By Dr. Mercola
In recent years, science has come to realize your gut microbiome is a significant factor driving genetic expression and supporting your immune system. Your body has nearly 1,000 different species of bacteria living in it and on it, as well as millions of viruses. Each of these organisms perform a multitude of functions, and need to be properly balanced and cared for in order to maintain good health.1
Research has linked the variety and makeup of your gut microbiome to specific health benefits and health conditions, including the elimination of chemical toxins, mental health,2 obesity,3 Types 1 and 2 diabetes,4 and brain diseases. The microbes in your gut may influence your immune response to a number of environmental pathogens as well as pharmaceutical drugs, including vaccinations.
One of the easiest ways to support or decimate your microbiome is through your diet. Research supports eating fermented foods5 and fiber6 to promote a healthy gut microbiome. Now, recent research has found an association between feeding infants formula and a change in gut microbiome that may lead to obesity.7
Food Has an Impact on Gut Bacteria
As you may have suspected, and research has confirmed, the food children eat impacts their gut microbiome and consequently their immune system and risk for obesity. A recent study published in the Journal of Pediatrics8 looked at how bacteria in an infant's digestive system affects the burning and storage of fat, and how the infant body uses energy.
Researchers gathered data from the Canadian Health Infant Longitudinal Development (CHILD) study, focusing on the first year for more than 1,000 infants at four different sites.9 Mothers reported the amount of breastfeeding, when formula was introduced and when solid food was introduced to the infant.
Confounding factors such as gender, birth weight, antibiotics, maternal smoking and more, were included. Stool samples collected from the infants at 3 to 4 months and again at 12 months were tested for a variety of gut bacteria.
By age 3 months, nearly half the women were exclusively breastfeeding their infants, 16 percent fed only formula and approximately 33 percent fed a combination of breastmilk and formula.10 Data from stool samples revealed the highest level of beneficial bacteria at 3 months and at 1 year was found in infants who were exclusively breastfed. Infants who were exclusively formula-fed had the least variety of bacteria and a proliferation of microbes more commonly found in older children and adults.
What's more, infants who were exclusively formula-fed had nearly double the risk of becoming overweight as compared to those who were exclusively breastfed. Those who were fed both breastmilk and formula had a lower risk than those exclusively formula-fed, but they still had a 60 percent greater risk of becoming overweight than exclusively breastfed babies.
Lead author Meghan Azad, Ph.D., assistant professor at the University of Manitoba, commented that breast milk contains complex sugars needed to feed specific types of bacteria, which in turn affects how a child's body burns and stores fat.11
Interestingly, most of the mothers in the group delivered vaginally, which is known to seed a baby's digestive system with beneficial bacteria, and 96 percent of the mothers were breastfeeding immediately after birth. This number dropped to 54 percent by three months.12 In breastfed infants, the beneficial bacteria Bifidobacterium were introduced into the infant's gut helping to digest oligosaccharides present in the breastmilk.
Once solid foods were introduced, microbiomes more closely resembling adult varieties began to grow. The study found when a more adult variety of gut microbiota was present at an earlier age, it was associated with an increased risk of obesity.13 While the American Academy of Pediatrics recognizes it is not always possible to provide breast milk exclusively in the first six months of life, they recommend it as the healthiest nutritional option for babies.14
