Study Traces Taxonomic, Functional Features of Infant Gut Microbiomes in Response to Solid Foods

Microbial composition changes outpace predicted functional shifts in gut microbial communities from infants who are gradually exposed to new, solid foods over their first year of life, according to work appearing in PLOS One. For the pilot stage of a study dubbed "Nourish to Flourish," a team from New Zealand and the US collected fecal samples from dozens of infants randomized to receive prebiotic or probiotic interventions, using metagenomic sequencing and liquid chromatography-mass spectrometry to track microbial community membership, gene repertoires, and metabolites prior to solid food introduction at around four months, at around nine months, and at around a year of age, when their diets were further expanded. "The Nourish to Flourish longitudinal study provided evidence that the infant gut microbiome responds to the introduction of solid foods with increased microbial taxonomic diversity, while the abundance of functional genes remains relatively stable," the authors report, noting that such results hint that "most of the genes required to make use of new substrates are already present at [four] months of age."