Bacteria are everywhere. They live in our mouth and our guts. Many of these bacteria help us digest our food and can even affect our immune systems. Probiotics are generally different strains and combinations of bacteria taken as supplements or added to food.
You can find probiotics products that claim they will make your digestion regular, prevent diarrhea, lower your cholesterol, and help you lose weight. Are probiotics useful or effective?
The answer is maybe yes, maybe not.
We say we know something is effective when we have studies and clinical trials. Studies have to be done in a way that actually provides evidence. That evidence has to be able to be reproduced and not a one-time result. Then the studies are published in peer reviewed journals so we know other scientists have looked at the results. Not a lot of probiotics have been studied that thoroughly before being added to your yogurt.
That doesn't mean probiotics are dangerous or useless. Probiotics are basically safe. They don't have side effects. Premature infants and adults with depressed immune systems should avoid probiotics. Most people, though, won't have any problems.
Probiotics that have been shown to be effective in rigorous clinical trials are:
- Align which is primarily used for adults with IBS
- Biogaia which treats infants with colic
- Culturelle treats diarrhea caused by diseases
- Florastor treats diarrhea caused by using antibiotics
- a preparation called VSL #3 helps treat ulcerative colitis and IBS.
That doesn't mean supplements and probiotics added to food aren't effective. It just means that there hasn't been a lot of study. Probiotics products are difficult to study because they're not all the same. Probiotics are made up of different strains and combinations of strains and how much of a concentration of bacteria there is. They vary by brand.
If you're looking for the most likely to be effective probiotics, check out the brand. Check out the bacteria and which ones will be still be live by the use by date. Look at information you can find on the web about how the product is certified, if it is. Testing in 2012 showed that some products contained far lower amounts of bacteria than they claimed.
There are studies that support probiotics being effective at treating diarrhea, especially diarrhea from antibiotics. Not just a very specific strain and combination, but bacteria that are in a number of probiotic products. Studies go both ways, unfortunately. A study in 2013 found placebos were just as effective as probiotics for diarrhea. Which mostly proves there is even more research to be done.
Your immune system is affected by the bacteria living in your gut. Some probiotics in studies boost immune response. Studies reviewed in 2011 showed that probiotics can be effective in preventing colds and respiratory infections but the studies didn't include older people. Which, again, mostly proves that more research is needed.
There are very few clinical studies that show probiotics help with weight loss. Two small studies show that probiotics might reduce body fat but there's nothing definitive. There is not a lot of evidence to support the many claims that this probiotic product or that one will help you slim down.
Some probiotics are effective for specific treatment purposes. In other cases, there is a lot more study to be done before we have a definite yes or no.