Effect of Mediterranean Diet During Pregnancy on Gut Microbiota and on the Epigenetics (PREMEDI)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT03337802
Recruitment Status : Recruiting
First Posted : November 9, 2017
Last Update Posted : November 9, 2017
Information provided by (Responsible Party):
Roberto Berni Canani, Federico II University

Brief Summary:

Food allergies (AA) are adverse reactions to food. Over the last decade, the AA scenario has changed profoundly. In many countries, there has been a significant increase in the prevalence, persistence and severity of AAs and a consequent increase in the socio-economic impact associated with these conditions. For these reasons, there is a strong need to develop effective strategies to prevent these conditions. To date, the AA etiopathogenesis is not yet fully defined. Genetic factors may predispose certain subjects to the development of AA, but these alone can not explain the change observed in the AA scenario over the last few years, renewing interest in environmental factors.

Numerous scientific evidence demonstrate the role of eating habits in influencing human health. Many of the effects of the diet on human health are due to a modulation of intestinal microbiosis. The regulation of the immune system is one of the pathways through which dietary modifications from the earliest times of life can alter the susceptibility of the individual to the development of allergic manifestations. The diet during pregnancy and lactation represents the earliest possible influence on the development of the baby's immune system. Observational studies suggest the association between maternal diet during pregnancy and lactation and development of allergic pathologies in the unborn, but the data are still preliminary. Often, other important parameters such as the atopic status of the parents, the type of delivery, the number of brothers, exposure to common allergens, maternal infections or early life, smoking exposure were not taken into account of cigarettes. The Mediterranean diet (MD) is characterized by a high intake of fruit and vegetables, legumes and whole grains combined with a moderate consumption of red wine, and the use of olive oil as the main source of lipids. In some studies adherence to MD was inversely related to the incidence of asthma and allergic rhinitis, especially in children. High adherence to MD was associated with a positive change in intestinal microbiosis and the production of short chain fatty acids (SCFA), particularly butyrate, the main SCFA produced by intestinal fermentation of food fibers. SCFA regulates mucosal integrity and the immunological and non-immunological mechanisms involved in the development of oral tolerance.

MD mechanisms during pregnancy in the prevention of childhood allergies are not yet fully known.

Condition or disease Intervention/treatment Phase
Food Allergy Behavioral: mediterranean diet Not Applicable

Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 60 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Prevention
Official Title: Effects of the Mediterranean Diet During Pregnancy on Maternal Gut Microbiota Composition and Function and on Neonatal Epigenetic Modulation Involved in Food Allergy
Actual Study Start Date : March 31, 2017
Estimated Primary Completion Date : June 30, 2018
Estimated Study Completion Date : June 30, 2019

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
No Intervention: Pregnant women at standard diet
Experimental: Pregnant women at mediterranean diet Behavioral: mediterranean diet
The Mediterranean diet (MD) is highly regarded as a healthy balanced diet. It is distinguished by a beneficial fatty acid profile that is rich in both monounsaturated and polyunsaturated fatty acids, high levels of polyphenols and other antioxidants, high intake of fiber and other low glycemic carbohydrates, and relatively greater vegetable than animal protein intake. Specifically, olive oil, assorted fruits, vegetables, cereals, legumes, and nuts; moderate consumption of fish, poultry, and red wine; and a lower intake of dairy products, red meat, processed meat and sweets characterize the traditional MD.

Primary Outcome Measures :
  1. The effects of Mediterranean diet in pregnancy on epigenetic mechanisms that regulate the expression of the genes involved in the allergic response in the offspring through epigenetic analysis on cord blood [ Time Frame: after 9 months (at the end of the pregnancy) ]
    The cord blood (5 ml) will be harvested in heparin tubes and transported immediately to the laboratory for extraction of peripheral blood lymphocytes by Ficoll gradient. The epigenetic mechanisms that will be explored are: DNA methylation of the major cytokines involved in Th1 / Th2 (IL-4, IL-5, IL-13, IL-10, IFN-γ and Treg-specific demethylated region of FoxP3 transcriptional factor) , Using the High Resolution melting (RealMore) method and confirmed by sequencing; Expression analysis of the major miRNAs involved in the pathogenesis of allergic pathologies (miR-125b, miR-146, miR-155, miR-29a / b, miR-27, miR-128, let-7b, miR-21, miR-126 , MiR-145, miR-106a, miR-375) on RNA extracted from peripheral blood lymphocytes by Real Time PCR; Analysis of the activity of Histone deacetylases (HDAC) 6 and 9, involved in the equilibrium of Th1 / Th2 cells by Real Time PCR.

Secondary Outcome Measures :
  1. The effect of Mediterranean Diet pregnancy on the composition of maternal gut microbiota through analysis of gut microbiota composition. [ Time Frame: after 9 months (at the end of the pregnancy) ]
    Fecal bacteria DNA will be extracted using standard technique outlined by the Earth Microbiome Project. 16S V4-region amplicon libraries will be produced using previously described primers and sequenced using the IlluminaMiSeqplatform (150bpx2). Bacterial load will be determined by qPCR using a standard curve derived from a plasmid containing a single copy of the 16S rRNAencoding gene. Sequence data has been deposited in MG RAST under accession numbers 4571868.3-4571924.3 and project number 10023. Paired end reads will be quality trimmed and processed for OTU (operational taxonomic unit) clustering using UPARSE pipeline, set at 0.97% identity cutoff. Taxonomic status will be assigned to the high quality (<1% incorrect bases) candidate OTUs using the "" script of QIIME software. Multiple sequence alignment and phylogenetic reconstruction will be performed using PyNast and FastTree.

  2. The effect of Mediterranean diet in pregnancy on the production of short chain fatty acids (butyrate and propionate) in the intestinal tract. [ Time Frame: after 9 months (at the end of the pregnancy) ]
    Fecal SCFAs concentration Frozen feces weighing 1g will be diluted with saline solution, vortexed, and centrifuged. Supernatants will be filtered and stored at -20°C until analysis. Frozen fecal extracts will be acidified and extracted in duplicate. A quantity of the pooled extract containing acidified butyrate, propionate or acetate will be transferred into a 2ml glass vial and loaded onto an Agilent Technologies 7890 gas chromatograph (GC) system. Detection will be achieved using a flame ionization detector. Peaks will be identified using a mixed external standard and quantified by peak height/internal standard ratio. To examine whether fecal butyrate levels correlates with bacterial diversity (Shannon diversity index) and evenness (Pielou's evenness index) and abundance patterns across multiple groups we will calculate the Spearman correlation using the cor.test function implemented in R (

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Ages Eligible for Study:   20 Years to 35 Years   (Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • women
  • caucasian ethnicity
  • aged between 20 and 35 years

Exclusion Criteria:

  • proven presence of infections during pregnancy and at delivery,
  • ongoing malignancies,
  • major gastrointestinal tract malformations,
  • immunodeficiencies,
  • diabetes and other chronic diseases at each organ or apparatus level,
  • chronic intestinal inflammatory diseases,
  • gastrointestinal function disorders,
  • celiac disease;
  • history of abdominal surgery with intestinal resection,
  • neuropsychiatric disorders,
  • central nervous system disorders,
  • vegan diet.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT03337802

Contact: Roberto Berni Canani, MD, PhD +390817462680

University of Naples Federico II Recruiting
Naples, Italy, 80131
Contact: Roberto Berni Canani, MD, PhD    +390817462680      
Sponsors and Collaborators
Federico II University

Responsible Party: Roberto Berni Canani, MD, PhD, Federico II University Identifier: NCT03337802     History of Changes
Other Study ID Numbers: 298/16
First Posted: November 9, 2017    Key Record Dates
Last Update Posted: November 9, 2017
Last Verified: November 2017
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Undecided

Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No

Additional relevant MeSH terms:
Food Hypersensitivity
Immune System Diseases
Hypersensitivity, Immediate