Probiotics are a great way to restore balance to your gut flora, improve digestion, and boost your immune system, but research suggests that they might have many more beneficial effects. Today’s post will cover some of the most promising insights into how probiotics might be used in the future.
Recent evidence suggests that probiotics may be used for the management of a number of debilitating, even fatal conditions. There are many factors leading physicians to examine probiotics and other alternatives to pharmaceutical treatments. For example, a top priority is addressing the potentially dire situation created by the swiftly growing multidrug resistance to antibiotics among pathogens, especially in hospitals. Consumers are also increasing demands for natural substitutes for drugs. The scientific and clinical evidence showing the effectiveness and safety of some probiotic strains is growing.
Many physicians, herbalists, naturopaths, and other care providers routinely use products containing lactobacilli, bifidobacteria, and other probiotics. They are regularly used to treat gut infections like Candida albicans and other gut-related conditions. There are still, however, many physicians and care providers who have never had the opportunity to learn about complementary or alternative medicine, and the role that probiotics can potentially play in treating disease.
According to the widely accepted definition issued in 2001 by the World Health Organization, probiotics are “live microorganisms, which, when administered in adequate amounts, confer a health benefit on the host.” They also issued guidelines for the properties of probiotics. For use in foods, probiotics must be capable of not just surviving in the gastrointestinal tract, but must also be able to multiply. They must be resistant to gastric juices, and consumed in foods that allow them to survive passage through the stomach and exposure to bile. Thus it is the growth and activity of the microorganisms in the body, not their source, that is important to defining probiotics.
Most people associate probiotics with digestion and gut imbalances like Candida. However, research is in progress on the use of probiotics for many uses in systems other than the gastrointestinal tract. Preliminary evidence exists for the beneficial activity of probiotics on the immune system, in cancer, allergies, cholesterol, blood pressure, and more. In this article I will summarize some of the latest research into these uses.
As with any new field in medicine, there is some controversy about the wider health benefits of probiotics. Despite the research that has been conducted, some doctors still assert that adding a few bacteria is unlikely to have the claimed effects. This is evident at the national level too. Whereas Japanese health officials have approved human health claims for more than 20 probiotic products, in Canada no probiotic products can be sold that carry health claims.(2,7)
Potential Uses For Probiotics
Lactobacillus and Bifidobacteria are the main organisms used as probiotics and available to consumers in foods or as dietary supplements. If you are looking to choose a good probiotic supplement, make sure that it contains several strains of each. Here is a list of just some of the potential uses which have been researched.
The inability of adults to digest lactose is a widespread problem, due to the way that our supplies of lactase (an intestinal enzyme) dwindles with age. However, some people who cannot tolerate milk may actually be able to tolerate yogurt. This is thought to be because the bacterial cultures in the yogurt convert lactose to lactic acid. On the other hand, pasteurized yogurt (without the bacterial cultures) is higher in lactose and not so well-tolerated. If you want to lower the lactose content, homemade yogurt is the best solution. (4)
Elevated cholesterol in the bloodstream is a risk factor for cardiovascular disease. At least 13 studies have investigated the effects of probiotics on cholesterol levels, with mixed results.
Some of the studies showed a decrease in cholesterol levels, both in total cholesterol and LDLs (low density lipoproteins – the “bad” cholesterol). Other studies showed elevated HDLs, (the “good” cholesterol), but the effects did not tend to last for longer than 6 weeks. One study actually showed an increase in total cholesterol and LDLs. These studies have subject to a number of criticisms: short duration, unreasonably large amounts of fermented milk ingested, not enough subjects, and others.
The mechanisms by which probiotics affect cholesterol are unknown. One hypothesis suggests that some strains of Lactobacillus acidophilus can incorporate the cholesterol molecules into its own structure. Another proposed mechanism is that the lactobacillus can break down bile, which the body manufactures from cholesterol. (4)
An Aid To Weight Loss
There is much interest in probiotics as an aid to weight loss, and in fact many studies have shown that probiotics can be helpful. However it should be noted that most of the studies were financed by probiotics manufacturers. While this doesn’t necessarily mean that the studies are flawed, there may be some bias present.
A fully independent study was published in the International Journal of Obesity, in which it was found that while some probiotics assisted in weight loss, others contributed to weight gain. “The research now is premature and requires more analysis.” says the study’s co-author, Didler Rault, MD, PhD.(5)
An important breakthrough in the management of peptic ulcer disease (PUD) was made when a single bacterium, Helicobacter pylori, was found to be a causative agent.
Wilhelm, Johnson, et al, reviewed the published research on H. pylori which included one or more of the following words: probiotics, lactobacillus, bifidobacterium, sacchromyces, bacillus clauii, and proprionibacterium. The subjects of these studies had received a standardized combination of drugs, including an antibiotic, that is used for eradicating helicobacter pylori. In the studies that Wilhelm examined, this treatment was supplemented with either probiotics or a placebo. The studies were “double-blinded,” neither the subjects nor the scientists knew who received the probiotic or the placebos.
The standard eradication therapy for H.pylori causes significant unpleasant side effects: nausea, taste disturbance, diarrhea, epigastric (just below the breastbone) pain and others. However, the subjects who received probiotics experienced significant relief from the unpleasant side effects of the standardized drug medley.
The review concluded that probiotics both reduce adverse side effects and boost a patient’s ability to tolerate the drug regimens used for treatment of H.pylori. The probiotics did not affect the eradication rate. The report states, “They may be helpful in patients with recurrent H.pylori infection and a history of adverse gastrointestinal effects.” It goes on to suggest that pharmacists can play an important role in educating patients about probiotic use during therapy to eradicate H.pylori.(6)
Healthy women have a variety of aerobic and anaerobic microorganisms colonized in the vagina. Lactobacillus are the most prevalent, and in the greatest number in the vaginal environment. They protect against infections by adhering to the vaginal walls and producing antimicrobial compounds (hydrogen peroxide, lactic acid and others). These probiotics are important to prevent colonization by pathogens (disease-causing substances.)
A review of the literature was done to consider whether probiotics are effective for the treatment and/or prevention of bacterial vaginosis (BV). Just like yeast infections, the development of bacterial vaginosis is associated with a low count (or total absence) of lactobacilli. It has been suggested that the hydrogen peroxide-producing lactobacilli may protect against BV, although not every study supported that. There are specific strains of lactobacilli which inhibit the adherence of Gardnerella vaginalis (the problem organism in bacterial vaginosis) to the vaginal walls and inhibit its growth. Indeed, a clinical trial showed that intravaginal administration of lactobacillus acidophilus for 6-12 days, or oral ingestion of other strains, resulted in the cure of BV and reduced recurrence. They helped restore the normal, protective vaginal flora. Overall, the use of lactobacillus for the treatment of BV was found to be generally effective, although the analysis failed to come to a definitive conclusion.(6,7)
Atopy & Asthma
Probiotics may reduce the risk of atopy (a hypersensitivity reaction to environmental allergens) and asthma in children. There have been multiple research studies in this area, which have sometimes been conflicting. A 2013 analysis from Nancy Elazab (University of Miami) compiled these studies to assess the effects of probiotic supplementation on allergen sensitivity and asthma prevention in children. Analyzed collectively, the data demonstrated that probiotics administered prenatally or in early life do reduce the risk of atopic sensitization. However the data related to asthma was inconclusive, and more studies are needed.(3)
Reducing The Risk Of Cancer
The ability of lactobacillus and bifidobacteria to alter the gut flora and reduce the risk of cancer is in part due to their ability to reduce cancer-associated chemicals in the gastrointestinal tract. The reoccurrence of cancer at other sites, such as the bladder, also appears to be reduced by the probiotics including L.casei, the strain used Japanese fermented milk. It is thought that the products of fermentation, such as butyrate, or a simple decrease in transit time in the gut decrease the risk of cancer. For now, the consensus remains that more research is needed.(4)
Diarrheal Illnesses In Children
The tragic fact is that every 15 seconds a child dies from a diarraheal illness somewhere in the world. However, there is some evidence that probiotics can help.
In a study in Peru, 204 undernourished children were given a strain of lactobacilli which resulted in fewer diarrheal illnesses per child per year. Conversely, children who didn’t receive the probiotics had many more diarrheal illnesses. It is difficult to draw definitive conclusions from this study because it is not known to what organisms the children were exposed, and if they complied fully with the treatment. The researchers stated, “At the least, probiotics provide safe and potentially beneficial effects when administered in milk … which provides the child with nutrition and a means to overcome adverse effects of fluid loss.” Current WHO recommendations for the management of acute diarrhea include fluids and electrolytes along with nutritional support.(3)
Irritable Bowel Syndrome (IBS)
IBS is a major cause of abdominal discomfort and dysfunction worldwide. It’s an elusive, poorly understood gastrointestinal disorder for which there are no satisfactory medications. It’s a largely benign disease, which can nevertheless take a heavy social and economic toll on an individual.
The symptoms of IBS include abdominal pain, bloating, flatulence and irregular bowel movements. Alterations in the intestinal microflora may cause inflammation and contribute to the development of IBS. Probiotics can rebalance the gut flora and relieve those symptoms. In a review of studies on irritable bowel syndrome, data suggest that certain probiotics or combinations of probiotics have beneficial effects on IBS and are safe for administration. Many of the studies, however, have been criticized for poor methodology, too few subjects and other parameters which were questionable. The review states that although evidence is promising, no general recommendations can be made on the use of probiotics for IBS. More clinical trials and data on the mechanisms of action are needed.
One of the most promising uses of probiotics is for the treatment and prevention of depression. It is known that stress changes gut flora, and one study in particular has shown the tremendous potential for probiotics. The connection between stress and digestive problems like Candida is certain to see lots of scientific research over the coming years.
Subjects completed a questionnaire in which they assessed their perceived stress. Half received active probiotic organisms and half received placebos (identical in appearance to the live probiotics, but with no active ingredients). The study was double-blinded — neither the subjects or scientists knew who received probiotics or who received placebos. Following weeks of treatment the subjects completed the same assessment tool. Many of the participants reported a statistically significant decrease in perceived stress. It was revealed that it was the subjects who received probiotics who reported significantly less stress than was present before treatment.(8)
The term “psychobiotics” has been coined for probiotics which show promise for the prevention and/or treatment of psychiatric illnesses. Dr. John Krystal, Editor, Biological Psychiatry, states, “This intriguing new area of research may open new possibilities for the treatment of depression.”(9)
Do Probiotics Have Side Effects?
Most people experience no side effects from probiotics, or only mild gastrointestinal effects such as gas. In fact, probiotics are used to reduce the side effects of other medications like antibiotics!
That said, there have been a handful of reports detailing more serious side effects from probiotics, and research is ongoing. A recent review of lactobacillus and bifidobacteria noted that the long-term effects of probiotics in children are still unproven. There is also some debate over whether probiotics should be given to critically ill patients. The Agency for Health Care Research and Quality Assessment concluded that the current evidence does not suggest a wide-spread risk of negative side effects, but the risks may be greater in people with underlying disease.
Other concerns have been raised about the quality of probiotic products. Some have been found to include bacterial strains other than those listed as ingredients. The establishment of standards and guidelines by the WHO/FAO represents a key step in ensuring that reliable products with suitable, informative, health claims become available. Using a reputable, high quality brand of probiotics is of paramount importance.(7)
1) World Health Organization: Guidelines for the evaluation of probiotics in food; http://www.who.int/entity/foodsafety/publications/fs_management/probiotics2/en
2) Crisplip, Mark (16Jan2009) Probiotics, science based medicine
3) Elazab, N. et al, Pediatrics, 2013 Sept:132(3):e666-76, http://pediatrics.aappublications.org/content/early/2013/08/13/peds.2013-0246.abstract
4) Sanders, ME (February 2000). Considerations for use of probiotic bacteria to modulate human health. The Journal of Nutrition 130(2S suppl)PMIB10721912
5) Dider, R., Probiotics and obesity – a link? Nat Rev Microbiology, 2009 Sept, 7(9). http://www.ncbi.nlm.nih.gov/pubmed/2148178
6) Wilhelm, SM, Johnson, AL et al, Treating bugs with bugs: the role of probiotics as adjuvant therapy for Helicobacter pylori. Ann Pharmacotherapy 2011July; 47(7-8):960-6 http://www.ncbi.nlm.nih.gov/pubmed/21693698
7) Reid G., Potential uses of probiotics in clinical practice. Clinical Microbiology Rev. 2003 Oct;16(4):658-72 http://www.ncbi.nlm.nih.gov/pubmed/23958764
8) Cryan, JF, Dinan, TG, Mind altering microorganisms: the impact of the gut microbiota on brain and behavior. Nat Rev Neursci 2012;13:701-712
9) Krystal, J, Psychobiotics: a novel class of psychotropics. Biological Psychiatry, 15 November 2013, Vol 74, Issue 10, p720-736