Written By Henry Chang
Eating isn’t quite as simple as chewing and swallowing. Most of the action is taking place inside the human body. In fact, a tremendous amount of effort is required to digest even a bite-sized carrot. What happens involves trillions of helpers – microorganisms—for humans to absorb the nutrients from food. In the digestive system alone, there are a variety of species that reside in the mouth and the stomach. They, as well as swaths of other microbes in humans, have been categorized together as the human microbiome; the collective identity of microorganisms that reside in and on the human body [1]. The fascinating truth is that each person holds a unique microbiome that has been continually customizing since birth.
Applications of this knowledge have been a hot topic of healthcare research because of the information that new high-speed, large-scale, repetitive techniques in technology yield. In April 2003, the Human Genome Project (HGP), a modern scientific feat formed through international collaboration, was finally completed. From it, the human genome was sequenced, allowing researchers worldwide to study the building blocks of what makes humans human [2]. Inspired by the HGP, the Human Microbiome Project (HMP) was launched in 2008, designed to “push the frontiers of human microbiology by providing the data, tools, and resources to inform medical science more fully about the role of changes in the resident human microbiome in disease and health” [3]. Besides being important in digestion, the human microbiome influences how individuals interact with their surroundings. This is manifested by certain diet restrictions or environmental sensitivities, and even diseases. These maladies have long been explained by referencing DNA modifications, but the extraordinary numbers of microorganisms living on every body inevitably play a part as well.
Past research has shown that the diet of mothers and their consequent gut microbiotas have a large impact on their children’s microbiomes, suggesting that disease susceptibility begins in the womb [4]. Furthermore, significant differences in gut microbiota have been observed between infants born vaginally and those delivered by cesarean sections, and these differences continue to develop based not only on how, but also where they live [5]. Given these findings, several scientists are now investigating how microbiome composition of populations from an array of regional socioeconomic statuses can lead to avoidable health differences known as health disparities [6]. This approach uses three overlapping concepts that shape human health–biological systems, social and physical environment, and the microbiome – to pinpoint what factors are strongly associated with disease. In time, it will allow them to better describe the value of nutrition and other factors in order to garner more political action and to strategically improve public health policies.
By questioning the eating process, scientists have learned more about the human microbiome, but its multifaceted activity, even outside of eating, has urged them to obtain a more encompassing understanding. To do so, researchers have globally initiated the ambitious HMP. Much still remains unknown, but the steps taken thus far look promising for the future.
References:
1. Van de Wiele, T., Van Praet, J. T., Marzorati, M., Drennan, M. B., & Elewaut, D. 2016. How the microbiota shapes rheumatic diseases. Nature Reviews Rheumatology. 12:398-411.
2. Collins, Francis S., Michael Morgan, and Aristides Patrinos. 2003. The Human Genome Project: lessons from large-scale biology. Science. 300:286-290.
3. Peterson, J., Garges, S., Giovanni, M., McInnes, P., Wang, L., Schloss, J. A., … & Baker, C. C. 2009. The NIH human microbiome project. Genome research. 19:2317-2323.
4. Wesolowski, S. R., El Kasmi, K. C., Jonscher, K. R., & Friedman, J. E. 2016. Developmental origins of NAFLD: a womb with a clue. Nature Reviews Gastroenterology & Hepatology. 14:81-96.
5. Kuang, Y. S., Li, S. H., Guo, Y., Lu, J. H., He, J. R., Luo, B. J., … & Xia, H. M. 2016. Composition of gut microbiota in infants in China and global comparison. Scientific Reports. 6:36666.
6. Findley, K., Williams, D. R., Grice, E. A., & Bonham, V. L. 2016. Health Disparities and the Microbiome. Trends in microbiology. 24:847-850.