Milk for Diabetes Prevention

DIETARY_SUPPLEMENT

Lactose-Containing Milk

Participants will be asked to drink regular milk (1% or 2%) for 12 weeks as follows: * Weeks 1-4: ½ cup milk per day * Weeks 5-8: 1 cup milk per day * Weeks 9-12: 2 cups milk per day Participants will continue drinking 2 cups milk/day for 2 weeks after the 12-week follow-up visit.

DIETARY_SUPPLEMENT

Lactose-Free Milk

Participants will be asked to drink 1% or 2% lactose-free milk for 12 weeks as follows: * Weeks 1-4: ½ cup milk per day * Weeks 5-8: 1 cup milk per day * Weeks 9-12: 2 cups milk per day Participants will continue drinking 2 cups milk/day for 2 weeks after the 12-week follow-up visit.

Gastrointestinal symptoms

Time frame: Daily From Screening visit to Week 12

Gastrointestinal symptoms, specifically abdominal pain, bloating, flatulence, and diarrhea, will be recorded daily from screening visit through 12 weeks of milk intervention. The occurrence and severity of these four adverse events will be summarized and reported by study arm. Average frequencies of none-mild vs. moderate-severe symptoms will be compared between treatment groups by week of study, as well as for specific time intervals corresponding to milk doses (weeks 1-4, 5-8, 9-12).

Change in Expired Breath Hydrogen

Time frame: From Baseline to Week 12

Expired breath hydrogen after lactose challenge will be measured during the baseline visit and after 12 weeks of milk intervention at the time of the follow-up visit using Hydrogen Breath Test (HBT) kits. Breath tubes will be mailed to an external laboratory where stable isotope analysis for expired breath hydrogen will be conducted. Expired breath hydrogen will be expressed as incremental Area Under the Curve (iAUC). Change in iAUC from baseline to week 12 will be summarized using basic descriptive statistics (group means and standard deviations), and change in iAUC will be compared between treatment groups.

Change in gut microbiome features - Relative Abundance of Species

Time frame: From Baseline to Week 12

Stool samples will be collected using home stool microbiome kits at baseline, 4-, 8-, and 12-week timepoints. Shotgun sequencing will be conducted. Change in relative abundance of species (with \>1% mean relative abundance) from baseline will summarized, using basic descriptive statistics (group means and standard deviations). Change in relative abundance of species from baseline will be compared between the treatment groups.

Change in gut microbiome features - Functional Pathway Relative Abundance

Time frame: From Baseline to Week 12

Stool samples will be collected using home stool microbiome kits at baseline, 4-, 8-, and 12-week timepoints. Shotgun sequencing will be conducted. Change in relative abundance of functional pathways (with \>1% mean relative abundance) from baseline will summarized, using basic descriptive statistics (group means and standard deviations). Change in relative abundance of functional pathways from baseline will be compared between the treatment groups.

Change in gut microbiome features - Metabolomics

Time frame: From Baseline to Week 12

Targeted metabolic profiling will be performed on serum and stool samples (baseline and week 12) using LC-MS/MS methods for absolute quantitation of 70 metabolites associated with gut bacterial metabolism. Change in stool and serum metabolites from baseline will be summarized using basic descriptive statistics (group means and standard deviations). Change in stool and serum metabolites from baseline will be compared between the treatment groups.

Change in glycemic outcomes - Fasting glucose

Time frame: From Baseline to Week 12

Blood sera samples for fasting glucose will be collected at baseline and Week 12. Fasting glucose, i.e., blood sugar levels following an 8-hour fast, will be analyzed via standard analytical chemistry approaches and reported in mg/dL or mmol/L units. Ranges vary but a fasting glucose level \<99 mg/dL is considered 'normal', between 100-125 mg/dL is within the 'pre-diabetic' range, \>126 mg/dL is within the 'diabetic' range. Change in fasting glucose from baseline will be summarized using descriptive statistics (means and standard deviations) and compared between the treatment groups.

Change in glycemic outcomes - Hemoglobin A1c (HbA1c)

Time frame: From Baseline to Week 12

Whole blood samples for HbA1c will be collected at baseline and Week 12. HbA1c, used to measure the amount of hemoglobin with attached glucose and reflects average blood glucose levels over the past several months, will be analyzed via standard analytical chemistry approaches. Ranges vary, however, a 'normal' HbA1c is generally \<5.7%, 5.7-6.4% is in the 'pre-diabetic' range and a value of 6.5% or greater is in the 'diabetic' range. Change in HbA1c from baseline will be summarized using descriptive statistics (means and standard deviations) and compared between the treatment groups.

Change in glycemic outcomes - Continuous Glucose Monitoring (CGM) mean glucose

Time frame: From Screening visit to Week 14 visit

During screening visit participants will have a 2-week continuous glucose monitor (CGM) applied to the skin on the upper arm in advance of the 2-week milk washout period. The CGM will be returned during the baseline visit 2 weeks later. After the 12 week visit, another 2-week CGM will be applied during which time participants will continue drinking milk concurrent with the 2-week CGM (i.e., until 14 weeks). Change in mean glucose (mg/dL) from screening to week 14 will be summarized using descriptive statistics (means and standard deviations) and compared between the treatment groups.

Change in glycemic outcomes - Continuous Glucose Monitoring (CGM) glycemic variability

Time frame: From Screening visit to Week 14 visit

During screening visit participants will have a 2-week continuous glucose monitor (CGM) applied to the skin on the upper arm in advance of the 2-week milk washout period. The CGM will be returned during the baseline visit 2 weeks later. After the 12 week visit, another 2-week CGM will be applied during which time participants will continue drinking milk concurrent with the 2-week CGM (i.e., until 14 weeks). Change in glycemic variability (%CV) from screening to week 14 will be summarized using descriptive statistics (means and standard deviations) and compared between the treatment groups.

Change in glycemic outcomes - Continuous Glucose Monitoring (CGM) time above range

Time frame: From Screening visit to Week 14 visit

During screening visit participants will have a 2-week continuous glucose monitor (CGM) applied to the skin on the upper arm in advance of the 2-week milk washout period. The CGM will be returned during the baseline visit 2 weeks later. After the 12 week visit, another 2-week CGM will be applied during which time participants will continue drinking milk concurrent with the 2-week CGM (i.e., until 14 weeks). Change in time above range (%) from screening to week 14 will be summarized using descriptive statistics (means and standard deviations) and compared between the treatment groups.

Change in glycemic outcomes - Continuous Glucose Monitoring (CGM) time in range

Time frame: From Screening visit to Week 14 visit

During screening visit participants will have a 2-week continuous glucose monitor (CGM) applied to the skin on the upper arm in advance of the 2-week milk washout period. The CGM will be returned during the baseline visit 2 weeks later. After the 12 week visit, another 2-week CGM will be applied during which time participants will continue drinking milk concurrent with the 2-week CGM (i.e., until 14 weeks). Change in time in range (%) from screening to week 14 will be summarized using descriptive statistics (means and standard deviations) and compared between the treatment groups.

Change in glycemic outcomes - Continuous Glucose Monitoring (CGM) time below range

Time frame: From Screening visit to Week 14 visit

During screening visit participants will have a 2-week continuous glucose monitor (CGM) applied to the skin on the upper arm in advance of the 2-week milk washout period. The CGM will be returned during the baseline visit 2 weeks later. After the 12 week visit, another 2-week CGM will be applied during which time participants will continue drinking milk concurrent with the 2-week CGM (i.e., until 14 weeks). Change in time below range (%) from screening to week 14 will be summarized using descriptive statistics (means and standard deviations) and compared between the treatment groups.

Change in Flatulence

Time frame: From Screening to Week 1, from Week 1 to Week 10, and from Week 1 to Week 14

The Smart Underwear device will be worn externally on regular underwear near the rectum/perineum during specified daytime wear periods. The device continuously detects hydrogen in expelled flatus and records supporting temperature and movement data. These data will be used to derive the frequency of flatus events per wear period, which reflects intestinal gas production and gut microbial activity. De-identified data will be transferred after each wear period through the Human Flatus Atlas mobile app and uploaded to servers. Change in frequency of flatus events per wear period will be summarized using basic descriptive statistics (group means and standard deviations).

What is a clinical trial?

A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.

Is it safe to participate?

Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.

Will I be compensated?

Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.

Will I receive a placebo instead of treatment?

When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.

Can I leave a trial if I change my mind?

Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.

How long does a clinical trial last?

Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.