A Guide to Your Gut: Why Probiotics Really Matter

November 18, 2019 18 min read

A Guide to Your Gut: Why Probiotics Really Matter

Gut health is driven by the bacteria you carry inside of your body. The composition of that bacteria can vary, depending on what you take in each day, and that composition (also often referred to as your microbiome) matters. People with few bacteria cells, and those with only a certain type of bacteria, could be at risk for a remarkable number of health issues that others don't face.

Meet the live creatures in your gut

The foundation of the gut biome begins at birth, say researchers writing in the journal Gastroenterology and Hepatology. As babies move through the birth canal, they swallow bacteria from mom's body. Babies who breastfeed take in even more bacteria. These cells move from the digestive tract to the gut, and they begin to grow and multiply once they have arrived there.

While babies and their moms may have very similar gut bacteria makeup, as those babies grow, things begin to change. Bacteria are live organisms, and they rely on food to thrive. Bacteria cells that do not get the right type of food may die off, while cells that get the right kind of nutrition may begin to thrive.

We also live in a world filled with germs and bacteria. Small cells are on almost everything, including the foods we eat and the surfaces we touch. That environment can play a role in the bacteria with in the gut.

Some medications can also play a role in gut bacteria diversity. Antibiotics, for example, may kill off entire colonies of bacteria. That's true whether we take the pills to treat some sort of illness, or whether we eat some a meat product that has been treated with antibiotics.

Everyone has a slightly different gut biome, and researchers with the American Gut project say there is no ideal biome defined quite yet. Those researchers are attempting to define the specific mix of bacteria that is most closely related with optimal physical and mental health, but their work isn't done.

Other researchers have examined just how some types of gut bacteria contribute to common illnesses, and that research could compel you to think about your own gut and what you could do to support it.

Your gut is your second brain

We typically think of the brain as the only source of thoughts and emotions. By controlling our thoughts, we think, we can also control how we feel about situations that are tough to handle.

However, gut health also has a lot to do with mental health. Research suggests that the makeup of the gut can influence how we feel about almost everything.

For example, in a study profiled by The Atlantic, researchers performed a series of anxiety tests on mice. Some were given a common antidepressant, while others were given a specific type of gut bacteria suspected to help reduce anxiety. The two sets of mice had the same type of reaction to the stress test. That seems to suggest, researchers say, that this type of bacteria is at least as effective as medications in reducing anxiety symptoms.

Studies like this are important, as they demonstrate just how much the colonies living in our digestive tracts impact what is happening in our minds. If we can amend what is living in the gut, perhaps we could improve what happens in the mind. The results could be amazing.

Research highlighted by Scientific Americansuggests that the gut and the brain communicate clearly and often. Sometimes, researchers say, that communication has to do with food cravings.

Bacterial cells have preferred types of food. Some thrive on glucose, while others prefer proteins. The bacteria are adept at knowing what will help to keep them alive and thriving. Research suggests bacterial cells can call to the brain and spark cravings for the foods they like best. It can become a self-perpetuating cycle, researchers say. People with a specific type of bacteria will crave foods that support that bacteria. They create a medium in which that bacteria thrives, and they (perhaps) exclude other types due to those cravings and eating patterns.

Similarly, some types of gut bacteria have been associated with body size. In a separate study highlighted by Scientific American, researchers collected intestinal samples from women who were obese and women who were not. Those samples were placed inside mice, and those with the obese samples gained weight while the others did not. They were in different cages, but they ate the same type of diet.

When researchers repeated the experiment, they placed both sets of mice into the same cage. This time, all of the mice remained thin. Researchers say the mice with the obesity sample picked up lean microbes from their neighbors, and that helped them to keep the weight off.

Humans aren't mice, and most of the studies that explore the link between the brain and the gut have been performed on rodents. More studies that enlist human participants are required before we understand just how this works and what it means. But these results do seem to suggest that gut health and mental health are closely linked.

Your gut is part of your immune system

Just as gut health can impact the way you think, the way you eat, and the way you handle emotional triggers, it can also play a role in your ability to fight off illness and disease.

Researchers at Johns Hopkins University point out that many of the cells that line your digestive tract secrete antibodies. These are the substances that help your body to identify and fight invaders—they're a key part of the immune system. They originate within the gut.

The gut can also control inflammation within the body. Specific cells within the gut can trigger a complex chemical reaction that can result in local tissue swelling. That swelling means the immune system is awake and active, and it isn't always positive.

When the immune system is triggered by something benign, such as a food moving through the digestive tract, it isn't able to fight against something that is serious, such as an infection. It's a bit like wasting resources. When it happens, there can be no energy left to fight off a threat that is very real.

The right gut biome can help to reduce inflammation throughout the body, which could make the body more likely to fight off infections. And that has clear implications for women.

Gut health and women

Women have a special reason to pay attention to gut health. Feeding the gut with the right kind of bacteria could help to prevent urinary tract infections (UTIs) and common methods used to treat UTIs could make poor gut health worse.

UTIs happen when bacteria that is naturally occurring (either on our bodies or in the environment) invades the urinary tract. Since a woman's anatomy leaves very little distance between the outside world and the warmth of the urinary tract, UTIs are common in women.

In the journal American Family Physician(AFP), researchers say that UTIs are common, and that women who have one UTI have a 50 percent chance of getting another at some point in life.

UTIs are best treated with antibiotics, researchers say, and they should be treated early. An infection that begins in the bladder can move to the kidneys, causing life-threatening complications. Antibiotics typically work quickly to resolve the infection, which helps to protect the kidneys.

Women who have recurring UTIs may be advised to take antibiotics for months or even years, AFP researchers say. This preventive antibiotic use is meant to help protect the urinary tract, so women don't get potentially life-altering infections on a repeated basis.

Unfortunately, antibiotics are known to kill bacteria within the gut. Recurrent use leads to tracts that are almost void of all bacteria. It is quite possible that women who take antibiotics repeatedly for UTI symptoms contribute to ongoing infections, as they do not experience the boost in immunity from the gut.

Research profiled in Live Science suggests that probiotic therapy could help women to avoid recurring UTIs. Here, researchers split women with recurring UTIs into two groups. One received a probiotic, and one did not. Of those who got the probiotic, only seven experienced a recurrent UTI; 13 had another in the other set.

We'll move into the clear benefits of probiotic supplements in a bit. But it's important for women to experience recurring UTIs to know about this link between the gut and urinary health.

To promote urinary tract health, Physician's Choice Women's Probiotic contains D-Mannose and clinically proven ProCran. ProCran is a patented and potent cranberry extract powder that has been shown to prevent UTIs effectively.

Probiotics and antibiotics

In an average year, there are 154 million prescriptions written for antibiotics, according to the U.S. Centers for Disease Control. Antibiotics can be life-saving medications when people are dealing with deep infections. But they can decimate the environment of the gut.

Antibiotics don't always discriminate between good bacteria and bad bacteria. And since they're typically taken internally, antibiotics have the power to move through the entire body quite rapidly. That means antibiotics can move into the gut, and once there, the medications can kill off all healthy bacteria inside of the gut. That can lead to terrible complications.

In a study published in the journal Expert Review of Anti-Infective Therapy, researchers report that diarrhea takes hold in up to 39 percent of those who take antibiotics. A very serious form of diarrhea, clostridium-difficile diarrhea, takes hold in about 10 percent to 25 percent of these cases.

Diarrhea can quickly lead to dehydration, particularly if it continues for a long period of time. For people on antibiotics, the diarrhea can continue until the course of therapy is complete. That means some people could deal with diarrhea for weeks.

Probiotics, filled with healthy bacteria, are tailor-made to help recolonize the body with healthy bacteria. Probiotic therapy will not counteract the work done by the antibiotics. Instead, it helps to ensure that the body has a nearly constant new supply of healthy gut bacteria. Even though the antibiotics may work to kill of all bacteria, the probiotic doses will continue to replace what has been lost.

Eating to help your gut

The foods you eat can have a huge influence on gut health. That is especially true for people who choose to dominate their meals with plants.

In New Atlas, researchers report that people who eat 30 or more different types of plants each and every week have more diverse gut bacteria than do people who eat 10 or fewer different types of plants each week.

Researchers aren't quite sure why varied plant eating is so vital to gut health. It could be that people who eat so many plants eat very little meat, so they're not exposed to antibiotics riding in the meats they eat.

A researcher quoted in The Guardian also suggests that plants help the gut because they encourage healthy bacteria to proliferate. The human gut is not designed to break down plant material, the researcher says, so we rely on bacteria to do the work. The more plants we eat, the more nutrition this type of bacteria can get.

Plants aren't the only foods that help the gut. Fermented foods, like tempeh and miso, are filled with bacteria. Those cells help to transform raw materials into the tasty, tangy products we eat. People who eat these fermented foods are ingesting that bacteria directly. Same goes for yogurt and kefir. These also have bacteria built right in. Adding these items to meals could be a great way to get a load of bacteria into the body very quickly.

Supplements can also help

Taking in 30 or more different types of fruits and vegetables can be incredibly time consuming—and some people don't appreciate the tang of foods like kefir. These people don't need to simply live with the guts they have. Probiotic supplements can help to fill the gap.

Probiotic supplements are loaded with the bacteria proven to help improve overall gut health. Most come in pill form, so they can be swallowed with a meal.

Since bacteria are living organisms that need food to thrive, the benefits of probiotics will not persist. As Harvard Medical School points out, people need to keep taking probiotics in order to get ongoing benefit. Once people stop taking the pills, the benefits fade away.

In addition, probiotics come in many formulations. A set that will work perfectly for one person might not work as well for someone else. Experts writing in Healthline recommend looking for probiotics that are designed to do something specific, rather than taking probiotics for general health and wellness. Reaching for that specific product can help to ensure that the right mix of bacteria is included within each dose.

Finally, The Daily Beast points out that probiotics are not regulated by the U.S. Food and Drug Administration, so it can be difficult for consumers to ensure that the products they take do what they are intended to do. Thankfully, there are outside companies that can look over samples of probiotic pills and test them for purity, strength, and quality. This seal helps consumers know they're getting the product they've asked for.

Beneficial probiotic strains

A "probiotic" is defined as a live microorganism that can be administered to bring about some kind of positive health change. In most cases, the live microorganisms we're talking about when discussing probiotics are bacterial cells.

Research published in the International Journal of Environmental Research and Public Health points out that the human body contains at least 10 times more bacterial cells than human cells. In a way, we are already made up of bacteria.

But the bacteria we take in when we consume probiotics are made to survive—and proliferate—within the gut. Each type of probiotic strain works a little differently. It's important to know what each strain can do, so you can make an informed choice as a consumer.

These are the strains typically included in probiotic products.

  • Bifidobacterium bifidum.A healthy human gut contains many B. bifidum cells. Researchers identified this bacterium more than 60 years ago, and it's been the focus of hundreds of research papers. In one set of research, published in The Microbiota in Gastrointestinal Pathophysiology, researchers found that B. bifidumwas effective in the treatment of inflammatory bowel disease and ulcerative colitis. Researchers suggest that this bacterium has the ability to colonize the gut and smooth out inflamed gut tissue. That could help to reduce symptoms such as pain, bloating, and urgency.
  • Bifidobacterium longum. This type of bacteria is common in the guts of breastfed babies. The bacteria helps these babies to digest mother's milk, and as these children grow and they move away from a milk-based diet, the bacterial colonies tend to die out. Supplementation with B. longum could be incredibly useful for people dealing with diarrhea. For example, in a study in the journal Alimentary Pharmacology and Therapeutics, researchers found that B. longumhelped to spur the immune system to fight against pathogens that lead to diarrhea. The bacterium also seemed to make the gut less susceptible to attack from diarrhea-causing bacteria.
  • Bifidobacterium breve.This is another form of bacteria that's common in a healthy gut. While we typically talk about a bacteria's ability to help slow down the digestive tract so diarrhea won't take hold, B. breve is a little different. In a study in Nutrition Journal, researchers found that this particular bacterium had the ability to regulate the work of the colon. That means people dealing with constipation may find relief with this probiotic. People with irritable bowl syndrome may appreciate this aspect of B. breve, as it could help them to overcome a constipation episode.
  • Bifidobacterium infantis. As the name implies, this is a type of bacteria common among babies. Movement through the birth canal, as well as breast feedings, help mom to pass this bacteria to baby. B. infantistypically helps a baby to ingest breast milk, but the benefits to adults are vast. For example, in a study in the journal Gut Microbes, researchers found that this bacterium reduced inflammation markers in people with inflammatory bowel disease. They experienced less bloating, less pain, and less blood in the stool with B. infantis supplementation. In a second study profiled in the journal Clinical Gastroenterology and Hepatology, researchers found that B. infantishelped people overcome the pain, bloating, and constipation caused by irritable bowel disorder. Those who got the supplement had significantly fewer symptoms than did those who got a placebo instead.
  • Lactobacillus casei.Cheese lovers owe a debt of gratitude to this bacterium. It's common in cow's milk, and its work is responsible for cheese, yogurt, and other fermented foods we eat. This bacterium can also do amazing work within the human gut. Research suggests that this bacterium interacts with the human immune system, which can help people to fight back against invaders that can make them feel ill. For example, in a study in the European Journal of Clinical Nutrition, researchers found that giving this bacterium to healthy people changed the composition of the intestinal microflora, and bacteria levels dropped significantly. In a second study in the journal Applied and Environmental Microbiology, researchers found that L. casei had the ability to inhibit the growth of the bacteria Helicobacter pylori. This is crucial, as H. pylori has been implicated in the development of ulcers. With supplementation, those painful ulcers could go away.
  • Lactobacillus acidophilus. This bacterium is found not only in the gut, but also in the mouth and the vagina. Since it is part of healthy vaginal microflora, it's not surprising that this bacterium is often used in probiotic products for women. Keeping the proper balance of bacterium in the vagina could help women to avoid painful urinary tract infections, yeast infections, and other similar bacterial infections. Studies also suggest, including this one from the American Journal of Gastroenterology, that L. acidophiluscan help to reduce diarrhea caused by antibiotic use.
  • Lactobacillus bulgaricus. This bacteria is found in both human bacterial tracts and in dairy products like milk and cheese. Unfortunately, just drinking milk is typically not enough, if the amount of L. bulgaricusin your gut is low. You'll need to work just a little harder to make sure your gut has the help it needs. This type of bacterium digests milk, so it could be helpful for people dealing with diarrhea due to lactose intolerance. It could also be helpful for people with inflammatory bowel conditions caused by bacteria. L. bulgaricus is competitive, and it will fight other bacteria for resources. Adding it to the gut could keep other bacteria from growing.
  • Lactobacillus brevis. If you've ever had a sip of spoiled beer or wine, you know how powerful L. brevis can be. This bacterium powerhouse feeds on sugars, and it can zap sweet tastes from fluids in mere minutes. In the gut, L. brevis has the ability to reduce inflammation, including inflammation in the mouth, according to a study in the Journal of Periodontal Research.
  • Lactobacillus rhamnosus. At one point, researchers thought L. rhamnosuswas the same as L. casei. Only after multiple studies did experts discover that these are two very different bacteria that do different things in the human body. L. rhamnosus is often included in probiotics products, for good reason. As a study in the journal Microbial Cell Factories points out, L. rhamnosus can persist in the human gut for about a week after supplementation, which means it keeps working long after people take their pills. And, it has the ability to reduce the impact of a variety of nasty germs inside the human body, which could help to reduce the risk of diarrhea, bacterial vaginosis, and more.
  • Bacillus subtilis. This bacterium is prominent in the human gut, but it's also found in the soil we walk on. Gardeners might take in this soil when they touch their mouths with dirty gloves, and farmers might breathe in spores when they walk through their fields. Taking in supplements that contain B. subtiliscan be beneficial, as it has been known to boost the immune system. Research published in the journal Molecular Microbiology suggest that B. subtiliscan produce more than two dozen different types of antibiotics.
  • Bacillus coagulans. This is considered one of our most beneficial bacterial strains. Medline suggests that it has been used to treat diarrhea, irritable bowel syndrome, inflammatory bowel disease, stomach ulcers, and respiratory infections.
  • Saccharomyces boulardii. This is a member of the yeast family, and research published in the journal Therapeutic Advances in Gastroenterology suggest that many of its benefits can be traced to the power of yeast. It can inhibit the growth of bacteria in the gut, help the gut's immune system, and stimulate healthy cell growth in the gut. It's been used to treat a variety of conditions from diarrhea to constipation to ulcers.

How do probiotics work?

The human gut is home to about 100 trillion bacteria, according to Harvard Medical School. These small systems have the potential to help us tackle everyday, lifesaving tasks. Some help us to break down foods, such as starches and milk. Others produce vitamins and hormones, so we have the nourishment we need to stay strong and healthy. And still others help to fend off invading species of other bacteria we might ingest daily.

Probiotic supplements contain bacteria. These bacterial cells are similar to those seen within a healthy adult's gut, but others are cells seen only in infants and not adults.

Probiotics are taken orally, and they must survive the acidic environment of the stomach in order to move down to the intestines. Once there, they can begin to multiply.

For people with decimated gut bacteria levels, due to disease or antibiotic use, the bacteria in the probiotic can create a new colony within the intestine. For those with an imbalance of gut bacteria, meaning they have cells within the intestine that cause harm and not good, bacteria within the probiotic can begin to wage war with the unhealthy bacteria. That can result in a more optimal gut biome.

Prebiotics vs. probiotics: What's the difference?

All probiotics are bacteria, and the human gut is a perfect environment for these cells. The spaces they colonize are dark and warm, so they're a perfect place for bacteria to grow and thrive.

But bacteria also needs food in order to grow. Without the right kind of nutrition, these cells just won't have the energy to replicate. That's where prebiotics come in. These are substances probiotics need to feed on.

Good prebioticsinclude:

  • Bananas
  • Apples
  • Leek
  • Cooked oats
  • Garlic
  • Greens, including seaweed and dandelion
  • Onion

If you're taking a probiotic supplement, adding these prebiotic foods to your diet can help you ensure that you're making the most of your investment. Physician's Choice probiotic products contain a blend of preobiotics with ingredients that are clinically proven to help probiotic organisms thrive.

Pros and cons of probiotics

Probiotics are available in a variety of formats, including drinks, foods, and pills. Some forms of probiotics are even available through transplantation. Fecal, vaginal, or other substances are removed from a healthy host and placed inside of someone who needs help. That's good news, as people who need the power of probiotics have several different methods to use to get the help they need.

For many people, using probiotic supplements in pill form is the most reasonable way to get that help. But there are pros and cons to supplementation that comes in pill form.

Probiotic pill pro: Taste

Probiotic foods are often fermented. A sugary substance, such as milk or cheese, is injected with a bit of bacteria. Those cells feast on the sugars in the food, and when the colonies grow big enough, that food is considered medicinal.

This is a natural way to ingest a probiotic, but the taste can be an issue for some people. Fermented foods tend to be tangy, tart, and a little fizzy. Some people simply can't get used to the taste, and they avoid the foods that can help them as a result.

Probiotic pills don't come with an unusual taste. The active cells are encased in a coating that stays in place until the pill reaches the acid of the stomach. That means people who are adverse to fermented flavors may be able to stick with therapy a little longer.

Probiotic pill pro: Ease

Probiotic food products can be expensive, and as a result, some people opt to make their own fermented foods at home. This can be incredibly time consuming--and it isn't always safe.

For example, Mother Nature Network reports that kombucha typically takes days to brew, and those who do so need to ensure that the pH level remains at 2.5 to 3 before taking a sip. Brewers also must worry about dangerous mold spores infecting their brews.

People who make yogurts and kefir at home deal with the same concerns. If their milk batches grow too warm, the products will clump, clot, and be unsafe to consume. If the milk is too cold, the fermentation will never take hold.

Probiotic pills come with none of these concerns. All the production happens within a factory, and the product is ready to consume when it is delivered. Those who struggle with the cooking aspect of probiotic foods might find this very appealing indeed.

Probiotic pill con: Adjustment may be required

Probiotic pills contain a great deal of bacterial types, and each dose is made to deliver real power. That means each pill is packed with cells that will begin to fight for space within the gut, and that early fight can produce uncomfortable symptoms.

The Cleveland Clinic reports that people taking probiotics may experience gas, bloating, and stomach discomfort for the first few days of supplementation. This tends to go away with time.

Since foods that naturally contain probiotics (like pickles) contain smaller amounts of probiotics, they may not require this kind of adjustment.

Probiotic pill con: Need to work with a reputable source

Probiotics are considered supplements, not medications. That means they're not regulated by the U.S. Food and Drug Administration. People who make probiotic pills may make claims about the types of bacterium included, and they may identify how many bacterial cells are in each dose. But the reality may be quite different.

That's why it is so vital to work with a company that provides outside testing of purity and potency. That testing can help to ensure that the label is an accurate description of the product included inside the bottle.

Probiotic-enhanced foods (like yogurt) may come with the same testing challenges. But natural foods like kefir and pickles may come with no claims about potency. The risk of deception with these natural products is, as a result, quite low. If nothing is promised, no promise can be broken.

Probiotics for women are available

At Physician's Choice, our goal is to help provide the supplements you need to stay healthy, active, and productive. We heard from women that they wanted a natural solution for common UTI problems, and we responded with this probiotic made just for women.

We've combined four of the most beneficial types of probiotics with ingredients made to support urinary health. We've had our product tested, so you can trust its potency. And we use all-natural ingredients, so you don't have to worry about taking in something harmful.

We’d love to have you try it.

Probiotics for everyone

We also offer a probiotic product for both men and women, designed to support gut and intestinal health, improve digestion, and enhance nutrient uptake. Our high-potency probiotic is perfect for people struggling with gut health, and who don't want to bother with probiotic-laden food.

Our probiotics have been tested in a laboratory for both strength and purity, so you can trust that you're getting a powerful product that contains the active ingredients we cite on the label. Our probiotic also comes wrapped in a coating that protects the ingredients as they move through the stomach. That means you'll have more of the active ingredient reaching your intestines.


Not all probiotics are the same, but there is a lot of research backing the importance of probiotic supplements and gut health in general. While some of the exact "why" questions are still being answered, we do have strong evidence that shows us that our gut health is vital to our overall health (and mental well-being), and that probiotics can have a significant impact on gut health. Taking a trusted, effective probiotic with a clinically proven prebiotic blend and other science-backed ingredients is an easy way to help restore the balance in your gut biome and help you feel great every day.