Baby and infant gastrointestinal (GI) microbiome
The GI microbiome represents the greatest area of contact with the environment and consists of bacteria, single-cell microorganisms, yeasts, fungi and viruses, collectively known as the GI microbiota. The microbiome reflects the entire collection of genetic material of the GI microbiota which shifts and changes easily during infancy and dysbiosis in infancy that may affect the long-term health of the GI microbiome.
Maternal breastmilk helps to promote the colonisation and maturation of the infant GIT microbiome. The introduction of solid food shifts the infant microbiome to more closely resemble an adult profile, however, the paediatric microbiome remains in flux for at least the first three years of life.
Microbial colonisation of the infant GIT expands rapidly following birth and bacterial colonisation of the GIT in a newborn infant is important for future microflora and functions. Probiotics in babies and infants help maintain a balanced, healthy composition of GI microbiota by re-establishing friendly GI bacteria and inhibiting the growth of unwanted GI bacteria. Bifidobacterium and Lactobacillus species have been found to significantly increase GI populations of beneficial bacteria, while simultaneously decreasing populations of less health-promoting bacteria.
In order to have a good therapeutic effect, probiotics need to withstand the harsh environment of the stomach’s acidity and the intestine’s bile salts and have good adherence to the intestinal mucosa. Good adherence to the intestinal mucosa is important as it prolongs the time a probiotic strain can reside in the intestine, giving it an opportunity to modulate the immune response and protect against pathogens by limiting their ability to colonise the intestine.
Beneficial effects of probiotics include:
- Maintaining a healthy balance of GI flora
- Improving the composition and diversity of intestinal flora
- Supporting immune health
- Maintaining healthy digestive function
- Maintaining digestive barrier function
- Inhibiting, displacing and competing for adhesion sites with pathogens
- Producing antimicrobial compounds
- Producing beneficial compounds e.g. short chain fatty acids (SCFAs) such as butyrate enzymes and vitamins
- Involvement in carbohydrate and lipid metabolism
Digestive system health
Babies and infants may experience digestive related complaints as their digestive systems mature and strengthen. Maintaining a fully functional digestive system is a delicate balance during the development of the GI flora and this delicate balance can be disrupted by many aspects, including diet, illness and antibiotic use.
An infant's digestive tract undergoes enormous change in the first six months of life as it develops the ability to produce enzymes to digest food. Anything that enters a baby's mouth makes its way to the GIT, which is still learning to fight off bacteria and other pathogens, further influencing digestive health. Altered digestive flora leads to poor digestion and increased GI permeability.
The immune system is actively downregulated during pregnancy which leaves the infant highly susceptible to infection during the first few months of life. After birth, the development of the immune system is closely related to GI maturation. Immunological factors found in breastmilk are key instigators in this maturation process, as well as the gut-associated and systemic immune systems The GI microbiota is one of the key elements in the body’s immune defence system.
Antibiotic use is commonly associated with disturbed GI flora and Probiotics can help maintain beneficial GI flora in babies and infants during antibiotic use and are best taken 2-3 hours away from antibiotics for greater effect1.
How to use probiotic powders with infant formula
Infant formula is given to babies at varying temperatures, from cool or cold, right through to warm. As probiotics are heat sensitive, it is recommended that probiotic powders not be put in a bottle of formula prior to warming. The best way to administer a probiotic powder is to place one dose in cool to warm (not hot) formula immediately before use. Placing the probiotic powder in warmed formula immediately before use should not impact the efficacy of the probiotics See Baby Probiotic 12 Billion.
1. Goldenberg, J., et al., Probiotics for the prevention of paediatric antibiotic-associated diarrhea, Cochrane Collaboration, (2015).