University of Toyama Study Reveals Probiotic Supplementation May Significantly Reduce Recurrent Preterm Birth Risk

New research from the University of Toyama shows Clostridium butyricum probiotics can reduce spontaneous preterm delivery recurrence. Learn more about the study.

By: AXL Media

Published: Mar 30, 2026, 6:58 AM EDT

Source: Information for this report was sourced from University of Toyama via EurekAlert!

The Clinical Breakthrough in Neonatal Preventative Care

Researchers at the University of Toyama have identified a promising nutritional intervention to combat one of the leading causes of neonatal mortality and long term disability. Spontaneous preterm delivery, defined as birth occurring before 37 weeks of gestation, remains a significant challenge for obstetricians, particularly among women with a prior history of the condition. The study, led by Associate Professor Satoshi Yoneda, indicates that the introduction of specific beneficial bacteria during the first trimester can alter the maternal immune trajectory and extend pregnancy duration for high risk individuals.

The Immunological Role of Gut Microbiota

The biological foundation of the study rests on the delicate balance of the maternal immune system, which must tolerate the fetus while defending against external pathogens. This tolerance is largely mediated by regulatory T cells, or Treg cells, which suppress excessive inflammatory responses that can trigger early labor. The research team noted that certain intestinal bacteria, specifically species within the Clostridium genus, are essential for the development of these Treg cells. Previous data had shown a marked deficiency of these bacteria in women who experienced premature births, suggesting a direct link between gut health and pregnancy maintenance.

Results from the Multicenter Clinical Trial

Between 2021 and 2024, a prospective trial involving 315 participants was conducted across 31 hospitals in Japan. Pregnant women with a history of spontaneous preterm delivery were administered oral probiotic tablets containing Clostridium butyricum, Enterococcus faecium, and Bacillus subtilis starting between 10 and 14 weeks of pregnancy. The results revealed a recurrence rate of 14.9 percent, a statistically significant reduction compared to the 22.3 percent national average found in Japan’s perinatal database. Furthermore, the treatment demonstrated a favorable safety profile with no serious adverse events reported among the participants.