Lactobacillus Johnsonii Supplementation in Adults With T1D

Inclusion Criteria: * Have confirmed T1D by physician diagnosis * Have normal values at screening for CBC and complete metabolic profiles (with the exception of fasting glucose and HbA1c). * Are able to swallow a capsule. * Are willing to complete weekly online questionnaires.\* * Are willing to consume a probiotic or placebo capsule daily for 24 weeks. * Are willing to provide stool samples throughout the study. * Are willing to provide blood samples throughout the study. * Are willing to take three 2-hour Mixed-Meal Tolerance Tests (MMTTs). * Are able to access a computer with Internet throughout the study.\* * Note: Going into the study, we want the participants to have daily internet access. However, if this changes once they are in the study, we will provide paper copies of the questionnaires. Exclusion Criteria: * Have had or are currently being treated for any diseases or illnesses such as gastrointestinal disease (gastric ulcers, Crohn's, ulcerative colitis, etc.). * Have chronic disease kidney disease. * Have had or are currently being treated for other immune-compromising diseases or conditions (HIV, AIDS, hepatitis, cancer, leukemia, transplant patient, Lupus, DiGeorge syndrome, selective deficiency of Immunoglobulin A (IgA), Bruton's disease etc.). * Have an underlying structural heart disease. * Currently live with an immunocompromised person. * Are currently taking medications for constipation and/or diarrhea. * Have taken antibiotics within the past 2 weeks prior to randomization. * Are currently taking a probiotic supplement and are unwilling to discontinue it a minimum of 2 weeks prior to the study start. * Are a current smoker. * Are currently pregnant or lactating or a female who plans to become pregnant in the next 6 months. * Have a known allergy to milk or milk protein.