You’re walking around right now with trillions of microorganisms (your intestinal flora) living in your gut. You’ve got so many of them, in fact, that they contribute around two kilos to your body weight!
Depending on their strain, they inhabit different parts of the digestive tract. In the colon, for instance most of the organisms are in the form of bacteria (they make up 60% of the dry material in faeces). The metabolic work performed by these bacteria is so great that the colon is the most metabolically active organ in the body.
Every individual has their own unique microbial profile, their own mix of the different strains of bacteria. This profile remains remarkably constant throughout life, but can be affected by age, diet, drugs and disease.
Intestinal flora are essential to our health and the correct functioning of our bodies. They help digest our food, support our immune system, produce certain vitamins and hormones, stimulate cell growth in the intestinal wall and repress the growth of harmful microorganisms.
Intestinal Flora and Digestion
Human cells lack enzymes necessary for breaking down certain carbohydrates. Some of the bacteria in our guts, though, have the necessary enzymes and break these carbohydrates down into Short Chain Fatty Acids – a major source of energy and nutrients.
Bacteria also manufacture B group vitamins, and help with the absorption of lipids and the minerals calcium, iron and magnesium.
The Barrier Effect of Good Intestinal Bacteria
Not all bacteria are “good”. Some strains can be harmful, not only to the functioning of the good bacteria, but also to the host (us).
The good bacteria fight the bad guys in an effort to maintain a balance of predominantly beneficial bacteria in the gut. But they do more than this. By competing with harmful bacteria for nutrients and “attachment sites” on the wall of the gut, they help protect us from diseases such as colon cancer, organ failure, sepsis and Irritable Bowel Syndrome. In effect, they create a barrier against disease.
As well as disease, good bacteria help prevent yeast overgrowth, excess gas and bloating.
Intestinal bacteria support the immune system by increasing T-cell counts, stimulating the gut mucosa to produce antibodies to pathogens and by producing natural antifungal and antibiotic substances
What Goes Wrong in the Gastro-Intestinal Tract?
Simply put, too much bad bacteria, not enough good – the intestinal flora suffers an imbalance. This can happen for a number of reasons – age and disease, for example – but the most prevalent cause is poor diet and lifestyle.
Bad bacteria thrives on animal fat and refined sugars. Eat too much of these and you are encouraging the growth of harmful flora.
Though certain foods like alcohol and coffee are purported to kill intestinal bacteria, by far the worst offenders are antibiotics. Those these are designed to cure bacterial illnesses, but they also have the side effect of decimating good bacteria as well. After a course of antibiotics, then, care should be taken to repopulate your intestinal flora.
Helping the Good Bacteria
Foods that nourish good bacteria include fresh vegetables, whole grains, garlic, green tea, and fermented foods like yoghurt and miso. Good bacteria love fibre too.
As well as choosing helpful foods (particularly yoghurt), good bacteria can be helped along with supplements called probiotics and prebiotics.
Probiotics are dietary supplements of beneficial microorganisms. Basically they are designed to add cultures of good flora to your gut and improve its microbial balance.
Probiotics come in a variety of forms including capsules, powders and liquids.
To have any beneficial effect, probiotics must survive the journey through the acidity of the stomach and small intestine. To help them do this a prebiotic is sometimes added to the probiotic supplement.
Prebiotics include the sugars inulin and fructooligosaccarides and can be obtained from onions, bananas, leeks, sweet potatoes, fruit and soybeans.
With their beneficial effects on digestion, immune system support, nutrient production and absorption and protection from disease, intestinal flora play a vital role in our health and wellbeing. Next time you prepare a meal or take a drink, spare a thought for the trillions of friendly bugs who call your intestines home.
Learn more about probiotics here: