How Probiotics Affect Your Gut Health
But our gut microbiome may not be so mysterious after all. It may be home to over 100 trillion different species of microbiota. But much like other complex systems, it shares a reciprocal relationship with all aspects of our health—physical, mental and emotional.
You may have heard a lot of discussion centered around probiotics over the past few years. After all, probiotics are a significant focus of everything from choreographed advertising campaigns to scholarly research. But what are they? How do probiotics affect both our gut health and our overall physical well being?
The Gut Microbiome and Your Physical Health
Common to popular belief, bacteria aren’t always harmful. In fact, there’s probably more bacteria living in our bodies at any given point than there are human cells.
And nowhere is this more apparent than in our guts.
Gut bacteria help regulate our metabolism and our digestion, as well as playing a significant role in producing and synthesizing vital nutrients in our bodies, including several B vitamins—chief among them being vitamin B1, biotin, folate and riboflavin. The latter is particularly important, as it’s intimately linked to cellular growth and regeneration as well as the absorption of fats, medications and steroids.
Collectively, these bacteria form our gut microbiome. And it’s a remarkably diverse kingdom that’s been with us all our lives. In fact, even before we’re born.
Gut bacteria and the immune systemOne of the keys to maintaining proper health is maintaining a healthy immune system. And gut bacteria help regulate our immunity by sending signals to our immune response pathways indicating when a potential threat is apparent in our bodies.
It’s a two way communication between cell receptors and bacteria which enable our immune system to function properly. But when the lines of communication become blurred or an imbalance of microbiota occurs, the result is what’s known as gut dysbiosis—a condition which compromises our gut barrier and floods our cells, tissues and organs with pathogens, free radicals and harmful bacteria.
As a result, our immunity is weakened and we become much more susceptible not only to seasonal illnesses but chronic diseases including rheumatoid arthritis, irritable bowel syndrome, ulcerative colitis, Crohn’s disease, diabetes and other inflammatory diseases.
Gut bacteria and mental healthBut our immune system is only one function which can be governed by gut microbes. There’s a growing body of evidence indicating that gut bacteria help play a much stronger role in our mental health than we might think.
Recent research has suggested that there is an increasingly more pronounced link between gut bacteria and cognitive and nerve disorders, including Alzheimer’s disease, multiple sclerosis and Parkinson’s disease, while ongoing research into the role that microbiota sequencing plays in both major depressive disorders and bipolar disorder suggests that gut bacteria work as functional biomarkers in both conditions.
One of the primary reasons behind the interest in the links between brain health and gut bacteria is the recent confirmation that there exists a definite bidirectional pathway of communication between the gastrointestinal tract and the brain—what’s commonly referred to as the “gut-brain axis.”
The link between probiotics and gut health have been well established. But can probiotics also influence both our immune system as well as our brain health?
How Probiotics Affect Your Gut Health
Probiotics are live bacteria and enzymes which reside in our bodies. They’re one of the more beneficial forms of gut bacteria, and take on a life of their own even after being absorbed by our bodies.
It’s best to think of probiotics as a balancing agent that helps maintain gut health integrity by both eliminating harmful excess bacteria and producing specific metabolites,in particular short chain fatty acids (SCFAs), and other substances which regulate our digestion and metabolism.
Short chain fatty acids (SCFAs) and inflammatory diseaseSCFAs are primarily known for acting as a gut health barrier defense. Yet their impact is far reaching and can affect everything from our immunity and blood glucose absorption to obesity at multiple levels in the cells, tissues and organs.
One particular SCFA, butyrate, has been noted for its ability to activate anti-inflammatory immune cells and reduce harmful inflammatory cytokines and natural killer cells. But there are several other SCFAs which also have a considerable impact on inflammatory conditions, including acetate and propionate—the latter of which may ultimately play a role in our understanding of certain cognitive diseases, including dementia and Alzheimer’s disease.
SCFAs occur as a result of non-digestible carbohydrates which become available to the gut microbiome after fermentation. But while SCFAs and other probiotics are naturally produced in the body, their growth can be subject to your body’s own metabolic rate.
What Foods Contain Probiotics?
An estimated 4 million people in the US regularly take probiotics, with a large number of them consuming the bacteria through food sources. And of those food sources, fermentation is the easiest and most effective way to ensure optimal probiotic growth.
During fermentation, bacteria feed on existing carbohydrates and produce lactic acid in the process, creating an optimal environment for the growth of good bacteria and enzymes while also supporting the digestion of B vitamins and omega-3 fatty acids. Some foods that are particularly high in probiotics include:
- Kefir and other types of fermented milk
- Fermented cheeses
- Kombucha and other fermented teas
- Fermented olives and extra virgin olive oil
- Apple cider vinegar
- Green peas
- Pickled cucumbers
Soy-based food products such as natto, tempeh and miso
Naturally, some of these foods may not be to everyone’s tastes. And while each microbiome pattern is unique and subject to change as a result of aging and lifestyle changes, more Americans are looking to probiotic supplements to boost their gut health.
But are probiotic supplements necessarily the best alternative to food sources? The answer depends on both your own specific needs and the supplement itself.
The bacteria contained in probiotic supplements are generally measured by colony-forming units (CFUs.) And a good rule of thumb to remember is that a supplement with a low amount of CFUs is more appropriate to maintain general health, while a higher CFU rate addresses specific conditions. Yet it’s not always the amount of CFUs you should be aware of, but the strains of bacteria. Common ones may include:
The precise dosage and strain should be determined by your physician or gastroenterologist, particularly if you’re looking to take probiotics to address specific issues. For example, probiotic supplements which contain bovine immunoglobulin microbes have been proven effective in neutralizing infections and reducing gastrointestinal inflammation, but further research may be needed to understand whether or not it’s equally sufficient to address cognitive and neuromuscular conditions.
You may also want to discuss whether or not the supplement also contains any prebiotics. While prebiotic fibers are frequently taken in conjunction with probiotics to boost their efficiency (a practice commonly referred to as microbiome therapy), cases of gas and acid reflux have been noted in some patients.
For the vast majority of people, probiotic supplements are safe and free from adverse side effects. However, some people have reported discomfort in the form of nausea, gas, bloating and upset stomach prior to adjusting to a daily regimen. These symptoms typically diminish once your body gets adjusted to the presence of new bacteria, but you may want to begin taking probiotic supplements at a lower dose (subject to your physician’s advice.)