๐ก This 12-week before-and-after intervention trial investigates the effects of daily incremental lactose consumption on microbiota composition, function, and intolerance symptoms in 25 healthy Asian adults with lactase non-persistence (LNP) genotype. The study reveals significant changes in microbiota, particularly an increase in ๐๐ช๐ง๐ช๐ฅ๐ฐ๐ฃ๐ข๐ค๐ต๐ฆ๐ณ๐ช๐ถ๐ฎ levels, and a two-fold rise in fecal ฮฒ-galactosidase activity. The lactose intervention leads to a reduction in expired hydrogen during a lactose challenge hydrogen breath test (HBT), indicating improved lactose tolerance. The findings suggest that repetitive lactose consumption, well-tolerated by participants, induces adaptation of the gut microbiota, potentially alleviating lactose intolerance symptoms.
๐ Key Scientific Findings:
๐ ๐๐ช๐ง๐ช๐ฅ๐ฐ๐ฃ๐ข๐ค๐ต๐ฆ๐ณ๐ช๐ถ๐ฎ Abundance: A significant increase in ๐๐ช๐ง๐ช๐ฅ๐ฐ๐ฃ๐ข๐ค๐ต๐ฆ๐ณ๐ช๐ถ๐ฎ relative abundance (5.5% to 10.4%) is observed after the 12-week lactose intervention. The bifidogenic effect is generic, involving various ๐๐ช๐ง๐ช๐ฅ๐ฐ๐ฃ๐ข๐ค๐ต๐ฆ๐ณ๐ช๐ถ๐ฎ species, with 14 out of 22 species showing a significant increase.
๐ Fecal ฮฒ-galactosidase Activity: Fecal ฮฒ-galactosidase activity doubles after the intervention, indicating enhanced lactose metabolism. ๐๐ช๐ง๐ช๐ฅ๐ฐ๐ฃ๐ข๐ค๐ต๐ฆ๐ณ๐ช๐ถ๐ฎ, which ferment lactose, contribute to this increase in ฮฒ-galactosidase activity.
๐ Hydrogen Breath Test (HBT): A 1.5-fold decrease in expired hydrogen during the second lactose challenge HBT is observed after the intervention, signifying improved lactose tolerance. ๐๐ช๐ง๐ช๐ฅ๐ฐ๐ฃ๐ข๐ค๐ต๐ฆ๐ณ๐ช๐ถ๐ฎ’s gas-free lactose fermentation is suggested as a contributor to the reduced hydrogen levels.
๐ Microbiota Functional Gene Diversity: Analysis of microbiota functional genes indicates increased alpha- and beta-diversity after the intervention.
Several orthologs related to energy, amino acid, cofactor, and vitamin metabolism show significant increases.
๐ Methylenetetrahydrofolate Reductase (MTHFR): The gene encoding methylenetetrahydrofolate reductase, essential for homocysteine and folate metabolism, significantly increases after the intervention.
๐ Total Symptom Scores (TSS): While there is a non-significant decrease in TSS (10.6 before vs. 8.1 after intervention), participants report mild to no gastrointestinal complaints during the intervention.
๐ Tolerance of Daily Lactose Consumption: Participants tolerate daily consumption of incremental lactose doses (2x12g) well, with no significant gastrointestinal discomfort reported.
๐ Implications for Dietary Recommendations: The study suggests that repetitive lactose consumption leads to microbiota adaptation, potentially eliminating the need to exclude nutrient-rich dairy from the diet of LNP individuals. The lactose intervention demonstrates the feasibility of consuming 2x12g of lactose daily, equivalent to 2 glasses of milk, without substantial intolerance symptoms.
๐ Repetitive consumption of incremental lactose doses induces favorable changes in microbiota composition and function in LNP individuals, as evidenced by increased ๐๐ช๐ง๐ช๐ฅ๐ฐ๐ฃ๐ข๐ค๐ต๐ฆ๐ณ๐ช๐ถ๐ฎ levels, enhanced lactose metabolism, and improved tolerance. These findings challenge the notion of complete dairy exclusion and highlight the potential health benefits of lactose fermentation by gut microbiota.
link to the article : http://tinyurl.com/2p8r85dp
