Introduction:

Kefir is a traditional fermented dairy beverage originating from the Caucasus mountains. It is composed of many important probiotic bacterial strains that confer psychobiotic effects (Bourrie et al., 2016; Tillisch et al., 2013). These psychobiotic effects may stem from the ability of kefir to modulate the microbiota gut-brain axis, and influence neurological functions and cognition (Van De Wouw et al., 2020). In humans, kefir has been shown to ameliorate cognitive dysfunctions in postmenopausal women and neurodegenerative disease patients (Ton et al., 2020; Özcan et al., 2019) Given that kefir is usually sold in grocery stores, drinking kefir can be an easily accessible and cost-effective approach to improve our brain health.

Future Research

Mechanisms on how kefir affects microbiota-gut-brain axis

Factors affecting the final quality and bacteria composition of kefir, e.g. % kefir grain, temperature

Larger and longer randomized controlled studies of kefir in neurological/neuropsychiatric diseases

References

Bourrie, B. C. T., Willing, B. P., & Cotter, P. D. (2016). The microbiota and health promoting characteristics of the fermented beverage kefir. Frontiers in Microbiology, 7(MAY), 1–17. https://doi.org/10.3389/fmicb.2016.00647

Tillisch, K., Labus, J., Kilpatrick, L., Jiang, Z., Stains, J., Ebrat, B., Guyonnet, D., Legrain-Raspaud, S., Trotin, B., Naliboff, B., & Mayer, E. A. (2013). Consumption of fermented milk product with probiotic modulates brain activity. Gastroenterology, 144(7), 1394-1401.e4. https://doi.org/10.1053/j.gastro.2013.02.043 

Van De Wouw, M., Walsh, A. M., Crispie, F., Van Leuven, L., Lyte, J. M., Boehme, M., Clarke, G., Dinan, T. G., Cotter, P. D., & Cryan, J. F. (2020). Distinct actions of the fermented beverage kefir on host behaviour, immunity and microbiome gut-brain modules in the mouse. Microbiome, 8(1), 1–20. https://doi.org/10.1186/s40168-020-00846-5 

Ton, A. M. M., Campagnaro, B. P., Alves, G. A., Aires, R., Côco, L. Z., Arpini, C. M., Guerra E Oliveira, T., Campos-Toimil, M., Meyrelles, S. S., Pereira, T. M. C., & Vasquez, E. C. (2020). Oxidative Stress and Dementia in Alzheimer’s Patients: Effects of Synbiotic Supplementation. Oxidative Medicine and Cellular Longevity, 2020. https://doi.org/10.1155/2020/2638703

Özcan, H., Oskay, Ü., & Bodur, A. F. (2019). Effects of Kefir on Quality of Life and Sleep Disturbances in Postmenopausal Women. Holistic Nursing Practice, 33(4), 207–213. https://doi.org/10.1097/HNP.0000000000000310 

Bourrie, B. C. T., Willing, B. P., & Cotter, P. D. (2016). The microbiota and health promoting characteristics of the fermented beverage kefir. Frontiers in Microbiology, 7(MAY), 1–17. https://doi.org/10.3389/fmicb.2016.00647

Hamet, M. F., Medrano, M., Pérez, P. F., & Abraham, A. G. (2016). Oral administration of kefiran exerts a bifidogenic effect on BALB/c mice intestinal microbiota. Beneficial Microbes, 7(2), 237–246. https://doi.org/10.3920/BM2015.0103  

Serafini, F., Turroni, F., Ruas-Madiedo, P., Lugli, G. A., Milani, C., Duranti, S., Zamboni, N., Bottacini, F., van Sinderen, D., Margolles, A., & Ventura, M. (2014). Kefir fermented milk and kefiran promote growth of Bifidobacterium bifidum PRL2010 and modulate its gene expression. International Journal of Food Microbiology, 178, 50–59. https://doi.org/10.1016/j.ijfoodmicro.2014.02.024

Cryan, J. F., & Dinan, T. G. (2012). Mind-altering microorganisms: The impact of the gut microbiota on brain and behaviour. Nature Reviews Neuroscience, 13(10), 701–712. https://doi.org/10.1038/nrn3346

Tillisch, K., Labus, J., Kilpatrick, L., Jiang, Z., Stains, J., Ebrat, B., Guyonnet, D., Legrain-Raspaud, S., Trotin, B., Naliboff, B., & Mayer, E. A. (2013). Consumption of fermented milk product with probiotic modulates brain activity. Gastroenterology, 144(7), 1394-1401.e4. https://doi.org/10.1053/j.gastro.2013.02.043 

Özcan, H., Oskay, Ü., & Bodur, A. F. (2019). Effects of Kefir on Quality of Life and Sleep Disturbances in Postmenopausal Women. Holistic Nursing Practice, 33(4), 207–213. https://doi.org/10.1097/HNP.0000000000000310

Ton, A. M. M., Campagnaro, B. P., Alves, G. A., Aires, R., Côco, L. Z., Arpini, C. M., Guerra E Oliveira, T., Campos-Toimil, M., Meyrelles, S. S., Pereira, T. M. C., & Vasquez, E. C. (2020). Oxidative Stress and Dementia in Alzheimer’s Patients: Effects of Synbiotic Supplementation. Oxidative Medicine and Cellular Longevity, 2020. https://doi.org/10.1155/2020/2638703

Van De Wouw, M., Walsh, A. M., Crispie, F., Van Leuven, L., Lyte, J. M., Boehme, M., Clarke, G., Dinan, T. G., Cotter, P. D., & Cryan, J. F. (2020). Distinct actions of the fermented beverage kefir on host behaviour, immunity and microbiome gut-brain modules in the mouse. Microbiome, 8(1), 1–20. https://doi.org/10.1186/s40168-020-00846-5