May 8, 2026 – Maternal antibodies transferred during pregnancy forge resistance to aggressive bacteria and prevent bone loss associated with adult gum disease, facilitating better lifelong oral health, according to a new study by researchers at the Hebrew University of Jerusalem (HU).

The research, published in Nature Communications, focuses on the transition period after birth when the oral cavity is first exposed to a surge of microbes. 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.

Led by Prof. Avi-Hai Hovav and DMD/Ph.D. student Reem Naamneh from the Institute of Biomedical and Oral Research (IBOR) at HU’s Faculty of Dental Medicine, the research showed that in laboratory models, the offspring lacking these prenatal antibodies exhibited hyperactivated immune cells and higher bacterial loads in their salivary glands and gums. This absence of early immune instruction 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 study found that antibodies transferred during pregnancy, known as in utero-derived IgG, reach the neonatal salivary glands and are secreted into the saliva. These antibodies are crucial for maintaining a healthy balance, as they teach the immune system to remain calm in the presence of friendly bacteria while preparing it for future threats.

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

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

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 pathobionts, such as the Pasteurellaceae family, which are known to drive aggressive forms of gum disease.

This discovery opens the door for potential preventive strategies, including maternal immunization. By vaccinating mothers during pregnancy, it may be possible to enhance the specific antibodies passed to the child, effectively preprogramming the immune system to resist chronic oral infections later in life.

The research paper titled “Maternal Antibodies Regulate the Establishment of Oral and Salivary Mucosal Immunity” is now available in Nature Communications and can be accessed here.

Researchers:

Reem Naamneh 1, Yarin Attar 1, Yasmin Netanely 1, Yasmin Jaber 1, Shahd Yacoub 1, Or Saar 2, Olga Georgiev 1, Paz Kles 2, Nadeem Darawshi 1, Reem Bsoul 1, Adina Heinberg 1, Luba Eli-Berchoer 1, Hagit Shapiro 3, Eran Elinav 3, 4, Asaf Wilensky 2, and Avi-Hai Hovav 1

Institutions:

  1. Institute of Biomedical and Oral Research, Faculty of Dental Medicine, Hebrew University, Jerusalem, Israel.
  2. Faculty of Dental Medicine, Hebrew University, Jerusalem, Israel; Department of Periodontology, Hadassah Medical Center, Jerusalem, Israel.
  3. Department of Systems Immunology, Weizmann Institute of Science, Rehovot, Israel.
  4. Microbiome & Cancer Division, DKFZ, Heidelberg, Germany.