How Eating Yogurt Affects Your Gut

Evaluating health claims for foods, such as yogurt, that are enriched with probiotic bacterial strains has never been easy, but a multi-institution team says their analysis of genes and metabolites could do the trick (Sci. Transl. Med., DOI: 10.1126/scitranslmed.3002701). Washington University School of Medicine microbiologist Jeffrey I. Gordon, with coworkers at Duke University and the University of Colorado, Boulder, examined how yogurt consumption affects gut microbiomes, which aid digestion. They examined stool samples from identical twin women and mice colonized with a select pool of human gut microflora to determine patterns of gene expression before, during, and after consumption of a popular yogurt brand. Eating yogurt didn’t alter the makeup of gut bacterial communities but did boost expression of genes linked to various metabolic pathways. In particular, the daily yogurt dose enhanced breakdown of certain polysaccharides, as confirmed through mass spectrometry of metabolites in the mice’s urine. The team suggests that their methods could be applied broadly to study probiotic foods’ effects.