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What’s that smell? Uncovering the mechanisms and bacteria behind body odor in pre-pubescent children and teenager

Background:

Body odor is a biological process that affects all humans. Many animals have scent glands and body odors that serve different purposes, and humans are no different. It is believed that human body odors might signal familial recognition and communication regarding sexual attraction and reproduction (Hoover, K. 2010). While some human-produced scents may be inoffensive or appealing at best, others are found to be entirely unpleasant (body malodor). These unpleasant aromas are created through interactions between the microbes that live on our skin and substances created by our bodies. Metabolic pathways facilitated by our skin bacteria result in the breakdown of lactic, acetic, and other acids that leave our bodies through sweat, which, by itself, is odorless (Barzantny, H. et al 2011).

Continue reading “What’s that smell? Uncovering the mechanisms and bacteria behind body odor in pre-pubescent children and teenager”

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The changing microbiome in cystic fibrosis: a key to diagnosis and treatment?

Background

Monogenic disorders are estimated to affect 1/100 people at birth (WHO). They are caused by individual mutations in individual genes that result in non-functional products such as RNA molecules or proteins. In the case of cystic fibrosis (CF), a mutation in an ion-transport protein causes CF patients to have thick, sticky mucus that easily traps bacteria, viruses and other contaminants that can cause disease. Thick mucus is particularly an issue in the lungs where trapped microbes can lead to lung inflammation and infection (Cystic Fibrosis Foundation). In healthy individuals, microbes are not uncommon in the upper and lower respiratory tracts. Usually, microbes are eliminated by little hairs that sweep microbes trapped in free-flowing mucus up and out of the respiratory tract to be coughed up or swallowed (Huffnagle et al., 2016). However, in CF patients thick mucus limits this elimination of microbes, trapping them in the lungs and respiratory tract (Fig. 1). 

Figure 1. Comparison of the healthy vs. diseased airway. Buildup of mucus in cystic fibrosis patients changes the respiratory tract environment, allowing pathogens to proliferate. (Huffnagle et al., 2016)

Continue reading “The changing microbiome in cystic fibrosis: a key to diagnosis and treatment?”

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The influence of the microbiome on brain development

bidirectional link of between gut and brain. Brain influences motility, secretion, nutrient delivery and microbial balance in the gut. Gut influences neurotransmitters, stress/anxiety, mood and behaviour for the brain.
Figure 1. (from PsychSceneHub, sourced from FodMapEveryday). The brain and gut have bidirectional influence on each other.

Background

We live with an astonishing number of microbes in our bodies. Recently, scientists have been finding increasing evidence that one’s microbial profile (the set of different types of bacteria within their bodies) is shaped at birth, often ‘inherited’ from a mother when babies pass through the birth canal. One’s microbial profile, along with the conditions within one’s body that create an environment that supports the growth of some bacteria and prevents the growth of others, is called microbiota. Its development and stabilisation co-occurs with the development of a child’s nervous system; abnormal microbiota development is suggested to cause disruption in later cognition and behaviour (Diaz et. al, 2016).   Continue reading “The influence of the microbiome on brain development”

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Nasty Salmonella Infections Could be Defeated by Viruses Inside Our Guts Without Antibiotics

    Salmonella up closeSalmonella up close (Food Safety News)

BACKGROUND

Salmonella are bacteria that are often responsible for food-borne illnesses. The symptoms of Salmonella infection is “nausea, vomiting, abdominal cramps, diarrhea, fever, chills, headache, and blood in stool’ (Mayo Clinic, 2019). Sometimes Salmonella infections need to be treated with antibiotics, but it is becoming more common that Salmonella and other infectious bacteria are antibiotic resistant due to overexposure to antibiotics (Centers for Disease Control and Prevention, 2019). When someone with an antibiotic resistant bacteria gets sick, it can be incredibly difficult to treat if the person’s immune system isn’t able to fight off the illness on its own. However, there’s an alternative, bacteriophages are viruses that infect and kill specific bacteria or archaea. This treatment option has gained interest in the last decade due to the increasing abundance of antibiotic resistant bacteria.   Continue reading “Nasty Salmonella Infections Could be Defeated by Viruses Inside Our Guts Without Antibiotics”

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Gut Instinct: Brains on Bacteria

Man meditating holding phone with digestive system and brain shown as connected.
(Image:   https://atlasbiomed.com)

Background

You are what you eat, or so many people have been told. Researchers today are discovering that this age-old saying may be even more true that previously thought. “The Human Microbiome Project (HMP) was a United States National Institutes of Health (NIH) research initiative to improve understanding of the microbial flora involved in human health and disease’(7). Actually, the human microbiome project is a continuing effort of scientists from across the globe working together to better understand how all of the microbiological members of the immediate human environment (the microbiome) interact with our daily lives. The human microbiome is vast network of trillions of microorganisms that live in and on the human body including bacteria, fungi, parasites, and viruses(9). According to the National Institute of Health’s website, the human body is made up of 1-3% of microorganisms by mass(1).       Continue reading “Gut Instinct: Brains on Bacteria”

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What’s in US Ambulances?

Background

Ambulances are in almost every city in the United States. Depending on the city and service, ambulances can go on over a dozen calls a day. With each call and patient, healthcare workers and ambulance surfaces are exposed to new organisms. EMS (Emergency Medical Services) providers are constantly treating and transporting patients with viral infections and bacterial infections, trauma patients with open wounds, and patients with weak immune systems, such as young children and elderly (Caroline, 2013). Depending on the service, certain ambulances might get a higher population of patients with weakened immune systems than others, or more patients that have spent prolonged periods of time in hospitals. Continue reading “What’s in US Ambulances?”

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Comparing the Dandruff vs. Healthy Scalp Microbiome

Background:

Around half of the adult population worldwide is affected by the condition known as dandruff (Soares et al. 2016). Dandruff is characterized by small white flakes that are shed from the scalp, which often end up in a person’s hair or on their shoulders. Dandruff can cause intense itchiness of the scalp. Having visible dandruff flakes can lead to social embarrassment, due to the stigma that dandruff is caused by poor personal hygiene (e.g., not washing your hair enough). This is not true, however. It is not known what the exact cause of dandruff is, but Malassezia yeasts, specifically an imbalance/overabundance of them, are/have been suspected to play a role in its development (Wang et al. 2015). Malassezia is a fungal genus, and it is normal for fungi belonging to it to live on human skin (Soares et al. 2016), along with other species of fungi and bacteria, like Propionibacterium acnes and Staphylococcus epidermidis (Clavaud et al. 2013). In 2018, researchers in India conducted a study on the scalps of 140 Indian women to learn more about what kinds of microbes (including bacteria and fungi) were present on dandruff scalps vs. healthy scalps (Saxena et al. 2018). Continue reading “Comparing the Dandruff vs. Healthy Scalp Microbiome”

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Bacteria and fat ratios: can being male or female determine your bacteria?

Background:

Much insight has been gathered about gut microbiota (the bacteria present in our bodies) and its overall role in human health, but a majority still remains unknown. Based on previous studies it is understood that gut microbiota and diversity are greatly influenced by individuals and their weight characteristics (lean and obese) (Min et al., 2019).   But little to nothing is known in regards to sex-specific association, fat distribution and their effects on the bacterial gut communities. While men tend to have a lower average body fat percentage than females, the locations in which men and women store their fat could also play a great role in overall gut microbiota (Min et al., 2019) . These variations in the microbiome could possibly be linked or help explain adverse health effects seen in men and women, such as abdominal obesity in men and metabolism differences (Min et al., 2019). It is believed that the distribution of body fat on women aids in the protection in metabolic diseases such as type two diabetes and other life threatening illnesses (Karastergiou et al., 2012). Continue reading “Bacteria and fat ratios: can being male or female determine your bacteria?”

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The Scoop on Poop: Possible Links Between Gut Microbes and Autism Spectrum Disorder

Background:

Autism spectrum disorder (ASD) is a developmental disorder that affects communication and behavior (NIMH,  2019).   The CDC reports that about 1 in every 59 kids is identified with ASD (CDC,  2019).   It is very common for children with ASD to have some degree of gastrointestinal (GI) issues, such as constipation, diarrhea, and abdominal pain (Hsiao, 2014).   It is estimated that between 30-50% of children with ASD also have GI problems (Buie et al., 2010, McElhanon et al., 2014), but it is unknown why this is and what is causing it.   Scientists have looked into an imbalance of the gut microbiome (all the living organisms, such as bacteria, within the gut) as a potential factor in causing ASD symptoms and have found differences between the gut microbes of ASD children and neurotypical, or ‘normal’, children (children with no mental disabilities) (Finegold et al., 2002, Adams et al., 2011).   The researchers think that reductions in beneficial microbes and increases in harmful microbes could be causing ASD symptoms and associated problems.   However, we lack evidence to determine if the differences in microbes are actually the cause of the ASD symptoms, or if the ASD is causing the differences in microbes. Continue reading “The Scoop on Poop: Possible Links Between Gut Microbes and Autism Spectrum Disorder”

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It Takes a Village: Selection Drives the Formation of Dental Caries in Children

Dentist cleans woman's teeth.
Photo credit Max Pixel

Background:

As children we are told to brush our teeth and floss twice a day. An uncomfortable dental experience as a child can create dental anxiety in adulthood. This anxiety can prevent patients from seeking the care they need. The development of caries, or cavities, in the mouth can have lasting impacts if not treated properly in both children and adults. Caries develop on teeth due to the creation of an acidic environment from the bacteria inhabiting the mouth (Marsh 1994). The acidity eats away at the enamel, and eventually the softer pulp, or dentin, within the tooth, leaving an exposed and sensitive area that requires medical attention (Bowen et al. 2017). The prevalence of decay in primary teeth is notably higher in children aged 1 to 4 while young adults aged 15-19 years old have a higher prevalence of decay present in permanent teeth (Kassebaum et al. 2017). Because children develop higher levels of cavities than adults, protecting young permanent teeth is an important area for research. Why are children more likely to develop caries? And what can be done to lessen the spread of this disease? For many years scientists attributed the development of caries to the bacterial species Streptococcus mutans. With the advent of new technology and further information of how microbes interact with each other, scientists are now looking at old problems with modern solutions. Instead of merely describing the presence of microbes, scientists are now beginning to see what is happening between various microbial species in the human microbiome.   Continue reading “It Takes a Village: Selection Drives the Formation of Dental Caries in Children”