Researchers are exploring synthetic communities to better understand infant gut microbiota interactions. These reduced-diversity communities consist of specific strains tailored to research questions, eliminating the need for fecal sample collection. They allow detailed characterization of composition and functionality, enabling studies on ecological processes like priority effects by adjusting growth conditions or member dispersal. Synthetic communities help test complex microbial dynamics across various setups (in vitro, in vivo, ex vivo, in silico) to investigate interactions and host relationships. They are particularly useful for studying the impact of diet and drugs on microbiota formation and their direct or indirect effects on infant immune and barrier maturation. As research models, synthetic communities offer insights into microbial ecosystems, advancing our knowledge of gut microbiota development and its broader implications.