Probiotics are live microorganisms, also known as "friendly bacteria," that help maintain the natural balance of organisms (microflora) in the human gut. They are vital for a healthy immune system, protect against disease-causing microorganisms, and aid in both digestion and absorption of food and nutrients. The normal GI tract contains several hundred types of friendly bacteria that are able to promote healthy digestion and reduce the growth of harmful bacteria. The most well- known probiotics are Lactobacillus acidophilus, occurring naturally in yogurt, and Bifidobacterium, commonly found in the gut of breast-fed infants and thought to help confer natural immunity from disease. There are certain strains of yeast, such as Saccharomyces boulardii, that also function as probiotics.
What are probiotics used for?
A healthy balance of friendly bacteria in the gut may be thrown off by disease-causing bacteria, fungi, and parasites. Drugs (particularly antibiotics), alcohol, stress and toxin exposure can also throw off the delicate balance in the body, allowing an overgrowth of bacteria, yeast, or harmful organisms, with subsequent development of vaginal yeast and urinary tract infections. When antibiotics are necessary to treat a bacterial infection, the concomitant destruction of beneficial bacteria often leads to diarrohea. Probiotics can be used to replace the loss of beneficial bacteria, helping to restore normal bowel function and prevent diarrohea from antibiotic use.
In addition, many immune cells reside in the intestines; overall health may be very dependent on the health of your GI system. For this reason, prophylactic daily use of a probiotic is helpful and may assist in improving overall immune function.
Scientific Evidence
Mounting research suggests that an imbalanced micro biome, or dysbiosis, is related to many health problems both within the gastro-intestinal tract, such as diarrohea and inflammatory bowel disease, and outside the gastro-intestinal tract such as obesity and allergy. Therapeutic applications of probiotics include irritable bowel syndrome, intestinal infection caused by Clostridium difficile, urinary tract or female genital tract infections and to prevent and manage inflammatory skin conditions such as dermatitis/eczema, particularly in children.
Intense exercise can affect the balance of healthy flora in the gut and immune tolerance. This beneficial flora also creates the body's own supply of B Vitamins needed for energy production. Preliminary research suggest that supplementing with strains such as bifidobacterium breve and Lactobacillus rhamnosus can improve metabolism, glucose regulation and protect the gut barrier from exercise induced oxidative damage.
More recently there has been some interest in the role of gut bacteria in depression and anxiety.
How to Take Probiotics
Yogurt is the most common food containing beneficial bacteria and can be an effective prophylactic source of probiotic. It is important to use plain yogurt as the addition of sugars to yogurt can negate the good effect of the probiotic.
When probiotics are suggested after a course of antibiotics to restore normal gut flora, supplementation in the form of capsules, powder, or liquid may help to improve gut flora more quickly than with yogurt alone. Powder is both more versatile and is argued to be more effectively utilised by the body in a free powder of liquid form.
As more is understood about the complexity of the human micro biome, we are also recognising that strains of beneficial flora work best in synergy. Look for complexes with multiple strains such as those containing lactobacillus, bifidobacterium, and streptococcus strains.
Some people can respond with digestive distention or discomfort if FOS (a source of pre-biotic) is included in the supplement. If this is the case with you, I suggest taking a product without added FOS and gradually build pre-biotic sources into your diet.
Fermented foods such as sauerkraut and yoghurt are rich sources of probiotics and prebiotics, compounds that the beneficial flora in our digestive tract feed from and thrive. They also play an important role in detoxification. The process of fermentation also makes these foods excellent sources of B vitamins and Vitamin K2. The key is to make sure you get a variety of the fermented foods though and introduce them to your diet gradually to avoid the less desirable side effects such as bloating and gas. These fermented foods have been used since ancient times by cultures that report great health and longevity.
Probiotic supplements should have both a manufacturing date and expiration date on the bottle, as potency is lost after time. The bottle should state "contains live cultures." Powders can be mixed with water, applesauce, or yoghurt, depending on label instructions.
As my clients will tell you I am adamant that the body is very clever at re-establishing balance when given the right tools. Therefore I suggest that for most people, long term supplementation with probiotics is not necessary. Rather I recommend, on average, a one month course to repopulate the gut. Then, if you are eating a micro biome friendly diet low in sugar and high in prebiotics, you can let your body do these rest....
Refs:
Vandenplas Y et al (2014) Probiotics: an update. Journal of Paediatrics Oct 23. pii: S0021-7557(14)00147-8. doi: 10.1016/j.jped.2014.08.005. [Epub ahead of print]
Vitata et al. (2014). The gastrointestinal tract microbiome, probiotics and mood. Inflammopharmacology Dec; 22 (6):333-9. doi:10.1007/s10787-014-0216-x. Epub 2014 Sep 30.
Shing et al (2014) Effects of probiotics supplementation on gastrointestinal permeability, inflammation and exercise performance in the heat. European Journal of Applied Physiology Jan;114(1):93-103. doi: 10.1007/s00421-013-2748-y. Epub 2013 Oct 23.