new onset type 1 diabetes 6-bromotryptophan, residual betacell function, autoimmunity
Conditions
Interventions
To assess safety and efficacy of oral dosage of the endogenously occurring 6-BT 8mg capsules once daily vs placebo in patients with new onset type 1 diabetes  
 
Sponsors
Amsterdam UMC
Eligibility
Age
18 Years to 64 Years
Inclusion criteria
Inclusion criteria: - recent diagnosis of type 1 diabetes (< 6 months)- seropositivity of (>1) autoantibodies against beta-cell autoantigens insulin/ GAD65/ IA2/ ZnT8`- BMI <30 kg/m2- age at T1D onset 18-30 years (to avoid including latent autoimmune diabetes in adults), -on MDI (multiple day injections of) exogenous insulin or insulin pomp- detectable residual beta-cell function, defined by plasma C peptide >0.2 mmol/L and/or >1.2 ng/mL after MMT and/or by urine C-peptide/creatinine>0.6 nmol/mmol (UCPCR)
Exclusion criteria
Exclusion criteria: - Use of antibiotics or proton-pump inhibitors within the last three months before screening or during study period-aberrant Kidney (clearance > 60 ml/min) and/or liverfuntion (ASAT and ALAT > 2 UpperLimit) - Use of other probiotic supplementation within the last month before screening or during study period- Overt untreated gastrointestinal disease, inflammatory bowel disease or abnormal bowel habits- Absence of a large bowel (ie colostomy)- Evidence for comprised immunity ( HIV infection, chemotherapy, other autoimmune diseases, systemic anti-inflammatory therapy)- Alcohol abuse (equal or above 21 units per week) with hepatic enzymes>2.5 higher than the upper limit of normal range- Inability or unwillingness to donate feces or urine.- Smoking or illicit drug use (e.g. MDMA/amphetamine/cocaine/heroin/GHB) during the study - Kidney failure (eGFR <15ml.min/1.73m2), dialysis, kidney transplantation- Inability or unwillingness to provide informed consent.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Primary endpoints: To determine if 6-BT can ameliorate beta cell dysfunction and improve glycemic control, participants will be subjected to a standard 2-hours (Boost) mixed-meal test (MMT) with blood sampling at 0, 15, 30, 45, 60, 90, 120 minutes to assess excursions of glucose and C-peptide (proxy for beta-cell function as we previously published 3) at 0,1,3,6,12, 18 months.. Also, at baseline and 2 hours post-MMT, a urine sample will be collected for assessing for urinary C- peptide/creatinine levels at each visit (performed at Exeter Univeristy laboratory UK). Additionally, at above mentioned timepoints glycemic variability will be continuously monitored throughout the study by means of CGM (continuous glucose monitoring) FreeStyle Libre 3 Technology to calculate the time in eu-/hypo-/hyper-glycemic range and determine if 6-BT consumption associates with longer time-in-range. Finally, exogenous insulin dosages will be recorded as well to establish if 6-BT reduces the patient’s necessity of taking insulin. Finally, at above mentioned time-points, fasted blood samples will be collected at each visit to measure glucagon, HbA1c, lipids, kidney and liver functions (ASAT, ALAT, GGT, creatinine, urea) as well as inflammatory markers (such as CRP, and pro-/anti-inflammatory cytokines IFN-beta/gamma, TNF-alpha, IL- 1beta, IL-10, TGF-beta). | — |
Secondary
| Measure | Time frame |
|---|---|
| Secondary endpoints: To dissect the treatment impact on immune cell responses, blood will be collected during study visits, following by PBMC isolation and immunophenotyping by flow and spectral cytometry. In vivo, 6-BT was found to increase the percentage of pancreatic immunosuppressive CD4 T cells and diminished the activation of both CD4 and CD8 T cells (see figure 2). Based on these preliminary findings, we believe that 6- BT is not specifically targeting autoreactive CD8 T cells but rather changing the whole T cell immunophenotypic profile, with a downstream effect on autoreactive CD4/CD8 T lymphocytes. Therefore, we will perform an in-depth analysis of circulating lymphocytes using the frozen PBMCs isolated at each above-mentioned time-point to dissect the mechanism of actions of 6-BT in human T1D. For this, we will use the SONY ID7000 Spectral Cell Analyzer, to dissect 6-BT-medaited changes in frequency and activation/exhaustion state of different T cell subsets, including Th1, Th2, Th17, Th22, Th9, Tfh, ThG, Treg, T follicular reg, classical and mucosal T cells, and MAIT (mucosal- associated invariant T) cells. Finally, to determine if 6-BT intake eventually reduces the frequency of cytotoxic CD8 T cells targeting beta cell antigens, we will employ the staining with MHC tetramers loaded with beta cell- derived peptides. To this end, PE-conjugated monomers HLA-A2 (2 mg/mL) will be loaded with beta cell-derived autoantigens. Tetramer-positive autoreactive CD8 T cells will be further analyzed to establish their activity (AUMC cytometry core facility). Finally, the effects on plasma metabolite profile (including absolute changes in plasma 6- BT concentrations by GC-MS/MS dr Melany Rios Morales and at Metabolon USA) , shotgun sequencing of fecal DNA (Microbiota Center Amsterdam, AUMC and Novogene,Duitsland) as well as dietary intake lists online (via mijn.voedingscentrum.nl/nl/eetmeter)) will be studied at 0,1,3,6,12, 18 months. | — |
Countries
Netherlands
Contacts
Public ContactM Nieuwdorp
Amsterdam UMC
Outcome results
None listed