Bifidobacterium and Lactobacillus capsules

Kefir is a fermented dairy product containing live and active microbial culture, including lactic acid bacteria and yeast. Preclinical studies and narrative reviews have reported potential modulatory effects of kefir on gut microbiota composition. Despite this, there isn't yet a thorough analysis of human intervention studies that fills this gap of research. Therefore, the aim of this review is to examine the role of kefir consumption on gut microbiota composition in humans. Comprehensive research was conducted using three major databases including Web of Science, PubMed, and Scopus. The risk of bias was assessed using Cochrane risk-of-bias tool and Risk of bias of non-randomized trials. The search resulted in 2743 studies, of which eight studies met our eligibility criteria. Overall, kefir resulted in minor changes in phyla and class levels. On the other hand, the Bifidobacterium genus increased in 3 out of 4 studies. Kefir-specific bacterial species and strains were found in participants fecal samples suggesting colonization properties. Kefir consumption was associated with modest and heterogenous changes in gut microbiota composition. Proposed mechanisms include transient persistent of kefir-associated taxa and modulation of the intestinal environment, although direct functional evidence in humans remains limited.

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ObjectiveThough microbial interventions such as probiotics and fecal microbiota transplantation have had a growing body of evidence suggesting their efficacy in alleviating the symptoms of psychiatric illnesses, their exact mechanisms of action and impacts on the brain are still not fully characterized. The aim of this review is to compile and summarize the current literature regarding neurobiological changes associated with microbial interventions targeting psychiatric symptoms in healthy and psychiatric populations.MethodsA systematic search of four databases was conducted using key terms related to neuroimaging, microbial interventions, and psychiatric illnesses and/or symptoms. All results were then evaluated based on specific eligibility criteria.Results10 studies met eligibility criteria and were included in this systematic review. Three of the five healthy control studies and all five of the studies conducted within psychiatric populations, observed significant neurobiological changes associated with probiotic intervention either in areas with psychiatric relevance, in the direction of a healthier profile, or correlated with improved psychiatric and/or affective symptoms. The interventions used in these studies consisted of probiotics with bacterial species primarily from the lactobacillus and bifidobacterium genera, at doses ranging from 1-900 billion CFU, taken for durations ranging from 4 weeks to 6 months.ConclusionsThe findings from this review suggest that probiotic intervention may be associated with neurobiological changes, and that these changes could play a role in ameliorating psychiatric symptoms. More research is needed to replicate these findings, explore other psychiatric populations and microbial interventions, and fully elucidate the mechanisms driving these promising neurobiological and clinical changes.

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ObjectiveThis study aimed to evaluate the comparative efficacy and safety of various probiotic regimens for treating Respiratory tract infections (RTIs) in otherwise healthy children.MethodsSix Chinese and English databases were searched for randomized controlled trials of probiotics for the RTIs in children published from inception to November 15th, 2025. Pairwise meta-analysis and network meta-analysis were used to assess the efficacy and safety.ResultsEight RCTs enrolling 1,158 children aged 0.69 to 6.4 years from Ukraine, China, Malaysia, India, and Italy were included. Bifidobacterium significantly shortened duration of cough, Lactobacillus reduced duration of illness, Lactobacillus+Bifidobacterium reduced both duration of cough and antibiotic use, and the four-strain combination (Lactobacillus+Bifidobacterium+Enterococcus+Bacillus) reduced durations of fever and cough. Low-certainty evidence suggested superior efficacy of the Lactobacillus+Bifidobacterium over both Bifidobacterium and the four-strain combination for reducing duration of cough, and over Lactobacillus for shortening antibiotic use. Stratified analyses revealed strain-specific effects across RTI subtypes: Bifidobacterium shortened cough in LRTI [-1.12 days, (-1.82, -0.42)]; Lactobacillus reduced illness duration in both URTI [-1.31 days, (-2.19, -0.43)] and LRTI [-1.36 days, (-2.29, -0.43)], and shortened antibiotic use in URTI [-1.70 days, (-2.40, -1.00)]; Lactobacillus+Bifidobacterium shortened fever in URTI [-2.00 days, (-2.57, -1.43)], cough in LRTI [-1.25 days, (-1.84, -0.66)], and both fever -7.10 days, (-8.54, -5.66)] and antibiotic use [-10.50 days, (-13.22, -7.78)] in RRTI; the four-strain combination reduced fever [-1.54 days, (-2.40, -0.68)] and cough [-2.51 days, (-3.89, -1.13)] in RRTI. One RCT reported comparable incidence of gastrointestinal adverse events between probiotic and control groups.ConclusionModerate- to high-certainty evidence supports Bifidobacterium for reducing cough duration and Lactobacillus for shortening illness duration in children with RTIs. While Lactobacillus+Bifidobacterium demonstrated large-magnitude reductions in cough duration and antibiotic use, these findings derive from low- to moderate-certainty evidence and require verification through rigorously designed randomized clinical trials. Strain-specific effects varied across RTI subtypes, suggesting the need for tailored probiotic selection. Future research should prioritize validating multi-strain efficacy, establish optimal dosing protocols, and evaluate long-term safety profiles to enable evidence-based guideline development.Systematic review registrationhttps://www.crd.york.ac.uk/PROSPERO/view/CRD420251074234, identifier CRD420251074234.

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