Issue 123: Probiotics and Prebiotics 101

We can’t swing a short stick these days without bumping into something in the news or an advertisement about the gut microbiome. There’s probiotic this and prebiotic that. What does it all mean? And do we really need them?

I thought I’d bring some clarity to the conversation about supplements for the microbiome to help you out. After all, our digestive tract carries about 70% of our immune system and all the same neurotransmitters as the brain, making this a pretty important topic to understand.

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What is the Gut Microbiome, Anyway?

Our health and our digestion really lean on a healthy gut microbiome. So what is that? The gut microbiome is literally the collection of microbes - bacteria, viruses, fungi, and other infinitesimally small living organisms - that make a home in our digestive tract, especially in the large intestine. In total, this microbial collection can weigh up to five pounds. Our whole bodies, especially our guts, are populated with these microorganisms as we travel through the birth canal and then encounter the outside world (fun fact: babies born by c-section have different, sometimes less robust, microbiomes than those by vaginal birth). Here’s one terrific short article I used for reference.

The Microbiome Keeps Us Healthy
→ It works symbiotically with its human host (when it’s in balance). In fact, there are bacteria that really go all out to keep us healthy: making certain B vitamins and vitamin K; maintaining the mucosal layer that protects the lining of the digestive tract; regulating our immune system; and helping us digest our food. I learned recently that bacteria even metabolize drugs we take before we absorb them, which may critically inform how well they work.

→ It directs our food choices and hunger and satiety cues. Literally, if you find yourself really wanting a certain food, it’s probably because a portion of your gut microbiome is asking for more of something so that group can live and grow. The microbiome composition has an effect on fat accumulation as well.

→ It helps us prevent or heal from everything from the common cold to cancer.

→ It also assures things run smoothly, i.e. comfortable, easy to pass stools. Don’t come at me! Stool quality tells me so much about what’s happening in there.

→ It plays a key role in mood balance, mental health, and brain function. Anywhere from 80% to 90% of serotonin and 50% of dopamine is produced along the gut’s nervous system. They require production of short chain fatty acids by bacteria in the gut microbiome to underpin their synthesis and release. The gut produces all of the same neurotransmitters that the brain does, and a healthy microbiome vitally supports a balanced mood, mental wellness, and brain health.

So you can see that we want to take good care of it!

The Big Picture

TBH, the microbiome is like outer space or the ocean. There’s a lot we know, and there’s even more still to find out. While research has parsed out many specific benefits and health risks of various genera and species of bacteria, we’re still working on the best way to use, increase, or reduce the right organisms to support our health. Complicating it even further, there are different strains of the same bacteria. Sometimes a specific strain is well studied, but others in the species aren’t as well understood.

But that’s ok! What we do know is hugely helpful and has allowed clinicians like me to use supplements and food to nourish the garden of a healthy microbiome. Here are the categories of products we use and what they do.

Probiotics

Probiotics are beneficial (pro-) bacteria (biotics) known to exist across the body, especially in the digestive tract, vagina, and mouth, that actively support our health - they are “pro-” human. They primarily can be found in two broad groups: live bacteria or spore-based bacteria.

Live bacteria fall into the genera of lactobacillus and bifidobacterium. When you read the label of a probiotic container, you’ll see names like L. acidophilus, or B. infantis. Live bacteria in supplements must be properly encapsulated so they can withstand stomach acid and be stored carefully to maintain their live status before consumption. Many commercial products have to be refrigerated, but there are brands that offer convenient and reliable shelf-stable containers.

These good bugs will hang around in the gut for about two weeks once you stop the supplement. They are amazing to support the body through healing (like traveler’s diarrhea or IBS/IBD) and can play an important role in therapeutic interventions. There’s one I really love to use for overcoming yeast infections! However, if you want them to proliferate so that they colonize your gut (yes, you want that), you’ll need to increase your prebiotic fiber intake, which I discuss below.

Health promoting bacteria also can be found in traditionally fermented foods like yogurt, sour cream, kefir, kombucha, miso (refrigerated only), sauerkraut, kimchi, and real pickles (fermented, not with vinegar). Interestingly, most of these contain prebiotic fibers that help the bacteria in the food establish themselves in the gut. Real food is the best way to populate and perpetuate a variety of good bacteria in your gut.

Spore-based bacteria or spore-based organisms (SBO) are typically sourced from soil and are species of the genus bacillus, such as B. clausii or B. subtilis. Here’s a terrific description of SBOs. Once upon a time we did not use antibacterial cleaners, antibiotics, pesticides, or herbicides, or scrub everything clean, and our food and water carried these important bacteria into our bodies. Playing in the dirt, with other people, and with our pets also transfers them to us. Another reason gardening is good for you!

SBOs are hearty souls and can withstand harsh environments, like stomach acid, and can’t be killed by antibiotics. When they reach the large intestine, they blossom and multiply, permanently colonizing the gut. They actively refurbish the cells and mucosal layer of the intestinal tract and promote the increase of other beneficial bacteria that we can’t consume in food or supplements.

S. boulardii: I would be remiss in not mentioning one of the best tools in my toolkit, a yeast-based probiotic called Saccharomyces boulardii. It’s terrific to treat diarrhea, including preventing or stopping antibiotic-triggered diarrhea. Like SBOs, it won’t be destroyed by antibiotics. It offers many of the same health benefits of other probiotic strains, and treatment for Helicobacter pylori infection is more effective when S. boulardii is given at the same time as the antibiotics.

When you work with a practitioner, they might choose specific probiotic species to help you heal from a particular health condition. However, we also choose products with variety. This allows us to cover the waterfront, assuring that there’s a good balance of health promoting bacteria being introduced.

Prebiotics

Prebiotics are fibers mostly in the carbohydrate categories of fructooligosaccharides (FOS), inulin, and galactooligosaccharides (GOS). Big words! These are types of indigestible fibers made from chains of tightly bound sugars. Because only bacteria can digest them, they are sometimes used in sugar substitutes because they provide a sweet flavor without causing a spike in blood sugar.

Prebiotic fibers feed and nourish beneficial bacteria. Their benefit comes from the fact that they are fermentable, and it is out of this fermentation process that we receive the health benefits.

We see how they support our health by the increase in Bifidobacteria and Lactobacilli, better calcium absorption, lower protein fermentation (ultimately less gas and better BMs!), fewer pathogenic bacteria, lower allergies and risk of developing them, a healthier gut lining, a better lipid profile (cholesterol), and improvement in our immune functioning. Prebiotics help create an overall anti-inflammatory environment in the body.

We can deliciously provide prebiotic fibers with foods especially rich in them: chicory root, dandelion greens, Jerusalem artichoke, onions, leeks, asparagus, avocado, bananas (the less ripe ones), barley, oats, apples, cocoa, flaxseeds, jicama, wheat bran, and seaweed.

All fibrous foods, though, will support a healthy microbiome: whole grains, vegetables, fruits, nuts, and seeds are all great sources of fiber. There’s also inulin in some new brands of carbonated soft drinks. Some people see a difference in their bowel habits when they drink these, but the amount of the inulin is honestly pretty meager. There are better sources, but no harm in enjoying these drinks!

Be aware that some people overdo a prebiotic supplement or foods and find themselves with uncomfortable gas and bloating. Their guts are unused to so much fiber! Definitely increase prebiotics and all fiber gradually to allow your system to grow into being able to utilize it. If you find you still have symptoms, it’s time to talk to a clinical nutritionist.

Phytochemicals

This is an area of research that is still developing, honestly. That said, what we’re learning is still very cool and encouraging:

“Phytochemicals are non-nutrient biologically active plant components that can modify the composition of gut microflora through selective stimulation of proliferation or inhibition of certain microbial communities in the intestine.” (read the article here).

That is to say, the more you eat the colorful rainbow of plant-based foods, the more complex and richly health-promoting your microbiome will be.

Questions I Get About Taking Probiotics

Should everyone be taking a pre- or probiotic supplement?
Not in my opinion. While supplements are really useful for therapeutic purposes and sometimes for prevention (e.g. traveler’s diarrhea), they also cost $$$. I make probiotic recommendations when I can see their therapeutic value, but I don’t just tell everyone to take them. It’s much more effective over the long haul to serve your microbiome with probiotic-, fiber-, and phytonutrient-rich foods and to attend to your stress, sleep, and movement.

How would I know if I should be taking one?
On your own it may be hard to know for sure. That said, if you were digesting your food well and feeling pretty good, and then something triggered a bout of digestive difficulties, a multistrain probiotic with some prebiotic fiber added (a combo product called a “synbiotic”) could be just the OTC ticket to help you recover.

Go for it if you develop a yeast infection. Yeast will show up in your vagina or penis, mouth, as jock itch and athlete’s foot, and even under finger and toe nails. If it’s in those places, then it’s almost for sure in the digestive tract. A probiotic that is designed for vaginal health and S. boulardii (see above) can crowd out the yeast and help reestablish balance, either alone or in conjunction with antifungal medications.

Clinically I thoroughly assess my clients to determine whether certain bacterial strains or blends will support the desired health status. However, if the symptoms are complicated or not resolving, I like to ask my clients for a stool panel so I can really target the imbalances.

How do I know which product to buy?
If you aren’t willing to or can’t go through an assessment and/or just really feel like taking a probiotic is right for you, keep these things in mind:

• It either requires refrigeration, comes in special shelf-stable packaging, or is spore- or yeast based (like S. boulardii), which are both automatically shelf-stable.
• Understand what you are trying to achieve and pick a product that talks about that health issue (even if it’s general health).
• Choose a multistrain product (caveat: to prevent and treat traveler’s diarrhea, there is a product I like that has only one bacteria in it).
• It fits in your budget. For your purposes, having 100 billion live bacteria probably won’t do a better job for your health than a less expensive one with 5, 10, or 20 billion.
• Switch it up: Choose a new product with a different mix of probiotic strains after a container or two. Diversity of bacteria is your friend in health.
• Look for products that contain prebiotic fiber.
  
  

Is there such a thing as too much?
Yes, there can be too much, but really only under specific circumstances. Most people with average health concerns are safe with following package directions. Always ask your doctor before taking a probiotic if you have an exceptional health condition.

One time I recommend you not take a probiotic is if there is any chance you have small intestinal bacterial overgrowth (SIBO) - please get tested. The overgrowth needs to be treated, which can be done with a very targeted antibiotic from your GI doc and/or a really effective herbal program from your clinical nutritionist.

Most of the time, it’s really an issue of diminishing returns. You’ll be spending a bunch of money to be doing something you could be doing with your delicious food choices instead.