London and Oxford Trip

The Gut-Brain Axis and How What We Eat Affects How We Feel

Recently I had the opportunity to visit Oxford and London with my Art in Science cohort. Several parts of our time there contributed to my ongoing microbiome research and they were all displayed to the public in different ways, including a lecture, performance art, and a museum exhibit. In the following I will reflect on each of these as they relate to my research and art-science collaborations as a whole, beginning with the lecture I attended.

While in Oxford, I attended a lecture given by Dr. Philip W.J. Burnet entitled “The Gut-Brain Axis and How What We Eat Affects How We Feel.” I was excited to be part of the crowd at this lecture, as it coincides quite well with my area of research.

Dr. Burnet began by explaining the difference between probiotics and prebiotics (if you are unsure of the difference, check out my earlier blog post here). Prebiotics include foods such as lentils, green peas, chickpeas, and garlic. He went on to explain how the gut-brain axis regulates food intake through hormonal feedback loops. For example, a nutrient-sensing G-protein-coupled receptor (basically, a gut “taste receptor”) in an intestinal L-cell will elicit a hormonal response, which will be picked up by the vagus nerve, which will send a signal up to the brain stem, and from there to the hypothalamus. The hypothalamus is a part of the brain that regulates increase and decrease in food intake. The brain and the gut are “talking” to each other via the vagus nerve, and this is a two-way conversation. While the brain will send neurotransmitters such as serotonin and dopamine to the gut, the gut microbiota can respond with serotonin, as well as leptin. Since the gut bacteria are in intimate physical contact with the intestinal walls, they affect the intestinal feedback to the brain.

photography of garlic on wooden table
Photo by Skitterphoto on

Contrary to popular belief, there are not actually twice as many bacterial cells than human cells in the human body. According to Dr. Burnet, recent research reveals that there are actually about 1.3 times as many bacterial cells than there are human cells. The most well-known “friendly” bacteria are Lactobacillus and Bifidobacterium (both of which I have previously come across in my research). But even “unfriendly” bacteria live in the human gut normally; they are just kept at bay by the other bacteria. The basic difference between good and bad bacteria is the type of coats they wear: bad bacteria wear coats that elicit a “pro-inflammatory” response, while good bacteria do not. High fat, high sugar diets promote the growth of the former kind of bacteria, while high fiber diets promote the growth of good bacteria. Bacteria affect the way the gut responds to the food it is fed, and thus influence the brain through the gut-brain connection

The novel part of probiotic studies is not that they make us healthier, but that they improve our mood. The first study to show a connection between gut bacteria and mood was with germ-free mice. These mice had been cleansed of all of their bacterial colonies and showed lower sociability and higher stress response. Upon addition of good bacteria, the mice became more sociable and less jumpy.

Since the germ-free mice study, probiotics have shown themselves to help improve mood in patients with chronic fatigue syndrome. They also appear to improve metacognition in patients with MDD. That means probiotics not only affect our mood but how we think about our mood, which is a form of metacognition.

Prebiotics have been shown to reduce anxiety, improve problem solving abilities, and possibly even optimize metabolism. They can even cause waking cortisol levels to decrease, much like an antidepressant. Schizophrenia can be affected by gut bacteria. Patients who took prebiotics noticeably improved in basic cognitive assessments, which led researchers to wonder if the same could be true for patients with dementia.

pre- and post-supplement waking cortisol
Waking cortisol levels (blue) noticeably  decreased with GOS prebiotic supplement. Find full article here

I found it particularly interesting to learn how probiotics break down other chemicals. Pomegranates contain chemicals that are good for the brain but cannot normally cross the blood-brain barrier. However, the addition of probiotics has been shown to break down the chemicals enough that they may cross the barrier and deliver their benefits to the brain. This goes to show that while one single food or ingredient probably won’t save you (for instance, a pomegranate), making it part of a healthy, balanced diet (in this case, one that includes probiotics) can indeed deliver a health benefit.

sliced pomegranate
Pomegranates contain chemicals that are good for the brain

I was curious what others are saying about food and mood, so I did some cursory reading of online sources. In so doing I was bombarded with many different articles claiming that different diets could beat depression, that I think if I was someone seeking help in that area, I would have become overwhelmed by trying to discern which of these diets I should try. I am skeptical of most lists that have titles sounding anything like “eat these 10 foods every day to beat depression,” as different people may respond to the same food product in different ways. However, a recurring theme seems to be that eating more leafy greens and seafood and less sugary and processed food is generally helpful. I cannot help but wonder if leafy greens and seafood were presented as mood-boosting, such as through package design or presentation, people might be more likely to put this advice into practice. That could be an interesting avenue of art/science collaboration for future research.

Do you have any experience with using diet to treat mood disorders? Do you think food packaging design and presentation can/should be used to encourage more mental health-conscious decisions? Please comment below.

Microbiome Rebirth Incubator

While in London, I saw the latest exhibit at the Science Gallery, Spare Parts, an exhibition informed by conversations about cutting-edge research into the transplantation and regeneration of the human body. One of the exhibits in Spare Parts, called the Microbiome Rebirth Incubator, I found particularly interesting in regard to my research. Created by biologist/artscientist François-Joseph Lapointe and art historian/bioartist Marianne Cloutier, the Microbiome Rebirth Incubator symbolically explores the possibility of seeding newborn babies with their mother’s microbiome in order to enhance their health. According to our exhibition guide, this is particularly relevant for babies born through caesarians. When a baby is born through the birth canal, it is introduced for the first time to certain essential bacteria that live in that locality of the mother’s microbiome. This essential contact is lost in a caesarian section. According to this article, the initial development of the neonatal microbiome is of such importance that disrupting it through C-section may increase risk of celiac disease, asthma, type 1 diabetes, and obesity. Therefore, engineering a way to introduce those bacteria regardless of birthing process could be a great development for infant health.

Microbiome Rebirth Incubator_1
The Microbiome Rebirth Incubator

A video is shown alongside the art work itself, showing it in use. In this way Microbiome Rebirth Incubator could be classified as performance art. It is also placed next to a small room with a couch and a video of a mother breast feeding her baby; a space designed for mothers to nurse while at the exhibit.

The placement of the exhibit is significant for the further reason that it is positioned in the “gut space” of Spare Parts. This “gut space” includes a peculiar little exhibit called “SuperTurd Card Game” by artists Caitlin Foley and Misha Rabinovich. In the card game, designed to highlight the complex ecology of bacterial exchange, players strive to collect cards that increase microbiome diversity. The players are encouraged to begin the game with freshly washed hands and trace the spread of bacteria using fluorescent hand gel and UV light.

SuperTurd Card Game [Photo credit: Sophia Charuhas; Science Gallery London, March 2019]

The Microbiome Rebirth Incubator demonstrates a recurring theme that I have noticed in microbiome research, as well as in the study of art-science collaborations: that often our best innovations are, in some way or another, returning to and/or mimicking nature. A natural process, be it eating a pomegranate or giving birth, tends to reveal itself to be much more multifaceted and complex than we originally realized. Who knows if such processes could turn out, through further research, to be even more complex than we currently can imagine?

Spare Parts is a great example of art-science collaborations. Even though it is marketed as an art gallery, and displayed as such, many of the art works are proposed technologies. They are not meant to be science experiments, but are, in a way, experimental. If they were not fully functional biotechnologies, they were at least prototypes. Microbiome Rebirth Incubator contributes to the conversation in which it originated, while also moving the conversation forward through an imagined future in which infants can receive microbiome-aware care. It brings the laboratory into the public eye, and is truly an art-science collaboration in the fullest sense of the term.

The ethics of the Microbiome Rebirth Incubator were debated in Copenhagen in 2017. The technology would involve immersing a newborn baby in a pool of amniotic fluid, vaginal secretions, human feces, and breast milk. Do you think this is ethical? Please comment below.

Bacterial Worlds

Embroidered petri dishes [Photo credit Sophia Charuhas; Oxford Museum of Natural History, March 2019]

I learned of a group of bacteria called Leuconostoc, also known as the food-fermenters. They were first discovered living in vats of bubbling syrup in sugar factories. These bacteria play a role in creating the fermented foods of many traditional diets, including but not limited to sauerkraut, kimchi, kefir, and sourdough bread. Leuconostoc converts the sugars in the food into lactic acid. Lactic acid acts as a preservative and gives fermented food its signature sour taste. The holes in certain cheeses appear because Leuconostoc convert lactic acid into carbon dioxide gas.

sliced cheese on brown table top
Photo by NastyaSensei Sens on

The exhibit covered much of the same information as did Dr. Burnet’s lecture – such as the differences between probiotics and prebiotics, and the studies of germ-free mice. It also included some artifacts of microbiome research, like a sampling kit that can be sent off to a lab for testing. Such a kit can aid in research as no one yet knows exactly what combination of bacteria ought to exist in a healthy gut (if such a particular combination is to be found), and a fecal transplant tube.

Display of artifacts [Photo taken by me; Oxford Museum of Natural History, March 2019]

As an art-science collaboration exhibit, I thought Bacterial Worlds heavily leans toward the science side. Although many of the points were illustrated, they were not illustrated for the most part in any artistically inventive way (save perhaps the embroidered petri dishes). It was not demonstrative art, as can be seen in Spare Parts, and the artwork did not invite visitor interaction for the most part, with the exception being some screens that could be tapped for more information, or to watch a short video. A writer from New Scientist wrote that Bacterial Worlds was “a tremendous exhibition, punching way above its tiny weight.”

I am afraid I did not feel the same way. Although Bacterial Worlds contained more content which was directly relevant to my current research, I found that Spare Parts to be more visually and intellectually compelling. While Bacterial Worlds was arranged in a line down a single hallway, with much of the visual interests posted flat on the walls, Spare Parts was arranged in several interconnected rooms, with the visual interests standing alone in the centers of the rooms and taking many forms (as opposed to poster presentations). Spare Parts was more tactile – Bacterial Worlds did not include much that was hands-on.

What are you experiences with art-science collaborations? Do you feel engaged by such installations? Please comment below.