Clinical trial NCT03269032: Mediterranean Diet and the Gut Microbiome
Official title: Impact of the Mediterranean Diet on the Gut Microbiome and Symptoms of Diarrhea-Predominant Irritable Bowel Syndrome
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Irritable Bowel Syndrome
Keywords: Mediterranean diet
gut microbiome
gastrointestinal
Lead sponsor: Wake Forest University Health Sciences
Sponsor class: OTHER
First posted: 2017-08-31
Enrollment: 10
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: The study will have two phases, Phase 1 will study healthy subjects, who will follow a typical American diet for 2 weeks, and then cross-over to a Mediterranean-style diet for 2 weeks. Phase 2 will study subjects who have IBS-D. As above, they will first eat a typical American diet for 2 weeks, and then cross-over to a Mediterranean-style diet.
Primary purpose: TREATMENT

Brief summary: This study will evaluate the impact of a Mediterranean-style diet on microbiome diversity compared to a typical American diet. The study will observe the microbiome composition comparisons in healthy volunteers as well as in patients with Irritable Bowel Syndrome with Diarrhea (IBS-D) to see if the consumption of a Mediterranean-style diet has a positive effect on improving symptoms of IBS-D.

Detailed description: Irritable bowel syndrome (IBS) is the most prevalent and well-studied functional gastrointestinal disorder. While IBS has no direct mortality, it does compromise quality of life, incurs morbidity, and has a substantial economic impact on society. The gut microbiome may play a significant role in the pathogenesis of IBS. Even though the exact mechanisms underlying this relationship have not been presented, it is suggested that certain microorganisms may increase gut permeability, activate the mucosal immune response, increase visceral sensitivity and alter intestinal motility via a bidirectional brain-gut interaction. Recent studies suggest that the salutary impact of the Mediterranean diet may be due to its effects on the composition of the gut microbiome. In a recent cohort study in Italy, subjects who adhered most closely to a classical Mediterranean diet had more favorable bacterial enterotypes (e.g., Prevotella) in their stool, as well as higher levels of short-chain fatty acids - which are essential for colonic function. Studies have also showed that diet alters the predominant microbiome enterotypes and that microbiome composition can change quickly, within 24 hours, after a dietary intervention. Therefore, consumption of a Mediterranean diet may ameliorate the gut dysbiosis associated with IBS-D.

Eligibility criteria: Inclusion Criteria:

* must be willing to eat pre-prepared foods for 4 weeks
* subjects must have no medical, religious, or cultural dietary restrictions that would preclude their eating a Mediterranean diet.
* Phase 2 subjects- must have diagnosis of IBS based on Rome III criteria and have diarrhea-predominant disease, defined as \>50% of bowel movements characterized as diarrhea

Exclusion Criteria:

* history of gastrointestinal disease, including celiac disease, inflammatory bowel disease, or lactose intolerance
* diabetes mellitus
* congestive heart failure
* coronary artery disease
* chronic liver disease or end stage renal disease
* pregnancy or breastfeeding
* trainees under the direct supervision of the PI and patients receiving direct ongoing medical care from the PI or Co-I will not be enrolled as subjects in this study

Primary outcomes:
measure: Phase 1- Change in predominant enterotypes and diversity of fecal microbiota
timeFrame: Baseline, 2 weeks, 4 weeks
measure: Phase 2-Change in predominant enterotypes and diversity of fecal microbiota
timeFrame: Baseline, 2 weeks, 4 weeks
Secondary outcomes:
measure: Changes in plasma inflammatory marker - Erythrocyte sedimentation rate (ESR)
timeFrame: Baseline, 2 weeks, 4 weeks
measure: Changes in plasma inflammatory marker - C-reactive protein (CPR)
timeFrame: Baseline, 2 weeks, 4 weeks
measure: Changes in IBS Symptom Severity Scores
timeFrame: Baseline, 2 weeks, 4 weeks
measure: Changes in Hospital Anxiety and Depression Scores
timeFrame: Baseline, 2 weeks, 4 weeks
Other outcomes:
Locations:
city: Winston-Salem
country: United States
facility: Wake Forest Baptist Heath
state: North Carolina
Study officials:
affiliation: Wake Forest University Health Sciences
name: Richard B Weinberg, MD
role: PRINCIPAL_INVESTIGATOR
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