Gut Microbiome, Parkinson's Disease Risks, and Red Light Therapy

Our bodies are covered in rich ecosystems invisible to the eye and inhabited by trillions of microscopic organisms, which collectively make up the human microbiome. Of these, studies increasingly show that one of the most consequential microbiomes lies inside the digestive tract, where microbes help break down food, but also perform tasks including producing hormones and neurotransmitters and training immune system cells.

> The gut microbiome's reach extends far beyond the stomach. (More)
> Specific gut microbiome patterns are associated with melanoma recurrence, with up to 94% accuracy. (More)

> Researchers generally group gut bacteria into six different categories, with varying amounts residing in different parts of the gastrointestinal tract. (More)

This 30-foot-long tube—which includes the large and small intestines—may have as many as 100 trillion microbes that help break down food and perform other essential tasks, including producing hormones and neurotransmitters and training immune system cells. The exact makeup of the gut microbiome varies from gut to gut and changes across different stages of life, but it is generally composed of yeast, protists, bacteria, viruses, and archaea. Finding ways to alter that composition and target specific microbes with future therapies is a key focus area as scientists learn about the microbiome's role in a wide range of mental and physical conditions, ranging from allergies to depression to autoimmune disorders.

> Watch how our gut microbiome may change over time based on our diet. (More)

> Probiotics, which are living bacteria and yeasts, are not recommended for most patients. (More)

> Gut microbes influence our immune cells, training them to recognize what should be tolerated. (More)

Scientists hypothesize that the gut microbiome comes from bacterial colonization that slowly covers the body, inside and out, after birth. 

> Recent experiments suggest gut microbes may influence behavior and personality more than previously known. (More) 

> Not all animals have gut microbes to help maintain their health and functioning—certain tropical ants have little or no microbial gut populations at all. (More) 

Discover more: 

> Fecal transplants can transform the gut microbiome, introducing donor microbes. (More)

> Artificial sugars may shift the composition of the gut microbiome and cause health issues. (More)

> What can 30-plus daily farts tell us about our gut microbiome and health? (More)
> ... explore everything we've learned about the gut microbiome.

 News in Context 

1440 brings you the knowledge and context behind recent intriguing stories:

About 9% of American adults use cannabis as a sleep aid, but recent research suggests it's harming sleep. (More)

> A primer on REM sleep, when we often experience intense dreams.

> We may have evolved to need less sleep than our ancestors.

CVS is now also filling pet prescriptions at its more than 9,000 stores. (More)

> The lifetime costs of caring for a cat or dog can be more than $50K.

FDA panel recommended easing access for 6 of 7 controversial peptides, including BPC-157, TB-500, and MOTS-c. (More)

> Explore our 1440 deep dive on peptides.

> The "P" in GLP-1 is for peptide.
> Peptides comprise about 8% of the new drugs approved by the US FDA between 2016 and 2023.

The slashing of USAID has had ripple effects for domestic foodborne illness response. (More)

> Explore how long it may take between eating contaminated foods and illness.

> Foodborne illness is typically contracted at restaurants.

 Medical Developments Spotlight 

We love spending time learning about the latest medical breakthroughs and spotlighting research that piques our interest, may influence future research directions, or inform healthcare conversations. Here's what we found this week.

Researchers have discovered that an excessive sweating disorder may originate in the nervous system, potentially fueling new treatments.

Neuroscience News | Koen Stein. Hyperhidrosis, which affects roughly 2% to 5% of the population, remains poorly understood. But a new genetic analysis of 32 families with the disorder links it to a rare genetic variant that increases the activity of nerve cells that affect sweat production. The researchers also found that in rodents, specific drugs targeting those cells helped to reduce excessive sweating—buoying hopes for future noninvasive human treatments. (More)

> "Sweat dating" is when partners select each other based on body odor.

> How sweating works.

Chronic exposure to traffic noise is associated with a higher risk of Parkinson's disease.

MedPage Today | Judy George. Tracking of more than 3 million adults in Denmark found that long-term exposure to road traffic noise was associated with an increased risk of developing Parkinson's. The study authors theorize that the noise may disrupt circadian rhythms and lead to poor sleep, which could trigger problematic inflammatory responses. Separately, air pollution and exposures to pesticides and toxic substances have also been linked to Parkinson's. (More, free w/email)

> Listen to an in-depth conversation on the links between Parkinson's disease and herbicide exposure.
> Explore what different decibel levels mean for hearing loss.

A novel Breathalyzer measures when the body is burning fat—in real time.

Nature | Mohana Basu. Early-stage work involving a dozen healthy volunteers found that a breath-testing device successfully detected a volatile compound that's produced when fatty acids break down during exercise. Its inventors say the tool's accuracy relies partly on their smartphone app, which guides a user's exhalation on the device's mouthpiece. The Breathalyzer approach requires further validation, but may one day lead to better long-term weight-loss tracking. (More, free w/email)

> The first patent for a Breathalyzer was for the "drunkometer."

An injectable allergy medication enabled 36% of kids with multiple food allergies to eat full servings of allergy-inducing foods after one year. 
Stanford Medicine | Erin Digitale. Mid-stage clinical trial results, published in JAMA Pediatrics, report that the FDA-approved injectable medication omalizumab (sold as Xolair) performed similarly to oral immunotherapy, enabling consumption of peanuts and other allergens with fewer side effects and better overall compliance. (More)

> More than 90% of America's food allergies are triggered by these 9 substances.

 Etcetera 

> See how Alzheimer's disease affects the brain, causing shrinkage.

> Male-pattern baldness is measured using this standardized scale.

> Humans accurately detect their goose bumps only about one-third of the time.

> Some people are genetically predisposed to be less smelly.

> Mosquitoes have olfactory receptors on their sperm, which may help their sperm find eggs.

> Western babies often lack a gut microbe common elsewhere.

> Type 1 diabetes comprises about 5%-10% of diabetes cases.

> Visualize the US role in the global medicine supply chain.

> Inmates granted compassionate release are staying in prison largely because nursing homes are reluctant to take prisoners.

> GLP-1 drugs are linked to a 17% drop in worker sick days.

> The Presidential Fitness Test is back in schools—reinstated by a 2025 executive order after it was retired in 2012.

> Red light therapy has its roots in space research.