Melatonin alleviates high temperature exposure induced fetal growth restriction via the gut-placenta-fetus axis in pregnant miceOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
Researchers tested whether melatonin could protect against heat stress induced fetal growth restriction in pregnant mice, and whether gut microbiota mediated that protection.
How was it studied?
Pregnant mice were exposed to daily heat stress (38°C for 2 hours) with or without oral melatonin. The team ran 16S rRNA sequencing of cecal microbiota, then used antibiotic depletion and fecal microbiota transplantation to test whether melatonin's effect depended on gut microbes, followed by an LPS-challenge experiment to probe the signaling mechanism.
What did they find?
Heat stress caused about 15 percent maternal weight loss and lower fetal and placental weight; melatonin recovered roughly two-thirds of that loss. Melatonin reduced the LPS-producing genus Aliivibrio and increased the butyrate-producing genus Butyricimonas, lowering LPS along the gut-placenta-fetus axis and preserving intestinal and placental barrier integrity. Antibiotic depletion and fecal transplant experiments confirmed the protection was partly microbiota-dependent, and in LPS-challenged mice melatonin blocked TLR4/MAPK/VEGF signaling, restoring placental nutrient transporter expression.
Why it matters
The findings identify gut microbiota as a novel, targetable pathway linking maternal heat exposure to poor fetal growth, suggesting melatonin or microbiota-based strategies could help protect pregnancies as global temperatures rise.