Probiotics: A HealthCentral Explainer


What are probiotics?

Probiotics are living microorganisms that naturally inhabit a host and provide a variety of health benefits.  According to The Harvard Medical School Family Health Guide, “An estimated 100 trillion microorganisms representing more than 500 different species inhabit every normal, healthy bowel.” It may sound scary, but most of these species are good for you.

The National Institute of Allergy and Infectious Diseases states that some of these microorganisms include supportive bacteria, viruses, fungi, and protective cells from the immune system. These  microorganisms all work collectively in a delicate balance to keep your intestines healthy to ensure proper absorption of nutrients from digestion, and normally have no negative effects on their host. Probiotics can be found in the bacteria of yogurt and other certain foods or via supplements.

Are there benefits?

Probiotics boost the immune system—it’s estimated that more than half of the immune system resides in the gut.  They also improve digestion and absorption, restore “good” gut bacteria and fight harmful pathogens. Clinical trials testing probiotics have shown they help alleviate gastrointestinal problems (such as diarrhea), fight against allergy development in children, and prevent yeast and urinary infections in women. They’ve also been shown to be beneficial for people with chronic GI diseases, such as Crohn’s and irritable bowel syndrome.

According to a World Health Organization and Food and Agriculture Organization report, preliminary research shows probiotics may help prevent certain cancers by signaling gut bacteria to decrease the production of carcinogens, such as nitrosamines. However, more research is required before a definitive correlation can be determined.

Probiotics may also help fussy infants. According to a study from Aldo Moro University in Italy, babies who took probiotics in their first three months were less colicky compared to those who didn’t. The study split 554 newborns into two groups. One group received the probiotic lactobacillus reuteri, and the other got a placebo. The babies taking probiotics cried and vomited for shorter periods of time, and experienced more bowel movements.  However, experimenting with a newborn’s immune system is not recommended and further testing on the future effects of probiotics in infants is needed.

A recent study from the British Journal of Nutritionsays probiotics may also help fight obesity in women. People who are obese have different intestinal flora compared to thin people due to diet differences. Testing 125 overweight women and men, researchers from Université Laval in Canada had half the participants ingest two probiotic pills daily. The other half received a placebo. This accompanied a 12-week weight-loss diet, followed by 12 weeks of maintaining that weight loss. During the initial 12 weeks, women on probiotics lost more weight than women taking the placebo. Moreover, the women using probiotics continued to lose weight in the second 12-week period, whereas the placebo group didn’t lose any additional weight. The probiotic group also reduced the amount of gut bacteria linked to obesity and reduced leptin levels, a hormone that regulates appetite. The researchers believe probiotics help promote the growth of healthy gut bacteria that aid in weight loss and management.

Taking probiotics with antibiotics

Taking probiotics and antibiotics together can be complicated. Some probiotics may counteract the effects of antibiotics, or cause adverse reactions. It really depends on the type of medication. Consult your pharmacist for more information and ask if it is safe to take your antibiotics with probiotics—many times the prescription bottles will have a warning label on them as well.  Make sure to tell your doctor you’re on probiotics before they prescribe any antibiotics.

It is, however, encouraged to consume probiotics following a course of antibiotics to help restore and recover the balance of “good” bacteria wiped out by antibiotics. Nutritionist Amy Hendel recommends looking for “live-action” on the label and consuming probiotics for duration of 10 days to two weeks after completing an antibiotic course. Probiotics should be stored in a cool, dry place away from sunlight.

Who should take probiotics?

Anyone can take them. Research indicates that probiotics do not appear to be harmful for either healthy or unhealthy people. However, it’s important to note that studies have not yet proven that taking probiotics daily improves life-long health regardless of diet and exercise habits. So maintaining a healthy regimen is still crucial, even if you take probiotics.

There are many different brands and types of probiotic supplements. If you’re thinking of taking pills, the two main probiotic groups to look for within the ingredients are Lactobacillus and/or Bifidobacterium. Talk to your doctor before taking probiotics. Or you could always skip the pills and expensive cost by including yogurt in your daily diet.


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