A clinical trial led by researchers at the Ca' Granda Ospedale Maggiore Policlinico and the University of Milan found a probiotic mixture that significantly shortened fever duration in children with upper respiratory tract infections (URTIs). Children who received a probiotic mixture containing Bifidobacterium breve M-16V, Bifidobacterium lactis HN019, and Lactobacillus rhamnosus HN001 experienced a median fever reduction of two days compared to those given a placebo.

The research is published in the journal JAMA Network Open.

Upper respiratory tract infections are among the most common illnesses affecting young children. Reports indicate that children typically experience five to eight URTIs per year, particularly in the first five years of life. Fever is a frequent symptom and a leading cause of healthcare visits, often contributing to inappropriate antibiotic use. Antibiotics provide no benefit for viral infections, which account for the majority of cases.

Current symptom management through antipyretics, such as acetaminophen (paracetamol), can temporarily lower body temperature without reducing fever duration. Probiotics have shown potential in modulating immune responses, yet limited clinical evidence exists regarding their role in treating respiratory infections in children.

In the study titled "Probiotics and Fever Duration in Children With Upper Respiratory Tract Infections: A Randomised Clinical Trial," researchers conducted a triple-blind, placebo-controlled randomised clinical trial to evaluate whether a probiotic mixture could reduce fever duration in children with URTIs.

Enrollment took place at a pediatric emergency department in Milan, involving children aged 28 days to 4 years with fever (≥38.5°C) and URTIs. Intention-to-treat analysis included 87 children who received either the probiotic mixture for 14 days (n = 37) or a placebo (n = 50).

The primary outcome focused on fever duration, defined as the number of days between the first and last recorded febrile day. Secondary outcomes included antibiotic prescription rates after discharge and the incidence of antibiotic-associated diarrhoea. Fever duration was recorded by caregivers, with follow-up conducted via telephone to assess compliance and adverse events.

Results indicated that children in the probiotic group experienced a significantly shorter fever duration than those in the placebo group. The median fever duration was 3 days in the probiotic group compared to 5 days in the placebo group.

Poisson regression analysis, adjusted for age, sex, and antibiotic intake, demonstrated that probiotic supplementation was associated with a fever duration risk ratio of 0.64. Adverse events, including constipation and abdominal pain, were infrequent and similar between both groups. No significant effects were observed on antibiotic prescription rates or the incidence of antibiotic-associated diarrhoea, and no meaningful safety concerns were identified.

The authors acknowledge the limitations, including the single-centre design and reliance on caregiver-reported temperature measurements. The trial did not distinguish between bacterial and viral URTIs, and participants may have received the probiotic at different stages of illness.

Investigators noted that while previous studies on probiotics have primarily focused on prevention rather than treatment, this trial provides evidence supporting their potential therapeutic role as an adjunct treatment for pediatric URTIs.