Composition and metabolism of the intestinal microbiota in consumers and non-consumers of yogurt

Br J Nutr. 2007 Jan;97(1):126-33. doi: 10.1017/S0007114507243065.


The objective of the present study was to evaluate the impact of a regular consumption of yogurt on the composition and metabolism of the human intestinal microbiota. Adult subjects were selected on the basis of daily food records and divided into two groups: yogurt consumers (at least 200 g yogurt consumed per d, n 30); non-consumers (no yogurt, n 21). Their faecal microbiota was analysed using molecular methods (in situ hybridisation and PCR amplification combined with separation by denaturing gel electrophoresis) and its metabolic characteristics were assessed by measuring glycosidase, P-glucuronidase and reductase activities and profiling SCFA, neutral sterols and bile acids. The yogurt starter Lactobacillus delbrueckii ssp. bulgaricus (identity confirmed by 16S rRNA sequencing) was detected in 73% of faecal samples from fermented milk consumers v. 28% from non-consumers (P=0.003). In yogurt consumers, the level of Enterobacteriaceae was significantly lower (P=0.006) and 13-galactosidase activity was significantly increased (P=0.048). In addition, within this group, 3-galactosidase activity and the Bifidobacterium population were both positively correlated with the amount of fermented milk ingested (r 0.66, P<0.0001 and r 0.43, P=0.018, respectively). Apart from these effects, which can be considered beneficial to the host, no other major differences could be detected regarding the composition and metabolic activity of intestinal microbiota.

MeSH terms

  • Adult
  • Bifidobacterium / isolation & purification
  • Bile Acids and Salts / analysis
  • Case-Control Studies
  • Colony Count, Microbial
  • DNA, Bacterial / analysis
  • Diet Surveys
  • Electrophoresis, Polyacrylamide Gel
  • Fatty Acids, Volatile / analysis
  • Feces / microbiology
  • Female
  • Food Microbiology*
  • Humans
  • In Situ Hybridization, Fluorescence
  • Intestines / enzymology
  • Intestines / microbiology*
  • Lacticaseibacillus casei / isolation & purification
  • Lactobacillus / isolation & purification
  • Male
  • Middle Aged
  • Polymerase Chain Reaction
  • Probiotics*
  • Yogurt*
  • beta-Galactosidase / analysis


  • Bile Acids and Salts
  • DNA, Bacterial
  • Fatty Acids, Volatile
  • beta-Galactosidase