Welcome to the November 2019 issue of Thorne’s Research Extracts – designed to keep busy practitioners and savvy consumers up-to-date on the latest research on diet, nutrients, botanicals, the microbiome, the environment, and lifestyle approaches to good health.

Our medical team, which includes NDs, MDs, PhDs, RDs, and an MS, LAc, and CCN, has summarized the essence of several of the most interesting studies. This issue includes two cutting edge studies on the microbiome.

Research summaries in this issue include (1) the effect of commonly used medications on the microbiome, (2) the effect of the microbiome on sleep, (3) blueberry juice for attention and memory in school-age kids, (4) the effect of blue screen exposure on aging, and (5) link to podcast on lutein and zeaxanthin for eye and brain health.


Impact of 41 commonly used drugs on the composition, metabolic function, and resistome of the gut microbiome

Contributed by Laura Kunces, PhD, RD

The gut is influenced by numerous lifestyle and environmental factors, including medications; in turn, the gut influences the responses and efficacy of drugs. Research presented at the UEG (United European Gastroenterology) Week – Europe’s largest and most prestigious GI meeting – evaluated the most commonly consumed medications and reported their impact on the gut microbiome in individuals with and without gastrointestinal disorders.

Metagenomic sequencing was conducted on 1,883 fecal samples from three groups: a general population-based cohort, adults with inflammatory bowel disease (IBD), and adults with IBD intermixed with healthy controls. Medication users were compared to non-users in each group. Analyzing 41 drug categories, the study found 18 to be associated with gut microbiota composition or functional changes.

Those with the largest impact were proton pump inhibitors (PPIs), metformin, antibiotics, and laxatives. Researchers then corrected for polypharmacy and found seven drug categories remained significant and were associated with 46 taxa and pathway changes. The abstract did not list all seven drug categories but did report that: (1) the abundance of Eubacterium ramulus was associated with the use of SSRI antidepressants, (2) fatty acid biosynthesis pathways were increased in those using PPIs, and (3) an increase in Escherichia coli-derived metabolic pathways was observed in those taking metformin.

Oral steroid consumption was associated with an enrichment of methanogenic bacteria. The researchers also reported an increase in antibiotic resistance mechanisms related to eight different medication categories.

The findings contribute to the increasing body of research on gut microbiome changes and their relation to chronic health conditions, including obesity, metabolic disorders, or even infections, and how medications prescribed for such conditions might actually exacerbate disease through dysbiosis. 

If you work with patients taking any of these researched medications, consider utilizing a Gutbio™ microbiome test by Onegevity to understand the impact of medications on their ratio and counts of bacteria. The Gutbio test results provide a full download of every microorganism found in an individual’s sample and compare levels to other adults. 

  • Vich Vila A, et al. Abstract OP334. Presented at: UEG Week. October 19-23, 2019; Barcelona.

Blueberry juice can improve attention and memory in school-age kids

Contributed by Danielle Paciera, LDN, RD, CCN

In a study published in the European Journal of Nutrition, wild blueberry consumption improved memory and attention in healthy children. To explore the benefits of blueberry consumption in real-world educational scenarios, in a randomized, single-blind, placebo-controlled study, children (ages 7-10) were given a single dose of a freeze-dried wild blueberry beverage or a placebo.

The wild blueberry drink was the equivalent of 240 g or 1½ cups of fresh blueberries and contained 253 mg anthocyanin. To rule out a glucose effect, the placebo contained fructose, glucose, and vitamin C. Both the placebo and the blueberry drink were given in an opaque drinking flask with an opaque straw to ensure blinding. All children were asked to follow a low-flavonoid diet the day before the study and to consume a low-flavonoid lunch.

After lunch, the children engaged in baseline testing, after which they were given five minutes to consume the blueberry or placebo drinks, then returned to the classroom. Two hours after consuming the beverage, they took another round of tests, including the Auditory Verbal Learning Task for assessment of verbal memory, Modified Attention Network Task for executive function (reaction time and accuracy), and Test of Word Reading Efficiency-2 for reading efficiency. 

Children who consumed the blueberry juice had significantly faster reaction times without reduction in accuracy, suggesting increased mental alertness. Enhanced verbal memory performance and reduced testing fatigue were also observed. Although reading involves working memory, selective attention, and executive functions – all of which improved in the experimental group – expected improvements in reading were not observed.

One limitation was the lack of standardization of lunch content and timing prior to testing. The authors concluded that future studies should be done with long-term blueberry ingestion to better assess effects on reading and to explore biological mechanisms of action. Click here for full text.

  • Barfoot K, May G, Lamport D, et al. The effects of acute wild blueberry supplementation on the cognition of 7-10 year-old schoolchildren. Eur J Nutr 2019;58(7):2911-2920.

Blue screen exposure and aging

Contributed by Kathi Head, ND

Because of the prevalence of exposure to blue-light emitting diodes from computer screens, tablets, cell phones, televisions, and LED lights, research has accelerated on the negative effects of such constant exposure – from eye fatigue to sleep disruption to obesity – and we have reported on that here.

The results of the current study are worrisome, even though it was conducted on fruit flies, which allows for accelerated studies of aging. Drosophila melanogaster is often chosen because numerous models for diseases of aging have been developed using this fruit fly species. In the current study, flies were exposed to constant darkness and then compared to another group that experienced 12 hours of fluorescent light and 12 hours of constant darkness.

The flies exposed to the darkness experienced a 42-percent increase in average lifespan, due to delayed aging, compared to the flies exposed to light. By using filters, the flies were then subjected to 12 hours of darkness alternating with 12 hours of blue LED light, which resulted in an approximately 50-percent reduction in lifespan.

But when white LED light was used with a yellow filter to filter out the blue light, the lifespan was only reduced by four percent. In addition to retinal cell damage, exposure to blue light caused neurodegenerative changes in the brain. 

Although, because of the accelerated nature of the study and the limited lifespan of a fruit fly, the results are significantly more dramatic than would be observed in humans, it is nonetheless important research to add to the expanding body of knowledge about the detrimental effects of exposure to blue-wavelength light. Click here for full text.

  • Nash T, Chow E, Law A, et al. Daily blue-light exposure shortens lifespan and causes brain neurodegeneration in Drosophila. NPJ Aging Mech Dis 2019 Oct 17;5-8. 

What can help protect you from blue screen exposure? Listen to our latest educational podcast

Host Alan Miller, ND, interviews Deshanie Rai, PhD, an expert in the use of plant-based carotenes like lutein and zeaxanthin to support eye and brain health.* Dr Deshanie discusses the research on these molecules that are an essential component of the retina and macula in the eye, as well as their effect on cognitive function. Explore Thorne products that contain lutein and zeaxanthin.

Episode 11: Deshanie Rai - Macular Carotenoids in Eye and Brain Function


The gut-sleep connection

Contributed by Kathi Head, ND

We hear a lot lately about the gut-brain connection – plus we know brain waves are closely related to sleep quality – so the results of a new study showing a connection between sleep quality and the gut microbiome shouldn’t be a big surprise. In this study, researchers at Nova Southeastern University in Ft. Lauderdale, Florida, used non-invasive actigraphy to evaluate sleep quality and quantity, fecal samples for microbiome testing using next generation whole metagenomic sequencing, and saliva samples for cortisol, interleukin-1β (IL-1β), and interleukin-6 (IL-6).

After sample collections (between 2-4 pm for consistency), sleep testing was commenced with participants wearing an Actiwatch for 30 days. Sleep testing included average time to bed, average time to rise, sleep latency (time to get to sleep), total sleep hours, total time in bed, time until awakening (in minutes), number of times awakened, and sleep efficiency. Twenty-six healthy males completed the study.  

Sleep time and sleep efficiency (percent of time asleep while in bed) positively correlated with microbiome diversity. In terms of richness, sleep efficiency was positively associated with amount of the phyla Firmicutes and Bacteroidetes.

On the other hand, several taxa were negatively correlated with sleep, including Cornebacterium, Blautia, and Lachnospiraceae. In addition, IL-6, a cytokine that tends to be elevated at night and associated with sleep, was positively associated with microbiome diversity. The study yielded numerous other correlations between sleep and the microbiome. For additional details, click here for the full text.

New offering from Onegevity Health

Speaking of comprehensive tests combining gut microbiome testing with other metabolic measures, check out the latest test offering from Onegevity Health – Performbio™ – designed for the high-performer in work, life, and athletics. It is an at-home test integrating your gut microbiome, blood, and saliva metrics to establish and track how your lifestyle, training, and work stress affects your hormones, energy, performance drive, metabolism, and recovery.

Just like other tests with Onegevity, it provides an easy-to-read report, with insights comparing you to others like you, and personalized recommendations for you to optimize all aspects of your daily performance.