The first 1000 days: Setting the foundation of lifelong health
Summary:
The first 1000 days are defined from conception to 2-3 years of age
That’s an important window of time where we lay the foundations of our immune system, metabolism and cognition - for life
The gut microbiome is the collection of microbes in our gut. During the first years of life, it plays a critical role in lifelong health
Decades of research have linked imbalances in the gut microbiome to many common symptoms in childhood, like colic, constipation, reflux and eczema
Gut microbiome imbalances have also been associated with a higher likelihood of asthma, allergy and obesity later in life
Why do gut imbalances occur? Some events can disrupt the gut microbiome, such as C-section birth, antibiotics and formula feeding. But they can also occur independently of these events
How common are gut imbalances? A recent study in the United States showed that 90% of babies in the US lack gut microbes associated to immune health
Can we do anything about it? The good news is that the microbiome is dynamic and can be influenced by many factors in our lifestyle, such as diet, feeding, probiotic and prebiotic supplements, and environmental exposures.
What does that mean for me as a parent? You have the opportunity to learn simple actions that can potentially positively impact your child’s health for life, based on the latest science, as well as to discover your child’s gut microbiome from a stool sample.
The first 1000 days
The first 1000 days refers to the critical period from pregnancy (conception) to a child’s second or third birthday [1], marking a time of significant growth and the development of metabolic, endocrine, neural, and immune systems.
This period is regarded as a window of opportunity for health because it is when the gut microbiome, the community of microbes living in the digestive tract, is established and matures. The gut microbiome plays a crucial role in supporting the development of these systems. During these early years, the microbiome is highly adaptable and can be influenced by various factors such as diet, probiotics, prebiotics, and other interventions. These modifications can promote healthy growth and development, laying the foundation for lifelong health [1],[2].
A well-established gut microbiome during the first 1000 days supports essential developmental processes, including [1]:
Immune system. A large part of our immune system is located in our gut and, in the first year of life, some bacterial species help train and regulate the immune system with long-lasting effects [3],[4]. That’s why the gut microbiome early in life can influence the risk of allergies, asthma, and other inflammatory diseases;
Brain and cognition. The gut and brain are connected through the gut-brain axis, a communication network that links the brain with the gut [5]. In babies and children, gut microbiome composition influences brain development and cognitive functions [6]. Certain gut bacteria produce neurotransmitters like serotonin, which affect mood and cognitive abilities [5]. Conditions like ASD and ADHD have also been associated with different gut microbiome profiles [5],[7];
Metabolism. The gut microbiome plays a crucial role in how we digest food and extract nutrients. It helps break down complex carbohydrates and fibers, producing short-chain fatty acids (SCFAs) that serve as energy sources and have anti-inflammatory properties [8],[9]. Disruptions can lead to metabolic imbalances, potentially increasing the risk of obesity and other metabolic diseases like diabetes [10],[11];
Endocrine system. The gut microbiome interacts with the endocrine system, influencing hormone production and regulation [12]. This interaction is crucial for growth, stress response, and energy balance [7];
And much more. The gut microbiome affects many other systems in the body, including heart health, skin health, and bone development. It helps synthesize vitamin K, protects against pathogens, and maintains the gut barrier integrity, preventing harmful substances from entering the bloodstream [13],[14],[15].
Given its crucial role, alterations to the gut microbiota in early life are associated with enduring health effects, potentially setting the stage for various long-term conditions [16],[17].
Want to learn more about Alba and Children's Gut Health? Join our free Instagram Lives with experts in child health.
Gut microbes: the programmers for good health
The gut microbiome, a pivotal ecosystem within us, harbors a vast array of microbes and in particular bacteria:
Symbionts. Beneficial microbes that support our health by aiding in digestion, producing essential nutrients, and protecting against harmful pathogens [18].
Pathobionts. Harmful bacteria that can cause diseases or are associated with diseases, especially when their balance is disrupted or they overgrow [19].
Commensals. Microbes that usually live harmlessly within us but can become problematic if their delicate balance is disturbed [20].
Each bacterial strain or species plays a unique role in our health, contributing in various ways [21],[22]:
Aiding digestion: Helps break down food and absorb nutrients [16].
Producing essential compounds: Synthesizes vitamins and short-chain fatty acids (SCFAs) that are crucial for our health [8],[13].
Training the immune system: Educates the immune system to distinguish between harmful and harmless substances, reducing the risk of allergies and autoimmune diseases [4].
Fighting disease: Competes with and inhibits the growth of pathogenic bacteria, protecting against infections [19].
Boosting resilience: Enhances the body's overall resilience to environmental stressors and promotes well-being [5].
Maintaining barrier function: Strengthens the gut barrier, preventing harmful substances from entering the bloodstream. Promotes the production of mucus and tight junction proteins that seal the gut lining [23].
Producing neurotransmitters: Produces neurotransmitters and neuromodulator metabolites such as serotonin, GABA, catecholamines and dopamine, which play key roles in regulating mood, anxiety, and cognition [5].
In general, once a baby starts to consume solid foods, the richer the diversity of these beneficial bacteria, the better equipped we are to maintain overall well-being and prevent disease.
You could say that these little microbes program us to good health. However, not just any microbes will do – it is all about acquiring the right combination at the right time. The gut microbiome goes from zero to adult-like composition in the first few years of life and the order at which microbes colonize the gut matters. For example, bacteria that interact with the immune system are very important in the first 6 months of life, while diversity becomes very important after the introduction of solid foods [24].
The very early microbes that inhabit our bodies first change the environment in the infant’s gut, so that the next microbes can move in. They set up the infrastructure for the other settlers to build upon. And this process starts right at birth. This is where the first 1000 days come into play. The first two to three years of your baby’s life are crucial for developing a healthy gut microbiome and this period is filled with several events that significantly shape its development.
The association between the gut microbiome and health conditions
In an ideal state, our gut bacteria live in harmony, supporting our health. However, it's not uncommon for certain species to dominate, leading to imbalances that may contribute to discomfort or illness.
Nearly 55% of babies experience symptoms related to the gut within their first 6 months of life, which are often stressful events for a family with a newborn or young child [25],[26]. For example, they could be constipation, colic, reflux or diarrhea. Often, these symptoms lead to the baby crying and not sleeping properly, with consequences on the entire family’s well-being. If you have experienced any of these conditions, we hear you – it can be incredibly challenging and feel overwhelming. Remember, you are not alone in this journey. Many families go through similar struggles, and seeking support and gaining knowledge can make a significant difference.
Emerging research has linked these common childhood symptoms to gut microbiome imbalances, including:
Colic [27],[28].
Constipation [29].
Regurgitation and reflux [30].
Diarrhea [31].
Sleep disturbances [32].
For example, multiple studies showed that babies with colic have a different gut microbiome composition compared with non-colicky babies. Alba Health’s co-founder Prof. Willem de Vos, a researcher with over 800 publications in this field, showed that babies with colic show lower gut microbiome diversity and stability than non-colicky babies in the first weeks of life.
The gut microbiome's impact extends beyond immediate health, and it has been associated with several chronic diseases later in life [16], such as:
Asthma [33].
Atopic dermatitis / Eczema [34].
Allergies [34],[35].
Diabetes [11],[36],[37].
Obesity [10].
These conditions are often chronic, which means they can persist for life, potentially limiting a person’s quality of life. If you have experienced any of these conditions, we know how stressful they can be - in particular, food allergies and eczema can make babies and young children cry and limit their ability to sleep consistently. Chronic conditions are becoming more and more common in Westernized countries, with over 40% of school-aged children having at least one chronic condition [38] in the US.
How common are gut imbalances?
In 2022, Stanford Medicine showed that an important bacteria for immune health, Bifidobacterium infantis, is missing in more than 90% of infants born in the U.S [39]. Researchers are concerned this loss of bacteria could mean rising cases of conditions common in the industrialized world, such as chronic inflammation.
Stanford Medicine researchers and colleagues found that as nations industrialize, this critical bacterium in early life fades away. It is possible that over the last few generations, high antibiotic use and changes to feeding and birthing practices have changed the baby's gut microbiome.
Why do gut microbiome imbalances occur?
So, what more specifically influences the baby’s gut microbiome? Well, many factors have been associated with gut microbiome alterations in babies:
Maternal elements: The mother's diet, vaginal microbiota, antibiotic use during pregnancy, and smoking behaviors significantly impact the infant's microbiome, setting the stage for their health [16],[40],[41].
Birth mode: Vaginal births facilitate the transfer of maternal microbes, while C-sections introduce a different set of initial microbes [42].
Antibiotics: Antibiotics can disrupt the gut microbiome by eliminating beneficial bacteria along with harmful ones, potentially leading to imbalances in microbial diversity [40],[43].
Type of feeding: Breastfeeding provides beneficial bacteria and prebiotics (human milk oligosaccharides) that promote a healthy microbiome, while formula feeding may lead to a different microbial composition [40],[44].
Introduction of solid foods: The introduction of solid foods and the variety of foods consumed by the infant significantly influence the composition and diversity of the gut microbiome [40],[45].
Environmental exposures: Interaction with pets, siblings, and exposure to natural environments can diversify the infant’s microbiome [45],[46].
Other medications: Medications other than antibiotics, such as acid-suppressing drugs or certain pain relievers, can also impact the gut microbiome [47].
Genetic predisposition: The infant’s genetic makeup can influence the composition of their gut microbiome, affecting how their body interacts with and supports different microbial species [45],[48].
Proactive steps promoting a healthy gut
With this being said – the 1,000 days hold great possibilities! In this window of time, actions to boost the gut microbiome might have positive effects for life.
As a parent, being aware of the significance of your baby’s gut microbiome and its impact on health allows you to take proactive steps in promoting a healthy gut for your child. While some early life events are beyond our control, understanding the factors that shape the gut microbiome enables us to make informed decisions to support our baby's well-being from birth to toddlerhood and beyond.
That’s why we started Alba Health - to help you discover your child’s gut microbiome and learn simple steps you can take to improve your family’s health when it matters most. Our approach is based both on gut microbiome analysis and on the assessment of your family’s lifestyle through a lifestyle questionnaire.
Glossary:
Microbe: a collective term for microorganisms such as bacteria, fungi and viruses
Microbiota: the microbes present in a particular location, like the gut
Microbiome: originally the collective microbial genomes that control the microbes' function, but nowadays also used to describe the microbiota and its activity in a specific environment [49].
Metagenome: the collective genetic material (DNA) obtained from a sample
Metagenomic sequencing: is a technique used to analyze the genetic material from an entire community of microorganisms in a sample. This is the technique Alba Health uses to analyze the gut microbiome from a stool sample.
[1] R. C. Robertson, A. R. Manges, B. B. Finlay, and A. J. Prendergast, “The Human Microbiome and Child Growth – First 1000 Days and Beyond,” Trends Microbiol., vol. 27, no. 2, pp. 131–147, 2019, doi: 10.1016/j.tim.2018.09.008.
[2] A. Likhar and M. S. Patil, “Importance of Maternal Nutrition in the First 1,000 Days of Life and Its Effects on Child Development: A Narrative Review,” Cureus, vol. 14, no. 10, pp. 8–13, 2022, doi: 10.7759/cureus.30083.
[3] S. P. Wiertsema, J. van Bergenhenegouwen, J. Garssen, and L. M. J. Knippels, “The interplay between the gut microbiome and the immune system in the context of infectious diseases throughout life and the role of nutrition in optimizing treatment strategies,” Nutrients, vol. 13, no. 3, pp. 1–14, 2021, doi: 10.3390/nu13030886.
[4] B. M. Henrick et al., “Bifidobacteria-mediated immune system imprinting early in life,” Cell, vol. 184, no. 15, pp. 3884-3898.e11, 2021, doi: 10.1016/j.cell.2021.05.030.
[5] J. F. Cryan et al., “The microbiota-gut-brain axis,” Physiol. Rev., vol. 99, no. 4, pp. 1877–2013, 2019, doi: 10.1152/physrev.00018.2018.
[6] E. Sherwin, K. V. Sandhu, T. G. Dinan, and J. F. Cryan, “May the Force Be With You: The Light and Dark Sides of the Microbiota–Gut–Brain Axis in Neuropsychiatry,” CNS Drugs, vol. 30, no. 11, pp. 1019–1041, 2016, doi: 10.1007/s40263-016-0370-3.
[7] J. F. Cryan and T. G. Dinan, “Mind-altering microorganisms: The impact of the gut microbiota on brain and behaviour,” Nat. Rev. Neurosci., vol. 13, no. 10, pp. 701–712, 2012, doi: 10.1038/nrn3346.
[8] J. Tan, C. McKenzie, M. Potamitis, A. N. Thorburn, C. R. Mackay, and L. Macia, The Role of Short-Chain Fatty Acids in Health and Disease, 1st ed., vol. 121. Elsevier Inc., 2014. doi: 10.1016/B978-0-12-800100-4.00003-9.
[9] K. Korpela, “Diet, Microbiota, and Metabolic Health: Trade-Off Between Saccharolytic and Proteolytic Fermentation,” Annu. Rev. Food Sci. Technol., vol. 9, no. December 2017, pp. 65–84, 2018, doi: 10.1146/annurev-food-030117-012830.
[10] M. Kalliomäki, M. C. Collado, S. Salminen, and E. Isolauri, “Early differences in fecal microbiota composition in children may predict overweight,” Am. J. Clin. Nutr., vol. 87, no. 3, pp. 534–538, 2008, doi: 10.1093/ajcn/87.3.534.
[11] M. Bélteky, P. L. Milletich, A. P. Ahrens, E. W. Triplett, and J. Ludvigsson, “Infant gut microbiome composition correlated with type 1 diabetes acquisition in the general population: the ABIS study,” Diabetologia, vol. 66, no. 6, pp. 1116–1128, 2023, doi: 10.1007/s00125-023-05895-7.
[12] G. Clarke, R. M. Stilling, P. J. Kennedy, C. Stanton, J. F. Cryan, and T. G. Dinan, “Minireview: Gut microbiota: The neglected endocrine organ,” Mol. Endocrinol., vol. 28, no. 8, pp. 1221–1238, 2014, doi: 10.1210/me.2014-1108.
[13] J. G. LeBlanc, C. Milani, G. S. de Giori, F. Sesma, D. van Sinderen, and M. Ventura, “Bacteria as vitamin suppliers to their host: A gut microbiota perspective,” Curr. Opin. Biotechnol., vol. 24, no. 2, pp. 160–168, 2013, doi: 10.1016/j.copbio.2012.08.005.
[14] W. M. De Vos, H. Tilg, M. Van Hul, and P. D. Cani, “Gut microbiome and health: Mechanistic insights,” Gut, pp. 1020–1032, 2022, doi: 10.1136/gutjnl-2021-326789.
[15] R. E. Moore and S. D. Townsend, “Temporal development of the infant gut microbiome,” Open Biol., vol. 9, no. 9, 2019, doi: 10.1098/rsob190128.
[16] A. Sarkar, J. Y. Yoo, S. V. O. Dutra, K. H. Morgan, and M. Groer, “The association between early-life gut microbiota and long-term health and diseases,” J. Clin. Med., vol. 10, no. 3, pp. 1–24, 2021, doi: 10.3390/jcm10030459.
[17] M. C. Arrieta, L. T. Stiemsma, N. Amenyogbe, E. Brown, and B. Finlay, “The intestinal microbiome in early life: Health and disease,” Front. Immunol., vol. 5, no. AUG, pp. 1–18, 2014, doi: 10.3389/fimmu.2014.00427.
[18] T. S. Postler and S. Ghosh, “Understanding the Holobiont: How microbial metabolites affect human health and shape the immune system,” Cell Metab., vol. 26, no. 1, pp. 110–130, 2017, doi: 10.1016/j.cmet.2017.05.008.
[19] N. Rolhion and B. Chassaing, “When pathogenic bacteria meet the intestinal microbiota,” Philos. Trans. R. Soc. B Biol. Sci., vol. 371, no. 1707, 2016, doi: 10.1098/rstb.2015.0504.
[20] A. J. Macpherson and N. L. Harris, “Interactions between commensal intestinal bacteria and the immune system,” Nat. Rev. Immunol., vol. 4, no. 6, pp. 478–485, 2004, doi: 10.1038/nri1373.
[21] N. Ottman, H. Smidt, W. M. de Vos, and C. Belzer, “The function of our microbiota: who is out there and what do they do?,” Front. Cell. Infect. Microbiol., vol. 2, no. August, p. 104, 2012, doi: 10.3389/fcimb.2012.00104.
[22] K. Hou et al., “Microbiota in health
Do you want to discover your child's gut health? Alba's pioneering test helps you discover you child's gut health and guides you on how to improve it, with the help of a certified Nutrition & Health Coach.
Get Alba
Join us in advancing gut health understanding for the generations to come.
Opt-in to help us discover new insights and build new solutions for child health.