Study links probiotics with lower death and bowel disease risk in very preterm infants
A Swedish cohort found lower rates of death and necrotizing enterocolitis among infants given probiotics, but the study cannot prove a cause-and-effect relationship.
Moderate evidenceHuman studySome caution advised
Medical disclaimer: This article summarizes research findings and is for informational purposes only. It is not medical advice.
Editorial illustration — not from the study.
This population-based cohort study used data from the Swedish Neonatal Quality Register from 2017 through 2024. It included live-born infants born from 28 weeks 0 days through 31 weeks 6 days of pregnancy, excluding some infants who died very early or had congenital or chromosomal abnormalities.
The infants who received probiotics had lower observed rates of death and necrotizing enterocolitis than those who did not. Since treatment was not assigned randomly, differences between the groups or other aspects of care may have contributed to the results.
What was studied
The researchers examined whether probiotic supplementation was associated with death, necrotizing enterocolitis (NEC), and culture-proven sepsis in very preterm infants. The study included 4,695 infants with a mean gestational age of 30.2 weeks. The probiotic exposure was a daily supplement containing 1 billion colony-forming units of Bifidobacterium infantis, Bifidobacterium lactis, and Streptococcus thermophilus, started after birth and stopped at postmenstrual week 34. The researchers used adjusted regression, propensity-score matching, inverse-probability weighting, and a Bayesian analysis to examine the associations.
Key observations
Probiotic exposure was associated with a lower rate of the combined outcome of death or NEC: 0.8% of infants in the probiotic group compared with 3.4% in the group without supplementation. The adjusted relative risk was 0.28, with a 95% confidence interval of 0.14 to 0.56. When considered separately, death occurred in 0.3% versus 1.4% of infants, and NEC occurred in 0.6% versus 2.5%; both differences were statistically compatible with lower risk in the probiotic group after adjustment. The Bayesian analysis estimated that a substantial share of the observed mortality difference may have occurred through lower NEC incidence, but this was a model-based estimate rather than proof of mediation. Probiotic exposure was not clearly associated with death or culture-proven sepsis: the rates were 3.4% versus 4.4%, with an adjusted relative risk of 0.86 and a 95% confidence interval of 0.58 to 1.26.
Where this may apply
These findings may be relevant to infants born from 28 weeks 0 days through 31 weeks 6 days of pregnancy who receive care in settings similar to those represented in the Swedish register. They should not be generalized to extremely preterm infants born before 28 weeks, to infants with different clinical characteristics, or to other probiotic products without additional evidence. The results are associations in a specific population, not evidence that probiotics cause the reported outcomes for every preterm infant.
The significance
NEC and death are important outcomes for very preterm infants, so the reported association may help inform research and discussions about probiotic use in settings similar to the Swedish hospitals and infants studied. However, this was not a randomized trial, so the findings do not establish that probiotics caused lower death or NEC rates. The results also do not show a clear association with culture-proven sepsis.
Limitations & evidence assessment
The main limitation is the observational cohort design: clinicians or hospitals determined whether infants received probiotics, so unmeasured differences in infants, timing, feeding, infection risk, or other care could have influenced the results. The abstract does not provide enough detail to assess all possible missing data, adherence to supplementation, or differences among hospitals. The study excluded some infants who died within the first 3 days or had congenital or chromosomal abnormalities, which may limit how broadly the findings apply. The analysis also came from one country's neonatal care system and evaluated a specific probiotic combination.
Why this evidence level: Cohort study on humans; observational but structurally stronger than cross-sectional designs.
Evidence levels are editorial estimates derived from study metadata — they are not clinical appraisals.
// Source
JAMA Network Open · 2026 · DOI: 10.1001/jamanetworkopen.2026.35560
Researchers analysed double-blind randomised trials of adults with major depressive disorder to compare 10 antidepressants with placebo during the first eight weeks of treatment. Some medicines were associated with longer QTc intervals, a heart rhythm measurement, but the analysis did not find higher rates of early major cardiovascular events or non-suicidal death compared with placebo.
This narrative review examined research on oral effects reported in people taking systemic isotretinoin for acne. It found that reduced saliva, dry mouth, chapped lips, and other dryness-related symptoms were the most consistent findings, while evidence about cavities and gum health was less uniform.
This systematic review examined whether educational activities in medical school influence students' emotional empathy. The eight included studies reported some effects, but results differed across types of empathy and across interventions, so the overall findings remain uncertain.
