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Guide Health: Are probiotics as good as they claim?

While probiotics are mostly considered safe, some people may need to avoid them

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Probiotics seem to be everywhere these days. You find them as capsules on store shelves and as ingredients in food products, and they’re even available through internet shopping.

Probiotics are promoted for a wide variety of conditions, but the main use is “good intestinal health.”

Your intestines contain more than 100 trillion (yes, trillion!) micro-organisms represented by about 500 different species of bacteria and viruses.

When a baby is born, its gastrointestinal tract has few micro-organisms, but by age two or three, they will have developed their own unique gut flora.

Most of these micro-organisms are beneficial in that they boost the immune system, inhibit invading microbes, extract nutrients and water from food, and manufacture nutrients on their own, including vitamin K, folate, and several B vitamins.

Probiotics are micro-organisms themselves. They have positive effects on your gastro-intestinal tract, and on your overall good health, at least according to some ads.

The idea is that you are introducing “good” micro-organisms into your gut.

Bowel infections like Clostridium difficile, poor diets, medication use such as antibiotics, and aging are the most common reasons for intestinal issues.

Research is extensive into probiotics, but no clear recommendations have resulted. For instance, using probiotics with antibiotics seems to prevent some complications like diarrhea in susceptible individuals, but the data is not strong enough to recommend routine use.

Bloating, cramping, and gas associated with irritable bowel syndrome may be reduced with probiotics, but the evidence is conflicting. Sometimes probiotics make a difference, other times not.

While probiotics are generally considered safe, there are some individuals who should avoid them, including people in critical care, those with short bowel syndrome (i.e. a lack of a functioning small intestine) and those with severe pancreatitis or inflammation of their pancreas.

Another group of people who may be adversely affected by probiotics are those with diminished immune systems due to a variety of causes, for example HIV infections, some types of cancer, and even some drugs like cancer therapy or oral steroid drugs. These individuals run the risk of the micro-organisms in the probiotics proliferating and causing new problems.

If you are considering a probiotic, look for a product listing the type of micro-organism it contains. That way, if you find one you like or don’t like you will be able to choose it again or avoid it.

You should always be aware of what you are putting into your body anyway.

Because probiotics are alive, you should also pay attention to “best before date,” and not use one that has expired (i.e. that has died).

Some probiotics require refrigeration, so pay attention to the manufacturer’s storage instructions.

Dosing can be difficult because you are looking for the colony-forming units or CFU. Here, a higher number isn’t always better in that some products are just as effective at lower doses, while others need a higher dose.

Unfortunately, there are no general dosing recommendations because of the differences in genetics, overall health, other disease conditions, age, and even concurrent drug use.

The bottom line seems to be that probiotics are safe for healthy individuals, and if you are consuming your probiotics in foods like yoghurt, they can be part of your normal diet.

About the author


Marie Berry is a lawyer/pharmacist interested in health and education.



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