2023: Year of the gut microbiota

2023: Year of the gut microbiota

Kevin Meza Achahue, Scientist - R&D Specialist at Bifidice. 3 minutes reading.

Science is advancing by leaps and bounds, and research on the gut microbiota is keeping pace. As we close out the year 2023, we want to highlight the most significant advances that have allowed us to better understand how the gut microbiota works and how it can impact numerous processes in our bodies.

1. In what way is Alzheimer's disease related to the intestinal microbiota?

Research has shown that specific symptoms associated with Alzheimer's disease could be transferred through the gut microbiota. Analyses revealed that recipient model animals, transplanted with the intestinal microbiota from patients with this type of dementia, developed cognitive and behavioral problems associated with hippocampal neurogenesis. 

The extent of dysfunction in mice correlated with the clinical cognitive scores of the donor patients. Thanks to this research, the direct involvement of gut microbiota imbalance in the development of this disease was demonstrated for the first time [1].

2. The Role of the Microbiota in the Heterogeneity of Depression

In an analysis conducted on 179 patients with major depressive disorder, it was found that alterations in the gut microbiota were significantly associated with mood disorders. Through the use of advanced bioinformatic tools, certain bacterial taxa associated with these symptoms were identified, including taxa from the families of microorganisms Ruminococcaceae, Christensenellaceae, and Clostridiales vadinBB60. 

Interestingly, other imbalanced bacteria were producers of butyrate, which could indicate that deficits in butyrate production at the level of the gut microbiota may contribute to clinical symptoms [2].

3. The Importance of a Diverse Microbiota in the Face of Pathogen Emergence

One of the most crucial roles of the intestinal microbiota is protection against pathogenic microorganisms. According to recent research, this property is achieved through “nutrient blocking” towards bacteria harmful to the host's health. 

Based on in vitro and in vivo results, it was found that as the microbiota increases in diversity, it collectively consumes multiple types of nutrients, some of which are the main source for pathogenic microorganisms, placing them at a disadvantage for colonizing the gastrointestinal tract [3].

4. More evidence of the gut microbiota - respiratory tract axis

In an in vitro study, a dose-dependent relationship was found between certain pathogenic bacteria of the intestinal microbiota and the increase in cytokines and interleukins, which is associated with an immune system response. According to the results, this inflammatory process could be directly related to the development of asthma in patients, thus connecting once again the role of an imbalanced microbiota with the development of respiratory tract diseases.

It is presumed that dysbiosis in early stages of life could predispose individuals to these diseases, which can be mitigated through changes in diet and the use of probiotics [4].

5. Maternal microbiota and fetal development.

Finally, new evidence shows an interesting connection between maternal microbiota and fetal development, at least when analyzed in murine models. It was found that mice with different gut microbiotas (germ-free or specific pathogen-free) could induce changes in the gene expression of mouse fetuses.

This differential gene expression was related to innate immunity, epithelial barrier, and inflammatory signaling, indicating the importance of maternal microbiota in the development of the offspring's immune system, even before birth. Although evidence pointing to these types of interactions in humans is lacking, this result could be crucial for understanding the importance of a balanced intestinal microbiota in pregnant individuals [5].

On behalf of the entire Bifidice team, we wish you a Merry Christmas and a prosperous New Year!



[1] Grabrucker, S., Marizzoni, M., Silajdžić, E., Lopizzo, N., Mombelli, E., Nicolas, S., Dohm-Hansen, S., Scassellati, C., Moretti, D. V., Rosa, M., Hoffmann, K., Cryan, J. F., O'Leary, O. F., English, J. A., Lavelle, A., O'Neill, C., Thuret, S., Cattaneo, A., & Nolan, Y. M. (2023). Microbiota from Alzheimer's patients induce deficits in cognition and hippocampal neurogenesis. Brain, 146(12), 4916-4934. doi: 10.1093/brain/awad303.


[2] Chin Fatt, C. R., Asbury, S., Jha, M. K., Minhajuddin, A., Sethuram, S., Mayes, T., Kennedy, S. H., Foster, J. A., & Trivedi, M. H. (2023). Leveraging the microbiome to understand clinical heterogeneity in depression: findings from the T-RAD study. Translational Psychiatry, 13(1), 139. doi: 10.1038/s41398-023-02416-3. https://www.nature.com/articles/s41398-023-02416-3 

[3] Spragge, F., Bakkeren, E., Jahn, M. T., Araujo, E. B. N., Pearson, C. F., Wang, X., Pankhurst, L., Cunrath, O., & Foster, K. R. (2023). Microbiome diversity protects against pathogens by nutrient blocking. Science, 382(6676), eadj3502. doi: 10.1126/science.adj3502. Epub 2023 Dec 15. https://www.science.org/doi/10.1126/science.adj3502 

[4] Kleniewska, P., Kopa-Stojak, P. N., Hoffmann, A., & Pawliczak, R. (2023). The potential immunomodulatory role of the gut microbiota in the pathogenesis of asthma: an in vitro study. Scientific Reports, 13(1), 19721. doi: 10.1038/s41598-023-47003-0. https://www.nature.com/articles/s41598-023-47003-0#Sec2 

[5] Husso, A., Pessa-Morikawa, T., Koistinen, V. M., Kärkkäinen, O., Kwon, H. N., Lahti, L., Iivanainen, A., Hanhineva, K., & Niku, M. (2023). Impacts of maternal microbiota and microbial metabolites on fetal intestine, brain, and placenta. BMC Biology, 21(1), 207. doi: 10.1186/s12915-023-01709-9. https://bmcbiol.biomedcentral.com/articles/10.1186/s12915-023-01709-9 

Back to blog