Breastfeeding Impacts Microbes in Late Infancy

Guest BloggerMicrobiome Environment


Breast is best when feeding infants.

Experts agree that with its curated blend of amino acids, carbohydrates, fats, minerals, vitamins, and a trove of other nutritional factors, human milk far surpasses formula in many aspects. For starters, it’s free. And easy and available. Breast fed babies achieve better weights and are less prone to allergies and asthma.

The list of benefits is long

Minutes after delivery, a new mother is creating nutrients for the newborn. The first milk– called colostrum— contains antibodies, growth factors and a rich stew of bioactive components. A study on piglets confirmed the concentration of probiotics in colostrum. The microbiota teems with lactic acid bacteria.

The “real milk” comes in soon after. Infants who breastfeed host different bacteria in their guts than formula-fed infants do. The first display a predominance of bifidobacteria and lactobacilli; in the latter coliforms, enterococci, and bacteroides prevail.

Most new mothers would breastfeed if they could. But a majority of women today work away from their babies—unlike when they strapped them to their backs and worked in the fields. Breast pumping can be tedious and interruptive. So the question becomes: how long should a mother breastfeed?

Respected organizations advise anywhere from 6 months to 2 years or longer–quite a range.

Unfortunately even some progressive societies frown upon toddlers sucking their mothers’ breasts. Are these “older infants” gaining anything besides an emotional connection?

A new study addressed whether breastfeeding duration influenced infants’ gut microbiota profiles at one year of age. Bacterial gene sequencing was prepared from the stool samples of 52 healthy 1-year-old Australian children.

Breastfeeding: a key modulator of gut microbiota characteristics in late infancy appeared in Journal of Developmental Origins of Health and Disease in November of 2018.

  • Breastfed children had stool microbiota profiles significantly different from that of children weaned earlier independent of the age of solid food introduction.
  • Breastfed children had more Veillonella spp. abundance.
  • Breastfed children who ate solid food had different microbiota profiles than those of children who received three sources: breastmilk, formula milk and solid food.
  • Children no longer breastfed displayed a more mature microbiota, with increases in Firmicutes.

The authors concluded: “This study provided evidence that breastfeeding continues to influence gut microbial community even at late infancy when these children are also consuming table foods. “

The original question of “how long should a mother breastfeed?” remains unanswered. Experts disagree as noted in the information below from the Centers for Disease Control and Prevention (CDC):

“The American Academy of Pediatrics recommends that infants be exclusively breastfed for about the first 6 months with continued breastfeeding along with introducing appropriate complementary foods for 1 year or longer.

WHO also recommends exclusive breastfeeding up to 6 months of age with continued breastfeeding along with appropriate complementary foods up to 2 years of age or longer.

Mothers should be encouraged to breastfeed their children for at least 1 year. The longer an infant is breastfed, the greater the protection from certain illnesses and long-term diseases. The more months or years a woman breastfeeds (combined breastfeeding of all her children), the greater the benefits to her health as well.”