Probiotics is a huge and rapidly growing industry, with annual global sales estimated to rise to $49 billion by 2020. The term probiotic refers to foods (yogurt and other fermented products) and dietary supplements (capsules, tablets, lozenges, powders, and gums) that contain “beneficial” or “good” bacteria. The public continues to be interested in the promoted digestive benefits that they could get from these products.
The market claims that probiotics improve digestion, help in weight loss, strengthen immunity, and even improve oral health. Many people include this in their daily diet, believing that it balances the bad bacteria in the gut. For this widespread trend, it’s worth investigating what probiotics really does to the body.
What People Are Saying
Advocates claim that probiotics (meaning “for life” compared to antibiotics) confer health benefits mainly by rebalancing the normal microflora in the colon. The most common types of bacteria used in these products are Bifidobacterium and Lactobacillus, and numerous other species as well as strains within species. They affect the human body, and thus possibly bringing some health benefits, including some possible risks.
Probiotic goods may contain a single or many strains, and the number of organisms in a daily dose can range from one to 250 billion. Numerous manufacturers advertise that their products hold unique probiotics or a combination of strains to increase your defense against illnesses – and often charge a premium for it.
What Studies Show
The large intestine is home to hundreds of trillions of bacteria. Most of these are neutral or even helpful, performing vital body functions. For example, they help keep the “bad” bacteria at bay, improve our digestion and absorption of nutrients, play a role in immunity, and may even show anticancer effects. But what will happen to a healthy person if they supplement their diet with more probiotics? Here’s what studies have to say:
The best evidence supporting probiotics has to do with its ability to reduce diarrhea, especially some kinds of infectious or conditions associated with antibiotic use. A 2010 review from the Cochrane Collaboration revealed that probiotics shorten periods of acute infectious diarrhea. In another study in 2011, the Health Canada monograph reported that goods containing certain organisms like Lactobacillus rhamnosus GG can help manage antibiotic-associated and infectious diarrhea.
In a 2012 paper published in the Journal of the American Medical Association (JAMA), researchers found that probiotics can lead to a 42 percent reduction in risks associated with diarrhea due to antibiotics. Nevertheless, many of the accounts had flaws, so it’s important to be careful when interpreting these findings. The largest and best-designed study to date, published in Lancet in 2013, shows that probiotics were no better than a placebo in preventing diarrhea in older people taking antibiotics.
There’s little published clinical work that proves probiotics promote weight loss, as some advertisers imply or claim. In 2011, the European Journal of Clinical Nutrition released a study showing that drinking fermented milk containing a specific strain of Lactobacillus gasseri for 12 weeks displayed a reduction in body weight and abdominal fat, compared to those who had to take a control drink.
A 2012 study published in the Journal of Functional Foods revealed small losses in body fat for people who ate yogurt containing novel probiotic strains. However, the respondents did not exhibit changes in body weight.
Immunity and Colds/Flu
There is a close connection between your immune system and the bacteria in your gut – and probiotics have been linked to enhanced immune responses (such as flu vaccines). Several studies, including one published in the British Journal of Nutrition in 2012 showed that certain strains boost measures of immune response.
But whether this instantly translates into any clinical benefits is yet to be proven. There is inconclusive research regarding this matter and whether probiotics help prevent such infections. A 2011 Cochrane review points that probiotics may help prevent colds and flu, though limitations in the studies make it ultimately unreliable.
In addition to the microflora occurring in the large intestine, bacteria also populate the mouth. An increasing number of gums and lozenges are being marketed for oral health – for instance, to reduce throat infections, periodontal disease, and bad breath.
While there is preliminary support that certain strains may provide some good effect, many commercial products may not have the same formulations as those tested in published research. More importantly, you still can’t replace flossing and brushing with these products.
There are other prevalent claims concerning probiotics – that they lower cholesterol and blood pressure, treat ulcers and urinary tract infections, alleviate skin conditions like eczema, and enhance vaginal health. Other reports also promote that thee products can ease depression and anxiety, prevent colon cancer, and keep traveler’s diarrhea at bay. Good evidence to support these, however, are lacking.
Among the 29 probiotic products ConsumerLab.com tested in 2012, not all products contained enough organisms to be beneficial, and some had even far lower amounts than what is written on the label. This is another issue that consumers need to be wary about.
They are generally safe for healthy people, but probiotics may cause short-term side effects like bloating and mild gas. Not all physiological effects of these products are good. At least, in theory, some may overstimulate the immune system or negatively affect metabolic pathways.
For immune-compromised individuals, those who are seriously ill or have certain bowel problems, avoid probiotics unless your doctor allows for it. Pregnant women, infants, and young children should be careful with their probiotics intake, and it should never be given to premature infants.
There is still a lot of research to be done in the field of probiotics. Because of its widespread use, it is better if we get some actual, verifiable facts about its health risks and benefits. Often vague claims that these products support good digestive health are meaningless. We definitely need more intensive studies to test specific strains on different conditions to determine proper doses and regimens.