Probiotics and The Microbiome
There is so much more discussion about probiotics and the microbiome now than ever before. There is research about the benefits for infants, mood, digestion, re-establishing a healthy gut after antibiotics, and so on. Even though there’s plenty of evidence to show that probiotics are good for us, many people are often still unsure if they can actually make a difference.
Generally, when we refer to the ‘gut’ as a collective we tend to think of our abdominal area only. However, the gastro-intestinal tract or GI tract actually begins in the mouth and ends at the exit point, the anus. For our purposes let’s focus on the small intestine and large intestine since that’s where the majority of probiotics have their most beneficial effects.
In the whole GI tract, there are over 100 000 billion bacteria. Different species in different numbers populate the gut. This is why it can be beneficial to change your probiotic on occasion because there is so much variety. If there are so many bacteria present, how could a few billion make a difference?
Well, that has to do with the composition and state of the small and large intestine. There are anywhere from about 10-100 billion microbes present in the small and large intestines. This helps us understand why giving a probiotic or eating fermented foods makes a difference because there’s enough to replenish and encourage the growth of good bacteria. Also, the small intestine is approximately 20 feet long, so it houses about 95% of the bacteria that live in our intestines. The large intestine on the other hand is only 4 feet long, but because things are moving much slower through the large intestine the bacteria layer in the mucosa can be up to 200 cells thick, compared to 1 cell thick in the small intestine. This allows this shorter stretch of organ to still accommodate 10-100 billion microbes.
Benefits of Probiotics:
There are many studies that have been done and are currently being done on the effects of probiotics and the microbiome as a whole. If you did a simple google or PubMed search you would come up with 1000s of results. I can’t summarize all of them, but here are a few highlights:
Infants and Probiotics:
Atopic conditions like eczema have become much more of a problem over the past few decades in children. In some of the studies, they looked at if intervening with probiotics at an early age could reduce the incidence of atopic conditions. The outcome of most of these interventions was either a moderate or significant reduction in symptoms of atopic skin issues.
Probiotics and Antibiotics:
More people are aware these days that we should take probiotics when we take an antibiotic. One of the downsides of an antibiotic is that it kills all bacteria; it doesn’t distinguish between types of bacteria. Therefore antibiotics have an overall impact on the ‘good’ bacteria as well, and one of the best ways to help replenish those bacteria is to use a probiotic. Studies have shown that taking a probiotic following an antibiotic helps to reduce dysbiosis, which is an imbalance or overgrowth of bacteria in the gut.
Gut and Brain connection:
One of the newer areas of study that’s been getting a good deal of attention is the impact that a healthy gut can have on our mood. More studies are coming out showing a positive impact of probiotics and healing the gut on issues such as depression, and anxiety. This work is still early, but promising.
Choices: Making sense of what’s available on the market
Over the last few years we’ve seen a huge increase in the number of probiotics available. Knowing you have all these choices, how do you make the right choice for you? There are a number of factors you want to consider:
- Do you have any gut problems (e.g. IBS)?
- Are you experiencing symptoms such as gas, indigestion, eczema, etc.?
- Do you have any current allergies or sensitivities?
- Do you know how many strains are best for you?
- Do you know which strains are best for you?
- Do you know roughly how many billion you need?
Knowing these things makes it much easier for you to select an appropriate probiotic. If you don’t know the answer to these questions or aren’t sure, then you may want to speak to a healthcare professional. They can help you figure out which probiotic might be best for you.