Intestinal flora and the baby's first 1000 days of life

In our first 1,000 days of life, the brain, body and immune system grow and develop significantly and our growth is faster than during any other time in our lives. Our first nine months we go from two cells to a newborn measuring about 50cm in length and about 3kg in weight. Between birth and the age of three, body size and weight double five times.

The three stages of development of the intestinal flora

With the help of so-called gene sequencing, which analyses all the genes present in an organism (including bacteria, fungi, viruses, etc.), the researchers have been able to establish that the development of the intestinal flora occurs in three distinct phases:

• Development phase (3 to 14 months)
• Transitional phase (15 to 30 months)
• Stable phase (31 to 46 months)

Microbial establishment

The intestinal flora is gradually established and developed in different stages during these 1,000 days. Diversity and composition of the intestinal flora is influenced by several factors.

• Mother's microbiome - Aimed at the mother's bacterial flora of the vagina and intestines.
• Mode of delivery - Babies born by caesarean section get bacteria from the mother's skin instead of the mother's vaginal flora and gut which affects which genera are established.
• Whether the baby is breastfed or not - Breast milk reflects the intestinal flora of the mother, and also contains important substances for the microbial establishment in the baby.
• The early diet - Just like in any other area of life, it is important to have a varied diet.

Bacterial species richness creates the right diversity

The first colonization of the intestine occurs during childbirth when the baby comes into contact with the vaginal flora and the intestinal flora of the mother, which leads to the establishment of microbial diversity of different bacterial genera in which the base is constituted by Lactobacillus and Bifidobacterium.

The intestinal flora of babies born by caesarean section is first colonised by bacteria from the mother's skin, making it less diverse and with fewer protective bifidobacteria than the gut flora of babies born vaginally.

The protective breast milk

Even breastfeeding is of great importance for the development of a diverse intestinal flora. Research shows that the bacterial composition of breast milk reflects the mother's intestinal flora and that the intestinal flora of breastfed babies has a better protection against gastrointestinal infections and allergies.

In addition, breast milk contains a number of important substances that protect the newborn baby from infections and other diseases. Breast milk nourishes the intestinal flora in the form of oligosaccharides, so-called HMOs (Human Milk Oligosaccharides) that favor the establishment of protective bifidobacteria.

The right bacteria are crucial

The right bacteria and microbial species richness in the gut flora are crucial to our health throughout life and lack of these can create problems such as increased establishment of pathogens (disease-causing bacteria), microbial imbalance (dysbiosis), increased risk of functional disorders and increased risk of chronic diseases.