There are several ways to increase proliferation of beneficial bacteria with our dietary choices. First, consume cultured and fermented food products, including yogurt, cottage cheese, kefir, tempeh, and unpasteurized fermented vegetables such as sauerkraut. These foods contain beneficial bacteria and encourage their colonization. Be sure to look for the term “active” or “live” cultures on the label and look for fermented vegetables that are refrigerated to be sure you are getting beneficial live bacteria. Second, aim to get a variety of foods rich in prebiotics. Prebiotics are a category of compounds that the human digestive tract is unable to break down but that beneficial bacteria can break down and use as food. This process also produces short chain fatty acids (SCFAs), which feed the cells of the large intestine and help to modulate inflammation.⁴⁰ Prebiotics are found in many healthy foods, including asparagus, bananas, dandelion greens, chicory root, burdock root, garlic, onion, leeks, flax seeds, oats, barley, Jerusalem artichokes, and many fruits.⁴¹ Often probiotic supplements will contain concentrated sources of prebiotics such as fructo-oligosaccharides (FOS), mannan-oligosaccharides (MOS), and inulin. No matter the source, some people with compromised digestion may not tolerate prebiotics well at first, and gradual introduction may be necessary.

Factors that Hinder the Gut Microbiota

Many factors, such as poor diet, aging, medications, illness, stress, environmental pollution, and infection can damage intestinal flora.⁴² Several factors, including healthy digestion, are vital to ensure an optimal bacterial presence in the body. The rate of peristalsis, the muscular contractions of the intestines that move food through the intestinal tract, affects your microflora. If it is too fast, as in diarrhea, the number of bacteria is reduced. If it is too slow, as in constipation, overgrowth of harmful bacteria can occur. A good goal is to have 2 to 3 natural, effortless bowel movements each day. 

It should come as no surprise that our food choices directly influence our internal bacteria. Simply put, the diet that is good for you is also good for your gut flora and vice versa. Foods that are not microbiota-friendly include sugars and refined foods. Alcohol also prevents implantation of health-promoting bacteria. Chemicals found in our food and water supply, such as pesticides and chlorine, can have a negative impact on our resident microflora as well.^{43 44}

Lastly, two factors that lead to microbe destruction are stress and the common treatment for stress-related symptoms: antacids. Stress has been shown to reduce the number of Lactobacilli in the intestines, and frequent use of antacids shifts the environment of the gut to alkaline, which is favorable for harmful bacteria.^{45 46} Just another reason practicing stress management is so important!

Supplemental Probiotics

Considering how easily our gut bacteria can be compromised in our modern lives, it may behoove you to take a high-quality probiotic supplement. Here are some tips on how to find and use a probiotic supplement.

What genus and species?

Probiotics are classified by their genus and species, for example, Lactobacillus (genus) acidophilus (species), and sometimes by their strain, denoted by letters and numbers that come after the species name. Unfortunately, there is no one-size-fits-all probiotic. Different varieties can be beneficial for different ages and different concerns. A good starting place is to supplement with Lactobacillus acidophilus and Bifidobacterium bifidum. From here, many other probiotics can be added to complement this base. 

Probiotic origin?

The “origin” of a probiotic strain is where the probiotic was originally isolated from. This may be the human gut, a fruit, kefir, the soil, etc. It does not necessarily mean it is the only place that particular probiotic is found naturally, though. Probiotic supplements are not taken from the original source, instead they are grown from a swab taken from a bank where the strain is registered and are then cultured. Human strains are sometimes thought to be superior because they are already adapted to thrive in the human gut, but there are plenty of probiotic strains with non-human origins that are known to be tremendously beneficial and have significant research to back them up.

Mixed or Separated?

There is much controversy over whether or not mixed species or single species products are better. One school of thought is that “cocktails” of the more important friendly bacteria should not be used since they are destined to inhabit different regions of the digestive tract and will compete with each other for nutrients and growing room. On the other hand, several studies in both humans and animals have found that properly selected multi-strain formulas are superior to single-strain products for a variety of conditions.⁴⁷ It is best to try both kinds for yourself and see which works best for your body. 

Dairy or dairy-free?

Probiotics are made similarly to traditional yogurt. These friendly bacteria are grown in what is called a “culture medium”. As the bacteria grow, the culturing medium is transformed into a different substance called the supernatant, which is filled with beneficial metabolic byproducts collectively known as postbiotics.⁴⁸ The supernatant also helps to preserve the bacteria while on the shelf and once ingested.⁴⁹ Milk is a common culturing agent, but other culturing mediums such as carrots, chickpeas, and soy can also be used for those who are sensitive to dairy. Because friendly bacteria produce lactase, dairy-based probiotics can sometimes be used by lactose intolerant individuals, but not always.⁵⁰ The package should clearly label as to whether it contains dairy or not. 

Processing methods?

Because bacteria are easily damaged by heat, oxygen, and acid there are two main challenges in the production and use of probiotic supplements. First, they must be grown, harvested, packaged, and delivered to the consumer all while preserving the integrity of the bacteria. Second, they must survive the acidic environment of the stomach to reach their desired destination, the intestines. Probiotic processing methods have come a long way since the early years. Today’s processes are both more efficient and cost-effective, yet still deliver viable bacteria.  As we have learned more about probiotics, manufacturers have also devised additional ways to maintain their viability, including the cultivation of more hardy strains, using different culturing mediums, coating the probiotics and/or the capsule they are delivered in, and adding prebiotics.^{51 52} There is even some research to suggest that many of the benefits offered by probiotics can be obtained from dead bacteria (aka, parabiotics).^{53 54}

How much?

Probiotics are measured in colony forming units (CFU), which is a measure of the number of cells that are viable. Dosages range from 1 billion CFUs to 50 or even 100 billion CFUs. While higher CFUs are commonly recommended for more therapeutic uses, more is not always better. Finding a product that fulfills your health goals, even at lower CFUs, is an effective strategy.   Keep in mind, no side effects have been reported, even with large doses of probiotic bacteria, although some individuals might experience bloating, bowel changes, and gas when first introducing probiotics. This is not necessarily a bad sign and is usually temporary. It usually signifies the killing off of pathogenic bacteria and fungi. To minimize this ‘die-off’ reaction, begin with very small amounts and build up your dose slowly. 

When?

Many probiotic experts feel the best time to take a probiotic supplement is in the morning on an empty stomach (when stomach acid is at its lowest) or just after meals, when the food can buffer the acid.¹

Storage?

Light, moisture, and heat destroy bacterial potency. In general, store your probiotic in the refrigerator if you bought it at the store from the refrigerated section or in a cool, dark place if you bought it off the shelf. 

Shelf Life?

Look for a product that lists potency through expiration date, not just the potency at the time of manufacture and be sure to store the product according to the manufacturer’s recommendation to maximize survivability. 

Capsule, tablet, liquid or powder?

The form used to deliver probiotics is largely dependent on your individual needs. Powdered forms can easily be added to smoothies or drinks and may also get into the gut faster than when taken in capsules. However, capsules are convenient and some are enteric-coated to keep the capsule intact (and the bacteria preserved) until it has passed the stomach and is into the intestines. In general, choose a product that meets your other criteria and that you are most likely to take regularly.

When choosing your supplement, do not hesitate to ask questions of the manufacturers. They should be able to provide you with research and hard facts about their products. 

To achieve optimal functioning of your internal ecosystem, place emphasis on lifestyle habits and choices that encourage its growth and remove any factors that cause its destruction. Although most people can use a “probiotic boost,” people who use antibiotics, have a poor diet, are under chronic stress, or suffer from digestive issues seem to be most deficient in friendly bacteria. No matter what your health and wellness situation or practices, encouraging the health of your internal probiotic friends can literally improve nearly every aspect of your overall health. 

References