Spectrum EQ™: A Balanced Mind Begins in the Gut

When shopping for equine feed and supplements both in store and online, it doesn’t take much to notice just how abundant the choices in the “Calming” category are.

This begs the question:
What is going on with our horses that so many of them need to be calmer?

Perhaps we are approaching this common issue in a backwards manner; instead of focusing on calming the mind, we may need to focus on the gut.

The gut-brain connection

Although the first discovery in Western medicine of a link to the gut-brain connection was by Ivan Pavlov – who won a Nobel Prize for this work in 1904 – Ayurvedic and Traditional Chinese Medicine have recognized the gut-brain connection for thousands of years.

The gut-brain connection is complex and bidirectional. Some researchers say the gut and the brain even “talk” to each other.

Serotonin and other neurotransmitters

Serotonin is responsible for boosting mood, reducing anxiety, influencing learning/memory, and regulating sleep and hunger – and 90% of it is produced in the gut.

Therefore, changes in serotonin levels not only affect the brain, but also the GI tract. Altered levels of serotonin can show up through various health challenges, such as irritable bowel syndrome, chronic gas, bloating, constipation, and diarrhea.

Gut microbiota also produce other metabolites, including the glutamate, GABA, and dopamine neurotransmitters.¹

Microbes help produce serotonin in the gut

Specific microbes like Bacillus, the spore-producing bacteria, can elevate serotonin levels. According to Jessica Yano, author and research technician of the Caltech study on bacteria in the gut, “…microbes normally [presented] in the gut stimulate host intestinal cells to produce serotonin.”²

These Bacillus strains – also known as Soil Based Organisms (SBOs) – can be found in soil ecosystems around the world. Horses with consistent access to healthy pastures will consume this bacterium via soil and grasses.

Bacillus, being a spore-producing bacteria, can crowd out pathogenic bacteria in the gut, helping to restore a healthy balance of the gut microbiome.

Important note: Herbicides negatively affect several beneficial Bacillus strains, inhibiting their growth.

Diversity of the gut microbiome

A key player in the gut-brain axis is the diversity presented in the gut microbiota. While all horses have large colonies of beneficial and pathogenic bacteria in their GI tract, each horse has a unique balance of genus’ species. This is also true of humans and dogs.

Microbiologists have associated loss of microbial diversity in the gut with dysbiosis (which affects neurotransmitters), systemic inflammation, glucose intolerance, and insulin sensitivity.³

A varied equine diet helps support this needed microbial diversity.

It can also improve nutrient absorption, as the gut microbiota influences the absorption of trace minerals and key vitamins (e.g. vitamin K, vitamin B) in the GI tract.⁴

What factors negatively affect the gut
microbiome in horses?

What we can learn from the wild horse herds

Research on wild horses shows microbiomes with much greater diversity than in domesticated horses.⁵

There are several factors that lead to this disparity: wild horses travel 18-20 miles per day walking (sometimes galloping or trotting) and eating, eating, eating. They eat a variety of plants, bark, leaves, and berries.

Wild horses that live on the range do not experience chronic stress like domesticated horses do. While they can experience chronic stress in droughts and from other environmental stressors, these horses don’t experience the common domesticated horse stressors:

The domesticated horse pasture

In the last 20-30 years, pasture grass and baled forage diversity has decreased. Native grasses and beneficial plants are no longer found, leaving us with limited choices:

Mono-culture farming (growing only one crop at a time) is not reserved for wheat, corn, and soy; pastures are often mono-cultures as well.

And on the other side of the coin, many commercial horse pasture mixes are made with grazing cattle and sheep in mind, being formulated to support the growth of all livestock. These mixes are often not the best choice for horses that are easy keepers or have metabolic imbalances.

Herbicides

Pastures are often treated with herbicides to kill both invasive plants and wild herbs. This has had a huge impact on reducing pasture diversity.

Studies have shown that pesticide residues alter the soil microbiome, which includes the beneficial spore-producing bacteria Bacillus.⁷

Looking to the UK

In recent years, farmers in the UK have brought back the traditional English hedgerow. The hedgerow grows along fence lines, featuring a variety of herbs and bushes for horses, livestock, and humans to eat. That variety benefits the equine gut microbiome greatly.

Coming soon: BioStar’s Spectrum EQ™

Think of your horses’ gut microbiome as a diverse native garden. If the garden becomes depleted or out of balance – like it would be if it were over-run by pathogenic pests – the plants (microbiota) cannot thrive.

BioStar’s Spectrum EQ™ works to support increased diversity of the microbiome, restoring that defeated garden back to its original, wholesome state. In particular, Spectrum EQ™ includes…

Meadow Mix®

Our proprietary Meadow Mix® equine blend includes nine different plants and seeds for supporting microbial diversity in the GI tract:

Tetradesmus obliquus

Tetradesmus obliquus, a microalgae from France, can improve the microbial community balance in the gut, mood, well-being, and stress levels.

Nanovesicles

Spectrum EQ™’s nanovesicles are sourced from ginger, sliced almonds, apple cubes, and notoginseng for regulation support of gut microbial homeostasis, inflammation, and tight junction proteins.

Featuring a unique microalgae: Tetradesmus obliquus

This green microalgae is widely distributed in freshwater lakes and rivers and is particularly resilient, as it can adapt to a wide range of conditions. It has demonstrated effectiveness in removing heavy metals and phosphorus from aquatic systems.

Further research shows that T.obliquus has diverse biological activities:

What makes it extra special?

In clinical studies, T.obliquus improved the balance of the microbiota in the gut (Alpha Diversity Index), improved well-being and mood state (decreased ‘negative’ score in the Positive and Negative Affect Schedule [PANAS]), and regulated stress via a reduction in plasma chromogranin A levels.

Tetradesmus obliquus

With its inherent resilience, T.obliquus can help the gut maintain balance in the face of daily challenges.

This amazing microalgae also supports GI barrier function and mucilage and has even shown to reduce inflammation and oxidative stress in vitro.

The specific strain used in Spectrum EQ™ is T.obliquus Mi175.B, which is grown and harvested sustainably in France using recycled water and solar panels.

Whole food nanovesicles

Nanovesicles are tiny, membrane-bound sacs that encapsulate and carry biomolecules like proteins, lipids, metabolites, and RNA. These nanovesicles benefit the gut microbiome and are found in different plants and foods.

Playing a role in the body’s communication network, they transport signals and cargo between cells, tissues, and organs. Nanovesicles (whether naturally or synthetically produced) show potential for delivering therapeutic molecules in drug delivery applications.

In particular, nanovesicles sourced from whole foods can help regulate gut microbial community homeostasis, restore tight junctions proteins, and assist in regulation of inflammation.^9,10 They are often sourced from:

Are there calming herbs in the Meadow Mix®
in Spectrum EQ™?

No, there are no calming herbs in the Meadow Mix® featured in the Spectrum EQ™ formula.

Remember: Spectrum EQ™ supports the foundation of the gut-brain connection, thus producing a more balanced mind.

Not a probiotic

There are no live bacteria or yeasts in Spectrum EQ™.

Why not?

We wanted to go back to the fundamental source of microbiome diversity: plants. Wild horses in herds have a more diverse gut eco system, due in part to their varied diet.

If your horse needs the added probiotic support, look to our BioStar probiotic formulas with Bacillus organisms:

Symbiota EQ™

…mimics the matrix of healthy soils through its inclusion of neutral SBOs and offers 50 billion CFUs per 4mL. The liquid also features fulvic and humic acids to support tight junctions in the gut, as well as chaga mushrooms to support homeostasis.

Hedgerow GI™

…combines prebiotics, probiotics, and postbiotics with fermented turmeric, medicinal fungi, reed sedge peat, and plants commonly found in old English hedgerows for homeostatic support of the GI tract.

Hedgerow Restore™

…includes supportive GI stress recovery ingredients (like eggshell membrane collagen) in addition to the same probiotic families, CFUs, hedgerow-inspired herb blend, and dimensional support for gut homeostasis as Hedgerow GI™.

Beta testing

We began beta testing the microalgae during the 2025 Winter Equestrian Festival (WEF) season in Wellington, Florida.

Snapshot of Team BioStar in action at WEF. Photo courtesy of Phelps Media Group

The focus was centered on horses who needed brain and stress support, observing whether or not the actions of the microalgae on the gut microbiome would have an impact on their behaviors.

It did.

Several horses responded within a few hours, looking calmer and more relaxed in their bodies. Other horses showed similar calmness and reduced stress around the 48-hour mark. Two horses needed a week on the algae before improvements were seen. Several beta test horses exhibited softer muscles and reduced tension and tightness. When fed once daily, the calmness and reduced tension was maintained.

We beta tested the Meadow Mix® this summer (2025) and had a resounding 100% palatability result. The Spectrum EQ™ beta testing followed, observing a range of horses: from ponies and competition horses, to young horses and retirees. And again: 100% palatability. Every single one of them gobbled up Spectrum EQ™. Several horses even ate it out of their owners’ hands.

Overall feedback from these horses’ riders and body workers included notes of improved performance in the show ring, better focus, and increased resilience after training and competing.

Benefits of Spectrum EQ™

How to feed Spectrum EQ™

Feed ½ cup (one scoop) once per day. In periods of high stress, increase feedings to twice per day.

It can be given for shorter periods, such as during a competition, lay-up, and recovery.

Spectrum EQ™ will come in three sizes that reflect its diverse applications:

Spectrum EQ™ with probiotics and medications

Spectrum EQ™ can be given alongside active probiotics. We recommend, based on the research, to use probiotic supplements with the species Bacillus included.

Spectrum EQ™ will not interfere with medications.

Coming soon: Spectrum EQ™ 

Available October 2025!

References

1 Regulation of Neurotransmitters by the Gut Microbiota and Effects on Cognition in Neurological Disorders | MDPI: https://doi.org/10.3390/nu13062099 (p. 4)

2 Microbes Help Produce Serotonin in Gut | Caltech: https://www.caltech.edu/about/news/microbes-help-produce-serotonin-gut-46495

3 The Role of Gut Microbiota in Health Functions | Longdom: https://www.longdom.org/open-access-pdfs/the-role-of-gut-microbiota-in-health-functions.pdf 

4 Intestinal microbiota as a route for micronutrient bioavailability | ScienceDirect: https://doi.org/10.1016/j.coemr.2021.100285

5 Gut Microbiome Characteristics in feral and domesticated horses from different geographic locations | Communications Biology: https://doi.org/10.1038/s42003-022-03116-2 

6 The gut microbiome of horses: current research on equine enteral microbiota and future perspectives | BioMed Central: https://doi.org/10.1186/s42523-019-0013-3 

7 Soil microbiome signatures are associated with pesticide residues in arable landscapes | ScienceDirect: https://doi.org/10.1016/j.soilbio.2022.108830

8 Multiparametric Evaluation of Tetradesmus obliquus Biomass: An Integrated Approach Including Antioxidant, Nutritional, and Energy Properties | MDPI: https://doi.org/10.3390/microorganisms13071583

9 Exploring new avenues of health protection: plant-derived nanovesicles reshape microbial communities | Journal of Nanobiotechnology: https://doi.org/10.1186/s12951-024-02500-w 

10 Aloe-derived Nanovesicles Attenuate Inflammation and Enhance Tight Junction Proteins for Acute Colitis Treatment | Biomaterials Science: http://dx.doi.org/10.1039/D3BM00591G

11 Ginseng-derived nanoparticles alleviate inflammatory bowel disease via the TLR4/MAPK and p62/Nrf2/Keap1 pathways | Journal of Nanobiotechnology: https://doi.org/10.1186/s12951-024-02313-x

About the Author: With over 30 years experience in the equine and human supplement industry, Tigger Montague knows nutrition from the synthetic side as well as the whole food side. She started BioStar US in 2006 with formulas she created in her kitchen. Before she started the company, she was an avid rider and competitor with eventing and show jumping, until she got hooked on dressage in the late 1980’s. She has competed on horses she’s owned and trained all the way from training level to Grand Prix.