The microbiome adjusts and shifts throughout life due to diet, medications (antibiotics), exercise, environment, disease states, and more.
Birth and Infancy
The method of delivery of an infant (vaginal verses caesarean delivery) has a significant influence on the make-up of the microbiota.1 Bifidobacteria is one of the predominate bacteria in infants who were born via vaginal delivery. A baby’s microbiota is similar to the microbiota of the vagina of the mother. Alternatively, those infants delivered by caesarean are likely to have microbiota that is similar to that of the mother’s skin, which consists of high levels of Escherichia coli, Clostridium difficile, Bacteroides fragilis, and lactobacilli.
Infants who are fed manufactured formula milk have a different microbiota composition than do those who are fed breast milk. However, by providing prebiotics like galacto-oligosaccharides (GOS), inulin, and fructo-oligosaccharides (FOS) to formula-fed children, the microbiota can shift to increase Bifidobacteria populations.2 Infant formulas with GOS and FOS have been available for years, but formula companies have recently been able to add Human Milk Oligosaccharides (HMOs) into many commercially-available infant formulas. The benefits of breastfeeding are vast, including bonding of mother and baby, providing essential nutrients for growing babies, and providing important HMOs, but many infants are fed formula in addition to or instead of breastmilk. For those children, the gut microbiome can now be optimized with new formula options.
Figure 1: (Ottman et al, 2012)
As humans age, the microbiome changes. Changes in the microbiome associated with age may cause an imbalance of Firmicutes to Bacteroidetes, causing dysbiosis.2 A recent study showed that as adults age, there is a reduction in total bacteria, which lowers the level of butyrate-producing bacteria (Firmicutes). These changes in the microbiome may account for the rising incidence of Clostridium difficile in nursing facilities.3
The microbiome shifts throughout the lifespan and plays a significant role in health. Supporting the microbiome with a diet that includes prebiotics and probiotics may have a significant impact through every stage of life.