Naturally Inspiring

April 13, 2023April 13, 2023

Sizing up Salmon

By Grace Veenstra

This article covers the 2020 study by Ulaski, Finkle and Westley on the direction and magnitude of natural selection of body size among age-classes of seaward-migrating sockeye salmon.

“Bigger Isn’t Always Better”

The idea that “bigger is better” is a prevalent one in biology. Body size has a significant impact on fitness, the ability of organisms to survive and reproduce, across all branches of life. In wolves, a larger body size gives them greater success in grappling and subduing large prey like moose or elk (MacNulty et al., 2009). In dall sheep, a larger body size gives males a reproductive advantage when they compete for the right to mate, and since adult sheep may lose up to 16% of their body mass during winter, those with a higher body mass are more likely to survive (U.S. National Park Service, 2020). However, “bigger” is not always a “better” lifestyle method for some animals, and can be actively harmful to their chances of survival.

Insects and arthropods are limited in their body size because they breathe by soaking in oxygen like a sponge. If they are too large, they cannot absorb sufficient oxygen and die of hypoxia. It was only during the Paleozoic, when oxygen concentrations reached as high as 35% during the Carboniferous period, that insects were capable of gigantism, with some dragonflies as large as seagulls (Harrison et al., 2010). Furthermore, it is costly to support a large body mass: the larger the body, the greater the energy requirements and the more food is required to sustain the animal. There are also factors of predation, where a larger body size may reduce agility, increase detection by predators, or increase costs to reproduction (Blanckenhorn, 2000). In essence, how natural selection acts on size is complex. Understanding how size correlates with survival is important, particularly when we are examining the salmon populations of Alaska.

April 11, 2022April 14, 2022

Finish your antibiotics completely, the future depends on it!

Background

You’ve most likely had an infection that required treatment with antibiotics. At the time that you were prescribed antibiotics, you probably heard that familiar spiel about needing to take the entire course of antibiotics even if you feel better before finishing them. You might be wondering, why does it matter? Hopefully after reading this post you will be able to answer that question for yourself.

As you might imagine, bacteria developing the ability to survive antibiotic treatment is bad news for us. This means that over time, our commonly used antibiotics are becoming less effective at killing bacteria. As bacteria evolves more antibiotic resistance, we may no longer be able to treat common infections unless we come up with another alternative treatment. It is important that we try to delay the evolution of antibiotic resistance as much as we can to buy time to develop other effective treatments. So what are the driving forces of bacterial evolution and what can we do about it?

October 22, 2021October 26, 2021

Rat Microbiomes and Metabolites; a Way to Learn About the Human Stress Response?

Stress, Development, and the Microbiome

Stress, the sort that persists and comes from sources beyond our control, can be detrimental to our health, and even more so to the young (Luna R. et al. 2015). When outside sources of stress are present from a young age, normal development and the adult stress response is impacted in a way that makes healthy coping with stress more difficult throughout life (McEwen et al. 2011) (Eliand L. et al. 2013). Environmental stressors can not only cause developmental changes and impact overall health but can also cause changes to a person’s microbiome or the sum of microbes that coexist with an individual. Which could in-turn alter the sort of metabolites a person secretes (Verbeke K et al. 2015).

Sprague Dawley rat from Charles River Laboratories Source: crivier.com

October 22, 2021

Mental to Dental Connection

Background

Mental health diseases like depression and anxiety have plagued humans presumably since we achieved sentience, and lately it seems like the mental health crisis in America is getting worse and worse. Everyone blames this rise on something different; social media, the pandemic, tumultuous politics, or just the dramatics of younger generations. No matter where the blame is placed, statistics show that the rise in the number of diagnoses is real. Almost all mental health diseases show growth, but anxiety and depression have skyrocketed (ADAA). Even before the COVID 19 pandemic, anxiety was at an all time high, as shown in the figure below.

Fig. 1: These graphs show the number of people diagnosed with anxiety in 1990 (left) and 2017 (right). The United States shows a drastic increase. Darker areas indicate higher numbers of anxiety diagnoses. Image sourced from Our World in Data.

October 22, 2021

Athletes Have Unique Gut Microbial Communities

Background

People may be familiar with products that claim to impact gut health via probiotics and prebiotics, like kombucha and supplements. Prebiotics are plant fibers that encourage growth of beneficial gut bacteria, while probiotics are usually live bacteria that are associated with good gut health (Mayo Clinic Staff, 2021). Diversity comes up often in discussions about gut microbes. Diversity refers to the amount of different species present in a sample, and more diverse samples contain a wider range of microbes. We know that a less diverse community of gut microbes is associated with inflammatory bowel diseases (Cénit et al., 2014) and obesity (Turnbaugh et al., 2008). However, relatively little is known about how the performance of endurance exercise might impact the microbes living within the gut.

October 22, 2021October 26, 2021

Gutsy Irish Cricket Players Remarkably Transformed by Their Travels

Background:

International travel is part of modern life, your life. Whether that is visiting family in Europe, business trips to Asia, or a dream vacation to the tropics, these all have something in common. The microbes and germs in these places are different and not what your body is used to at home.

Your body is covered, inside and out, with little microbes that influence your health both mentally and physically (Beaumont et al. 2018. Hathaway et al. 2021). These symbionts (organisms that coexist and interact closely with another organism) are not the same for every person, especially at a global scale. Recent advancements in global sampling of microorganisms has shown that novel and unknown microbes are not only common in the cities of the world but often differ based on the climate, country, and various other environmental factors. Consequently, when a person travels to a new part of the globe, they are exposed to microbes that their bodies may never have seen before and contact with microbes like these can lead to some uncomfortable conditions (Danko et al. 2021).

October 22, 2021

The Future of Predicting Cancer Could Involve Microbes

Background

Colorectal Cancer (CRC) makes up a large proportion of cancer in the United States. CRC occurs in two locations, the colon and rectum. It is the 3rd most diagnosed type of cancer in the U.S., and in 2021 it is estimated there will be just over 100,000 cases of colon cancer and around 45,000 cases of rectal cancer leading to more than 50,000 deaths (American Cancer Society, 2021).

Colorectal cancer causes the third most cancer-related deaths among men and women separately, and if you combine into one population it causes the second most. The actual death rate of CRC has decreased in the last couple of decades due to increase in effectiveness and quantity of screenings (e.g. colonoscopy) which look for signs of CRC, including polyps (small clump of cells that can be cancerous) located in the rectum/colon (Stewart and Carter-Templeton, 2017). Even with the ability to screen and look for physical changes in the colon/rectum, many people still die from CRC and it is a major problem facing the field of oncology and medicine in general.

October 22, 2021October 26, 2021

Are Your Microbes Making You Anxious?

Background:

Anxiety and depression are at an all-time high, with more diagnoses and higher disability ratings (Spitchak, 2020). Mental health disorders like this have been linked to inflammation in the gut, as the immune system is activated by stress (Spitchak, 2020). Cognitive Behavioral Therapy and anxiety-reducing medications like benzodiazepines are the current gold standard for managing long-term chronic stress and anxiety, as well as short-term needs like panic or anxiety attacks (Ballenger, 2000). These methods do help, but some people have drug-resistant depression, and others simply prefer a greater variety of options to manage their symptoms. Getting outside more has long been accepted as a mental health boost, both from the calming peaceful environment to the vitamin D exposure, to the clean air, and even the soil microbes (Asprey, 2021). A less conventional option than a simple walk may exist and appears to be emerging after 16 plus years of research by Chris Lowry, who has been working with the soil bacterium M. vaccae since the early 2000s.

October 22, 2021

The way to one’s heart is through their stomach

Background:

Over the pasting years, atherosclerosis continues to be the number one killer in the United States (Heart disease facts 2021). This chronic inflammatory disorder is the foundation of heart disease (CVD) and happens when dietary cholesterol builds up in our arteries. With the accumulation of cholesterol comes arterial wall damage and the prevention of oxygen-rich blood circulating smoothly throughout the body. Fatty streaks then progress into advanced lesions followed by strokes, heart attacks, and death.

There have been several suggestions to decrease the illness and mortality of CVD. Statins have been prescribed to patients to reduce the production of cholesterol. Alternatively, stents have been surgically inserted in patients to keep blood flowing through narrowed arteries. Yet, the mortality rate from CVD continues to rise. Researchers propose to tackle this issue at a different angle: the gut microbiome. Does your gut health play a role in promoting CVD? You bet it does. Previous studies have suggested that the excessive consumption of animal products along with their interactions with the gut microbiome can play a substantial role in the progression of CVD (Witkowski et al., 2020).

October 21, 2021

Are Pet Owners’ Microbiome Unique?

A Brief Background:

Microbes found in our body and gut are responsible for many different functions of everyday life. Specifically, the human microbiome has prominent influences on health and disease (Kates et al., 2020). Have you ever questioned what can contribute to changes in our microbiome? The microbiome is defined as the community of microorganisms such as bacteria or fungi in a specific environment (Ursell et al., 2012). Although microbial changes are being considered in diet trends, probiotics, and environmental factors, pet ownership is often overlooked. Today, approximately 67% of U.S. households own a pet (APPA, 2021). Pet ownership brings us to the question, how may our microbiomes be impacted by pets living in our households? Many cats and dogs have similar microbiota compared to humans (Honneffer et al., 2014). Human-pet relationships can bring to light many pros and cons within our health. Many animals, especially those that roam outside, tend to bring in bacteria from the environment. This bacteria can then be easily transmitted (Resnick, 2012) to those living in the house, whether it’s via furniture, snuggling with your pet, or even something we consider harmless, like kissing your pet. Not only that, but bacteria such as Salmonella, E. coli, Clostridia, and Campylobacter are transmitted via pets and cause severe intestinal diseases for humans.