What Our Gut Microbiota Can Tell Us About Ourselves

Researchers have discovered a unique way to get a glimpse into how our body works. Gut microbiota, the composition of the bacterial species in our intestine, can serve as a physical display of the activity of important body processes. Our daily behavior, diet, and mental health can impact the gut microbiota, which then mediates the way that our body functions through metabolic processes and mental functioning. Overall, looking at the bacterial species in our gut is an important start to developing new methods to diagnose and treat issues faced by the bodies.

The composition of our gut microbiota has a vital influence on our metabolic processes. Understanding the influence of bacterial composition in different organisms can help researchers identify the roles that microbial species play in our body. For instance, in a study by Dr. Ridaura from Washington University, researchers transplanted the gut microbiota of obese mice into lean mice. To reduce the influence of external bacteria and genetic differences, the mice were same-sex twins and the lean mice were germ-free. In no time, these lean mice were experiencing the symptoms of obesity found in the obese mice, such as metabolic dysfunction and increased fat accumulation rates, demonstrating the causal impact the bacterial makeup of one’s body can have on metabolism (Ridaura et al., 2014).

This seminal paper indicated that our bacterial composition has a causal role in the functions of our body. Identifying this causal role was vital, as it informed researchers on the role of the gut microbiota in other aspects of our body and made it a point of intervention for new treatments. Further research into the differences between obese and lean organisms can help researchers identify specific microbial species that play a role in influencing our bodies. For instance, a bacterial species known as Akkermansia muciniphila, isolated more than a decade ago, is involved with body metabolism and serves as an anti-inflammatory agent. Studies have shown its depletion in those experiencing the symptoms of obesity and metabolic dysfunction, as well as its presence in those with reduced levels of liver dysfunction and inflammation markers (Depommier et. al, 2019). The bacteria’s significant impact on the body makes Akkermansia muciniphila a target for therapeutic use, perhaps in the form of a probiotic meant to provide additional beneficial bacteria to the body.

Furthermore, researchers have discovered that it is not only the presence of bacterial species that matters, but their diversity as well. The overexpression or suppression of bacterial species can also lead to serious health implications. This disruption, known as dysbiosis, is an important topic of study in the field, as this phenomenon mediates our physical and mental health (Larsen & Claasen, 2018).

The Gut-Brain axis is a bidirectional relationship between our brain and bacterial species which particularly suffers the consequences of dysbiosis. A study that worked with soldiers in a military training session measured the relationship between their gut microbiota composition and physiological stress, and discovered a change in bacterial diversity: the increased presence of less dominant taxa (Karl et al., 2017). This bacteria included Peptostreptococcus, Staphylococcus, Peptoniphilus, etc. that are potentially infectious and harmful. There were also changes in metabolism and increased inflammation, a glimpse into the attributes that the gut microbiota could potentially mediate. These interactions between stress and the gut microbiome have been constantly identified, yet it is very difficult to establish the primary agent of this interaction. Studies indicating this bidirectional relationship suggest that psychosocial factors, such as hostility, stress levels, and even relationship satisfaction, manipulate our gut microbiota into responding in their own way.

As we learn more about the importance of microbial species, researchers are trying to refine methods of gut microbiota manipulation. Common methods include the use of antibiotics, probiotics, and prebiotics targeted toward harmful gut bacterial species and their overexpression. However, antibiotics, which usually have a wide range of targets, could also eliminate healthy bacteria. This encourages us to find methods that are more specific in their outreach. Physicians and clinical scientists involved in bariatric surgery (Debedat et al., 2019) and type 2 diabetes mellitus (Gurung et al., 2020) have found the gut microbiota as a prospective avenue for treatment.

There is a lot more to unearth regarding the gut microbiota, especially concerning the specifics of the pathways that they engage in, but studies thus far have shown its potential as a tool for screening, analysis, and treatment of our body’s state of functionality. From a public health perspective, as we are aware of how our diet and our gut microbiome interact (Rowland et al., 2018), we must understand the type of food that is accessible to communities. Further analysis can be done to understand how a poor diet and food deserts can disrupt our gut microbiome, and as a result, our overall physical and mental health.

References

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G., Raes, J., Maiter, D., Delzenne, N. M., de Barsy, M., Loumaye, A., Hermans, M. P., Thissen, J. P., de Vos, W. M., & Cani, P. D. (2019). Supplementation with Akkermansia muciniphila in overweight and obese human volunteers: a proof-of-concept exploratory study. Nature medicine, 25(7), 1096–1103. https://doi.org/10.1038/s41591-019-0495-2

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(2020). Role of gut microbiota in type 2 diabetes pathophysiology. EBioMedicine, 51, 102590. https://doi.org/10.1016/j.ebiom.2019.11.051

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