Synergy in Gut Health

by Kyle Perkovich, BS

In the intricate ecosystem of the human gut, a new frontier is emerging, marked by the strategic paring of probiotics and prebiotics working synergistically to help provide optimal gut health and well-being. This combination, known as synbiotics, is gaining prominence for its potential to enhance gut health and immune function.

As research has advanced, the role of our gut microbiota has become increasingly recognized as a vital part of overall health, influencing not only proper digestion, but also the health of our immune systems and even mental well-being.  Studies have shown that an imbalance in the intestinal microbiota can be linked to numerous chronic conditions, including inflammatory bowel disease, obesity, and some neurological conditions¹. Factors including poor diet, stress, certain medications, and a sedentary lifestyle can all contribute negatively towards the composition and function of our gut microbiota¹. With this knowledge, it is important to pay more attention to how we can protect this sensitive balance in our bodies, as these tiny microorganisms make a profound impact on our lives.

Restoring Balance In the Gut

The spotlight in nutritional science has increasingly highlighted the benefits of various probiotic and prebiotic supplements, marking a trend in understanding gut health’s pivotal role in overall well-being. Probiotics, often referred to as “friendly” or “good” bacteria, have been researched for their beneficial effects on the gut microbiome, the intricate community of microbes residing in the human digestive system. Prebiotics, non-digestible food ingredients that promote the growth of beneficial microorganisms, help feed and keep the probiotics healthy.

While you may have seen probiotics on the shelves of your local drug store, these microorganisms are a vital component of our body systems that already exist naturally and abundantly; in fact, there are at least as many microbial cells in the human body as there are human cells^2,3. These microorganisms provide a variety of functions, including harvesting energy from food, manufacturing neurotransmitters and vitamins for immune and metabolic functions, and balancing good versus bad bacterial composition². Similarly, prebiotics have a pivotal function for our gut and overall health, strengthening our gut microbiota and protecting systems in our bodies including the gastrointestinal, nervous, immune, and cardiovascular systems⁴.

With the modern factors that can weaken our gut balance, it is often important to supplement our natural gut microbiota with probiotics and prebiotics, to increase and support our microbial helpers. Research is quickly advancing on optimal probiotic strains and prebiotic sources to strengthen our natural microbial supplies, as well as the emergence of supplements that combine these key health boosters to create a synergistic effect. Below, a few exciting probiotic and prebiotic options will be examined, as well as the ways in which their interaction can create compounding positive effects.

Bacillus Probiotics: Better Health Through Spores

With probiotics sold and marketed all around us, it is difficult to know which options will provide the desired benefits to our gut well-being. One group of probiotics attracting the attention of researchers for its health potential is Bacillus, a genus of bacteria with the unique ability to produce spores.

The Bacillus spores are resistant to high temperatures and can survive in the stomach’s harsh acidic environment, only germinating in the intestine when nutrients are present. This trait enhances the survival rate in the gastrointestinal tract, thereby better exerting probiotic effects⁵ because of this, probiotics in the Bacillus genus are displaying powerful potential health effects in clinical studies. Two strains in particular, Bacillus coagulans and Bacillus subtilis, have impressive results for gastrointestinal (GI) and overall health.

Bacillus coagulans: A Gastrointestinal Savior

Bacillus coagulans, a probiotic strain gaining recent interest from researchers, is a facultative anerobic bacterium which can be isolated from spoiled milk⁶.  Recent studies on Bacillus coagulans have displayed promising results regarding its benefits for the human GI system and digestion. A 2021 randomized controlled trial⁶, which compared Bacillus coagulans to a placebo in 80 participants with intermittent constipation, found meaningful changes for the group taking the probiotic. These patients had significant improvements in colonic transit time, complete spontaneous bowel movement scores, bowel discomfort symptoms, and fecal microbiome profiles⁶. The study revealed the probiotic was effectively delivered to the gut and provided important data on the strain contributing to improved gut motility and benefitting adults with mild intermittent constipation.

This spore-forming probiotic is well-researched in adults and children, demonstrating various improvements for GI disorders and overall gut health. Studies in the past 20 years have displayed significant results for Bacillus coagulans improving adult symptoms of gastrointestinal discomfort⁷, irritable bowel syndrome⁸, constipation⁹, and acute diarrhea¹⁰, conditions affecting many millions of people worldwide. Its use has also been shown to be safe and effective for improving GI conditions in children and infants, with data on improvements for conditions including  irritable bowel syndrome¹¹ and functional abdominal pain¹², among others.

The research on Bacillus coagulans appears convincing and abundant, signifying positive effects on different gastrointestinal conditions and overall GI health. Supplemental Bacillus coagulans has been theorized to beneficially interact with our bodies in a variety of ways, including:

• Creating an anaerobic and acidic intestinal environment to discourage pathogen growth and promote probiotic growth⁵
• Consuming free oxygen in our gut to reduce redox reactions⁶
• Producing antimicrobial compounds to hinder pathogenic growth and balancing microbiota populations⁵
• Secreting lactic acid, which has antimicrobial properties and may promote gut epithelial development and repair⁵

These mechanisms, combined with the survival advantages of the spore-forming bacteria, may help explain why Bacillus coagulans appears to be a powerful probiotic to consider supplementing for gut health.

Bacillus subtilis: A Probiotic That Does it All

A member of the same spore-forming genus, Bacillus subtilis is another clinically researched bacterial strain with strong probiotic effects. This microorganism naturally enters the human GI and respiratory tracts through food, air, and water; in fact, Bacillus bacteria overall are thought to be one of the dominant components of our normal gut microflora¹³. Despite the abundance of these probiotics, studies show promising health benefits of supplementing additional Bacillus subtilis for both children and adults.

Bacillus subtilis has been researched extensively, exhibiting a variety of benefits to our health. Studies display improvements to gastrointestinal function, such as significantly improving GI discomfort, constipation, diarrhea, and frequency of normal stools¹⁴. A 2022 randomized controlled trial also showed improvement to symptoms of bloating, burping, and flatulence in participants¹⁵. These GI benefits may be attributed to the abilities of Bacillus subtilis to preserve intestinal homeostasis, maintain normal gut microflora, and prevent intestinal inflammation¹³.

The benefits of Bacillus subtilis, however, do not only affect GI health, making it a promising probiotic for overall well-being; clinical studies have produced results indicating the bacteria can support our immune systems and even cardiovascular health in a variety of patient types. A 2022 randomized controlled trial examining the effects on adults immediately after ingestion of supplemental Bacillus Subtilis found an increase in beneficial molecules with anti-inflammatory and anti-oxidant effects; the probiotic group also displayed increased levels of proteins involved in leucocyte recruitment, antibacterial peptides, and detoxification, suggesting the probiotic’s role in immune regulation¹⁶. Studies on special populations have displayed Bacillus subtilis supplementation having immune system benefits as well, including:

• Supporting healthy immune function and GI health in day-care attending chiildren¹⁷
• Stimulating mucosal immune responses in the elderly¹⁸
• Decreasing levels of pro-inflammatory cytokine TNF-α in college athletes¹⁹

One study on healthy adults even found evidence of Bacillus subtilis supporting the cardiovascular system; the supplement helped lower total cholesterol and non-HDL cholesterol by an average of 8 mg/dL and 11mg/dL respectively²⁰.

With this wide range of health effects, Bacillus subtilis appears to be another formidable probiotic option. Probiotic microorganisms, such as aforementioned spore-forming Bacillus species, have been shown to maintain and improve our gut health and normal microflora; however, our natural bacteria would not function as effectively without their food source – prebiotics.

Chicory Root: A Very Supportive Prebiotic

Prebiotics are the nutrition for those vital microorganisms in our guts; they help our microbiota flourish and perform the numerous helpful functions they are capable of. Prebiotic foods, which are usually high in fermentable soluble fiber, can be found in certain foods including yogurt, sauerkraut, whole grains, and soybeans. Despite this, supplementing our diets with specific prebiotics with proven nutritional value can optimize our gut microbial health.

One such prebiotic is chicory root, a substance rich in inulin-type fructans, which are among the most widely studied prebiotic fibers. Inulin-type fructans cannot be digested by the enzymes in the GI tract; thus, they reach the colon intact and are utilized by the gut microbes, leading to the production of short-chain fatty acids and other metabolites that elicit health benefits^21,22.

Chicory root supplementation has demonstrated capability to support our gut probiotics. Per a 2022 meta-analysis, chicory-based supplements significantly increased the abundance of Bifidobacterium, an important health-promoting bacteria for the GI and immune systems, at a dose of as little as three grams per day²³. This change led to increased stool frequency in healthy adults and softer stool in healthy infants and children.

The raise in Bfidobacterium levels has been echoed in numerous studies^24,25, as well as further benefits of chicory root supplementation, including increased fiber intake²⁴, decreased gas retention²⁵, constipation relief²⁶, and even possible anti-inflammatory properties²⁷.

Research demonstrates that chicory root and other prebiotics, with the nutrition they provide to our gut microbes, can offer a range of benefits to our health – similar to the advantages of probiotics. With an increased emphasis in the scientific community on the importance of gut health, researchers have asked: what happens if we supplement prebiotics and probiotics together?

Synbiotics: Probiotic and Prebiotic Synergy

Probiotics and prebiotics are effective individually, but may also have synergistic capabilities when paired together in the form of a synbiotic. A synbiotic is a mixture of live microbes (generally probiotics) and substrates (generally prebiotics) that confers a health benefit on the host, with the goal of enhancing the effect of each and improving gastrointestinal health²⁸.

An ideal synbiotic supplement will contain ingredients that complement or synergize each other, such as a prebiotic selectively favoring or providing nutrition for the probiotic organism²⁹.  A synbiotic might also be effective if the prebiotic component improves the survival of the probiotic bacteria as it passes through the intestinal tract, as a more efficient implantation in the colon along with stimulating the growth of probiotics can help maintain intestinal homeostasis³⁰.  Some potential effects of prebiotics, probiotics, and their combination as synbiotics are shown in the figure below³⁰.

With these criteria on optimal synbiotics and the clinical research presented above, an argument could be made for potential synbiotic properties of Bacillus coagulans, Bacillus subtilis, and chicory root. Chicory root forms a matrix composed of multiple types of prebiotic fibers³¹. Combining these three ingredients into a supplement would create a synbiotic, with the chicory root housing and complementing the probiotic strains in a nutritional matrix and providing support to the probiotics and gut microbiota. Bacillus coagulans and Bacillus subtilis, with their spore-forming capabilities, have increased survival abilities in the GI tract, further allowing the bacteria to make it to the gut and promote a healthy system.

These ingredients are just one of a wide range of options for powerful and effective synbiotics. While more research needs to be done on specific synbiotic combinations³⁰, such as quantifying the synergistic effects of various prebiotic and probiotic mixtures and understanding the mechanisms of how they can work together, there is clear potential for these bacteria and nutrition sources to work together and provide effective health benefits. Clinical research is continuing to grow and is demonstrating the nutritional advantages of probiotics like Bacillus coagulans and Bacillus subtilis and prebiotics like chicory root. As research moves forward, we will continue to gain valuable insight into how these supplements can help us live healthier lives with a well-balanced and properly supported gut.

Citations

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Kyle Perkovich is a medical writer with a background in clinical research and leading medical writing teams in the completion of clinical reports to get products approved for global sale. He graduated from the University of California, Santa Barbara with a degree in microbiology and a minor in professional science writing, while writing for the university newspaper and completing a technical writing internship with the Vandenberg Air Force Base. Kyle has helped manage documentation for large-scale clinical studies of medical devices and has been involved in various clinical and scientific research studies. He hopes to educate healthcare practitioners and consumers on the science behind the world of supplements and vitamins to help people better understand the complexities of nutrition and live healthier lives.