All 5 studies report beneficial effects of Bifidobacterium plantarum on immune function, with predominantly moderate effect sizes. However, none of the studies reported statistically significant findings, and all are narrative reviews rather than primary clinical trials. No dose, duration, or form data were extracted, and study populations varied (animal models, general, older adults), limiting specific recommendations.
Caveats: Available evidence is overwhelmingly positive — clinical literature in this area is subject to publication bias (null-result studies are less likely to be published or indexed). Many of the included studies did not reach statistical significance — effect may be smaller than the predominant direction suggests. All five studies are narrative reviews; no primary RCTs or meta-analyses are included. Doses, durations, and forms were not reported, making practical application uncertain.
and increases immunity
They enhance antioxidant enzymes... promote the maturation and function of immune cells, and increasing secretory IgA production.
In vitro studies indicate that probiotics can activate immune cells like peripheral blood mononuclear cells (PBMCs), NK cells, T cells, and antigen-presenting cells to help fight tumors.
Their interaction with the immune system plays a crucial role in offering protection and therapeutic effects, particularly in enhancing immunity in older adults.
Probiotics, such as Lactobacillus, Bifidobacterium, and Saccharomyces, modulate the gut microbiota, enhance the gut barrier, and regulate the immune system.