Brief Summary: 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 StudyStudy of Latinos HCHSSOL found that consumption of 1 serving cup of milkday 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
Detailed Description: The trial will feature a 2-week milk washout period followed by 11 randomization to lactose-containing or lactose-free 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 ie 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 kitsdevices
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