Recent evidence suggests that the development of gut microbiota during infancy affects several metabolic, immune, and endocrine pathways in humans. An imbalance in gut microbiota diversity or function, also known as dysbiosis, not only affects early child growth and development, but is also linked with the development of chronic, non-communicable diseases in later life. The Child Health And Microbiome Development Study – Pakistan (CHAMP) study aimed to longitudinally assess gut microbiota development and associated factors (maternal, child, and demographic) during early childhood in populations residing in malnutrition-endemic communities in Pakistan. A prospective cohort of mother-infant pairs (n=70) will be recruited from District Swat, Pakistan, and followed for two years. Complete information about demographic characteristics, anti-natal and post-natal care, dietary intake, feeding practices, and child health will be collected at baseline and 3, 6, 12, 18, and 24 months. Anthropometric measurements (height, weight, mid-upper arm circumference, and head circumference), dry blood spots, and fecal samples were also collected. Ethical approval for the study was obtained from Khyber Medical University, Pakistan. The study is also registered on clincaltrial.gov (Ref no: NCT05793294). The study findings will help researchers understand gut microbiota development, associated factors, and their impact on longitudinal growth in infants during the first two years of life.