Intrapartum Group B Streptococcus Prophylaxis and Postpartum Mood Susceptibility: A Testable Hypothesis Integrating the Microbiota–Gut–Brain Axis, Hormonal Change, Fascial Mast Cells, and Allostatic Load

This paper presents an interdisciplinary research hypothesis examining potential relationships between intrapartum Group B Streptococcus (GBS) antibiotic prophylaxis, maternal microbiome alterations, postpartum hormonal transitions, mast-cell signaling, and the microbiota–gut–brain axis. The proposed model explores how fascial connective tissue, neuroimmune signaling, hormonal sensitivity, and cumulative physiological stress (allostatic load) may interact to influence postpartum depression and anxiety susceptibility. It also considers overlapping autonomic, immune, and connective-tissue conditions as potential modifiers of individual responses. Drawing on 36 research references, the manuscript integrates existing biological evidence, identifies gaps in current understanding, and proposes experimentally testable pathways for future investigation. The framework is presented as a scientific hypothesis rather than an established causal mechanism.