AUTHOR=Bartos Ales , Weinerova Josefina , Diondet Sofia 

TITLE=Effects of human probiotics on memory and psychological and physical measures in community-dwelling older adults with normal and mildly impaired cognition: results of a bi-center, double-blind, randomized, and placebo-controlled clinical trial (CleverAge biota)

JOURNAL=Frontiers in Aging Neuroscience

VOLUME=15

YEAR=2023

URL=https://www.frontiersin.org/journals/aging-neuroscience/articles/10.3389/fnagi.2023.1163727

DOI=10.3389/fnagi.2023.1163727

ISSN=1663-4365

ABSTRACT=<sec><title>Objectives</title><p>This study presents results of our randomized clinical trial studying the effect of human probiotics on memory and psychological and physical measures following our study protocol registered at <ext-link xlink:href="http://clinicaltrials.gov" ext-link-type="uri" xmlns:xlink="http://www.w3.org/1999/xlink">clinicaltrials.gov</ext-link> NCT05051501 and described in detail in our previous paper.</p></sec><sec><title>Methods</title><p>Community dwelling participants aged between 55 and 80  years were randomly assigned to receive a single dose of 10<sup>6</sup> colony-forming units of human <italic>Streptococcus thermophilus</italic> GH, <italic>Streptococcus salivarius</italic> GH NEXARS, Lactobacilus plantarum GH, and <italic>Pediococcus pentosaceus</italic> GH or placebo. A cross-over design allowed each group to receive probiotics and placebo for 3  months each in reverse order. A small subset of participants was examined online due to the COVID-19 pandemic. After 6  months a small number of volunteers were additionally assessed after 2  months without any intervention. Primary outcome measures included changes in cognitive functions assessed using brief tests and a neuropsychological battery and changes in mood assessed using validated questionnaires. Secondary outcome measures included changes in self-report and subjective measures using depression and anxiety questionnaires, seven visual analog scales of subjective feelings (memory, digestion, etc.), and physical performance.</p></sec><sec><title>Results</title><p>At baseline, the probiotic-placebo group A (<italic>n</italic> = 40, age 69 ± 7 years, education 16 ± 3 years, 63% females, body mass index 28.5 ± 6, subjective memory complaint in 43%) did not differ from the placebo-probiotic group B (<italic>n</italic> = 32) in any of the sociodemographic characteristics and evaluated measures including cognitive status. At follow-up visits after 3, 6, and 8  months, no cross-sectional differences in any of the measures were found between the groups except worse sentence recall of the ALBA test after 3  months of probiotic use. Score changes were not observed for all cognitive tests but one in any group between visits 1 and 3 and between visits 3 and 6. The only change was observed for the TMT B test after the first three months but no change was observed after the second three months.</p></sec><sec><title>Conclusion</title><p>The treatment with human probiotics and prebiotics did not improve cognitive, affective, or physical measures in community-dwelling individuals with normal or mildly impaired cognitive functions.</p></sec><sec><title>Clinical trial registration</title><p><ext-link xlink:href="http://clinicaltrials.gov" ext-link-type="uri" xmlns:xlink="http://www.w3.org/1999/xlink">clinicaltrials.gov</ext-link>, identifier NCT05051501.</p></sec>