An interventional study of Lactose-Containing Milk and Lactose-Free Milk in Lactose Intolerance, Lactose Intolerant and Lactase Persistence, sponsored by Albert Einstein College of Medicine. Recruiting at 1 site in United States. Open to participants aged 18 Years to 70 Years. Per ClinicalTrials.gov, last updated 2026-05-26.
Sponsored by Albert Einstein College of Medicine · Not applicable, Interventional, and Prevention
Individuals with lactase non-persistence (LNP; determined by a functional variant in the LCT gene [rs4988235, GG genotype]) are susceptible to lactose intolerance in adulthood due to deficiency of lactase, the enzyme which digests milk lactose sugars. However, many LNP individuals still drink ≥1 cup of milk daily. Recent analysis in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) found that consumption of 1 serving (cup) of milk/day was associated with \~30% lower risk of type 2 diabetes among LNP individuals, but not among individuals with lactase persistence (LP). This beneficial effect might be partially explained by favorable alterations in gut microbiota and related metabolites associated with higher milk consumption among LNP individuals. Based on these observational study findings, the investigator team proposes to conduct a randomized, controlled trial of lactose-containing vs. lactose-free milk in LNP individuals with pre-diabetes, to comprehensively investigate the effects of milk intake on the gut microbiome and glycemic outcomes.
The trial will feature a 2-week milk washout period, followed by 1:1 randomization to lactose-containing (1% or 2%) or lactose-free (1% or 2%) milk for 12 weeks (4 weeks each of ½ cup, 1 cup, and 2 cups milk). Before and after the 12 weeks, visits will entail lactose challenge hydrogen breath tests (HBT; i.e., lactose tolerance tests) and blood tests for fasting glucose, hemoglobin A1c, and metabolomics; while stool samples and continuous glucose monitoring (CGM) data will be collected at home using provided kits/devices.
Specific aims of the study are to: (1) establish feasibility and tolerability of a randomized trial of lactose-containing vs. lactose-free milk; (2) to examine the effect of lactose-containing milk on gut microbiome species, functions, and metabolites in LNP individuals with pre-diabetes; and (3) to examine the effect of lactose-containing milk on glycemic outcomes in LNP individuals with pre-diabetes.
53 studies on the registry are indexed under Lactose Intolerance; 6 are open to participants now.
This study's planned enrollment of 40 is close to the median of 41 across 41 interventional studies indexed under Lactose Intolerance.
Browse Lactose Intolerance studies →Albert Einstein College of Medicine is the lead sponsor of 201 studies on the registry; 21 are open to participants now.
Of its 46 completed or terminated interventional studies of FDA-regulated products, 37 (80%) have results posted.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
HbA1c
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will be randomized to lactose-containing milk in strata of age (\<60, ≥60) and sex (female, male). Within each age and sex stratum, 10 participants will be randomized into two intervention groups in a 1:1 ratio
Dietary Supplement: Lactose-Containing Milk
Participants will be randomized to lactose-free milk in strata of age (\<60, ≥60) and sex (female, male). Within each age and sex stratum, 10 participants will be randomized into two intervention groups in a 1:1 ratio
Dietary Supplement: Lactose-Free 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.
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
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).
Time frame: Daily From Screening visit to Week 12
Change in Expired Breath Hydrogen
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.
Time frame: From Baseline to Week 12
Change in gut microbiome features - Relative Abundance of Species
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.
Time frame: From Baseline to Week 12
Change in gut microbiome features - Functional Pathway Relative Abundance
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.
Time frame: From Baseline to Week 12
Change in gut microbiome features - Metabolomics
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.
Time frame: From Baseline to Week 12
Change in glycemic outcomes - Fasting glucose
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.
Time frame: From Baseline to Week 12
Change in glycemic outcomes - Hemoglobin A1c (HbA1c)
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.
Time frame: From Baseline to Week 12
Change in glycemic outcomes - Continuous Glucose Monitoring (CGM) mean glucose
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.
Time frame: From Screening visit to Week 14 visit
Change in glycemic outcomes - Continuous Glucose Monitoring (CGM) glycemic variability
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.
Time frame: From Screening visit to Week 14 visit
Change in glycemic outcomes - Continuous Glucose Monitoring (CGM) time above range
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.
Time frame: From Screening visit to Week 14 visit
Change in glycemic outcomes - Continuous Glucose Monitoring (CGM) time in range
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.
Time frame: From Screening visit to Week 14 visit
Change in glycemic outcomes - Continuous Glucose Monitoring (CGM) time below range
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.
Time frame: From Screening visit to Week 14 visit
Change in Flatulence
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).
Time frame: From Screening to Week 1, from Week 1 to Week 10, and from Week 1 to Week 14
Plan to share: No
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