Effects of ResB supplementation on gut microbiome composition in elderly pneumonia: a randomized pilot trial.

rationalePneumonia remains a leading cause of morbidity and mortality in older adults, often exacerbated by immune dysregulation and prolonged hospitalization. The gut-lung axis is increasingly recognized as a modulator of respiratory immunity, yet the therapeutic potential of targeted probiotic interventions in elderly pneumonia patients remains underexplored.

objectivesTo characterize gut microbial compositional changes, temporal shifts, and microbial interaction network dynamics associated with ResB® Lung Support probiotic supplementation in elderly patients hospitalized with pneumonia in this exploratory, hypothesis-generating pilot trial.

methodsIn a randomized, double-blind, placebo-controlled trial, patients aged ≥60 years admitted with Pneumonia received either resB® probiotic capsules or placebo for 14 days alongside standard care. Stool samples were collected at baseline, day 15, and day 30 (or discharge). Microbiome profiling was performed using 16S rRNA gene sequencing. Statistical analyses included linear mixed-effects Modeling, Wilcoxon rank-sum tests, and trajectory and network assessments.

resultsSixteen patients completed the study. The probiotic group exhibited increased abundance of several beneficial taxa, including Bifidobacterium longum (p = 0.08, FDR = 0.16) and Blautia_A_141781 (p = 0.05, FDR = 0.1), along with positive temporal shifts in Prevotella copri and CAG_83. Pathogenic genera such as Corynebacterium (p = 0.06, FDR = 0.3) and Streptococcus (p = 0.07, FDR = 0.3) declined in the treatment arm. Log-fold change analysis showed significant increases in CAG_83 (p = 0.02, FDR = 0.09) and P. copri (p = 0.027, FDR = 0.09), with an upward trend for B. longum (p = 0.09, FDR = 0.18). Microbiome trajectory analysis indicated temporal shifts in gut microbial composition in the treatment group, and network analysis demonstrated enhanced connectivity among commensal taxa with reduced pathogenic interactions.

conclusionsProbiotic supplementation with resB® Lung Support was associated with changes in gut microbiome composition in elderly pneumonia patients, including shifts in several commensal and potentially pathogenic taxa. Given the exploratory nature of this pilot trial, these findings should be interpreted cautiously. The results suggest that microbiome-targeted nutritional interventions may influence gut microbial dynamics during acute respiratory illness and warrant further investigation in larger, multicenter studies. TRIAL REGISTRATION NUMBER: CTRI/2022/04/041687 (URL: https://ctri.nic.in/Clinicaltrials/pmaindet2.php?EncHid=NjY5MjI) .