In a recent study published in Nature Metabolism, researchers explored the connection between milk consumption and the risk of developing type 2 diabetes (T2D) in individuals who do not produce lactase, known as lactase non-persistent (LNP) individuals.
Background
While cow's milk is a common part of the human diet, its impact on T2D has been a topic of debate. Previous research has yielded inconclusive results regarding the relationship between milk and T2D risk, with variations observed among different populations. Recent studies have shed light on the interplay between the lactase (LCT) gene, milk consumption, and gut microbiota. Genome-wide association studies (GWAS) have linked the LCT locus to Bifidobacterium species, which absorb milk oligosaccharides/lactose and may act as probiotics to reduce inflammation.
Study Details
The research aimed to investigate whether increased milk intake could decrease the risk of T2D in LNP individuals, potentially by influencing gut microbiota composition and circulating metabolites that impact metabolic health.
The team conducted a GWAS on daily milk intake using 12,653 participants from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL). Single nucleotide polymorphisms (SNPs) associated with milk intake were identified. The study also involved genotyping DNA from blood samples, analyzing serum metabolomics, and performing metagenomics sequencing on fecal DNA.
Results
The study revealed that higher milk intake was associated with a decreased risk of T2D in LNP individuals (relative risk, 0.7), while no such correlation was observed in lactase-persistent individuals (RR, 1.2). The findings remained consistent across demographic, socioeconomic, and behavioral factors. A meta-analysis of non-white groups also supported these results.
Analysis of microbiomes identified specific factors related to milk consumption in both LNP and lactase-persistent individuals. Certain Bifidobacterium species showed positive associations with milk consumption in LNP individuals, while other bacterial species were related to lower milk consumption.
Conclusion
In summary, this study suggests a protective association between increased milk consumption and reduced T2D risk in Hispanic/Latino individuals, particularly in those who are lactose non-persistent. The influence of the LCT genotype on this interaction was evident, emphasizing the need for further research to confirm these findings. Understanding the impact of milk consumption on metabolic health involves exploring host genetics, gut microorganisms, and circulating metabolites, and additional experimental trials may provide further insights.
