Interaction Between Levothyroxine and Probiotics in Hypothyroid Patients
Condition: Hypothyroidism
MeSH terms: Hypothyroidism
Study type: Interventional

Summary: 
      A prospective, randomized, single-blind, controlled, investigator-started clinical trial was
      carried out. Patients with primary hypothyroidism were randomly assigned to the study
      (VSL#3®+ LT4) and the control group (LT4). A two months treatment phase was followed by two
      months of follow-up. Clinical examination, blood tests for thyroid function and for
      peripheral tissue markers of thyroid hormones effect were performed monthly for 4 months. LT4
      dose adjustments were performed during the study when necessary.
    

Detailed description: 
      Consecutive patients on LT4 replacement therapy attending the Endocrinology Unit of Modena
      (Italy) were screened. According to inclusion and exclusion criteria, eighty participants
      were enrolled and randomized in study or control group. The random allocation sequence was
      generated using 'Statistical Package for the Social Sciences' software for Macintosh (SPSS)
      considering a 1:1 ratio by the statistician of the Unit. Clinicians evaluating and enrolling
      patients were blinded to the randomization list. The study design provided a monthly visit
      for a 4 months overall time-frame. Patients assigned to the study group took the probiotic
      supplement VSL#3® for two months, followed by a two months period of follow-up. Study group
      patients were taught to assume the probiotic supplement at least two hours after LT4
      administration, to dissolve it in a cold beverage and to store it in a refrigerator (2°-8°C)
      in order to preserve bacteria load. The study design was single-blind since only the
      clinician was aware of the allocation. The VSL#3® administration was provided by nurses.
      Participants were invited to return all used and unused sachets to count the number of opened
      sachets per the number of treatment days.

      All patients underwent five visits (baseline, visit 1, 2, 3 and 4) in which anthropometrical
      evaluation (weight and height) and hormonal function assessment were performed. A blood
      sample was taken in the morning at each visit, on empty stomach and before LT4 ingestion. In
      occurrence of hormonal alteration, LT4 daily dose was adjusted according to clinical
      guidelines. At baseline, visit 2 and visit 4, patients underwent clinical examination with
      heart rate and blood pressure evaluation. During each visit, the following data were
      collected: probiotic assumption, sex, age, hypothyroidism aetiology, LT4 formulation dose and
      brand, body mass index (BMI), body surface area (BSA), systolic blood pressure, diastolic
      blood pressure, heart rate, TSH, fT4, fT3 and any possible LT4 posology adjustment. All the
      clinical data have been further databased.
    

Intervention name(s): a mixture of highly charged Lactobacilli and Bifidobacteria (VSL#3®); levothyroxin
Intervention type(s): Other; Drug
Intervention description(s): Patients assigned to the study group took the probiotic supplement VSL#3® for two months, in addition to levothyroxine; replacement therapy for hypothyroidism
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Investigator)
Primary purpose: Other