The current meta- analysis revealed that probiotic supplementation may result in increasing TAC and lowering MDA , which improve antioxidant status .
Previous studies have supposed that probiotic supplementation led to a positive effect on different health outcomes .
Furthermore , several studies indicated that probiotics supplementation improved antioxidant status , while some studies did not indicate these effects .
Hence , current systematic review and meta- analysis study was conducted to determine the effect of probiotic supplementation on some oxidative stress biomarkers  among adult subjects .
Oral supplementation with Lactobacillus delbrueckii subsp. bulgaricus 8481 enhances systemic immunity in elderly subjects
Abstract Throughout life , there is an aging of the immune system that causes impairment of its defense capability . Prevention or delay of this deterioration is considered crucial to maintain general health and increase longevity . We evaluated whether dietary supplementation with Lactobacillus delbrueckii subsp . bulgaricus 8481 could enhance the immune response in the elderly . This multi-center , double-blind , and placebo controlled study enrolled 61 elderly volunteers who were r and omly assigned to receive either placebo or probiotics .  Each capsule of probiotics contained at least 3 × 107 L. delbrueckii subsp . bulgaricus 8481 . Individuals in the study were administered three capsules per day for 6 months . Blood sample s were obtained at baseline ( time 0 ) , end of month 3 , and month 6 . We characterized cell sub population s , measured cytokines by flow cytometry , quantified T cell receptor excision circle ( TREC ) by real-time PCR ( RT-PCR ) , and determined human β-defensin-2 ( hBD-2 ) concentrations and human cytomegalovirus ( CMV ) titers by enzyme-linked immunosorbent assay ( ELISA ) . Elderly responded to the intake of probiotic with an increase in the percentage of NK cells , an improvement in the parameters defining the immune risk profile ( IRP ) , and an increase in the T cell subsets that are less differentiated . The probiotic group also showed decreased concentrations of the pro-inflammatory cytokine IL-8 but increased antimicrobial peptide hBD-2 . These effects disappeared within 6 months of stopping the probiotic intake . Immunomodulation induced by L. delbrueckii subsp . bulgaricus 8481 could favor the maintenance of an adequate immune response , mainly by slowing the aging of the T cell sub population s and increasing the number of immature T cells which are potential responders to new antigens
The current meta- analysis revealed that probiotic supplementation may result in increasing TAC and lowering MDA , which improve antioxidant status .
Previous studies have supposed that probiotic supplementation led to a positive effect on different health outcomes .
Furthermore , several studies indicated that probiotics supplementation improved antioxidant status , while some studies did not indicate these effects .
Hence , current systematic review and meta- analysis study was conducted to determine the effect of probiotic supplementation on some oxidative stress biomarkers  among adult subjects .