The Importance of Good Intestinal Flora for All of Us

Usually, when we think of bacteria, we think of organisms that can cause illness, infections, stomach aches, and so on. But a human’s digestive system is actually home to tens of trillions of these microorganisms. The different species, and different strains within a species of bacteria, fulfill a multitude of important functions affecting the body’s overall health. All of us, from the instant that we are born, develop in our guts an assortment of bacteria that helps digest foods, transport nutrients, and “program” our immune systems.

Though populations of bacterial species vary greatly among different individuals, there is a small number of species that we all share in common.

Working to maintain an appropriate balance of good gut flora is essential to our well-being. An abnormal or damaged gut flora can be the source of serious illness, including auto-immune disorders and dangerous food allergies.

The Three Categories of Gut Flora

There are three classifications of intestinal flora:

  1. Essential or Beneficial Flora: also called friendly or probiotic bacteria. The entire surface of the digestive system is covered and dominated by these beneficial bacteria. They control all other bacteria in the digestive system. Friendly bacteria provide a natural barrier and protect us against all kinds of invading bacteria, parasites, fungi, viruses, and toxins that are in the foods and drinks we consume every day. Beneficial bacteria produce antibiotic-like substances that keep fungi populations in check, and fight viruses and “bad” bacteria.
  2. Opportunistic Flora: there are an estimated 500 species of this flora known to science. In a healthy person, their numbers are limited and are kept in check by the beneficial bacteria.
  3. Transitional Flora: These are different types of microbes that we swallow every day in the foods and liquids we consume. When the gut is well-protected by the beneficial bacteria, this group of flora passes through our digestive tract without harming us. But when the population of beneficial flora is damaged and not working properly, transitional flora can cause diseases.

Beneficial Flora Have Many Important Functions

Beneficial bacteria stimulate appropriate cell growth in the digestive system. But they do much more:

They aid in the digestion and absorption of food by producing different enzymes that break down proteins, carbohydrates, fiber, and fat. Good bacteria also make substances that transport vitamins, minerals, and other nutrients from the foods and supplements that we ingest, through the gut wall and into the blood stream.

Beneficial bacteria also actually manufacture nutrients that are short-lived in the body, including: vitamins K2, B1, B2, B3, B6, and B12, folic acid, pantothenic acid, and some amino acids. Without a healthy flora composition, the body will be lacking in nutrients, which will not be made or absorbed properly.

Additionally, good floras play a key role in keeping our immune systems healthy, by protecting the gut from invading species and repressing the growth of harmful microorganisms that are normally found in the gut in small numbers. Good flora also train the immune system to respond only to bad organisms — antibodies (cells that attack invading toxins) learn to recognize harmful bacteria but leave the helpful species alone; this mechanism is developed early in infancy.

Friendly bacteria can also influence “oral tolerance,” in which the immune system is less sensitive to foreign substances (including those produced by gut bacteria) once they’ve been ingested. This tolerance can lessen an exaggerated immune response, like those that occur with allergies and auto-immune diseases.

How an Infant Acquires Beneficial Gut Flora

During childbirth, as a baby passes through the birth canal, the infant is orally exposed to bacteria from its mother. These then settle in the baby’s sterile gut and become gut flora. Breastfeeding is another way in which an infant acquires the mother’s gastrointestinal flora. Whatever flora mom has in her gut will become the baby’s gut flora. Bottle-fed babies acquire very different gut flora from those who are breastfed. And infants born by Caesarian section take longer to establish primary bacteriological ecosystems in their guts than babies born vaginally.

Ways to Improve Intestinal Flora

One of the ways in which diet affects human health is by changing the gut’s bacterial composition. Long-term dietary changes may allow adjustments to an individual’s gut flora and thereby improve health.

Prebiotics are high-fiber, antioxidant-rich or nutrient-rich foods, including onions, garlic, green vegetables, and bananas. These foods help maintain the balance of good gut flora.

Bad flora prefer the sugars and bad fats found in processed foods. A low-fiber, high-fat diet helps breed more harmful bacteria. But a healthy, natural diet that’s low in bad fats (animal fats and hydrogenated oils), and rich in vegetables, fruits, spices, and the foods mentioned above, is an excellent way to help the gut keep the right balance of good versus bad bacteria.

Probiotics are live bacteria contained in foods like yogurt and dietary supplements; these can introduce more of the good microorganisms into the gut, thereby promoting good digestion.

Avoiding antibiotics is another way to maintain gut flora in proper balance, as antibiotics change the composition of good and bad bacteria. That is why doctors recommend that a person abstain from using antibiotics, unless they are truly needed and are known to fight the particular virus that the person is trying to get rid of.

Finally, it is best to stay away from heartburn pills; these are less harmful to gut flora than antibiotics, but they still alter the proportions of intestinal bacteria.