Carbohydrate-induced Resilience of the Gut Microbiome After Antibiotics Use
Condition: Overweight and Obesity; Insulin Resistance; Dysbiosis
MeSH terms: Overweight; Insulin Resistance; Dysbiosis
Study type: Interventional

Summary: 
      The gut microbiome is a complex ecosystem with a wide range of functions, and it is thought
      that it can influence multiple processes in the human body. In turn, the composition and
      activity of the gut microbiome is affected by many factors as well.

      Antibiotics can be very effective in treating bacterial infections, but they are also
      associated with detrimental health effects. Previous studies have already shown that
      antibiotics disturb the human gut microbiome composition by destroying commensal bacteria. As
      it is well known that the microbiome influences host metabolism, perturbation of the healthy
      microbiome (dysbiosis) is thought to be disease causing.

      Prebiotics, on the other hand, are beneficial for the gut microbiome. These so-called
      indigestible fibers are naturally present in our foods, but cannot be metabolised by the
      human body. Many bacteria in the human gut are able to ferment these fibers and they
      subsequently produce beneficial products for the rest of the body. Besides this, fiber intake
      stimulates growth of commensal bacteria in the human gut.

      Although it has become increasingly clear that prebiotics have a beneficial effect on the gut
      microbiome and general health, it is still unclear to which extent the beneficial effects of
      prebiotics supplementation occur after the gut microbiome is disturbed by antibiotics. We
      hypothesize that prebiotic supplementation after antibiotics use will improve restoration of
      the gut microbiome to a healthy state compared to placebo.
    

Detailed description: 
      In this double-blind, randomized placebo-controlled study, 40 overweight, but otherwise
      healthy adults will first receive vancomycin for 7 days (3x 500mg per day) to disturb the gut
      microbiome. They will then receive either indigestible fiber supplementation (classified) ór
      a placebo for the following 8 weeks. All study parameters will be assessed in two parallel
      groups, to which subjects will be assigned using minimization.

      After initial screening, participants will be asked to visit the university for a total of 6
      times during a period of 11 weeks. A clinical investigation day will take place at baseline,
      after antibiotics use and after the supplementation period. The remaining 3 visits will be
      short visits during the supplementation period (week 2, 4 & 6 of supplementation).
      Participants will be asked to collect feces every day before the university visits.

      During the clinical investigation days, an abdominal subcutaneous adipose tissue will be
      taken under fasting conditions. Participants will also perform a 7-point oral glucose
      tolerance test to assess their insulin sensitivity. Furthermore, blood samples will be taken
      in the fasted state to assess markers of fat metabolism, short-chain fatty acids, gut
      hormones and inflammatory markers. Participants will be asked to hand in collected feces and
      to fill in questionnaires regarding stool consistency, stool frequency and physical activity.
      Lastly, they will be asked to hand in filled-in 3-day food diaries.

      On the 3 remaining visits during the supplementation period, participants will hand in
      collected feces and food diaries, and fill in the questionnaires.

      For these 6 visits, participants will have to invest approximately 14 hours.
    

Intervention name(s): Indigestible fiber (classified); Placebo
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): Participants will be asked to ingest 12 grams of indigestible fiber powder per day for a period of 8 weeks. Three times daily, they will take 4 grams of powder with their meal.; Participants will be asked to ingest 6 grams of placebo powder per day for a period of 8 weeks. Three times daily, they will take 2 grams of powder with their meal.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Treatment