Impact of short-chain galactooligosaccharides on the gut microbiome of lactose-intolerant individuals

Proc Natl Acad Sci U S A. 2017 Jan 17;114(3):E367-E375. doi: 10.1073/pnas.1606722113. Epub 2017 Jan 3.


Directed modulation of the colonic bacteria to metabolize lactose effectively is a potentially useful approach to improve lactose digestion and tolerance. A randomized, double-blind, multisite placebo-controlled trial conducted in human subjects demonstrated that administration of a highly purified (>95%) short-chain galactooligosaccharide (GOS), designated "RP-G28," significantly improved clinical outcomes for lactose digestion and tolerance. In these individuals, stool samples were collected pretreatment (day 0), after GOS treatment (day 36), and 30 d after GOS feeding stopped and consumption of dairy products was encouraged (day 66). In this study, changes in the fecal microbiome were investigated using 16S rRNA amplicon pyrosequencing and high-throughput quantitative PCR. At day 36, bifidobacterial populations were increased in 27 of 30 of GOS subjects (90%), demonstrating a bifidogenic response in vivo. Relative abundance of lactose-fermenting Bifidobacterium, Faecalibacterium, and Lactobacillus were significantly increased in response to GOS. When dairy was introduced into the diet, lactose-fermenting Roseburia species increased from day 36 to day 66. The results indicated a definitive change in the fecal microbiome of lactose-intolerant individuals, increasing the abundance of lactose-metabolizing bacteria that were responsive to dietary adaptation to GOS. This change correlated with clinical outcomes of improved lactose tolerance.

Keywords: GOS; lactose intolerance; microbiome; prebiotic.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Bifidobacterium / drug effects
  • Colon / metabolism
  • Double-Blind Method
  • Faecalibacterium / drug effects
  • Feces / microbiology
  • Female
  • Gastrointestinal Microbiome / drug effects*
  • Humans
  • Lactobacillus / drug effects
  • Lactose / metabolism*
  • Male
  • Oligosaccharides / administration & dosage*
  • RNA, Ribosomal, 16S / metabolism


  • Oligosaccharides
  • RNA, Ribosomal, 16S
  • RP-G28
  • Lactose