Over the past six years, I received various opportunities to explore a small-but-diverse universe, a collection of microorganisms that lives within us, known as the human microbiome. This fast-developing research field of human microbiome led me to venture out from my original field of biology into learning how to code and importantly connecting the dots from data to potential clinical applicability and daily habit. Besides the abundance in human microbiome numbers and remaining mysteries surrounding them, what intrigues me the most is the association of its compositions, particularly those living in the gut, into later health status and even mortality risk.
When my baby was born last spring, I remembered certain findings that the majority of microbiome colonization occurs in early years of life. Then, I started to wonder what I can do to nurture my baby’s microbiome so that she could get the long-term health benefit. While pondering about this idea, I constantly remind myself to not oversimplify it, especially because the composition of our “little friends” is driven by a complex interaction between host genetics and environmental factors, such as diet, lifestyle, and geography. Particularly in babies, mode of delivery (vaginal or cesarean section delivery) has shown to be largely impacting the early microbiome colonization. Environmental exposures, including diet, then later influence their microbiome dynamics.
So far, recent evidence has shed light on how diet could influence our gut microbiome from the beginning of life. However, the causal directions on diet-microbiome interactions and how it impacts health status is still a big question. For example, it has been apparent that children with autism have different microbiome compositions compared to their healthy counterparts. Although popular speculation on microbiome-autism association suggests that gut microbiome is a causal factor for autism, an intriguing recent study revealed that changes in gut microbiota among children with autism are instead driven by restricted diet due to their food preference. This example excellently captures the complexity of microbiome study. Although many questions remain unanswered, several research has elucidated how the gut microbiome matures along with ages and the potential of gut microbiome-directed foods in helping undernourished children bounce back to the healthier trajectory. These studies keep reminding me that my baby’s initial feeding journey plays an essential role in laying the foundation for her lifelong health, for example lowering the risk of developing cardiovascular diseases, obesity, or type 2 diabetes later in life. Thus, formulating a nutrition plan for her early childhood has become an important personal project that I have embarked upon.
Starting from birth, I have decided to breastfeed my baby. Despite being dubbed as the most natural way of giving precious nutrition to a baby, breastfeeding was not an easy process for me. There are various challenges I faced along the way, especially when I had to be away from her. But I always wanted to push the limit because I know it is worth the effort. On top of strong medical recommendations and a bit of social pressure, my decision was also driven by evidence from microbiome study that highlighted the benefit of breastfeeding for the priming of the gut microbiome which is potentially beneficial for long-term metabolic and immune health. Breast milk was revealed to be teeming with bacteria that colonize the baby’s gut and could help to set the course of their growing immune system and metabolism.
When my baby turned 6-month-old, we started to introduce solid food while maintaining breastfeeding, also known as complementary feeding. In this phase, which is also essential in shaping future healthy dietary habits, parents need to understand how to fill the nutrition gap between the nutrition from breastmilk or formula and the child’s growing calorie requirement through other sources of food. Luckily, various guidelines are available to ease this learning process. For me who is an Indonesian living in Finland, I mostly refer to guidelines provided by WHO, Finland, and Indonesia (in Indonesian Language). All the guidelines primarily suggest the introduction of diverse diets that are available locally. This also resonates with a planetary-health diet for adults alike which I started to incorporate as well during our baby’s feeding journey.
In the lens of the microbiome field, the introduction of solid food is associated with higher bacterial load and diversity which is further important in aiding dietary metabolic processes such as in complex carbohydrate digestion and vitamin biosynthesis. The first few years of life is also characterized by gradual specialization of microbiota according to the substrate available in the gut, from Human Milk Oligosaccharides (HMOs)-digester in breastfeeding babies into diverse microorganism responsible for digesting protein, plant-derived complex carbohydrate, and resistant starch. Thus, introducing a diverse diet early in life could reduce the nutritional gaps between early life and adulthood that may occur. This dynamic happens rapidly, and studies reported that the baby’s gut microbiome started to resemble adult-like configuration around the age of 3 years. It is also important to note that diverse diets for allergic children also become critical to fulfill the nutritional requirements that are limited by food selections.
My baby is not yet 1 year old now. But to this end, her feeding journey has been one of the challenging yet exciting processes throughout my motherhood phase. It has stirred our dietary habits as a family and forced me to exercise my time and emotion management. At the same time, this journey allows me to revisit some fantastic research in my field and marvel at the beauty of scientific progress behind it. The journey was still in an early phase, and I will enjoy it in figuring out how to optimize this key period to establish her gut microbiota. Finally, let me close this story by borrowing a message I interpreted from my baby’s favorite book, “The Very Hungry Caterpillar”. Just as the caterpillar’s journey to become a beautiful butterfly, it is essential to nourish ourselves with a diverse and healthy diet to (nourish our gut microbiome and) reach fruitful health outcomes.