Mothers can protect babies from gum disease before birth

New research shows maternal antibodies may shape a baby’s oral immune system before and after birth, offering long-term protection against gum disease.

You may have brushed your baby’s teeth even before it was born.

Well, not exactly, but according to new research carried out at the Hebrew University of Jerusalem (HUJI), mothers can protect their child’s teeth and gums even before birth by providing a hidden immune legacy that protects their dental condition long after they have finished weaning them.

The new study, reveals how maternal antibodies act as early life architects, programming the mouth to resist aggressive bacteria and prevent bone loss associated with adult gum disease.

By setting a healthy immune tone while the fetus is in the womb, these maternal defenses ensure that the foundation for a lifetime of oral health is laid from the very beginning.

Link between maternal care, oral health

The team identified a significant link between maternal care and lifelong oral health. The researchers discovered that maternal antibodies do not just offer a temporary shield for newborns but actually program the offspring’s immune system to fight oral diseases well into adult life.

The research focused on the transition period after birth when the oral cavity is first exposed to a surge of microbes. To cope with this unprotected stage, mothers provide their offspring with essential immune tools through two distinct pathways: in utero transfer and breastfeeding. While both are important, they play very different roles in the body’s long-term defense strategy.

The study showed that maternal antibodies acquired both in the womb and through breastfeeding play a pivotal role in shaping adaptive immunity in the salivary glands and the moist, protective lining of the mouth.

The lack of in utero-derived immunoglobulin G (IgG) elevates immune activation in the salivary glands and gingiva, and alters the load and composition of the oral microbiota, leading to oral dysbiosis (an imbalance in the mouth’s microbial community, where beneficial bacteria decrease and harmful, pathogenic bacteria grow in number).

“Here, we show that maternal IgG, transferred both in the uterus and via breastfeeding, reaches the neonatal salivary glands that are immature at birth and undergo significant postnatal differentiation, with major development – especially of the parotid glands that are the largest pair of salivary glands, located just in front of and below each ear – occurring during the first three weeks.”

“This coincides with weaning and is secreted into saliva, where it recognizes maternal oral microbes and regulates colonization,” he said.

In humans, children who are not breastfed for at least three months or who get antibiotics that destroy beneficial antibodies are at higher risk of autoimmune diseases, asthma, food allergies, irritable bowel syndrome, obesity, and even attention-deficit hyperactivity disorder. When born, the baby transfers the beneficial antibodies to his or her saliva, where they protect the mouth, and then they move to the infant’s digestive system.

“Three months of breastfeeding is the minimum for this protection of the teeth and gums, but at least six months of nursing is recommended.

They found that IgG antibodies transferred during act as a primary architect for the mouth’s complex barrier system designed to protect against pathogens while maintaining tolerance toward the diverse microbiome that inhabits it. These antibodies reach the neonatal salivary glands and are secreted into the saliva.

Their presence is important for maintaining a healthy balance, as they essentially teach the immune system to remain calm in the presence of friendly bacteria while preparing it for future threats.

Lacking these prenatal antibodies exhibited hyper-activated immune cells and higher bacterial loads in their salivary glands and gums. Caused by poor hygiene, high-sugar diets, or medications, this disruption leads to cavities, gum disease, and chronic inflammation, which is linked to systemic conditions like diabetes, cardiovascular disease, and experimental periodontitis in adulthood.

While prenatal antibodies focus on internal immune “tone,” those delivered through breast milk serve a different purpose. The research showed that antibodies produced for lactation are essential for the proper physical maturation of the protective lining of the mouth.

An early deficit in protective antibodies led to significant changes in adulthood, specifically an increased susceptibility to periodontitis, a condition characterized by destructive inflammation and bone loss around the teeth.

The postnatal antibodies help regulate the timing of “barrier sealing,” ensuring that the mouth’s protective lining becomes a sturdy defense at just the right moment. This process is highly sensitive to the microbial environment. The study noted that when these antibodies were absent or their effects were disrupted by antibiotics, the physical integrity of the oral barrier was compromised.

Infant formula provides complete nutrition but does not contain living immune components, and therefore it does not offer the same direct biological immune protection as breast milk.

The findings offer a new perspective on the origin of oral diseases. The team identified that maternal IgG specifically recognizes and binds to certain oral members of the normal, native microbiome that typically coexist peacefully with the host but can trigger inflammation or disease when the microbial balance is disrupted.

The team said that the research findings open the door for potential preventive strategies, such as maternal immunization. By vaccinating mothers during pregnancy, it may be possible to enhance the specific antibodies passed to the child, effectively pre-programming their immune system to resist chronic oral infections later in life.

This research suggests that the foundations of a healthy adult smile are laid even before the first tooth appears.