Joan Jacobs Science & Music Series - April 26, 2026

Why It Matters

Understanding how maternal immunity and microbiota influence lactation and early brain development opens pathways for biomarkers and interventions that could improve lifelong cognitive health.

Key Takeaways

• Maternal gut T cells migrate to mammary gland during lactation
• T cells in milk influence infant growth and immune development
• Microbial presence essential for normal mammary gland structure and function
• Immune‑brain link highlighted; early immunity impacts lifelong brain health
• Salk’s research integrates immunology, microbiome, and brain health strategies

Summary

The Joan Jacobs Science & Music Series at the Salk Institute featured Dr. Shika Ramanan’s presentation on how maternal immunity shapes lactation and long‑term brain health. She framed the talk within Salk’s broader focus on cognitive health, emphasizing that brain function is tightly linked to systemic factors such as cardiovascular, metabolic, and immune health.

Ramanan detailed a series of discoveries: during pregnancy and lactation the mammary gland experiences a 50‑to‑100‑fold surge in immune cells, especially a unique T‑cell population normally resident in the intestine. Single‑cell sequencing and imaging showed these T cells migrate to the gland, where they interact with milk‑producing cells and depend on microbial cues to maintain normal gland architecture. Human milk samples confirmed T cells are present in varying numbers across individuals, suggesting a potential biomarker for maternal and infant health.

Key examples included experiments where introducing microbes restored immune‑cell numbers and normal gland morphology, and mouse studies where offspring lacking maternal T cells were smaller and exhibited altered immune profiles. Ramanan highlighted the broader implication that early‑life immune imbalances can drive neuroinflammation and contribute to adult brain disorders, linking maternal gut health directly to lifelong cognitive outcomes.

The findings point to new diagnostic and therapeutic avenues: monitoring T‑cell levels in milk could predict infant development, while modulating maternal microbiota may enhance lactation efficiency and protect brain health. Salk’s interdisciplinary approach—uniting immunology, microbiome science, and neuroscience—underscores the institute’s commitment to translating basic research into preventive strategies for age‑related cognitive decline.

Original Description

Where science meets sound. The Joan Jacobs Science & Music Series brings together groundbreaking scientific ideas and live musical performance for a truly unique, mind-expanding experience. In this event, Dr. Shika Ramanan explores the role of immunity as it relates to Salk’s 2026 Year of Brain Health, followed by an unforgettable performance from acclaimed jazz pianist and vocalist Champian Fulton.