Association between functional lactase variants and a high abundance of Bifidobacterium in the gut of healthy Japanese people

PLoS One. 2018 Oct 19;13(10):e0206189. doi: 10.1371/journal.pone.0206189. eCollection 2018.


Previous studies have shown that Japanese people exhibit a higher abundance of Bifidobacterium compared to people from other countries. Among the possible factors affecting the gut microbiota composition, an association of functional lactase gene variants with a higher abundance of Bifidobacterium in the gut has been proposed in some reports. However, no Japanese subjects were included in these studies. In this study, we investigated the possible contribution of functional lactase loci to the high abundance of Bifidobacterium in Japanese populations. Based on a data analysis assessing 1,068 healthy Japanese adults, a number of subjects is at least seven times greater than that reported in available online data. all subjects possessed CC genotype at rs4988235 and the GG at rs182549, which are associated with low lactase activity. We observed a positive correlation between dairy product intake and Bifidobacterium abundance in the gut. Considering previous reports, which revealed that four additional functional lactase loci, rs145946881, rs41380347, rs41525747 and rs869051967 (ss820486563), are also associated with low lactase activity in Japanese people, our findings imply the possible contribution of host genetic variation-associated low lactase activity to the high abundance of Bifidobacterium in the Japanese population.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Asian Continental Ancestry Group / genetics*
  • Bifidobacterium / growth & development*
  • Dairy Products
  • Female
  • Gastrointestinal Microbiome
  • Genotype
  • Healthy Volunteers
  • Humans
  • Japan
  • Male
  • Middle Aged
  • Polymorphism, Single Nucleotide*
  • Young Adult
  • beta-Galactosidase / genetics*


  • beta-Galactosidase

Grant support

Our work was funded by Morinaga Milk Industry Co., LTD., DeNA Life Science, Inc., and the Kanagawa Prefecture’s model project related to the creation of ME-BYO industry in FY2016. Employees of Morinaga Milk Industry Co., LTD., KK, EM, JX and TO, and those of DeNA Life Science, Inc., SI and MT, were received salary from each company. The specific roles of these authors are articulated in the ‘author contributions’ section. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.