Effects of Probiotics and Fibers on Albuminuria in Persons With Type 1 Diabetes

Three morning urine samples will be collected for assessment of UACR. The geometric mean of the 3 samples will be calculated.

Renal function (GFR) and extracellular volume (ECV) will be assessed during 4 hours with the measurement plasma clearance of 99mTc-DTPA to provide accurate GFR measurement. A bolus of 0.5 mL Technetium-99m DTPA (approximately 10 MBq) is injected and blood samples are drawn at 0, 180, 200, 220 and 240 minutes after the injection. Urine is collected during the investigation. Plasma concentrations of 99mTc-DTPA at these time points are measured and used to calculate the plasma clearance of 99mTc-DTPA which approximates GFR.

24-hours blood pressure will be measured using a standard cuff-based device (boso TM-2430 PC2) that measures the blood pressure every 15 minutes between 07 in the morning and 23 in the evening and every 30 minutes during the night.

GlycoCheck is a handheld video capillary microscope that measure glycocalyx thickness and sublingual capillary density under the tongue. The measurement will be performed by investigator and is a measure of the microcirculation damage. The distribution of the red blood cell column width at each capillary segment is used to calculate the perfused boundary region, which is the distance between the median and the outer edge of the red blood cell perfused lumen. The perfused boundary region reflects the thickness of the endothelial glycocalyx, based on the idea that loss of its integrity allows deeper penetration of the red blood cells into the gel-like layer covering the endothelial lining. Higher perfused boundary region, therefore, indicates thinner glycocalyx. The software also returns total and perfused capillary density in segments per millimeter square.

Biomarkers drawn from blood will include markers of endothelial dysfunction (von Willebrand factor, endothelin-1, ADMA, ICAM-1, VCAM-1 and E-selectin),

Markers of oxidative stress (F2-isoprostanes and 8-oxodG) will be measured in urine by ELISA and multiplexing methods.

Fecal samples will be collected for calprotectin analyses.

Biomarkers drawn from blood will include markers of intestinal permeability (LPS and zonulin)

Biomarkers drawn from blood will include markers of inflammation (hs-TNT, TNF-alfa, IL6, IL8, IL1-beta, SAA, sICAM1, sICAM3, suPAR)

Markers of tubular kidney injury (NGAL, KIM-1, Beta2microglobulin, hepatocellular growth factor (HGF) and adiponectin) will be measured in urine by ELISA and multiplexing methods.

Autonomic nervous system function will be evaluated with the VagusTM device. The heart rate will be measured by 5-minute resting measures and in response to deep breathing, position change from lying to standing position and by exhaling through a mouthpiece against 40 mmHg of pressure (Valsalva maneuver).

Biomarkers will include markers of bacterial uremic toxins (hippuric acid, kynurenic acid, indoxyl sulfate and p-cresol sulfate).

Fecal samples will be collected at visit 2, 3, 4 and 5 for calprotectin and gut microbiome analyses. Feces is collected according to current standard operation procedures in order to characterize the gut microbiome. The fecal samples should be stored at -20 °C in the participants' freezer and be delivered to SDCC in the provided cooling bag no more than 48 hours after collection. At SDCC the samples will be stored at -80°C. The gut microbiome characterization is based on 16S rRNA gene sequencing. After standardized microbial DNA extraction, the microbial DNA will be subjected to sequencing, microbial gene analyses, taxonomy analyses including enterotypes known species and unknown meta-species and functional annotation.