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Probiotics Could Help Tame Some Nasty Side-Effects Of Antibiotics

A new study suggests a possible solution to the diarrhea and stomach infections that can accompany a regimen of antibiotics.

You've probably heard of probiotics at some time over the last decade. These bacterial species, with names such as Lactobacillus and Bifidobacterium have gained quite a bit of attention both in the scientific community and the media. While studies have shown they can offer a benefit to health, there continues to be a debate over how they help us to stay healthy.

Gut bacteria rendering of fauna including Staphylococcus, Enterococcus and Lactobacillus.
Gut bacteria rendering of fauna including Staphylococcus, Enterococcus and Lactobacillus.

Probiotics are designed to help keep your gut healthy. At first glance, the idea of using bacteria to maintain any kind of health may seem odd. But over the last few decades, we've learned our intestines are home to trillions of bacteria made up of hundreds of different species. More importantly, many of them are not just hitching a ride; they are actually influencing the way we live.

Several of the species in our gut produce chemicals that can be sensed by our gastrointestinal tract. As researchers have learned, these interactions can influence several different bodily functions such as our metabolism, immunity and cardiovascular function. As the research into the importance of these bacteria in our lives continues to be found, one reality appears to hold true: a diverse population of species is good for our health.

This is why probiotics are well worth considering when you are taking an antibiotic — which, as the name implies, is designed to kill bacteria. When you take a prescription, you are going to wipe out a wide variety of different types of species. This can lead to a loss of diversity and the potential for the development of complications, such as diarrhea and infection with C. difficile. Numerous clinical trials have shown the ingestion of probiotics can help to sustain diversity, if only slightly, and reduce the likelihood of these troubles.

One reality appears to hold true: a diverse population of species is good for our health.

This population-based reasoning for probiotics may be enough to convince some people to use them during an antibiotic prescription and possibly afterwards. Yet, others may have lingering questions as to what is happening at the molecular level. After all, adding bacteria of any kind means the gut environment will be altered in some way. How exactly probiotics can achieve a benefit has been difficult at best to determine.

Now, thanks to an American team of researchers, we may have one of the answers. The team examined what happens in the gut during an antibiotic prescription and tried to determine how these changes could lead to problems. While the information did not specifically address probiotics, the results suggest beneficial bacteria may help to keep the gut environment from becoming overrun with pathogens.

The main goal of the study was to determine how antibiotics change the gut to allow potential pathogens to thrive. However, the focus wasn't biological in nature. It was chemical. Based on previous studies of pathogens in the gut, a higher level of oxygen and nitrates seemed to allow these bacteria to grow. If the team was right, antibiotics would lead to an increase in the levels of these chemicals making the environment ripe for pathogen survival.

The group gave mice a variety of antibiotics and after a day, measured the environment for what is known as the redox potential. As the name implies, the calculation is a measurement of oxygen in the environment. They expected to see a higher redox level as the killing of bacteria would lead to more oxygen in the gut. Not surprisingly, they did. In as little as one day, the environment had become a haven for potentially pathogenic bacterial growth.

One of the reasons for this rise was the sudden disappearance of a wide variety of bacterial species. But a closer look at the chemical environment revealed another factor. Many of the byproducts of bacteria such as short chain fatty acids also help to balance redox levels. With the bacteria gone, the production of these molecules went down allowing redox to skyrocket.

After the antibiotic treatment was completed, the team kept an eye on the mice to determine if potential pathogens would continue to take over the gut. Again, the results were not surprising as the unwanted bacteria maintained their hold. Without any kind of supplementation to deal with the redox imbalance, the outlook for the mice was not good.

These particular results in mice do not translate into the human context

Thankfully, the team did find a way to return the gut microbial population back to normal. The mice simply required oral supplementation of bacteria. When this happened, baceterial diversity eventually returned to normal.

The outcome of this stage might stand as an excellent reason to take probiotics. However, these particular results in mice do not translate into the human context. It's because the way mice achieved this introduction of bacteria was not through the ingestion of probiotic pills as we might do. Instead, they accomplished this feat through the practice known as coprophagia, or the ingestion of feces.

Overall, the authors suggest the study may offer a few reasonable courses of action for anyone who might be taking an antibiotic and wishes to keep the redox levels low. One route is to utilize chemicals known to reduce redox potentials. The most common of these is Vitamin C and may one day be investigated to determine its value in preventing the effects of antibiotics.

The other option is to use competitors to the troublemaking bacteria to keep them from growing out of control. While the authors did not state any specific species, there is evidence to show many probiotic types balance redox levels in the gut. Granted, this exact association would need to be proven specifically in future studies. However, at the moment, this known ability of probiotics to control redox levels may offer a mechanistic advantage to taking probiotics during an antibiotic prescription.

If you do consider taking probiotics along with antibiotics, just don't take them together. You need at least two hours after an antibiotic is taken before you can take a probiotic. As for which type to take, the best option is to choose brands that have been tested in clinical trials. You can call up the company and ask or you can head to the Health Canada Licensed Natural Health Products Database and be certain you're getting the benefit you wish.

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