Investigating the Gut Microbiota Modulation Effects of Allicin for Cardiovascular Disease Protection and Establishing Microbiota Directed Personalized Nutrition Guidance With Novel Humanized Gnotobiotic Mice Model, Microbial Culturomics and Metabolomic Technique
Condition: Atherosclerosis
MeSH terms: Cardiovascular Diseases; Atherosclerosis
Study type: Interventional

Summary: 
      Investigators recruited 10 trimethylamine N-oxide (TMAO) producers to test the effect of
      garlic juice containing allicin on gut microbiota modulation and TMAO production.
    

Detailed description: 
      Trimethylamine N-oxide (TMAO) was recently discovered as a novel and independent risk factor
      for promoting atherosclerosis while it is generated from dietary carnitine through the
      metabolism of gut microbiota for decades. Allicin, the major compound in raw garlic juice, is
      a naturally antimicrobial phytochemical found in raw garlic juice and easily acquired from
      the diet. Investigators' previous study suggests dietary allicin reduces the transformation
      of L-carnitine to TMAO through the impact on gut microbiota in mice. Therefore, it is worth
      investigating whether raw garlic juice intake could reduce the TMAO productivity of human gut
      microbiota as well as modulate gut microflora. Investigators plan to recruit 10 TMAO
      producers to receive garlic juice for one week. The plasma and urine TMAO concentration will
      be measured by the LC-MS, and the gut microbiota composition will be analyzed by the
      next-generation sequencing, through bioinformatics analysis. Investigators expected after
      intake garlic juice for one week, it could prevent the cardiovascular disease risk via gut
      microbiota modulation and reduction of plasma and urine TMAO.

      Screening of the TMAO producer:

      The healthy participants were recruited, the criteria as follows: (1) age ≥ 20 years old; (2)
      no exposure to antibiotics, probiotics, or carnitine supplements within the previous month;
      (3) have no history of chronic diseases including, diabetes mellitus, myasthenia gravis,
      chronic renal disease, hyperparathyroidism, epilepsy, and severe anemia; (4) Participants
      were excluded from the study if they reported recent gastrointestinal discomfort (such as
      abdominal pain or diarrhea). To screening the TMAO producer, Investigators use the oral
      carnitine challenge test (OCCT) method which previously exhibited better efficacy than
      fasting plasma TMAO to identify the TMAO producer phenotype. All of the participants fasted
      at least 8 hours before performing OCCT. 1500 mg of L-carnitine (3 tablets, General Nutrition
      Centers, Inc., USA) orally administrated to the participants. The blood and urine of
      participants were collected at 0, 24, 48, and 72 hours after carnitine intake. Participants
      with plasma TMAO ≧ 10 μM after OCCT were defined as high TMAO producers and proceeded into
      the garlic juice intervention test.

      Garlic Juice Intervention:

      High-TMAO producers asked to consume 55 mL of raw garlic juice (48 mg of allicin equivalent)
      once a day during dinner for one week. High-TMAO producers suggested consuming the garlic
      juice with a meal. The high-TMAO producers were free to choose their diet, no restriction on
      the type of food. After one week of raw garlic juice intervention, the second OCCT was
      performed.
    

Intervention name(s): Raw garlic juice containing allicin
Intervention type(s): Dietary Supplement
Intervention description(s): Fresh garlic juice containing around 48mg allicin for 7 days
Intervention MeSH terms: Allicin
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Basic Science