Efficacy of a combination of probiotics in children (1 year –15 years)
Introduction
Probiotics are live microorganisms that, when consumed in adequate amounts, confer a health benefit to the host. The combination studied here contains three specific strains –Lactobacillus acidophilus(~0.94 billion CFU),Lactobacillus rhamnosus(~5.94 billion CFU) andBifidobacterium infantis(~3.13 billion CFU) – for a total of approximately 10 billion CFU per dose. These strains are commonly found in the intestine and are attributed with various beneficial effects. We review clinical studies evaluating the efficacy of this combination (or multi-strain formulas including these bacteria) in children aged 3 to 15 years. The main domains of effect considered are: immunity and infection prevention, intestinal transit and functional digestive disorders, and the treatment/prevention of acute diarrhea (infectious or antibiotic-related). For each domain, we will summarize the measured effects, significant results, and study protocols (population, duration, dosage), before presenting the relevant medical consensus or official recommendations.
Effects on immunity and infection prevention
Several trials suggest that probiotics includingLactobacillusAndBifidobacteriumcan favorably modulate children's immunity and reduce the incidence of common infections. For example, a randomized, double-blind study followed 326 healthy children (aged 3 to 5 years) during 6 winter months: one group received dailyL. acidophilusalone (NCFM strain, ~10⁹–10¹⁰ CFU) and another receivedL. acidophilus+Bifidobacterium lactis(Bi-07 strain) twice daily, compared to a placebo. Results showed a significant decrease in the incidence of fever (~73% reduction with the probiotic combination compared to placebo), cough (~62% reduction), and cold (~59% reduction) in the dual-strain group, as well as a nearly halved reduction in the average duration of these symptoms. In addition, antibiotic use was significantly lower in children taking the probiotics (84% fewer prescriptions compared to placebo). These children also missed significantly fewer days of daycare or school due to infectious diseases. Such an improvement in respiratory infection indices suggests a stimulation of local and systemic immunity by probiotics. A more recent study (Italy, 2021–2023) involving 128 young children (1 month to 4 years) hospitalized for upper respiratory infection confirmed these immune benefits: a commercial mixture of probiotics (containingL. rhamnosus+B. lactis+B. breve, 14 days of treatment) reduced the median duration of fever to 3 days compared to 5 days under placebo (i.e. 2 days less,p<0.001). The authors attribute this improvement to the immunomodulatory effect of probiotics, noting that they can enhance humoral immunity and increase the production of antibodies against common respiratory viruses.
Regarding atopic allergic diseases (such as eczema), some data suggest a possible preventive effect of probiotics administered early in life. For example, the use ofL. rhamnosusGG in at-risk infants has been associated in studies with a lower subsequent incidence of atopic dermatitis. However, the exact strains and optimal administration window remain debated, and the evidence is heterogeneous. Currently, it is believed that probiotics may beconsideredfor the prevention of eczema in at-risk infants (conditional recommendation), but no strain or combination is officially approved as a standard measure for the prevention of other atopic diseases.
Notable protocols:Studies in this area have generally used daily supplements over long periods of time (several months). Total doses ranged from 10^9 to 10^10 CFU per day. Participants were often preschool-aged children, in daycare, or at school, followed over an entire winter season to assess the incidence of infections. Endpoints included the number of febrile episodes or respiratory symptoms, their duration, and indirect indicators such as antibiotic use or school absenteeism. Overall, these trials suggest that regular intake of multi-strain probiotics (includingL. rhamnosusAndL. acidophilus, sometimes withBifidobacterium) may boost children's immune defenses and modestly reduce the frequency or severity of common infections. However, the magnitude of the effect varies between studies and strains used, and not all trials have achieved positive results (see sectionConsensus).
Effects on intestinal transit and functional digestive disorders
The intestinal microbiota influences transit and can contribute to functional disorders such as irritable bowel syndrome (IBS) or chronic abdominal pain in children. Multi-strain probiotics containingL. acidophilus,L. rhamnosusAndBifidobacteriumhave been tested in these indications. A reference study focused on the VSL#3 product (mixture of 8 strains includingL. acidophilus,L. rhamnosusAndB. infantis), administered to children and adolescents aged 4 to 18 years suffering from IBS. In this multicenter, double-blind trial with crossover (59 patients who completed the study, 6 weeks of probiotic vs. placebo, then reversal of groups), VSL#3 significantly improved theoverall symptom reliefcompared to placebo. Specifically, 3 of the 4 secondary endpoints favored the probiotic: reduction in abdominal pain and discomfort (p<0.05), reduction of bloating and intestinal gas (p<0.05), and improvement in symptom-related family quality of life assessment (p<0.01). On the other hand, no significant change in the rhythm or appearance of stools was observed (no clear modification of the intestinal transit itself,p≈0.06). No notable adverse effects were reported. These results suggest that the probiotic combination mainly affected functional symptoms (pain, bloating) and general well-being, rather than stool frequency.
Other work confirms the interest ofLactobacillusfor functional disorders. A recent meta-analysis compiling several trials (doses ranging from ~10^7 to 10^10 CFU, 6 to 8 weeks of treatment) concludes that probiotics, particularly species ofLactobacillus, offer a positive response in functional abdominal pain in children, particularly in IBS. Clinicians can thereforeconsiderthe use of probiotics based onLactobacillusin these patients.
Regarding bowel movements in the sense of stool regularity (e.g., in functional constipation), the evidence is more limited. No major study has specifically evaluated our trio of strains in childhood constipation, although some closely related strains (L. rhamnosusGG,B. lactis…) have been tested with mixed results. Overall, while several probiotics can modestly soften stools or increase their frequency, they are not a substitute for first-line treatments for constipation (fiber, osmotic laxatives, etc.).
Notable protocols:In IBS and functional pain, studies have often used symptom questionnaires and quality of life scales over 4 to 8 weeks of intervention. The CFU dosage is high in the case of VSL#3-type mixtures (several hundred billion CFU per day), while other trials use ~10^9–10^10 CFU/day. The study populations include school-aged children or adolescents diagnosed with IBS or equivalent. In summary, multi-strain probiotics includingL. acidophilus,L. rhamnosusAndBifidobacteriumseembeneficial for relieving abdominal pain and bloatingin children, improving comfort without significant side effects. The effect on objective intestinal transit (stool frequency) is, however, less obvious.
Efficacy in acute diarrhea and its prevention
Acute infectious diarrhea in children (viral or bacterial gastroenteritis) has been the subject of numerous trials with probiotics. Our combination of strains is found in some of the tested preparations. For example, a synbiotic formula calledProbiotical(containingL. rhamnosus,L. acidophilus,B. infantis,B. lactis,Streptococcus thermophilus+ prebiotic fibers) was evaluated in children with acute gastroenteritis of probable infectious origin. In a randomized controlled trial conducted in Belgium (46 children aged 3.6 months to 12 years, all treated with oral rehydration), the group receiving Probiotical (dose of approximately 4–5 billion CFU per day, during the acute phase) saw areturn to normal stools fasterthan the placebo group. From thefirst dayof treatment, 20% of children in the probiotic group already had stools of normal consistency, compared to 0% in the placebo group (p=0.046). ToJ2, 46% of the treated children had normal stools, versus 16% under placebo (p=0.024). At the same time, theaverage duration of diarrheawas reduced by more than one day in the probiotic group (3.04 ± 1.36 days vs. 4.20 ± 1.34 days under placebo,p=0.018). These data indicate that the probiotic combination accelerated the resolution of acute diarrhea compared to the absence of probiotics.
Another randomized study, conducted in Spain, evaluated the synbioticProdefen®(containing 7 strains includingL. rhamnosus,L. acidophilusAndB. infantis, at a dose of 1×10^9 CFU of each strain per dose) in children aged 6 months to 12 years suffering from acute viral diarrhea. The children received either the standard treatment (rehydration + diet) alone or this treatmentadded from Prodefenduring the acute phase. The results showed afaster healingin the probiotic group: on the fifth day, 95% of children taking Prodefen no longer had diarrhea, compared to 79% in the control group (p<0.001). The median duration of diarrhea was reduced by approximately one day (3 days [IQR 2–5] vs. 4 days [IQR 3–5] for the no-probiotic group), although this one-day difference did not reach strict statistical significance (p=0.38). No difference in side effects was noted, and the probiotic was rated as excellent by parents. Overall, this trial suggests thatadd a probiotic mixto standard treatment can slightly shorten the duration of pediatric acute gastroenteritis and accelerate the return to normal, while being well tolerated.
Finally, regarding theprevention of diarrhea(especially those associated with antibiotics), studies indicate a real benefit of probiotics. The administration ofL. rhamnosusGG during antibiotic therapy, for example, has been shown in several trials to significantly reduce the risk of antibiotic-associated diarrhea in children. A Cochrane meta-analysis also concluded that probiotics reduce the incidence of post-antibiotic diarrhea, with a benefit that is even more pronounced when the daily dose exceeds 5–10 billion CFU. Based on these data, pediatric experts recommendconsiderthe use ofL. rhamnosusGG (or ofS. boulardii) for the prevention of antibiotic-associated diarrhea, particularly in high-risk children. However, for the prevention of community-acquired infectious diarrhea (e.g., in daycare centers), the evidence remains insufficient for a formal recommendation.
Notable protocols:In acute gastroenteritis, clinical trials typically include young children (a few months to ~10 years) from the onset of acute diarrhea (≤48h of symptoms). Probiotics are given for an average of 5 to 7 days, in addition to oral rehydration therapy. Primary endpoints are diarrhea duration (time to last loose stool), number of stools per day, or stool consistency over time. In the prevention of antibiotic-associated diarrhea, protocols administer the probiotic simultaneously with the antibiotic, and assess the onset of diarrhea in the weeks following treatment. Effective doses vary but are generally between 10^9 and 10^10 CFU/day. The strainL. rhamnosusGG is the most documented in this context, often as monotherapy, but combinations includingL. acidophilusandBifidobacteriumare also used in nutritional supplements for children.
Medical consensus and official recommendations
Several medical authorities have issued recommendations on the use of probiotics in children, based on the overall analysis of studies (all probiotics combined). There is no official guideline specific to theexact combination L. acidophilus–L. rhamnosus–B. infantis, but the recommendations by area of application allow us to situate the interest of these strains:
Although no probiotic is yet an approved standard treatment for pediatric IBS, there is emerging consensus to encourage therapeutic trials in selected patients. The SCP concludes that it is possibleconsiderto use strains ofLactobacillus(of whichL. rhamnosus) to relieve abdominal pain in IBS or other functional disorders in children. This cautious recommendation reflects positive evidence in several trials (such as the one with VSL#3 detailed above), counterbalanced by the heterogeneity of strains and individual responses. In practice, some pediatric gastroenterologists propose a course of multi-strain probiotics for 4 to 8 weeks in children with IBS, especially in the presence of bloating, with subsequent reassessment to verify the benefit. The absence of documented serious side effects supports the safety of this trial approach.
There are no official pediatric recommendations yet that endorse the routine use of probiotics to prevent colds, ear infections, or other ENT infections. The SCP table describes the data for infection prevention in general as "insufficient to recommend." However, it is recognized that probioticsseem promisingto modestly reduce the frequency of respiratory infections (with, for example, 6 out of 11 randomized trials showing a benefit). These encouraging results have not yet led to a firm consensus, but they open the way for further research. In practice, some professionals could suggest probiotics during the winter period in children who are frequently ill, but this remains at clinical discretion in the absence of formal guidelines.
Currently, probiotics (including our combination) are not part of standard treatment for conditions such as eczema, asthma, inflammatory bowel disease or cystic fibrosis – in these areas, guidelines estimate the evidenceinsufficientOrinconstant. A notable exception is the eradication ofHelicobacter pylori: studies have shown that addingL. acidophilusAndB. bifidumtriple antibiotic therapy increases the eradication rate in children and reduces the digestive side effects of treatment. Also, some learned societies suggest incorporating an adjuvant probiotic into the anti-H. pyloripediatric in order to improve outcomes.
In summary, probiotics containingL. rhamnosus(particularly the GG strain) have the most solid clinical data in pediatrics (infectious diarrhea, post-antibiotic diarrhea, prevention of eczema, etc.).L. acidophilusAndB. infantisare often used in combination with other strains and appear to contribute to the overall beneficial effects, although their individual role cannot always be isolated. No serious contraindications exist in immunocompetent children aged 3 to 15 years, and authorities emphasize thegood tolerancegeneral use of these probiotics. Thus, official recommendations encourage the use of probiotics in certain cases (in particularL. rhamnosusGG) to prevent or treat targeted disorders, while recalling that these productsdo not replacestandard treatments and that their effectiveness may vary depending on the strain and clinical situation.
Conclusion
Clinical research on probiotics in school-aged children has progressed considerably, although there are still some gray areas. The combination ofLactobacillus acidophilus,Lactobacillus rhamnosusAndBifidobacterium infantis– typically administered in multi-strain formulas totaling ~10⁹ to 10¹⁰ CFU per day – shows beneficial effects in several areas. Quality studies suggest: aimproved immunity(fewer respiratory infections and fever, and possibly a preventive effect on certain allergies), areduction of functional digestive symptoms(abdominal pain, bloating from IBS), and amodest decrease in the duration of acute diarrheaof infectious origin. In addition, inpreventionantibiotic-related diarrhea, the use of probiotics containing these strains (in particularL. rhamnosus) is supported by robust evidence. Protocols vary but often involve daily treatments over a few days (for acute diarrhea) to several months (for immunity or IBS), with excellent reported tolerability.
Sources:The above information is sourced from peer-reviewed scientific publications, including randomized clinical trials and systematic reviews/meta-analyses. Notable references include trials on the prevention of respiratory infections, the treatment of acute infectious diarrhea, the prevention of antibiotic-associated diarrhea, and the management of irritable bowel syndrome in children. The official recommendations cited come from the Canadian Pediatric Society, among others, reflecting the current medical consensus on the use of probiotics in pediatrics. All studies cited were published in peer-reviewed scientific journals and are referenced in detail below.
