Could Probiotics Improve Asthma?

Good Bacteria May Be Key In Preventing Asthma

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While the impact of probiotics on asthma is not clear, the allure of this class of drugs for the prevention and treatment of asthma is. Administration of natural, live micro-organisms with minimal side effects that can provide a beneficial health outcome for a disease with increasing impacts on patient and society is very desirable to patients.

While there have been a number of small studies showing benefits of treatment with probiotics on asthma when these studies are combined through the process of systematic review and meta-analysis an overall benefit has not been seen. Overall, probiotics cannot currently be recommended for either the prevention or treatment of asthma.

What Are Probiotics

Probiotics are live microorganisms (most commonly bacteria) that you may take to confer a positive impact on your asthma or decrease the risk of developing asthma. They are commonly referred to as “friendly bacteria” or “good bacteria.” In medicine, they are most commonly used to prevent or treat diarrhea caused by antibiotics. They have also been used for a number of health conditions including irritable bowel syndrome, atopic dermatitis (eczema), allergic rhinitis (hay fever), colic, and the common cold.

Probiotics were the 5th most commonly used natural health product in kids, but use in adults was much less according to the 2007 National Health Interview Survey.

How Might Probiotics Help Asthma

The microflora hypothesis suggests that changes in bacteria impact the development of asthma and allergic disease. Gut bacteria are thought to help the immune system develop and perturbations to the process impact allergic disease. In fact, changes in gut bacteria precede the development of atopic dermatitis and are noted to be the first step in the development of allergic symptoms. Overuse of antibiotics decreased rates of breastfeeding, and changes in diet have led to changes in the gut microflora and potentially an increase in allergic disease. While difficult to prove, studies in animals have shown that administration of antibiotics has led to hyper-responsive airways.

A number of studies have demonstrated that administration of Lactobacillus rhamnosus and Lactobacillus fermentum either during pregnancy or shortly after birth leads to a decreased incidence of asthma and other allergic diseases. However, a number of studies have also failed to show a similar benefit.

In one interesting study researchers looked at children that had different risk levels for asthma based on a number of different factors. They then looked at their "poo" or stool for the presence of bacteria. The investigators looked at differences in bacteria found in the different at-risk groups. They found that among children who had wheezed and had allergies lowers levels of Faecalibacterium, Lachnospira, Rothia, and Veillonella bacteria were found in the stool compared to the group with the lowest risk of wheezing and allergy. This group was significantly more likely to be diagnosed with asthma by age 3. The differences in stool content were only seen in the first few months of life. This finding caused investigators to hypothesize that changes in the bacterial content in the first few months of life may impact asthma risk. They further suggested that it may be possible to develop a cocktail of bacteria that could be given in early life to decrease the risk of asthma.

In an interesting animal study researchers fed bacteria-free mice either a stool sample from a child at high risk of asthma, or a sample with higher levels of Faecalibacterium, Lachnospira, Rothia, and Veillonella bacteria. The animals were allowed to reproduce and the investigators attempted to make the baby mice have asthma. The mice with supplemented bacteria had less inflammation in the lung compared to mice that did not get the additional bacteria. While an interesting study, animal studies do not always translate similar into human studies, so please do not go ask your doctor for a stool prescription.

Probiotics primarily impact asthma through its anti-inflammatory component.

However, all probiotics are not all alike and may not produce the same result. Just because a specific kind of probiotic helps with asthma, that doesn’t necessarily mean that another kind of probiotic will have the same or similar effect. Likewise, differences can be seen with the same probiotic but manufactured by a different company. As a result, if you get advice from a health professional about a probiotic, you probably need to get a brand name recommendation. If you read about a research study the only way you are likely to achieve the same result is to use the probiotic that was mentioned in the research article.

Clinical Trials of Probiotic Use on Asthma Outcomes

In 4 randomized trials of probiotics in the treatment of asthma, a number of outcomes have been reported. One study demonstrated increased symptom-free periods, while another showed a decreased need for cromolyn sodium. One study demonstrated improvements in peak flow with use of probiotics.

Other clinical outcomes did not improve and include quality of life, the total number of asthma episodes, use of controller or rescue medications. FEV1 did not demonstrate a significant difference in patients receiving probiotics compared to those receiving placebo.

Are Probiotics Safe

With the exception of gas like symptoms, patients seem to experience very few side effects and tolerate probiotics. However, there is relatively little available data on the long-term use of probiotics or the combination of probiotics with other medical treatments. There have been reports of serious complications if you have a weakened immune system or other health problem so it is important to discuss with your doctor before beginning treatment.

While not a true safety issue, probiotics are not regulated as they are considered a supplement. Because of this, there are also not strict regulations governing the manufacturing process. As a result, some probiotics have been found to contain strains that are not listed on the label as well as smaller amounts of live organisms than what is claimed.

It is also important to realize that many of these products are not regulated by the FDA in the same manner as your regular asthma medications. FDA monitors supplements for side effects, but since they are not approved as drugs they are not monitored the same. Probiotics do not carry indications for asthma as your medications do. These products will not come under FDA jurisdiction unless the company is making a claim of medical treatment or there are suspected side effects that the FDA becomes concerned about. To be safe you should discuss any supplement with your doctor before beginning supplementation and let your doctor know about any potential side effects you experience.

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