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Effects of probiotics on cognitive function across the human lifespan: a meta-analysis

European Journal of Clinical Nutrition volume 80, pages 46–61 (2026)Cite this article

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Abstract

Background

In recent years, probiotics have become one of the research hotspots in the scientific community, and its potential role in intestinal health, immune regulation, and the relationship with the brain has attracted much attention. However, the improvement of cognitive function by probiotics shows different effects in different stages of the human life cycle.

Objective

Therefore, we conducted a meta-analysis of randomized controlled trials to examine the specific effects of probiotics on cognitive function in different age groups.

Methods

We searched four databases from creation to December 2023. A meta-analysis of 21 randomized controlled clinical trials was conducted, using random effect Meta analysis combined with standardized mean difference (SMD) (95% confidence interval [CI]).

Results

Our meta-analysis found that the effects of probiotics on cognitive performance were primarily seen in older age groups, with significant effects on overall cognitive performance, processing speed, memory, and spatial ability (SMD = 0.40, 95% CI [0.13, 0.67], P = 0.004), (SMD = 0.37, 95% CI [0.11, 0.63], P = 0.006), (SMD = 0. 51, 95% CI [0.25, 0.78], P = 0.0002), (SMD = 0.35, 95% CI [0.09, 0.62], P = 0.008). In addition, probiotics improved executive function in infants and children (SMD = 0.30, 95% CI [0.04, 0.56], P = 0.03). In young adults, the effects of probiotics were mainly seen in verbal ability (SMD = 0.43, 95% CI [0.15, 0.71], p = 0.003).

Conclusion

Probiotic supplements primarily improve overall cognitive function, information processing speed, memory, and spatial ability in older adults, with the best results observed after 12 weeks of daily intake of approximately 2 × 10¹⁰ CFU.

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Fig. 1: Flow chart showing the search result of the meta-analysis.
Fig. 2: Methodological risk of bias summary review authors’ judgment about each methodological bias item for each included study.
Fig. 3: Methodological risk of bias graph.
Fig. 4: Forest plot showing the effect of intervention vs control on global function (n = 12).
Fig. 5: Funnel plot of probiotics’ cognitive effects by age subgroup.
Fig. 6: Forest plot showing the effect of intervention vs control on executive function (n = 14).
Fig. 7: Forest plot showing the effect of intervention and control on processing speed(n = 7).
Fig. 8: Forest plot showing the effects of intervention and control on delayed memory (n = 16).
Fig. 9: Forest diagram showing the effect of intervention and control on attention (n = 13).
Fig. 10: Forest diagram showing the effect of intervention and control on spatial capacity (n = 10).
Fig. 11: Forest diagram showing the impact of intervention and control on language ability (n = 14).

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Data availability

The data, coding manual, and analysis code described in this manuscript are available from the corresponding author upon request.

References

  1. Lövdén M, Fratiglioni L, Glymour MM, Lindenberger U, Tucker-Drob EM. Education and cognitive functioning across the life span. Psychol Sci Public Interest. 2020;21:6–41. https://doi.org/10.1177/1529100620920576.

    Article  PubMed  PubMed Central  Google Scholar 

  2. Basile MS, Ciurleo R, Bramanti A, Petralia MC, Fagone P, Nicoletti F, et al. (2021) Cognitive decline in rheumatoid arthritis: insight into the molecular pathogenetic mechanisms. Int J Mol Sci. 22. https://doi.org/10.3390/ijms22031185.

  3. Estimation of the global prevalence of dementia in 2019 and forecasted prevalence in 2050: an analysis for the Global Burden of Disease Study 2019 (2022). The Lancet Public Health. 7 :e105-e125. https://doi.org/10.1016/s2468-2667(21)00249-8.

  4. Gabrielli M, Zileri Dal Verme L, Zocco MA, Nista EC, Ojetti V, Gasbarrini A (2024) The role of the gastrointestinal microbiota in Parkinson’s disease. Biomolecules. 15. https://doi.org/10.3390/biom15010026

  5. Liu Y, Li H, Wang X, Huang J, Zhao D, Tan Y, et al. Anti-Alzheimers molecular mechanism of icariin: insights from gut microbiota, metabolomics, and network pharmacology. J Transl Med. 2023;21:277. https://doi.org/10.1186/s12967-023-04137-z.

    Article  PubMed  PubMed Central  Google Scholar 

  6. Tahmasbi F, Mirghafourvand M, Shamekh A, Mahmoodpoor A, Sanaie S. Effects of probiotic supplementation on cognitive function in elderly: a systematic review and Meta-analysis. Aging Ment health. 2022;26:1778–86. https://doi.org/10.1080/13607863.2021.1966743.

    Article  PubMed  Google Scholar 

  7. Mo R, Jiang M, Xu H, Jia R. Effect of probiotics on cognitive function in adults with mild cognitive impairment or Alzheimer’s disease: a meta-analysis of randomized controlled trials. Med Clin. 2024;162:565–73. https://doi.org/10.1016/j.medcli.2024.01.013.

    Article  Google Scholar 

  8. Eastwood J, Walton G, Van Hemert S, Williams C, Lamport D. The effect of probiotics on cognitive function across the human lifespan: a systematic review. Neurosci Biobehav Rev. 2021;128:311–27. https://doi.org/10.1016/j.neubiorev.2021.06.032.

    Article  PubMed  Google Scholar 

  9. Liberati A, Altman DG, Tetzlaff J, Mulrow C, Gøtzsche PC, Ioannidis JP, et al. The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration. J Clin Epidemiol. 2009;62:e1–34. https://doi.org/10.1016/j.jclinepi.2009.06.006.

    Article  PubMed  Google Scholar 

  10. Flemyng E, Dwan K, Moore TH, Page MJ, Higgins JP. Risk of bias 2 in cochrane reviews: a phased approach for the introduction of new methodology. Cochrane database Syst Rev. 2020;10:Ed000148 https://doi.org/10.1002/14651858.Ed000148.

    Article  PubMed  Google Scholar 

  11. Balshem H, Helfand M, Schünemann HJ, Oxman AD, Kunz R, Brozek J, et al. GRADE guidelines: 3. Rating the quality of evidence. J Clin Epidemiol. 2011;64:401–6. https://doi.org/10.1016/j.jclinepi.2010.07.015.

    Article  PubMed  Google Scholar 

  12. Higgins JP, Thompson SG, Deeks JJ, Altman DG. Measuring inconsistency in meta-analyses. BMJ (Clin Res ed). 2003;327:557–60. https://doi.org/10.1136/bmj.327.7414.557.

    Article  Google Scholar 

  13. Begg CB, Mazumdar M. Operating characteristics of a rank correlation test for publication bias. Biometrics. 1994;50:1088–101.

    Article  PubMed  Google Scholar 

  14. Sterne JA, Egger M. Funnel plots for detecting bias in meta-analysis: guidelines on choice of axis. J Clin Epidemiol. 2001;54:1046–55. https://doi.org/10.1016/s0895-4356(01)00377-8.

    Article  PubMed  Google Scholar 

  15. Czajeczny D, Kabzińska K, Wójciak RW. Effects of Bifidobacterium Lactis BS01 and Lactobacillus Acidophilus LA02 on cognitive functioning in healthy women. Appl Neuropsychol Adult. 2023;30:552–60. https://doi.org/10.1080/23279095.2021.1967155.

    Article  PubMed  Google Scholar 

  16. Elhossiny RM, Elshahawy HH, Mohamed HM, Abdelmageed RI. Assessment of probiotic strain Lactobacillus acidophilus LB supplementation as adjunctive management of attention-deficit hyperactivity disorder in children and adolescents: a randomized controlled clinical trial. BMC psychiatry. 2023;23:823. https://doi.org/10.1186/s12888-023-05324-4.

    Article  PubMed  PubMed Central  Google Scholar 

  17. Akar M, Eras Z, Oncel MY, Arayici S, Guzoglu N, Canpolat FE, et al. Impact of oral probiotics on neurodevelopmental outcomes in preterm infants. J Matern-fetal Neonatal Med. 2017;30:411–5. https://doi.org/10.1080/14767058.2016.1174683.

    Article  PubMed  Google Scholar 

  18. Akhgarjand C, Vahabi Z, Shab-Bidar S, Etesam F, Djafarian K. Effects of probiotic supplements on cognition, anxiety, and physical activity in subjects with mild and moderate Alzheimer’s disease: A randomized, double-blind, and placebo-controlled study. Front aging Neurosci. 2022;14:1032494. https://doi.org/10.3389/fnagi.2022.1032494.

    Article  PubMed  PubMed Central  Google Scholar 

  19. Chung YC, Jin HM, Cui Y, Kim DS, Jung JM, Park JI, et al. Fermented milk of Lactobacillus helveticus IDCC3801 improves cognitive functioning during cognitive fatigue tests in healthy older adults. J Funct Foods. 2014;10:465–74. https://doi.org/10.1016/j.jff.2014.07.007.

    Article  Google Scholar 

  20. Lew LC, Hor YY, Yusoff NAA, Choi SB, Yusoff MSB, Roslan NS, et al. Probiotic Lactobacillus plantarum P8 alleviated stress and anxiety while enhancing memory and cognition in stressed adults: a randomised, double-blind, placebo-controlled study. Clin Nutr (Edinb, Scotl). 2019;38:2053–64. https://doi.org/10.1016/j.clnu.2018.09.010.

    Article  Google Scholar 

  21. Mahboobi S, Ghasvarian M, Ghaem H, Alipour H, Alipour S, Eftekhari MH. Effects of probiotic and magnesium co-supplementation on mood, cognition, intestinal barrier function and inflammation in individuals with obesity and depressed mood: A randomized, double-blind placebo-controlled clinical trial. Front Nutr. 2022;9:1018357. https://doi.org/10.3389/fnut.2022.1018357.

    Article  PubMed  PubMed Central  Google Scholar 

  22. Ohsawa K, Nakamura F, Uchida N, Mizuno S, Yokogoshi H. Lactobacillus helveticus-fermented milk containing lactononadecapeptide (NIPPLTQTPVVVPPFLQPE) improves cognitive function in healthy middle-aged adults: a randomised, double-blind, placebo-controlled trial. Int J food Sci Nutr. 2018;69:369–76. https://doi.org/10.1080/09637486.2017.1365824.

    Article  PubMed  Google Scholar 

  23. Shi S, Zhang Q, Sang Y, Ge S, Wang Q, Wang R, et al. Probiotic bifidobacterium longum BB68S improves cognitive functions in healthy older adults: a randomized, double-blind, placebo-controlled trial. Nutrients. 2022 15. https://doi.org/10.3390/nu15010051.

  24. Xiao J, Katsumata N, Bernier F, Ohno K, Yamauchi Y, Odamaki T, et al. Probiotic bifidobacterium breve in improving cognitive functions of older adults with suspected mild cognitive impairment: a randomized, double-blind, placebo-controlled trial. J Alzheimer’s Dis : JAD. 2020;77:139–47. https://doi.org/10.3233/jad-200488.

    Article  PubMed  Google Scholar 

  25. Asaoka D, Xiao J, Takeda T, Yanagisawa N, Yamazaki T, Matsubara Y, et al. Effect of probiotic bifidobacterium breve in improving cognitive function and preventing brain atrophy in older patients with suspected mild cognitive impairment: results of a 24-week randomized, double-blind, placebo-controlled trial. J Alzheimer’s Dis : JAD. 2022;88:75–95. https://doi.org/10.3233/jad-220148.

    Article  PubMed  Google Scholar 

  26. Firmansyah A, Dwipoerwantoro PG, Kadim M, Alatas S, Conus N, Lestarina L, et al. Improved growth of toddlers fed a milk containing synbiotics. Asia Pac J Clin Nutr. 2011;20:69–76.

    PubMed  Google Scholar 

  27. Jacobs SE, Hickey L, Donath S, Opie GF, Anderson PJ, Garland SM, et al. Probiotics, prematurity and neurodevelopment: follow-up of a randomised trial. BMJ Paediatr Open. 2017;1:e000176 https://doi.org/10.1136/bmjpo-2017-000176.

    Article  PubMed  PubMed Central  Google Scholar 

  28. Azuma N, Mawatari T, Saito Y, Tsukamoto M, Sampei M, Iwama Y. Effect of continuous ingestion of bifidobacteria and dietary fiber on improvement in cognitive function: a randomized, double-blind, placebo-controlled trial. Nutrients 2023 15. https://doi.org/10.3390/nu15194175.

  29. Chong HX, Yusoff NAA, Hor YY, Lew LC, Jaafar MH, Choi SB, et al. Lactobacillus plantarum DR7 alleviates stress and anxiety in adults: a randomised, double-blind, placebo-controlled study. Beneficial Microbes. 2019;10:355–73. https://doi.org/10.3920/bm2018.0135.

    Article  PubMed  Google Scholar 

  30. Kim CS, Cha L, Sim M, Jung S, Chun WY, Baik HW, et al. Probiotic supplementation improves cognitive function and mood with changes in gut microbiota in community-dwelling older adults: a randomized, double-blind, placebo-controlled, multicenter trial. J Gerontol Ser A, Biol Sci Med Sci. 2021;76:32–40. https://doi.org/10.1093/gerona/glaa090.

    Article  Google Scholar 

  31. Kobayashi Y, Kuhara T, Oki M, Xiao JZ. Effects of bifidobacterium breve A1 on the cognitive function of older adults with memory complaints: a randomised, double-blind, placebo-controlled trial. Beneficial microbes. 2019;10:511–20. https://doi.org/10.3920/bm2018.0170.

    Article  PubMed  Google Scholar 

  32. Rudzki L, Ostrowska L, Pawlak D, Małus A, Pawlak K, Waszkiewicz N, et al. Probiotic Lactobacillus Plantarum 299v decreases kynurenine concentration and improves cognitive functions in patients with major depression: A double-blind, randomized, placebo controlled study. Psychoneuroendocrinology. 2019;100:213–22. https://doi.org/10.1016/j.psyneuen.2018.10.010.

    Article  PubMed  Google Scholar 

  33. Sakurai K, Toshimitsu T, Okada E, Anzai S, Shiraishi I, Inamura N, et al. Effects of lactiplantibacillus plantarum OLL2712 on memory function in older adults with declining memory: a randomized placebo-controlled trial. Nutrients 2022;14. https://doi.org/10.3390/nu14204300.

  34. Sanborn V, Azcarate-Peril MA, Updegraff J, Manderino L, Gunstad J. Randomized clinical trial examining the impact of lactobacillus rhamnosus GG probiotic supplementation on cognitive functioning in middle-aged and older adults. Neuropsychiatr Dis Treat. 2020;16:2765–77. https://doi.org/10.2147/ndt.S270035.

    Article  PubMed  PubMed Central  Google Scholar 

  35. Wang X, Ma R, Liu X, Zhang Y. Effects of long-term supplementation of probiotics on cognitive function and emotion in temporal lobe epilepsy. Front Neurol. 2022;13:948599. https://doi.org/10.3389/fneur.2022.948599.

    Article  PubMed  PubMed Central  Google Scholar 

  36. Bajaj JS, Heuman DM, Hylemon PB, Sanyal AJ, Puri P, Sterling RK, et al. Randomised clinical trial: Lactobacillus GG modulates gut microbiome, metabolome and endotoxemia in patients with cirrhosis. Alimentary Pharm Ther. 2014;39:1113–25. https://doi.org/10.1111/apt.12695.

    Article  Google Scholar 

  37. Baucells BJ, Sebastiani G, Herrero-Aizpurua L, Andreu-Fernández V, Navarro-Tapia E, García-Algar O, et al. Effectiveness of a probiotic combination on the neurodevelopment of the very premature infant. Sci Rep. 2023;13:10344. https://doi.org/10.1038/s41598-023-37393-6.

    Article  PubMed  PubMed Central  Google Scholar 

  38. McMath AL, Aguilar-Lopez M, Cannavale CN, Khan NA, Donovan SM. A systematic review on the impact of gastrointestinal microbiota composition and function on cognition in healthy infants and children. Front Neurosci. 2023;17:1171970. https://doi.org/10.3389/fnins.2023.1171970.

    Article  PubMed  PubMed Central  Google Scholar 

  39. Lin FL, Chen CM, Sun CK, Cheng YS, Tzang RF, Chiu HJ, et al. Effects of probiotics on neurocognitive outcomes in infants and young children: a meta-analysis. Front Public Health. 2023;11:1323511. https://doi.org/10.3389/fpubh.2023.1323511.

    Article  PubMed  PubMed Central  Google Scholar 

  40. Schneider E, Doll JPK, Schweinfurth N, Kettelhack C, Schaub AC, Yamanbaeva G, et al. Effect of short-term, high-dose probiotic supplementation on cognition, related brain functions and BDNF in patients with depression: a secondary analysis of a randomized controlled trial. J Psychiatry Neurosci. 2023;48:E23–e33. https://doi.org/10.1503/jpn.220117.

    Article  PubMed  PubMed Central  Google Scholar 

  41. Kurian SJ, Unnikrishnan MK, Miraj SS, Bagchi D, Banerjee M, Reddy BS, et al. Probiotics in prevention and treatment of COVID-19: current perspective and future prospects. Arch Med Res. 2021;52:582–94. https://doi.org/10.1016/j.arcmed.2021.03.002.

    Article  PubMed  PubMed Central  Google Scholar 

  42. Gavelin HM, Dong C, Minkov R, Bahar-Fuchs A, Ellis KA, Lautenschlager NT, et al. Combined physical and cognitive training for older adults with and without cognitive impairment: A systematic review and network meta-analysis of randomized controlled trials. Ageing Res Rev. 2021;66:101232. https://doi.org/10.1016/j.arr.2020.101232.

    Article  PubMed  Google Scholar 

  43. Akbari E, Asemi Z, Daneshvar Kakhaki R, Bahmani F, Kouchaki E, Tamtaji OR, et al. Effect of probiotic supplementation on cognitive function and metabolic status in Alzheimer’s disease: a randomized, double-blind and controlled trial. Front aging Neurosci. 2016;8:256 https://doi.org/10.3389/fnagi.2016.00256.

    Article  PubMed  PubMed Central  Google Scholar 

  44. Hu L, Luo M, Huang H, Wu L, Ouyang W, Tong J, et al. Perioperative probiotics attenuates postoperative cognitive dysfunction in elderly patients undergoing hip or knee arthroplasty: a randomized, double-blind, and placebo-controlled trial. Front aging Neurosci. 2022;14:1037904. https://doi.org/10.3389/fnagi.2022.1037904.

    Article  PubMed  Google Scholar 

  45. Ascone L, Garcia Forlim C, Gallinat J, Kühn S (2022) Effects of a multi-strain probiotic on hippocampal structure and function, cognition, and emotional well-being in healthy individuals: a double-blind randomised-controlled trial. Psychol Med:1-11. https://doi.org/10.1017/s0033291722000988.

  46. Zhang J, He Z, Liu L, Li H, Wang T, Zhu X, et al. Probiotic has prophylactic effect on spatial memory deficits by modulating gut microbiota characterized by the inhibitory growth of Escherichia coli. Front Integr Neurosci. 2023;17:1090294. https://doi.org/10.3389/fnint.2023.1090294.

    Article  PubMed  PubMed Central  Google Scholar 

  47. Lee S, Eom S, Lee J, Pyeon M, Kim K, Choi KY, et al. Probiotics that ameliorate cognitive impairment through anti-inflammation and anti-oxidation in mice. Food Sci Anim Resour. 2023;43:612–24. https://doi.org/10.5851/kosfa.2023.e22.

    Article  PubMed  PubMed Central  Google Scholar 

  48. Sikorska M, Antosik-Wójcińska AZ, Dominiak M. Probiotics as a tool for regulating molecular mechanisms in depression: a systematic review and meta-analysis of randomized clinical trials. Int J Mol Sci. 2023 24. https://doi.org/10.3390/ijms24043081.

  49. Trzeciak P, Herbet M. Role of the intestinal microbiome, intestinal barrier and psychobiotics in depression. Nutrients. 2021 13. https://doi.org/10.3390/nu13030927.

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Acknowledgements

This research was supported by the National Natural Science Foundation of China, and we would like to express our gratitude for their support.

Funding

The National Natural Science Foundation of China (NSFC) program provided financial support for this study [Grant number: 82060596].

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Authors and Affiliations

  1. Key Laboratory of Environmental Factors and Chronic Disease Control, School of Public Health, Ningxia Medical University, Yinchuan, China

    HanQing Guo, XueMei Qin, Qing Luo & Qinghan Gao

  2. Pediatrics Department, Ningxia Hui Autonomous Region Maternal and Child Health Care Hospital, Peking University First Hospital, Yinchuan, China

    YanHua Liang

  3. Department of Nutrition, Laizhou People’s Hospital, Shandong, China

    XiuMei Gong

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Contributions

HQG: Conceptualized study, conducted literature search, screening, data extraction, risk of bias assessment, statistical analysis, result interpretation, evidence grading, and drafted manuscript. XMG: Contributed to study conceptualization. XMQ: Conducted literature search, screening, data extraction, risk of bias assessment, and result interpretation. QL: Conducted risk of bias assessment and result interpretation. QHG: Performed statistical analysis and revised manuscript. All authors have carefully reviewed and agreed to the published version of the paper.

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Correspondence to Qinghan Gao.

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Guo, H., Liang, Y., Qin, X. et al. Effects of probiotics on cognitive function across the human lifespan: a meta-analysis. Eur J Clin Nutr 80, 46–61 (2026). https://doi.org/10.1038/s41430-025-01660-8

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