Probiotics have become somewhat of a buzzword in the world of health and wellness as of late, with thousands of products crowding the market with probiotic capsules, tablets, and even juices. But what are probiotics actually supposed to do?
Probiotics are live microorganisms or bacteria that can be consumed via fermented foods and specialised supplements. Although most of us usually think of bacteria as disease-causing, probiotics represent a special kind of “friendly” bacteria that can actually help our digestive systems to absorb nutrients more efficiently. In fact, without a useful source of probiotics, our guts experience an imbalance caused by too much “bad” bacteria that harms us relative to the “good” bacteria that helps us.
Although many people choose to buy probiotic supplements, probiotics can be found naturally in store-bought food items such as sauerkraut (as long as it’s fermented), raw cheeses, apple cider vinegar, salted gherkin pickles, brine-cured olives, yoghurt, kefir, and others.
Primarily, probiotics can help replenish and restore the natural supply of good bacteria in the gut which helps to prevent digestive issues, obesity, mood imbalances, allergies, and more. In particular, one strain of probiotic known as Saccharomyces boulardii or S.boulardii is the only yeast strain of probiotic and is known for its ability to prevent and relieve diarrhea, with one large systematic review finding that this strain of probiotics reduced the time spent suffering from diarrhea by more than 24 hours on average. Source
The anti-diarrhea effect found in probiotics is mainly due to its ability to counter the negative side effects of antibiotics by restoring the balance of good vs. bad bacteria in the gut and fighting off negative pathogens so the body can absorb nutrients properly. Since the S.boulardii strain of probiotic is a yeast, it’s important to be cautious when taking this type of supplement if your immune system is poor. Furthermore, probiotics are a great supplement to take while on antibiotics. Probiotics can also reduce the risk of traveler’s diarrhea when visiting underdeveloped countries with contaminated water and can aid in infectious diarrhea in children caused by viruses. Source
Of course, digestive issues can mean more than just diarrhea. Probiotics have also been found to reduce the symptoms of Irritable Bowel Syndrome (IBS) and ulcerative colitis, which is a chronic disease characterized by abdominal pain and discomfort, bloating, gas, constipation and/or diarrhea. Some studies have found that cheaply produced probiotic supplements may be as effective as medical drugs (Source). Probiotics perform so many interesting functions in the bowel that some medical researchers are now exploring its potential as a treatment for certain highly serious illnesses; recent research has identified probiotic supplements as a key way of reducing the risk of a fatal condition called necrotizing enterocolitis (which tends to affect prematurely-born babies) (Source).
One important thing to remember about these digestive benefits is that supplement users will only experience positive changes if they were suffering from problems to begin with. If you already have a well-balanced gut flora, research has shown that there nothing to be gained from taking a probiotic supplement.
Although digestive benefits are probiotics’ main claim to fame, some studies have uncovered a range of positive side effects that could prove beneficial for dieters.
Some probiotics (particularly lactobacillus gasseri and lactobacillus rhamnosus) have been found to block fat from being absorbed in the gut. In turn, causing more fat to be excreted and reducing the amount of fat stored in the body. meaning that relatively more is excreted out rather than stored as fat.
The overall effect of this has shown to reduce belly fat in otherwise healthy people, and increase the amount of weight lost by those who take probiotics compared to those who don’t.
Another interesting side effect that probiotics seem to display is that they help lower cholesterol and blood pressure levels. The mechanism by which this happens is related to bile, a liquid substance that breaks down probiotic bacteria in the gut. Since bile is primarily made up of cholesterol, this has the effect of reducing the levels of cholesterol found in the bloodstream (Source). Customers shouldn’t expect a miraculous change, with most probiotic supplements reducing cholesterol levels by 4-5% (Source). However, probiotics can reduce blood pressure, with one meta-analysis reporting that a high daily dosage of probiotics can produce “moderate” reductions in blood pressure (Source).
It’s important to note that not all probiotics have the same effects. In order to achieve the desired effect of weight loss, make sure you purchase the right strain of bacteria. In fact, certain probiotic strains can negatively affect weight loss, such as lactobacillus acidophilus which has been linked to weight gain. Source
Many probiotic supplement manufacturers claim that probiotic bacteria can boost the immune system, which is broadly correct. The human body’s immune system is heavily concentrated in the gut (apparently 70-80% of what we consider to be the immune system is located in the intestines). Probiotics help to reduce the rate of unnecessary inflammation in the bowels, which subsides problems like infections, allergies, from flaring up (Source). Probiotic bacteria also help the body fight off harmful bacteria. This promotes the intestine’s immunologic barrier and stimulates the immune system to resist harmful pathogens. Source
This may all seem a bit technical, but the effects are fairly easy to grasp. One double-blind, placebo-controlled study found that probiotic supplements were able to reduce the risk of healthy individuals catching the common cold (Source). Other studies have found probiotics to be effective in reducing the frequency and severity of respiratory infections in children (Source), and applying probiotic bacteria intra-vaginally, women can reduce the risk of urinary tract infections. Source
Numerous studies have come out in recent years that link probiotic to improved mental health. Some of these beneficial side effects include the ability to battle anxiety, depression, autism spectrum disorders (ASD), obsessive-compulsive disorder, and memory loss. Although these claims seem obscure, researchers have proof from numerous double-blind, placebo-controlled studies conducted on both animals and humans. Source
What on Earth could be causing this? Some researchers have theorized that intestinal bacteria affects psychiatric conditions, due to the intestine’s use of neurotransmitters like serotonin or acetylcholine.
These neurotransmitters help move digested food through the gut, but also are connected to the brain with highly linked psychiatric outcomes. If the gut communicates with the brain as often as scientists believe it does then it makes sense that gastrointestinal pain and disorders might actually contribute to psychiatric problems. Source
Before we get too excited, it’s important to note that this is perhaps the least credible statement in this article. Despite being backed by lots of excellent studies, there are similarly high numbers of studies out there that have found no link between probiotics and mental health outcomes (Source). There are definitely better solutions out there for those who suffer from psychiatric disorders. But if you’re looking for yet another reason to give probiotics a try, this might be one of them! We also covered the benefits of taking a prebiotic in another article.
Disclaimer: Our reviews and investigations are based on extensive research from the information publicly available to us and consumers at the time of first publishing the post. Information is based on our personal opinion and whilst we endeavour to ensure information is up-to-date, manufacturers do from time to time change their products and future research may disagree with our findings. If you feel any of the information is inaccurate, please contact us and we will review the information provided.