to healthy controls. Key findings included a substantial increase in the family Enterobacteriaceae, particularly unclassified genera, which are known to encompass pathogenic species. Conversely, the beneficial genus Faecalibacterium, particularly F. prausnitzii, was significantly reduced in D-IBS patients. Faecalibacterium is recognized for its anti-inflammatory properties and is generally considered protective for gut health. This reduction may indicate an underlying pro-inflammatory state within the gut microbiota of D-IBS patients. Additionally, D-IBS patients exhibited lower microbial diversity (α-diversity) and greater variability in microbial community composition (β-diversity), suggesting an imbalance in microbial homeostasis. The study also identified specific increases in Enterococcus, Fusobacterium, and unclassified members of Lactobacillaceae and Veillonella, which were largely undetectable in healthy individuals. These shifts point towards a microbial environment that may exacerbate gut inflammation and motility disturbances characteristic of D-IBS.
| Parameter | Findings in D-IBS Patients |
|---|---|
| Microbial Diversity | Reduced α-diversity, indicating lower microbial richness |
| Microbial Community Structure | Increased β-diversity, suggesting greater community variability |
| Increased Genera | Enterobacteriaceae, Enterococcus, Fusobacterium, Veillonella |
| Decreased Genera | Faecalibacterium, specifically F. prausnitzii |
| Pathogenic Associations | Elevated Enterobacteriaceae includes potentially pathogenic species |
| Inflammatory Indicators | Loss of F. prausnitzii, a known anti-inflammatory bacterium |
| Microbial Dysbiosis | Imbalanced harmful and beneficial bacteria, indicating gut inflammation |
What are the greatest implications of this study?
The findings underscore the significant role of gut microbiota in the pathophysiology of D-IBS, marked by a distinct microbial signature that includes elevated Enterobacteriaceae and diminished Faecalibacterium populations. These microbial alterations reflect potential mechanisms driving gut inflammation and motility disorders. Importantly, the study suggests that microbial dysbiosis could serve as both a biomarker for diagnosing D-IBS and a potential target for therapeutic interventions aimed at restoring microbial balance. Future strategies may include microbiome-targeted therapies such as probiotics or prebiotics aimed at re-establishing beneficial bacterial populations and mitigating pro-inflammatory species.
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.