The good, bad, and friendly
Priyanka Gupta, ND
One of the main benefits of probiotics is their effect on the immune system. Various probiotic strains can improve digestive health and relieve IBS symptoms.
They are everywhere: lurking in dairy products such as yogourt and cheese and skulking in fermented foods such as sauerkraut and miso. They can even be found in enriched drinks and taken as a supplement. These hidden healthy gems are probiotics, and they’re getting a lot of attention these days.
Many companies are attracting health-savvy consumers by increasing or prominently advertising the probiotic content of their foods (think of all the yogourts on the market with the probiotic content displayed on the front). But while probiotics may be popular now, they have been around for a long time, with the fermentation of food playing a major role in their development.
Long before refrigerators, fermentation was used to keep milk from spoiling by considerably extending its shelf life. Historically, fermented milk can be traced back to 10,000 BC. Although the specific origins are not known, fermentation of dairy likely arose from the indigenous bacteria and microflora in milk.
Not harmful to humans, the indigenous bacteria prevented the growth of dangerous bacteria, which in turn allowed milk to be used for longer periods of time. Interestingly, the evolution of certain types of fermentation likely came about due to the differences in climate. Thermophilic bacteria found in the tropics are possibly the origins for Indian dahi, a yogurt made from heated milk, while mesophilic bacteria in cooler climates were likely responsible for cr? fra?e, a soured cream favourite in France.
Lactic acid and longevity
It wasn’t until the early 1900s that scientists made the connection that cultured dairy products contributed to the longer lives of some Europeans. The idea that probiotics offer protection to our immune system was first put forth by Russian scientist and Nobel Prize winner Elie Metchnikoff (1846-1916), often termed the father of natural immunity.
It was well known in Metchnikoff’s time that lactic acid could greatly reduce infectivity in harmful bacteria such as Clostridium. Metchnikoff observed that certain Bulgarian and Russian peasants who consumed large amounts of fermented milk lived very long lives. He went on to make the connection that consuming fermented milk using lactic-acid-producing bacteria such as Lactobacillus acidophilus would decrease intestinal infections.
Metchnikoff believed that probiotics were likely the key to longevity.
Health benefits of probiotics
According to the World Health Organization, probiotics are “live micro-organisms that when taken in adequate amounts confer a health benefit to the host.” With the growing acceptance that intestinal health promotes overall wellness, more research is being devoted to uncovering the importance of probiotics on a multitude of aspects of human health.
One of the main protective features of probiotics is on the body’s immune system. In the very basic sense, probiotics do not give harmful bacteria the chance to physically inhabit the colon. Essentially, probiotics grow and take over space along the intestinal wall, leaving no room for harmful bacteria to take hold. In biology this is known as competitive inhibition.
In immunological studies, Lactobacillus bulgaricus bacteria had direct effects in aiding the immune system. These were evidenced by increasing the numbers of immunoglobulin A, a protective molecule against harmful bacteria, as well as by improving phagocytosis, a mechanism of engulfing and killing foreign invaders.
In February 2010 researchers at the University of Pennsylvania School of Medicine proposed that individuals taking probiotics are less likely to have secondary infections after finishing a round of antibiotics. The theory put forth is that probiotics keep the immune system primed and ready to attack, while taking antibiotics alone may turn the immune system off and open it to re-infection.
Quite commonly, antibiotic therapy can lead to diarrhea. Although not confirmed, it is speculated that antibiotics may cause an overgrowth of Clostridium difficile bacteria, which can cause diarrhea.
Several studies suggest that probiotic therapy can reduce the incidence of diarrhea associated with antibiotics. However, not all probiotics confer the same level of protection. Specific strains such as Lactobacillus rhamnosus GG, Bacillus coagulans, and Saccharomyces boulardii appeared to be most effective.
Colon cancer prevention
Another important benefit of probiotics is the ability of certain strains to decrease the impact of carcinogens or cancer-causing agents in the body. The probiotic strain Lactobacillus bulgaricus was shown to bind and eliminate carcinogenic substances called heterocyclic amines found in cooked meats. Another cancer-protective mechanism is the probiotics’ ability to reduce levels of beta-glucoronidase, which is thought to be cancer promoting.
One interesting study reported that individuals who consumed yogourt on a regular basis had a lower rate of cancer than those who did not consume yogourt.
Irritable bowel syndrome
In a number of studies, various strains of probiotics have been found to be helpful in reducing irritable bowel syndrome (IBS), an uncomfortable digestive concern characterized by abdominal pain, diarrhea, or constipation. In a systematic review of 19 randomized, controlled studies involving 1,628 individuals, probiotics were found to be effective for IBS, although the researchers could not confirm if a particular strain was more effective or a combination of strains would work better.
In another study concerning children from pediatric centres in India, Italy, and the US, researchers found that probiotics are safe and significantly more effective than placebo in relieving IBS.
Probiotic strains: deciphering the data
In recent years, a host of probiotic strains have become available through supplements and commercial yogourts. With advances in molecular genetics, it is possible to develop and cultivate strains that confer benefits by amplifying the expressions of certain genes.
While supplements offer specific amounts of various listed strains, many yogourt and even probiotic drinks now have particular cultures incorporated into the fermentation process, which makes choosing the right product easier.
Sources of probiotics in the diet
Supplement with probiotics and include these foods regularly in your diet to add probiotic power:
|Bacillus coagulans||• considered safe and effective for abdominal pain and bloating |
• may be helpful for individuals with IBS
|Bifidobacterium infantis||• may significantly relieve abdominal discomfort, pain, bloating, or difficulty with bowel movements|
|Lactobacillus reuteri ATTC 55730||• may help to eradicate H. pylori |
• improves gingivitis
• supports general illness prevention in children and adults
|Saccharomyces boulardii||• protects against antibiotic-associated diarrhea and Clostridium difficile infections |
• used to help treat acute diarrhea in adults and children
|Lactobacillus acidophilus NCFM and Bifidobacterium bifidum BB-12||• assists in the reduction of C. difficile-associated disease|
|Lactobacillus acidophilus CL1285 and Lactobacillus casei||• improves digestive health |
• prevents antibiotic-associated diarrhea
|Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14||• aids in vaginal colonization and prevention of vaginitis|
Far from being a recent discovery, probiotics have been the backbone for the human diet from ancient times. While Fleming’s discovery of penicillin started the age of modern antibiotics, we seem to be coming full circle from total reliance on antibiotics to a deeper appreciation of the need for friendly bacteria in our daily regimes.
So whether it’s called yogourt, cre`me fraiche, dahi, or something else entirely, a daily dose of probiotics may help keep your system healthy longer, from the inside out.