Lower Bifidobacteria counts in both duodenal mucosa-associated and fecal microbiota in irritable bowel syndrome patients Original paper
Researched by:
-
Kimberly Eyer
ID
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.
-
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.
-
Kimberly Eyer
Researched by:
-
Kimberly Eyer
ID
Kimberly Eyer
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
Netherlands
Sample Site
Feces
Mucosa of small intestine
Species
Homo sapiens
What was studied?
This study investigated the levels of bifidobacteria in both duodenal mucosa-associated and fecal microbiota of patients with Irritable Bowel Syndrome (IBS) compared to healthy controls. The primary goal was to identify whether IBS patients exhibited significant reductions in bifidobacteria populations, which could play a role in gut dysbiosis and symptom expression. To achieve this, the researchers employed molecular-based techniques including Fluorescent In Situ Hybridization (FISH) and real-time PCR analysis to quantify bifidobacterial species in both fecal and duodenal samples.
Who was studied?
The study cohort consisted of 41 IBS patients meeting the Rome II criteria and 26 healthy subjects without GI symptoms or major abdominal surgery. The IBS group included patients with diarrhea-predominant (IBS-D), constipation-predominant (IBS-C), and alternating subtypes (IBS-A). Samples of fecal matter and duodenal mucosa were collected for microbial analysis, with careful exclusion of participants who had used probiotics, antimicrobials, or other medications known to influence gut flora composition.
What were the most important findings?
The analysis revealed that IBS patients had significantly lower levels of bifidobacteria in both fecal and duodenal mucosa-associated samples compared to healthy controls. FISH analysis demonstrated a 2-fold decrease in bifidobacteria levels in fecal samples of IBS patients (4.2 ± 1.3%) versus healthy subjects (8.3 ± 1.9%, p <0.01). In particular, Bifidobacterium catenulatum levels were markedly reduced in IBS patients, with concentrations of 6 ± 0.6% compared to 19 ± 2.5% in healthy controls (p <0.001). The disparity was consistent across all IBS subtypes, indicating a broad-spectrum deficiency rather than subtype-specific microbial shifts.
The study also highlighted that while overall bifidobacteria counts were lower, other major bacterial groups did not show significant differences between IBS patients and healthy subjects, suggesting a targeted disruption rather than widespread microbial imbalance. This finding underscores the potential role of bifidobacteria depletion in IBS pathophysiology, possibly through mechanisms involving mucosal integrity, anti-inflammatory activity, and short-chain fatty acid production.
| Microbial Group | IBS Patients | Healthy Controls | Statistical Significance | Associated Effects |
|---|---|---|---|---|
| Total Bifidobacteria (Fecal) | 4.2 ± 1.3% | 8.3 ± 1.9% | p <0.01 | Reduced short-chain fatty acid production, disrupted gut barrier |
| Bifidobacterium catenulatum | 6 ± 0.6% | 19 ± 2.5% | p <0.001 | Potential role in symptom expression through gut dysbiosis |
| Total Bifidobacteria (Duodenal) | Reduced | Normal levels | p <0.01 | Suggests mucosal disruption in IBS patients |
| Other Major Bacterial Groups | No significant change | Normal levels | Not significant | Indicates targeted depletion rather than widespread dysbiosis |
| FISH Detection Coverage | 32% | 44% | p <0.05 | Lower overall detection in IBS samples |
What are the greatest implications of this study?
The results strongly suggest that reduced bifidobacteria populations, particularly Bifidobacterium catenulatum, may contribute to IBS symptomatology through impaired mucosal protection and altered gut homeostasis. This finding is crucial as bifidobacteria are known to produce lactic and acetic acids that lower gut pH, inhibit pathogenic bacteria, and support barrier function. Therapeutic strategies that restore bifidobacteria levels—such as targeted probiotics or prebiotic interventions—may offer novel approaches for symptom management in IBS patients. These insights pave the way for more microbiome-focused therapeutic strategies aimed at recalibrating microbial populations in the gut.
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.