Prolonged Antibiotic Exposure During Gestation Increases the Severity of Perinatal Asphyxia as Measured by EEG Reactivity in Rodents

Background/Objectives: Birth asphyxia is a frequent neonatal complication in humans. Its outcome is variable, and the factors underlying this variability remain incompletely understood. Maternal gut microbiome impairment has been proposed as one factor that may influence offspring neurodevelopment, especially when the immature brain is exposed to additional vulnerability such as perinatal asphyxia (PA). Building on our previous maternal microbiome disruption model and on our prior observation that electroencephalography (EEG) reactivity to photic stimulation under deep anesthesia detects functional impairment two months after PA, we assessed whether this reactivity was further impaired after prolonged gestational antibiotic administration and whether probiotics modulated this effect. Methods: Wistar dams received antibiotics, probiotics, antibiotics with probiotics, or control treatment, and offspring underwent PA. Adult EEG reactivity to photic stimulation was assessed during chloral hydrate-induced burst suppression. Burst count reactivity (BCR) was used as the primary event-based readout of stimulus-evoked burst recruitment and was compared with the suppression-ratio-based burst-suppression reactivity index (BSRi). Results: Burst suppression remained reactive to photic stimulation in all groups. BCR was lower after gestational antibiotic treatment than in controls. The magnitude of the effect was attenuated by probiotics coadministration. BSRi showed the same overall pattern. Conclusions: Prolonged gestational antibiotic exposure increased the severity of perinatal asphyxia as measured by EEG reactivity in the adult offspring. The converging BCR and BSRi results support burst-suppression reactivity as a functional neurophysiological readout in this PA model and support further methodological development of EEG reactivity measures for translational studies of hypoxic–ischemic brain injury.