Lactobacillus gasseri KS-13, Bifidobacterium bifidum G9-1, and Bifidobacterium longum MM-2 Ingestion Induces a Less Inflammatory Cytokine Profile and a Potentially Beneficial Shift in Gut Microbiota in Older Adults: A Randomized, Double-Blind, Placebo-Controlled, Crossover Study

Abstract

Objective: This study determined whether older adults who consumed a probiotic mixture would have a greater proportion of circulating CD4+ lymphocytes, altered cytokine production, and a shift in intestinal microbiota toward a healthier microbial community.

Methods: Participants (70 ± 1 years [mean ± SEM]; n = 32) consumed a probiotic (Lactobacillus gasseri KS-13, Bifidobacterium bifidum G9-1, and Bifidobacterium longum MM2) or a placebo twice daily for 3 weeks with a 5-week washout period between intervention periods. Blood and stools were collected before and after each intervention. The percentage of circulating CD4+ lymphocytes and ex vivo mitogen-stimulated cell cytokine production were measured. In stools, specific bacterial targets were quantified via quantitative polymerase chain reaction (qPCR) and community composition was determined via pyrosequencing.

Results: During the first period of the crossover the percentage of CD4+ cells decreased with the placebo (48% ± 3% to 31% ± 3%, p < 0.01) but did not change with the probiotic (44% ± 3% to 42% ± 3%) and log-transformed concentrations of interleukin-10 increased with the probiotic (1.7 ± 0.2 to 3.4 ± 0.2, p < 0.0001) but not the placebo (1.7 ± 0.2 to 2.1 ± 0.2). With the probiotic versus the placebo a higher percentage of participants had an increase in fecal bifidobacteria (48% versus 30%, p < 0.05) and lactic acid bacteria (55% versus 43%, p < 0.05) and a decrease in Escherichia coli (52% versus 27%, p < 0.05). Several bacterial groups matching Faeacalibactierium prausnitzii were more prevalent in stool samples with the probiotic versus placebo.

Conclusions: The probiotic maintained CD4+ lymphocytes and produced a less inflammatory cytokine profile possibly due to the changes in the microbial communities, which more closely resembled those reported in healthy younger populations.

Key words:

• probiotics
• older adults
• inflammation
• cytokines
• immune function
• gastrointestinal function
• gut microbiota
• Lactobacillus gasseri KS-13
• Bifidobacterium bifidum G9-1
• Bifidobacterium longum MM-2

ACKNOWLEDGMENTS

The authors thank all study coordinators and study participants involved in this research study.

Funding

Wakunaga of America Co., Ltd., Mission Viejo, California, funded this study and provided the study supplements. The funders played no role in data collection, analysis, or interpretation. Though they reviewed the article prior to submission, the authors made the final content decisions. This work was also supported by the USDA National Institute of Food and Agriculture Hatch project FLA-FOS-005129.

Author Contributions

The authors’ responsibilities were as follows: B.L.-H., M.C.C., V.M., C.N., S.S.P, S.J.S., and T.C. designed the study; S.J.S., C.N., T.C., M.U., and B.L.-H. conducted the study; M.C.C., B.L.-H., T.C., and V.M. analyzed the data; S.J.S, T.C., B.L.-H, M.C.C., V.M., and C.N. wrote the article; and B.L.-H. had primary responsibility for final content. All authors read and approved the final article.