Data published in Microorganisms also showed that the probiotic was also associated with shorter URTI duration and longer periods between infections in the healthy adult participants.
“Considering that URTI often act as triggers for exacerbations of chronic respiratory diseases, these findings could be valuable for guiding future research,” reported scientists from Sacco Srl (Italy), the Hospital Universitario de Elche (Spain), the Catholic University of Murcia (Spain), and the Reference Center for Lactobacilli [CERELA-CONICET] (Argentina).
“The limited number of studies focusing on probiotic use to alleviate URTI in the adult population make this study especially relevant in trying to address the existing gap in knowledge.”
The CRL 1505 strain belongs to the culture collection of CERELA-CONICET, and the study was funded by Sacco S.R.L.
Strengthening the scientific foundations
Valentina Taverniti, microbes & health R&D leader at Sacco S.r.l. and lead author of the paper, said that L. rhamnosus CRL1505 is among the most extensively studied probiotic strains for immune health and is supported by more than 50 scientific publications.
“New clinical evidence now extends its documented benefits beyond pediatric populations, demonstrating a reduction in upper respiratory tract infections in healthy adults, particularly those prone to recurrent episodes,” she said.
“By expanding the body of evidence from children to adults, this study further strengthens the scientific foundation supporting CRL1505 and highlights its potential role in immune support throughout life.”
Study details
The new randomized, double-blind, placebo-controlled, parallel-group clinical trial included 140 healthy adults aged between 18 and 65. Participants were randomly assigned to receive either 1 billion CFUs per day of L. rhamnosus CRL 1505 or placebo for 12 weeks. The subjects were followed for another four weeks after the end of the intervention.
The data showed that for the 122 people who completed the study, the proportion of participants experiencing two or more URTIs was 15.5% lower in the probiotic group after 16 weeks, compared to placebo. Moreover, participants experiencing three or more URTIs saw a 12.7% reduction, compared to placebo.
The L. rhamnosus CRL 1505 group also experienced significantly fewer URTI episodes than placebo after 16 weeks, with a total of 53 in the probiotic group compared to 78 in the placebo group.
CRL 1505 supplementation was also associated with a 2.9% higher rate of URTI-free time than placebo, said the researchers.
On the other hand, no differences between the groups were recorded for salivary IgA levels, which decreased in both groups over the 12 weeks of supplementation.
“Although L. rhamnosus CRL 1505 did not alleviate the severity of each common cold episode,” wrote the researcher, “importantly L. rhamnosus CRL 1505 intake was associated with a lower need for over-the-counter drugs. This result is of specific relevance in view of the increasing misuse of over-the-counter drugs and related safety risks.”
Source: Microorganisms; doi: 10.3390/microorganisms14061270; “Randomized, Double-Blind, Placebo-Controlled Clinical Trial Assessing the Efficacy of Lacticaseibacillus rhamnosus CRL 1505 in Preventing Upper Respiratory Tract Infections in Healthy Adults." Authors: V. Taverniti et al.
