Probiotics to reduce fever in children with URTI
Upper respiratory tract infections (URTI) are one of the most frequent reasons for pediatric consultations, especially when accompanied by fever. A recent study published in JAMA Network Open analyzed the effectiveness of a probiotic mixture in reducing fever duration in young children with URTI. The results showed a significant reduction in fever duration compared with placebo, opening the door to new therapeutic perspectives.
Randomized clinical trial on probiotics and fever
The study was conducted at the pediatric emergency department of Ca’ Granda Ospedale Maggiore Policlinico in Milan between November 2021 and June 2023. It was a randomized, triple-blind, placebo-controlled clinical trial involving 128 children aged between 28 days and 4 years, all with fever (≥38.5 °C) associated with URTI.
Participants were randomly divided into two groups: one received the probiotic mixture (Bifidobacterium breve M-16V, Bifidobacterium lactis HN019, and Lactobacillus rhamnosus HN001), while the other received a placebo. The treatment lasted 14 days, in drops or stick form, depending on caregiver preference.
Main results: 2-day reduction in fever
The results showed that children who received probiotics had a median fever duration of 3 days, compared with 5 days in the placebo group. The difference, about 2 days, was statistically significant (P < .001).
Analysis using a Poisson regression model confirmed that fever duration was shorter in the probiotic group, even after adjusting for factors such as age, sex, and antibiotic use. The positive effect was observed both in the intention-to-treat and per-protocol analyses, confirming the robustness of the result.
Safety and tolerability of probiotics
From a safety perspective, the study showed that probiotics were well tolerated, with no significant differences in adverse events between the two groups.
The most frequently reported events were:
- Constipation: 16% in the probiotic group vs 12% in placebo
- Abdominal pain: 8% in the probiotic group vs 4% in placebo
- Diarrhea: 8% in the probiotic group vs 5% in placebo
All events were mild and transient, with no clinically relevant consequences. This confirms that the probiotic mixture used is safe in children without particular risk conditions, such as immunodeficiencies.
Clinical implications: probiotics as supportive therapy
The study represents an important novelty because, until now, most research had focused on the role of probiotics in preventing respiratory infections rather than in treatment.
The results suggest that probiotics may become a valid therapeutic support to reduce fever duration in children with URTI, with possible benefits also in terms of reducing the inappropriate use of antibiotics.
In particular, probiotics would act by modulating the immune response through:
- stimulation of immune cells such as macrophages and dendritic cells,
- increased production of immunoglobulins (IgA, IgG, IgM),
- antiviral activity against common respiratory viruses (influenza, rhinovirus, RSV, coronavirus),
- regulation of inflammatory cytokines (IL-1, IL-6, TNF), involved in fever development.
Comparison with previous studies
Previous literature had provided contrasting data. Some studies suggested that probiotics could reduce the incidence and severity of URTI, while others found no significant benefits. Moreover, many studies had not considered fever as the primary endpoint.
This study stands out because it:
- included only children with URTI and fever,
- used a rigorous triple-blind design,
- applied robust statistical analyses,
- considered confounding factors such as age and antibiotic use.
Conclusions: probiotics useful in children with URTI
The clinical trial showed that a specific combination of probiotics (Bifidobacterium breve M-16V, Bifidobacterium lactis HN019, and Lactobacillus rhamnosus HN001) can reduce fever in children with upper respiratory tract infections by about two days.
These results open the way to a possible use of probiotics as support in pediatric URTI, with benefits for both young patients and the healthcare system, also reducing unnecessary use of antibiotics. However, further larger studies conducted in multiple centers are needed to confirm these findings and better understand how probiotics work.
If your company is interested in creating or manufacturing a product for respiratory infections:
Source: March 14, 2025, Probiotics and Fever Duration in Children With Upper Respiratory Tract Infections: A Randomized Clinical Trial, JAMA Network Open
