Effects of the Synbiotic Formulation EDC-HHA01 on Glucose Regulation in Adults with Type 2 Diabetes and Prediabetes : A Randomized, Placebo-Controlled Study

Background: Microbiome-targeted interventions have shown promise for metabolic health, yet clinical evidence remains inconsistent, particularly across stages of metabolic disease. This study evaluated the metabolic effects, safety, and tolerability of EDC-HHA01, a microbiome-informed, non-pharmacologic intervention, in adults with prediabetes (PD) or Type 2 Diabetes (T2DM). Methods: In a randomized, double-blind, placebo-controlled clinical trial, participants received EDC-HHA01 or placebo for six months. The study was adequately powered (≥80%) for the primary endpoint. Outcomes included changes in glycated hemoglobin (HbA1c), indices of insulin resistance, markers of metabolic endotoxemia, safety-related laboratory parameters, and exploratory patient-reported measures. Analyses were stratified by metabolic status and background metformin use. Results: In participants with PD, EDC-HHA01 supplementation was associated with a statistically and clinically meaningful reduction in HbA1c compared with placebo, supported by concordant improvements in fasting insulin, insulin resistance indices, and reductions in endotoxemia markers. In participants with T2DM, changes were directionally similar but attenuated and did not reach statistical significance. The intervention was well tolerated, with no serious adverse events, high adherence, and no clinically relevant adverse changes in renal or lipid parameters. Exploratory patient-reported outcomes indicated favorable acceptability but were not interpreted as efficacy endpoints. Conclusions: EDC-HHA01 was associated with biologically coherent, stage-dependent metabolic effects, most evident in PD. These findings support further investigation of microbiome-informed strategies as metabolic support in early-stage dysregulation.