There is no doubt that the first years of a child are very important for the development of a healthy system, including the gut microbiota! Researchers have been trying to understand the implications of what happens during those years with healthy microbiota later in life. And yes, those first years of life seem especially important to lay the foundations of a future health system. So, let’s have an insight into this fascinating topic!
During the first years of your life, the growth is faster than in any other moment, building up your system for the future, and the gut microbiota will be established during those years, starting mainly at the moment of birth. As the researcher Joseph Petrosino says: "We know that the first few years of life are important for microbiota establishment. You are born with very few microbes, and microbial communities assemble on and in your body through those first years of your life" .
It seems that the alteration of the gut microbiota can be associated with cases like asthma, allergies, IBS, obesity, and inflammatory or autoimmune diseases. And because of this, researchers try to understand if gut health in children could prevent the later development of these conditions .
So, what are actually some of the factors it depends on? They have observed that vaginal birth is associated with increased certain types of good bacteria, that breast milk already has probiotics, and that antibiotics negatively impact the gut microbiota. And that later on, the early dietary habits would continue to contribute to establishing a healthy bacterial community.
That means that if you start eating mainly junk food at the age of 4, it doesn't matter how healthy your mother was while she was pregnant or if you were breastfed, it would not make you very healthy anyways. So, it is also important to include in a child's diet enough foods that nourish the gut microbiota and give it subtracts to ferment, like fibre and probiotic foods.
As Professor Eline van del Beek from the University of Groningen says:
"It's not that the early development stage can make you healthier or sick, but that the systems that have been established in early life are the ones you will have in later life, a toolbox for dealing with the challenges that come from the environment" .
And remember that, in the end, health is a constant process over the years, so even if you didn't have the best health conditions when you were a child, you could still improve it now!
 Christopher J. Stewart, Nadim J. Ajami, Jacqueline L O’Brien, “Temporal development of the gut microbiome in early childhood”, Nature magazine, 2018. Doi: 10.1038/s41586-018-0617-x
 Masaru Tanaka, Jiro Nakayama,“Development of the gut microbiota in infancy and its impact on health in later life”, Kyushu University, Japan , Aug 2017, doi S1323-8930(17)30111-9
 Van der Beek, E,. "Nutritional Programming and Later Life: The role of macronutrient quality during the first 1,000 days.", Sight & Life E-magazine, 2018, 32(1), 46-52.