Mycobacterium are among the oldest co-evolutionary partners of humans. The attenuated Mycobacterium bovis Bacillus Calmette Guérin (BCG) strain has been administered globally for 100 years as a vaccine against tuberculosis. BCG also shows promise as treatment for numerous inflammatory and autoimmune diseases. Here, we report on a randomized 8-year long prospective examination of type 1 diabetic subjects with long-term disease who received two doses of the BCG vaccine. After year 3, BCG lowered hemoglobin A1c to near normal levels for the next 5 years. The BCG impact on blood sugars appeared to be driven by a novel systemic and blood sugar lowering mechanism in diabetes. We observe a systemic shift in glucose metabolism from oxidative phosphorylation to aerobic glycolysis, a state of high glucose utilization. Confirmation is gained by metabolomics, mRNAseq, and functional assays of cellular glucose uptake after BCG vaccinations. To prove BCG could induce a systemic change to promote accelerated glucose utilization and impact blood sugars, murine data demonstrated reduced blood sugars and aerobic induction in non-autoimmune mice made chemically diabetic. BCG via epigenetics also resets six central T-regulatory genes for genetic re-programming of tolerance. These findings set the stage for further testing of a known safe vaccine therapy for improved blood sugar control through changes in metabolism and durability with epigenetic changes even in advanced Type 1 diabetes.

Mycobacteria are among the oldest co-evolutionary partners of humans. Attenuated Mycobacterium bovis, known as the Bacillus Calmette Guérin (BCG) vaccine, has been administered globally for 100 years for TB prevention. BCG vaccination shows clinical promise in numerous autoimmune diseases, including multiple sclerosis (MS) and type 1 diabetes (T1D). In published Phase II clinical trials in MS, BCG shows benefit starting 2 years after administration with continuing effectiveness at year 5. Here we report on the long-term stabilizing effect of BCG vaccination on blood sugar control in advanced T1D with 8 years of follow-up data. The data examines T1D subjects with long-term disease (>10 years duration) who received 2 doses of BCG 4 weeks apart. Starting after year 3, only BCG vaccinated T1D subjects had lowered HbA1c near normal (BCG treated 6.18+/-.34, placebo 7.07+/-.41, reference diabetic 7.22+/-.17, p=0.02; year 5 data with n=46 total subjects). Continued follow-up of 6 subjects for 8 years total confirmed the ability of BCG vaccinations to maintain lowered HbA1c levels without hypoglycemia (BCG treated 6.65+/-.26 vs. 7.22+/-.38, p=0.0002). Glucagon challenge tests were performed once HbA1cs were lowered but did not confirm a therapeutic return of C-peptide levels for improved blood sugar control. Pre-clinical NOD mouse data had shown in mice that BCG induces massive islet regeneration for restore murine blood sugars. In humans, BCG’s impact on blood sugars appears to be driven by a novel mechanism—a systemic shift in glucose metabolism from oxidative phosphorylation to aerobic glycolysis, a state of high glucose utilization as measured by metabolomics, RNAseq and cellular glucose uptake, in subjects receiving a long-term benefit with BCG vaccinations. These clinical and novel mechanistic findings, buttressed with further murine testing, set the stage for a safe and cost effective way to possibly improve blood sugars in humans with diabetes. Disclosure W. Kuhtreiber: None. L. Tran: None. B. Nguyen: None. S.E. Janes: None. A.A. DeFusco: None. D.L. Faustman: None.

In type 1 diabetes (T1D), long-term blood sugar control measured by HbA1c can vary over a wide range. Although metabolites are commonly studied in type 2 diabetes (T2D) as they relate to HbA1c, similar studies in T1D are few. Since the underlying etiologies of T1D and T2D are different, we explored the overall pathways of metabolism in T1D subjects with tight vs. poor blood sugar control. T1D subjects (n=50) were divided into two groups (n=25 each) based on low vs. high HbA1c (Screen 1, low: mean 6.7 ± 0.1%; high: mean 8.7 ± 0.3%). Serum samples were analyzed on a metabolomic GC/HPLC/MS platform and analyzed for differences in biochemicals between the groups. The screen was repeated with a second group of 50 patients for verification (Screen 2, mean 6.3 ± 0.1%; mean 8.0 ± 0.2%) and then both screens combined. For each detected biochemical, average scaled intensity was determined and statistical significance of differences was calculated using a two-tailed, unpaired Student’s T test (p-values) and False Discovery Rate (q-values). The platform distinguished 690 components in Screen 1 and 623 biochemicals in Screen 2. In Screen 1, two biochemicals, including glucose, showed significant differences (≦0.05) for both p and q value. In Screen 2, none of the biochemicals reached threshold. When the screens were combined (100 samples), 10 biochemicals were significant for both p and q. Three components (glucose, mannose and 1,5-AG) were carbohydrates related to blood sugar control and thus expected in a high and low HbA1c analysis. Significant biochemicals commonly found in T2D and related to blood sugar control were not significant in T1D for both p and q in the screens. We conclude that few metabolites are correlated in T1D with tight vs. poor blood sugar control compared to T2D. Unlike T2D, metabolites related to intracellular sugar utilization, the Krebs cycle and purine synthesis are unrelated to blood sugar control in T1D cohorts. Disclosure W. Kuhtreiber: None. S.E. Janes: None. M.W. Yang: None. D.L. Faustman: None.

We report on a randomized, placebo-controlled prospective examination of adult subjects with long-term type 1 diabetes who received 2 bacillus Calmette-Guerin (BCG) vaccine doses 4 weeks apart and were studied for up to 5 years. All enrolled subjects had disease >10 years duration without complications. Starting after year 3 of follow-up, only BCG vaccinated subjects had lowered HbA1c for 1 year (Year 05 data: BCG-treated HbA1c 6.18+/-.34 [n=9], placebo 7.07+/-.41 [n=3], reference subjects with type 1 diabetes 7.22+/-.17 [n=34, p=0.02]). Continuing follow-up of 6 subjects who have been followed for a total of 8 years, 4 years after the first documented lowering of HbA1c (Phase 1 trial participants), confirms the ability of repeat BCG vaccination to maintain lowered HbA1c levels without hypoglycemia in long-term disease (BCG-treated HbA1c 6.65+/-.26 vs. placebo 7.22+/-.38, p=0.0002) for a total of 5 continuous years. For all BCG-treated subjects, the stable reductions in HbA1c were not associated with hypoglycemia. BCG-treated subjects had no change in their enrollment use of insulin pumps and none utilized a CGM device. The apparent stable and long-lasting impact of BCG on blood sugars in humans with type 1 diabetes appears to be the result of a novel mechanism, as documented with metabolomics, mRNAseq, and epigenetic methods; namely, a systemic shift in glucose metabolism from oxidative phosphorylation to aerobic glycolysis, a state of high glucose utilization on cellular levels. BCG via epigenetics also resets T-regulatory genes for genetic reprogramming of tolerance. Trials are being designed to confirm the value of BCG for blood sugar control in humans. The identification of a novel mechanism for blood sugar lowering with BCG opens the door for future trials in both type 1 and 2 diabetes with a safe, novel and affordable approach. Disclosure W. Kuhtreiber: None. L. Tran: None. S.E. Janes: None. A.A. DeFusco: None. H. Zheng: None. D.L. Faustman: None.