NEW INSIGHS ON THE EFFECTS OF MATERNAL GUT MICROBIOTA MODULATION ON RAT OFFSPRING’S IMMUNE RESPONSES IN THE SPLEEN AND SMALL INTESTINE

Aim: Maternal gut microbiota modulation during pregnancy may influence offspring immune development. This study investigated the effects of maternal probiotic supplementation on intestinal and splenic immune responses in rat offspring, particularly under conditions of maternal dysbiosis and perinatal stress.
Methods: Wistar rat offspring were obtained from dams assigned to four gestational treatment groups: control, antibiotics, probiotics, and antibiotics+probiotics. Maternal gut dysbiosis was induced by an antibiotic cocktail (ampicillin, vancomycin, neomycin, meropenem) administered from embryonic day E11, while a multi-strain probiotic was given throughout gestation.
On postnatal day 6, pups were exposed to perinatal asphyxia-(PA) or normoxia-(N). Twenty-four hours later, spleen and small intestine tissues were collected and homogenized for ELISA-based quantification of S100B, IL-6, and TNF-α. Additional tissue samples were fixed, paraffin-embedded, and processed for immunohistochemical analysis.
FFPE sections were immunostained for immune cell markers-CD4⁺, CD8⁺(T lymphocytes), CD20(B lymphocytes), and CD68(macrophages)-using a Mouse and Rabbit Specific HRP/DAB Detection IHC kit and examined with a Zeiss Axiolab5 microscope. Intestinal barrier integrity was assessed by evaluating zonula occludens-1 (ZO-1) expression.
Results: Probiotic supplementation enhanced intestinal barrier integrity, as evidenced by increased ZO-1 expression. Offspring exposed to maternal antibiotic treatment and/or PA exhibited reduced splenic immune cell populations. Probiotics significantly modulated immune responses in both the spleen and small intestine, leading to decreased levels of pro-inflammatory cytokines IL-6 and TNF-α, as well as reduced splenic S100B concentrations.
Conclusions: Maternal probiotic supplementation exerts immunomodulatory effects through gut microbiota regulation, attenuates inflammatory responses, and supports intestinal barrier function in offspring.
Funding: PSCD_Project NEURO_Depress.