A Gut Feeling About Baby Formula

Microbiome differences in formula-fed babies

Our Beloved FoundFamily:
Baby formula manufacturers have worked for decades to make their products mimic the nutritional profile of breast milk, but new evidence is showing that as similar as the two may appear on the outside, their effects on the inside of a baby’s digestive tract are very different.

Breast milk generated by a mother is biologically formulated to propagate the growth of specific kinds of microbes that will populate her baby’s digestive tract. These microbes are crucial for good health, as they perform countless activities including crowding out disease-causing bacteria, influencing metabolism, and synthesizing many vitamins and amino acids, which are the building blocks of proteins that construct our bodies.

Formula makers spend much time adjusting their ingredient profiles to encourage the same kind of bacteria growth in the infant gut as breast milk. Research is now showing that in spite of all their tweaking and the fact that both formula and breast-fed babies show similar gut bacteria profiles, how those bacteria function in each set of children is very different.

Scientists identified the DNA of all the specific bacteria strains that populated the gut microbiome, the bacteria that live in the digestive tract, of 60 children. They also analyzed over 400 fecal samples collected monthly from birth to 8 months from 30 sets of twins, as well as a separate set of fecal samples over a three year period from the St. Louis Neonatal Gut Microbiome Project. Extensive data was also collected on how parents fed babies and the specific brands of formula used. What they found doesn’t bode well for formula fed babies.

Breast milk is high in protein, but only during the first few days after birth. As protein levels gradually start to decline, the gut microbiomes of breastfed babies compensate for the new lower levels of amino acids by increasing the population of bacteria that are genetically adapted to synthesize or make those amino acids themselves. These included methionine, isoleucine, leucine, valine, cysteine, serine, threonine, and arginine.

Interestingly, the same gut bacteria of formula fed babies created an entirely different set of amino acids. They produced much less methionine and cysteine, amino acids more plentiful in breast milk, and more histidine and tryptophan, which are seen in far lower levels in breast milk. What this means for a child’s health, even into adulthood, is still being explored.

Some formula manufacturers are now adding sugar molecules to their products to mimic human milk sugar in an effort to encourage the growth of a more breastfed-like microbiome. It seems these added sugars do increase the growth of Bifidobacteria, an essential microbe of the digestive tract, when compared to babies consuming formula without them. Unfortunately, how the microbiomes of breastfed babies and added sugar formula babies still differs in how they synthesize and metabolize micronutrients.

There can be no better recipe for a baby’s optimal development than that which is contained in the breast milk of the mother in whose body the child lived and thrived for nine months. Nothing created in a lab will ever come close.

The worst gut health of all babies was found in those fed soy formula. Their gut microbiomes were strikingly different, had very few Bifidobacteria, and were much more genetically inclined to produce short chain fatty acids. This combination is a sure sign of gut imbalance. It’s not surprising that babies with low Bifidobacteria are also known to be more colicky. Interventions are currently underway to encourage Bifidobacteria growth in these children. To learn more about the dangers of soy for adults and children, especially in baby formula, see “The Dark Side of Soy” in MegaZEN 2016 or visit the Soy Alert at the Weston A. Price Foundation and see their shocking investigations into soy baby formula here, here and here.

Infancy is a crucial time for neurological and physiological development. All the necessary nutrients for this vital phase of growth are contained in breast milk. There can be no better recipe for a baby’s optimal development than that which is contained in the breast milk of the mother in whose body the child lived and thrived for nine months. Nothing created in a lab will ever come close. If at all possible, always breastfeed your baby. In the rare event this isn’t feasible, discuss the matter with your doctor, with an emphasis on supporting interventions to encourage a healthy microbiome in your developing child.

Love and Light in the Month Ahead,
Dr. Habib Sadeghi and Dr. Sherry Sami

1. Baumann-dudenhoeffer, A et al. (2018). Infant diet and maternal gestational weight gain predict early metabolic maturation of gut microbiomes. Nature Medicine, 102(11), 245-259, doi:10.1038/s41591-018-0216-2.