AP Biology class blog for discussing current research in Biology

Author: mitochondriana

Health and Disease in a New Light

Microbiota are groups of organisms that live on and in some mammals. Animals, such as humans, who live in a state of mutualism with these organisms have them mostly on parts of their body with large surface areas. This includes skin and the intestinal tract. The human gut microbiome is a complex community of organisms that have been studied over the past decades and most intensely within the past fifteen years. So far the information on the human gut microbiome is limited and the research on it is somewhat inconclusive, raising more questions than it answers questions; however, that is a side effect of most research that is just beginning to be analyzed more in depth. The idea that we are just now starting to study and understand these organisms that have lived on and in us for centuries is a topic that is cutting edge and very interesting.


A short coverage of information about microbiota in the intestinal tract includes the following. In mammalian animals, these organisms play an important role in the formation of intestinal mucosa as well as a healthy systematic immune system. Animals that lack microbial cells contain abnormal numbers of several immune cell types and immune cell products, as well as have deficits in local and systemic lymphoid structures. Therefore, their spleens and lymph nodes in them are poorly formed and their intestinal mucosa, deficient. Mice with a lack of microbiota were known to have a lower amount of plasma producing cells – which make antibodies of a certain type. This is due to the fact that the microbiota is regulated by the plasma cells in mammals and it is found unnecessary to have a large amount of them in animals lacking the organisms. These mice also exhibited an impaired ability to regulate cytokine levels – any of a number of substances, such as interferon, interleukin, and growth factors, which are secreted by certain cells of the immune system.

In 2010 there was a study done that was comprised of making cultures of these organisms and bacteria in the human intestinal tract outside of the human body because we do not have the necessary technology to study the microbiota in their hosts. This study yielded the publication of a paper titled “Gut Microbiota in Health and Disease” which gives a detailed overview of the findings of this study. Briefly, a colonization of mice lacking microbiota with altered Schaedler flora (ASF) was insufficient to promote differentiation of Th17 cells (which play an important role in defense against infection), despite the fact that ASF includes a number of bacteria from the Bacteroidetes phylum (microbiota). Researchers concluded the there is no way to be sure of the affects of microbiota. Meaning although there was no lack of microbiota, the mice still had an immune system deficiency in the same way that mice lacking any microbiota did. Since the health and abundance of microbiota in the gut microbiome is so closely related with the ability of the immune system of the host, it is concluded that changes in the microbiome can lead to onset of diseases/illnesses in the host. These factors can also change with environmental changes such a dietary choices of the host. Understanding the dynamics of the gut microbiome under different conditions will help us diagnose and treat many diseases that are now known to be associated with microbial communities.

Analyzing the affects of microbiota in the human gut can reveal topics about human pathology that we did not know before. Therefore, scientists look forward to the development of studies on this topic.

Climate Change Affecting Marine Life

In 2016 Luisa Marcelino, research assistant professor of civil and environmental engineering at Northwestern Engineering, and Vadim Backman, Ph.D. Professor of Biomedical Engineering studied biomass of coral reefs. In doing so, their research team developed a quantitative coral bleaching response index. This database took historical statistics pertaining to mass of coral and compared it to an index of later development. By measuring the difference in the two groups of statistics, the team was able to draw conclusions on what specific species and locations were susceptible to bleaching – a phenomenon where coral expel’s its life prolonging algae. As of now, marine biologist do not have a clear response to why does thermal stress affect coral’s ability to sustain itself.


On October second of 2019 a team of researchers from the McCormick school of Engineering published a paper expanding on Marcelino and Backman’s previous work. It validates the current technology used for imaging coral since the technology was initially invented to examine carcinogenic cells in human tissue. The paper, titled “Measuring light scattering and absorption in corals with Inverse Spectroscopic Optical Coherence Tomography (ISOCT): a new tool for non-invasive monitoring,” starts by introducing the fact that the methods by which coral and Symbiodinium (life-prolonging algae within the coral) interact with one another are still unknown. It continues to state how ISOCT is a non-invasive, yet effective way to quantify living tissue in coral reefs along with their structures.

ISOCT measures the sub-micron spatial mass density distribution which helps develop estimates of the spatial directionality of light scattering (i.e. the coefficient and chemical concentration in coral). This technology, through the same methods, can characterize chlorophyll a concentration in skeletal structures of coral as well. By being able to compartmentalize different types of coral and measuring their individual success rates, researchers can then find correlational data and conclude which species and locations are in need of biomedical support against thermal stress. Characterizing their differences is a crucial part because it will also help scientists hypothesize and eventually discover in what way Symbiodinium and coral interact.






In the same way that biologists are not currently knowledgable about the relationship between the algae coral secretes under sub-optimal environmental conditions and the coral reef itself, they are also not certain about the ways in which escalated temperatures affect the physiology of coral. Once both of these occurrences are studied further it is believed that newly gathered information could give rise to new ways to protect coral reefs as well as new ways to harness solar energy.

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