{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T14:11:28Z","timestamp":1787062288876,"version":"build-2736575974"},"reference-count":56,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2025,6,24]],"date-time":"2025-06-24T00:00:00Z","timestamp":1750723200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Life"],"abstract":"<jats:p>Probiotics offer a non-pharmacological approach to support immune function, yet clinical evidence for strain-specific benefits remains limited. We conducted an 8-week, randomized, double-blind, placebo-controlled trial of Lacticaseibacillus rhamnosus LM1019 in 121 generally healthy adults. Both the active and placebo arms produced comparable within-group increases in natural killer (NK) cell cytotoxicity and modest, non-differential declines in circulating cytokines; safety and tolerability were excellent, with mild adverse events evenly distributed. In a post-hoc subgroup defined by age \u2265 40 years, baseline white blood cell count \u2265 5.0 \u00d7 103\/\u00b5L, and LDL cholesterol &lt; 130 mg\/dL, the probiotic arm demonstrated statistically significant enhancements in NK activity (p = 0.021\u20130.008 across all effector-to-target ratios), whereas no change was observed in the placebo group. These findings suggest that this intervention may selectively boost NK-mediated immunity in individuals with preserved baseline immune and lipid profiles. Future larger trials using phenotype-driven enrollment and controlled dietary intake are warranted to confirm and extend these results.<\/jats:p>","DOI":"10.3390\/life15071002","type":"journal-article","created":{"date-parts":[[2025,6,24]],"date-time":"2025-06-24T06:49:38Z","timestamp":1750747778000},"page":"1002","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Lacticaseibacillus rhamnosus LM1019 Enhances Natural Killer Cell Activity in Defined Adult Subsets: A Double-Blind, Placebo-Controlled Trial"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2663-7195","authenticated-orcid":false,"given":"Jeseong","family":"Park","sequence":"first","affiliation":[{"name":"Microbiome R&D Center, Lactomason Co., Ltd., Jinju 52840, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1227-3690","authenticated-orcid":false,"given":"Yeji","family":"You","sequence":"additional","affiliation":[{"name":"Microbiome R&D Center, Lactomason Co., Ltd., Jinju 52840, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sung-Hwan","family":"Kim","sequence":"additional","affiliation":[{"name":"Food Research Center, Binggrae Co., Ltd., Namyangju 12253, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hye-Jin","family":"Ku","sequence":"additional","affiliation":[{"name":"Food Research Center, Binggrae Co., Ltd., Namyangju 12253, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hye-Jung","family":"Han","sequence":"additional","affiliation":[{"name":"Food Research Center, Binggrae Co., Ltd., Namyangju 12253, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chul-Hong","family":"Kim","sequence":"additional","affiliation":[{"name":"Food Research Center, Binggrae Co., Ltd., Namyangju 12253, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tae-Rahk","family":"Kim","sequence":"additional","affiliation":[{"name":"Microbiome R&D Center, Lactomason Co., Ltd., Jinju 52840, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Minn","family":"Sohn","sequence":"additional","affiliation":[{"name":"Microbiome R&D Center, Lactomason Co., Ltd., Jinju 52840, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Inah","family":"Kim","sequence":"additional","affiliation":[{"name":"Global Medical Research Center, Seoul 06526, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chaemin","family":"Baeg","sequence":"additional","affiliation":[{"name":"Global Medical Research Center, Seoul 06526, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,6,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Goyani, P., Christodoulou, R., and Vassiliou, E. 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