Probiotics - what can they do for you?

For thousands of years microbial cultures have been used to ferment foods and prepare alcoholic beverages. Even the book of Genesis references the preparation of fermented milk.[6]

Evidently, probiotics have been with us for as long as people have eaten fermented products. However, their association with health benefits dates only from the turn of the century.[1]

Today, probiotics are used to help many different things - mostly related to the gut and the intestines. They are often referred to as ‘good’ bacteria, because of their perceived health benefits.

Most recently, there has been some suggestion of probiotics being beneficial to those suffering from issues like IBS. Generally, the belief in the beneficial effects of probiotics is based on the knowledge that the intestinal microflora provides protection against various diseases.[1]

This suggests that probiotics have a positive effect on the microflora, either enabling their specific functions or adding to the range of ‘good’ bacteria.

Despite the history of the knowledge of microbes and their properties, the use of the term ‘probiotic’ to describe food supplements only dates from 1974.[1]

It was then that RB Parker first defined them as 'organisms and substances which contribute to intestinal microbial balance'.[1]

Generally, the probiotics currently on the market are mainly based on lactic acid bacteria (lactobacilli, streptococci, and bifidobacteria).[1] 

Benefits

Over the past Century, various different probiotic microorganisms have been tested for their ability to prevent and cure diseases in animals and humans.[6]

The general consensus is that probiotics are becoming an increasingly important part in the diet of everyday Western life, as their general and gastrointestinal beneficial effects are being gradually proven.[4]

This may be partly due to the fact that under natural conditions a protective gut microflora develops and there is no need for a probiotic supplement; but humans and farm animals in the West live under rather unnatural conditions.[1]

We eat a great deal of processed and in many cases sterile food which may affect our access to, and colonisation by, certain types of ‘helpful’ or ‘good’ bacteria.[1]

Therefore, probiotics could be seen as a means of repairing deficiencies in the flora induced by dietary and environmental stress.[2]

The increased interest in fermented foods (such as kimchi, kefir, kombucha, and miso) in Western health communities recently also demonstrates a push to involve more probiotics in our diets. We are quite late to the game, however, as many fermented foods that contain probiotics have been staples of East and West Asian cuisine for centuries.

So what do probiotics specifically help with? Since there are many different strains of probiotic bacteria, they all have different functions.

For example, Lactobacillus acidophilus is widely considered to be useful in mitigating the symptoms of lactose intolerance. This is because during fermentation, lactobacilli produce lactase, which breaks down the lactose in dairy products into glucose and galactose.[6] It is this process that people with lactose intolerance cannot do naturally.

Lactic acid bacteria (which are the majority of probiotics on sale) have also been shown to increase the content of the vitamin B complex in fermented foods.[6]

Because of the amount of research into the bacteria, many theories have been proposed. Recent studies demonstrate that a probiotic can be effective in treating antibiotic-induced diarrhoea in adults, diarrhoeal disease acquired during travel, and diarrhoeal disease in young children.[6]

This conclusion is particularly useful, as it could mean that the use of probiotics may be an important tool in improving health and nutrition in many developing countries.[6]

Overall, the data collected over the last few decades shows that probiotics have significant potential in improving human health and preventing and treating disease.[6]

Further research is required, however, to better define this potential and to develop new and improved probiotics.[6]

One major proposal for the use of probiotics is for Irritable Bowel Syndrome. It is one of the most frequent gastrointestinal problems, but its cause is not yet known.[4, 5]

IBS is characterized by abdominal pain or discomfort, which is relieved by defecation or the passage of gas.[4] There is considerable evidence to show that things that disturb the gut may contribute to the development of IBS, and with so many factors contributing to the stability of the normal human gastrointestinal microflora, it’s no wonder.[5]

Some of the aspects controlling the gut’s stability include gastric acidity, gut mobility, immunological defence factors, and colonic pH.[5]

As it’s well known that probiotic strains have numerous positive effects in the gastrointestinal tract, it is not unreasonable to suggest the positive effect of probiotic bacteria on IBS.[4]

In general, it appears that probiotics are effective in IBS patients, but the trials that have been performed have centred on a symptomatic reduction or cure, rather than trying to eradicate the disease within the body.[4, 5]

The good news is that the use of probiotics in IBS patients (and the healthy subjects taking part in various studies) involves a very low risk of bacterial complications. Plus, the abnormalities seen in the colonic flora of IBS sufferers suggest that a probiotic approach will ultimately be beneficial.[4, 5]

So, it seems as if the use of probiotics for IBS is looking very promising. 

Safety

Unfortunately, with things like bacteria, there is always the question of safety. Since most probiotics are marketed as foodstuffs or drugs, consideration of the safety of probiotics is of utmost importance.[3]

There is a lot to consider when evaluating the safety of probiotics. Often, these factors include pathogenicity, infectivity, and virulence factors comprising toxicity, metabolic activity, and the properties of the microbes.[3]

A lot of people consider the safety of the microbes that have been used traditionally in probiotics (strains of lactobacillus and bifidobacterium) to have been confirmed through a long period of use.

This is because, thankfully, reports of harmful effects of the bacteria on the human host are rare.[3]

As a result, the conclusion that most researchers have come to is that with the exception of enterococci, the overall risk of lactic acid bacteria infection is very low, which is extremely encouraging and relieving.[3] 

Conclusion

Probiotics display a range of properties that are very useful within the human body. This is not surprising, as the gut is such a rich source of nutrients, and the concept of probiotics is now [over] 100 years old.[1, 4]

They are one of the most popular products on the supplement market at the moment (for good reason), and the recent popularity of fermented foods in the West is also testament to their positive effects.

Though the most scientifically supported uses for probiotics are for treating lactose intolerance and helping to reduce the symptoms of IBS, many people use them for other gut infections and inflammation, as well as helping the bowel recover after antibiotic treatment.

With all of this to offer, it’s worth seeing what they could do for you. 

References

1) Fuller R. Probiotics in human medicine. Gut [Internet]. 1991 [cited 7 June 2021];32(4):439-442. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1379087/

2) TANNOCK GW. Effect of dietary and environmental stress on the gastrointestinal microbiota. Human intestinal microflora in health and disease. 1983:517-39.

3) Ishibashi N, Yamazaki S. Probiotics and safety. The American Journal of Clinical Nutrition [Internet]. 2001 [cited 7 June 2021];73(2):465s-470s. Available from: https://academic.oup.com/ajcn/article/73/2/465s/4737580?login=true

4) Dai C. Probiotics and irritable bowel syndrome. World Journal of Gastroenterology [Internet]. 2013 [cited 7 June 2021];19(36):5973. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3785618/

5) Madden JAJ, Hunter JO. A review of the role of the gut microflora in irritable bowel syndrome and the effects of probiotics. British Journal of Nutrition [Internet]. Cambridge University Press; 2002 [cited 7 June 2021];88(S1):s67–s72. Available from: https://www.cambridge.org/core/journals/british-journal-of-nutrition/article/review-of-the-role-of-the-gut-microflora-in-irritable-bowel-syndrome-and-the-effects-of-probiotics/C554CC9AE5C5F36A2153F87F085F4570