Mediterranean Diet and the Gut Microbiome

Wake Forest University (WFU)

Status: Completed

Conditions: Irritable Bowel Syndrome

Treatments: Other: Mediterranean-style Diet; Other: American Diet

Study type: Interventional

Funder types: Other

Identifiers

NCT03269032

IRB00039422

Details and patient eligibility

About

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.

Full 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.

Enrollment: 10 patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

Primary purpose: Treatment

Allocation: Non-Randomized

Interventional model: Crossover Assignment

Masking: Single Blind

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10 participants in 2 patient groups

Phase 1 Healthy Volunteers

Experimental group

Description:

Healthy volunteers will eat a typical American diet for 2 weeks and then eat a Mediterranean-style diet for 2 weeks.

Treatment:

Other: American Diet

Other: Mediterranean-style Diet

Phase 2 IBS Patients

Experimental group

Description:

Participants with IBS will eat a typical American diet for 2 weeks and then eat a Mediterranean-style diet for 2 weeks

Treatment:

Other: American Diet

Other: Mediterranean-style Diet