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What's Good for the Gut: The Health Benefits of Probiotics

Updated: Apr 3, 2019

Did you know that we actually have more bacteria in our bodies than we do cells that make up our bodies?  Just think about that for a second... Are you thinking:

A. That's kind of gross?   Or   B. These things might be pretty important?

Either way, you are correct!

Our bodies are naturally colonized by many different types of organisms that live on our skin and throughout our intestinal tract and other mucus membranes. It is collectively referred to as the body's microbiome. According to Harvard Medical School, there are nearly 100 trillion micro-organisms in a healthy and normal bowel. They are a mix of both helpful and potentially harmful agents but luckily the beneficial micro-organisms keep any pathogenic ones under control. I always tell my patients to think of maintaining a healthy balance as a numbers game: as long as there are more good micro-organisms than bad ones, the good will crowd out the bad and all will be well. But how does one maintain this balance?


Probiotics are defined as living micro-organisms, usually bacteria, that can be ingested for health benefits including digestive, immune, urogenital, mental and metabolic health.

Probiotics & Digestion

Research has shown that they can improve digestive function including conditions like diarrhea, constipation, irritable bowel syndrome and even decrease H. pylori in the stomach to prevent or treat ulcers.

Probiotics & the Immune System

Probiotics are great for reducing the side effects of antibiotic therapy. Probiotics have also been shown to reduce the risk of many common infectious diseases (colds, flus etc) and improve immune function in general since a large part of the immune system (85%), called the enteric nervous system, resides in the gut and the beneficial bacteria present there stimulate the production of immune cells that are active in mounting responses to infections.

Microflora Imbalance & Urogenital health

The female urogenital system also has it's own unique microflora. Common conditions like yeast infections, bacterial vaginosis and urinary tract infection and interstitial cystitis are related to a microflora imbalance or dysbiosis, that can be re-established by either local/topical applications or oral ingestion of probiotics.

Gut Microbiome & Mood/Mental Health

The bacteria within the gut also manufacture hundreds of different neurochemicals that manage both basic metabolic and physiological processes as well as mental functions such as learning, memory and mood. For example, 95% of the serotonin in the body is produced in the gut. Serotonin is vital in maintaining both a healthy mood and digestion and it is therefore a big part of the ever mysterious and important gut-brain connection. The gut and the brain are in constant communication, regulating responses to various stimuli. Ever had a “gut feeling” about something? You can thank your very astute gut microbiome for that! The appropriate strains of probiotics have also shown great potential to improve symptoms of anxiety, depression and autism.

Gut-Dwelling Micro-organisms & Obesity and Metabolic disease

A imbalance in gut-dwelling micro-organisms, or dysbiosis, is  liked to obesity, metabolic syndrome, diabetes and atherosclerosis. These conditions are all related to inflammatory states within the body which can be addressed with therapeutic nutrition. It has been shown that obese people have less diverse gut flora and poorer metabolism than others. Eating high sugar and processed foods promotes the growth of harmful bacteria that can contribute to inflammation, insulin dysregulation and increased appetite and fat storage, resulting in weight gain. Incorporating fiber-rich foods (fruits and vegetables), increasing protein and  reducing overall caloric intake helped these people both lose weight and change the makeup of their intestinal flora.


There are two main options to increase your beneficial gut flora – eating fermented foods or taking probiotic supplements.

Improving Gut Flora with Fermented Foods

Fermentation is the process through with bacteria or yeast convert the natural sugars present in foods into lactic acid, gases and alcohol which helps to preserve the foods. Fermented foods contain friendly bacteria, digestive enzymes, vitamins (for example, Vitamin K2) and other phytonutrients. Common fermented foods include yogurt, kefir, cheese, cultured butter, sauerkraut, pickles, kimchee, sourdough bread, tempeh, miso, beer, wine, vinegar, kombucha and salami. There are lots to choose from here! Even those who are lactose intolerant may be able to eat fermented dairy since the bacteria contained in it begin the lactose digestive process well before consumption.

These foods can be bought or made at home. If buying them, be sure to choose unpasteurized products as those will still contain the beneficial bacteria needed to reap all the wonderful health benefits. Making your own fermented foods can be straight forward and safe provided that you follow the appropriate precautions. Here is a great blog and video demo to get you started with culturing your own vegetables.

Improving Gut Health with Supplemental Probiotics

The most common species of probiotics contained within supplements are Lactobacillus, Bifidobacterium and Sacchromyces, a yeast. They can be found in powder, capsules or drinkable yogurt products in several millions to billions per dose! This is a great option for treating acute illnesses like diarrhea and urinary tract infections or for those who do not enjoy fermented foods.


  1. Maintain a balanced diet including plenty of fiber-rich foods like vegetables, fruits and whole grains which can act as prebiotics. These are fiber compounds that remain undigested until they reach the large bowel where they stimulate the growth and activity of beneficial bacteria. Raw garlic, onions, oats, wheat; artichokes, bananas and cooked beans are great sources of prebiotic fiber.

  2. Avoid high sugar, artificially sweetened and processed foods in general which can disrupt for gut flora and contribute to metabolic, immunity and mood problems.

  3. Also avoid any foods you may be sensitive or allergic to as these can cause inflammation within the digestive system that disrupts the microbiome, making one more susceptible to illness.

  4. Get a daily dose of fermented foods. As little as 1/2 a cup a day can go a long way.

  5. If making your own fermented foods, be sure to take the necessary safety and storage precautions.

  6. Choose probiotic products that are unpasteurized and refrigerated. This better ensures the freshness, potency and effectiveness of the bacteria contained within them.

  7. Take your probiotic supplements with other foods (or within 30 minutes of eating) so that the food can somewhat buffer or protect the bacteria from stomach acid. This gives them a better chance of reaching your lower digestive tract where all the magic happens.

Enjoy your new, beautiful relationship with these very helpful bugs!

As always, be sure to consult your health care provider before making changes to your diet or beginning any new supplements.


That Gut Feeling, American Psychological Association

Dr. Adeola Mead, ND is the Natural Choice Network's Healthy Living Content Coordinator. She is a Bastyr University graduate and Seattle based naturopathic physician. Dr. Mead is passionate about using natural medicine education as a powerful healing tool for both individuals and communities.


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