The first 1000 days of a baby's life, from conception to their 2nd birthday, are a critical period for their long-term health. Contact with beneficial bacteria early in life can support the development and maturation of the immune system. By the age of three, a child’s microbiome starts to resemble the microbiome of an adult.
The makeup of the mother’s microbiome changes during pregnancy and is extremely influential. Factors like whether a baby was born vaginally or via C-section, at home or in hospital, can affect the composition of the baby’s microbiome.