Peter Rogers asked me to write a few thoughts on probiotics. He tried a probiotic supplement for three months and didn’t see any benefit. His partner, however, felt an improvement and has stuck with them. You will have seen advertisements for both yogurt with Lactobacillus acidophilis and Bifidobacteria, as well as small bottles of supplemental live bacteria eg Yakult; these are examples of probiotics.
Probiotics is a general term for live bacteria that you consume in a food or as a supplement and which survive the passage all the way through the stomach and the small intestine to arrive safely in the large intestine. Here they settle down and become vigilant against evil forces.
Probiotics = back end health
Having a healthy bacterial balance in the large intestine is linked to normal bowel habits, healthy immunity, improved bioavailability of nutrients and possibly less risk of bowel cancer. With more healthy bacteria in the large intestine means that fewer nasty bacteria are able to get a foothold and cause internal turmoil. For example, the good bacteria like Lactobacillus produce organic acids that retard the growth of nasty bacteria such as Salmonella.
Where probiotics can be very helpful is when you get food poisoning or any condition with diarrhea, because you may have washed out a lot of healthy bacteria too. If you have been prescribed antibiotics then they may kill both the nasty bacteria causing your illness as well as some of the healthy bacteria in your bowel. In both cases taking some probiotics as a supplement or via a food like a yogurt with Lactobacillus bacteria will help re-establish the good bacteria in the bowel and make it difficult for pathogenic bacteria to take a hold. Some people today take probiotics in the precautionary hope it will prevent travelers diarrhea.
Athletes & probiotics
As an athlete’s training load increases so does their risk of illness, such as respiratory tract infections, so anything that has the potential to help the immune system may be able to keep an athlete healthy through heavy training and competition. There have been a few studies on the effects of probiotics and the results have been either positive or neutral.
One study found that a probiotic significantly reduced the severity and duration of respiratory tract illnesses in 20 male elite distance runners (Cox 2010). Another study of male and female athletes found that those taking a probiotic also had a much lower incidence of respiratory tract infections (Gleeson 2011). The authors speculated that this positive outcome might be due to higher levels of immunoglobulin A in those on the probiotic.
Other studies have not seen much difference and a review of all the evidence was not that enthusiastic about taking probiotics, although they did concede that they had potential for athletes undergoing heavy training. These studies are done in elite athletes who are likely to be under greater immune stress and may not have the same benefit for the generally fit and healthy.
There will be more research on probiotics because there is a food industry that can benefit. The future will see more refined knowledge where we will recommend different probiotic bacteria types for different conditions. Whether you have Irritable Bowel Syndrome, food poisoning or have a family history of bowel cancer could determine the type of bacteria you take as a supplement.
What does it all mean?
Remember that for most of human history we never worried about probiotics. I doubt whether anyone mentioned “probiotic” at a dinner party until 1997. If you eat well, keep active, give to charity and overtake safely then there is an excellent chance that the bacteria in your large intestine are in perfect order, doing exactly as they should. In other words, good bacteria are naturally present.
You know your guts better than I do, indeed better than I want to know. So, I’ll leave you to make the decision whether to take probiotics. You might find little benefit like Peter did, or it could add a song to your day as his partner experienced. I’m like Peter. Happy to have yogurt with bacteria, but my resident gut bacteria are doing fine on their own with all that fibre I send their way each day. I don’t think they need “back up”.
Cox, A.J., et al 2010. British Journal of Sports Medicine 44 (4): 222-226
Gleeson, M., et al. 2011. International Journal of Sports Nutrition and Exercise Metabolism 21 (1): 55-64.