Young mother breastfeeding your 2-3 month baby boy lying on blanket at home

The earliest nourishment a newborn receives shapes the foundation of lifelong health, not just for nutrition, but for immunity, metabolism, and disease resistance. The gut microbiome, the diverse community of bacteria that inhabit the digestive tract, begins forming at birth and is influenced by a baby’s first food: breast milk. A healthy gut microbiome along with breastfeeding protects the gut lining, supports the baby’s immune system, and provides long-term benefits to both child and mother.

“Babies receive the most nutrition from milk the first year of life and breastmilk is the optimal milk" said Elaine Hart, MD, FACOG, fellow Academy of Breastfeeding Medicine an obstetrician/gynecologist at Loma Linda University Health

Vaginal birth and skin-to-skin contact can help seed the gut with beneficial bacteria, but perhaps the most significant contributor is breast milk. Breast milk can decrease the types and virulence of dangerous bacteria in the gut.

Unlike formula, which can alter gut permeability and introduce proinflammatory molecules and a more diverse bacterial load, breast milk supports the development of a more favorable gut microbiota.

Breast milk is rich in antibodies, white blood cells, enzymes, and oligosaccharides, complex sugars that serve as prebiotics to feed healthy gut bacteria. Early milk, called colostrum, is particularly potent in these immune-boosting compounds.

“It’s like giving the baby their first vaccine,” said Hart. “There’s a reason nature designed it that way.”

The long-term benefits of breastfeeding extend well beyond infancy. Numerous studies have shown that breastfed infants have lower risks of asthma, allergies, obesity, type 1 and type 2 diabetes, and even certain cancers like leukemia and lymphoma. Cognitive benefits have also been observed, with breastfed babies performing better on intelligence tests later in life.

Breastfeeding is not only a gift to the child. For mothers, it reduces the risk of breast, ovarian, and endometrial cancers, lowers the chance of developing type 2 diabetes, especially in those who experienced gestational diabetes, and supports postpartum weight loss and emotional bonding.

Still, breastfeeding is not initially always easy. “It takes perseverance and determination,” Hart said. “It’s a learning curve for both the mother and the baby. But if moms stick with it, the health benefits are enormous.”

For mothers who are unable to breastfeed, or feed their baby their pumped breast milk, donor milk is considered the next best option. Formula, while sometimes necessary, lacks many of the immune and gut-protective components found in human milk.

Pediatricians and OB-GYNs agree: the more breast milk a baby receives in the first year, the better their chances for a strong, resilient gut, and a healthier future.

To learn more about breastfeeding support and maternal health services at Loma Linda University Health, visit online.