From our collaborators at Johns Hopkins Medicine International | Probiotics: Consider this before taking
In this article and video exclusive to Medcan, Dr. Lee explains the benefits and limits of probiotics
We have all heard the message that we need to eat right to be healthy. It is great that the medical field is finally endorsing the notion that food is medicine. But it is troubling that the food industry has altered that message by creating food products that contain added nutrients and probiotics, bacteria that are supposed to be good for us. We are often told that probiotics may help “boost our immune systems” or “promote digestive health.” But how good are probiotics, really? Will they make us healthier beyond eating the food in which they are packaged?
The role of our gut microbiota
You may know that each of us has a large, diverse community of bacterial organisms that inhabits our colons, with over 1 trillion different bacteria representing over 1,000 different species. Our colon’s bacterial community, also referred to as the gut microbiota, performs several functions that benefit us. A diverse population of gut microbiota is essential for the development of a healthy immune system. These “good” bacteria produce substances that prevent harmful organisms from adhering and invading our colon lining, and they also make other substances that nourish the lining cells of the colon.
Why diversity in the gut bacterial community matters
Numerous factors can affect the population and function of our gut microbiota. For example, if you take an antibiotic to treat a dental abscess, the antibiotic might also target some members of your colon’s bacterial community, leading to a temporary loss of diversity. This might allow harmful organisms to flourish if the lost bacterial strains do not come back. Most healthy people do not have problems replenishing their lost strains, but those who do might be at risk for developing chronic diseases. We know that certain chronic diseases, like inflammatory bowel disease or obesity, can be associated with less diversity in the gut microbiota. Theoretically, if we are at risk for losing diversity in our gut microbiota, then it might make sense to do what we can to repopulate it. This is where taking a probiotic might be helpful.
Clinically-supported probiotic strains
In the United States, Lactobacillus and Bifidobacterium are the probiotic genera that are most commonly used. But there are many other types, available individually or sometimes mixed together. Certain probiotic strains have been tested in clinical trials to determine whether they are helpful for managing a specific symptom or disorder. For example, some studies have looked at the probiotic strain Lactobacillus infantis for the management of bloating in women with irritable bowel syndrome, and other studies have examined Bifidobacterium lactis Bb-12 or Lactobacillus strain GG for atopic dermatitis. But just because a particular probiotic formulation was effective for one condition does not necessarily mean it is effective for all conditions.
Factors to consider when choosing a probiotic
Although there are no studies to determine whether taking a probiotic is good for general health, many people are still interested in taking them. Probiotics are classified as food supplements and are obtained without a prescription in any grocery or drugstore, or on the internet. The FDA does not regulate probiotics, and their quality can vary tremendously, so it may be hard to know if products really contain what their labels say. Other factors to consider when choosing a probiotic are cost and ease of use. The prices of probiotics range considerably, and you should not assume that the most expensive is the most effective. Also, it is unknown how many organisms one needs to take to produce an effect, but some studies have used numbers that approximates 50 billion to 100 billion colony-forming units per day. No one knows if fewer or greater numbers are more effective. Some probiotics need to be refrigerated, but this does not mean they are better than those strains that can survive at room temperature. Probiotics come as pills or powders, and food manufacturers may also add them to commercially prepared beverages or foods. Whether the probiotics added to foods are more or less effective than the supplements themselves is unknown.
The limits of probiotics’ efficacy and importance of diet
Not all healthy humans have the same bacteria that comprise their gut microbiota. For this reason, probiotics that seem to work for one individual may not work for someone else. Some very smart researchers studied the gut microbiota of healthy individuals in different countries and determined that there are at least three distinct gut microbiota community profiles associated with being healthy. Each of the three profiles had a different bacterial genus that dominated and defined the community; we call these distinct profiles enterotypes. The single greatest determinant of an individual’s enterotype is not their genes, age, gender or country of origin, but their diet. Those who eat predominantly a plant-based diet more likely have an enterotype that is different from those who eat a high-protein and carbohydrate diet. We do not have a way of knowing what each individual’s enterotype is at this point in time, and even if we did, we do not have studies that inform us as to what probiotic might be most effective for each specific enterotype. A lot more work needs to be done.
People who want to take a probiotic for general health can choose one and see how it makes them feel. It is their prerogative to continue or discontinue taking it, but studies show that as soon as they stop taking it, the probiotic strain will disappear from the colon. Probiotics do not permanently change the gut’s bacterial community, but they might be able to effect a temporary change.
The surest way to boost your immunity: plant-based, fiber-rich foods
What we eat rapidly changes our gut microbiota, so I recommend eating less processed and refined foods, or foods with artificial sugars or additives, because we are still learning what artificial substances do to our gut microbiota. Eating a lot of red meat has been shown to encourage the growth of an organism in our colons that produces a substance associated with an increased risk of coronary artery disease. Consume fresh fruits, vegetables and whole grains because they contain fiber and complex carbohydrates, like inulin, that support healthy bacteria. Until we understand more about how to manipulate the gut microbiota, eating a healthy diet is the surest way to “boost your immunity” and promote optimal digestive health.
In this video, Dr. Linda Lee discusses when and how probiotics are helpful to gut and overall health.
Content courtesy of Linda Lee, M.D., director of the Johns Hopkins Integrative Medicine and Digestive Center and clinical director of the Division of Gastroenterology and Hepatology at the Johns Hopkins University School of Medicine. The content was reproduced with permission of the office of Marketing and Communications for Johns Hopkins Medicine International. Additional reuse and reprinting is not allowed. The information aims to educate readers and is not a substitute for consultation with a physician.
