Stress, the consumption of certain drugs, and improper nutrition can harm our gut flora and have negative effects on our health. In this post, I want to explain what probiotics and prebiotics are, their differences and functions, in which cases they are recommended or not, etc. If you want to learn about how to maintain a healthy microbiota, I invite you to continue reading carefully and save this article for future consultation :)
Probiotics
First things first, what is a probiotic? It is a culture of one or several types of living microorganisms, in sufficient quantity, that, when administered to a person or animal, exert a beneficial effect on their intestinal microbiota and on their general health.
Goals when consuming a probiotic
Regulate the intestinal flora: Favoring the proliferation of beneficial microorganisms to the detriment of potentially pathogenic ones.
Modulate the metabolism and function of the intestinal mucosa.
Improve the immune response: An adequate intestinal flora contributes to maintaining the immune system in optimal condition, among other mechanisms, by regulating the activity of the kappa B transcription factor (NF-kB), which regulates certain genes responsible for the innate and adaptive immune response. It is involved in inflammatory, cancerous, autoimmune processes, viral infections…
Likewise, a healthy intestinal flora has a large number of benefits, such as improving intestinal transit, increasing the renewal of intestinal cells, reducing metabolites such as urea, or modifying the intestinal pH, among others.
Not all probiotic is suitable for everyone
Undoubtedly, it is very common to know many people who have benefited from the consumption of probiotics, either through probiotic foods or supplements, however, in the same way, it is very common that the consumption of probiotics is not well tolerated.
Why does this happen? Well, on the one hand, each person has a unique intestinal microbiota, with a greater or lesser presence of certain strains, and on the other hand, probiotics, whether in the form of food or supplements, have a great diversity of strains, each of them presenting a different tolerance and impact on the intestinal flora. Thus, the key to the use of probiotics lies in the individualization of the person, and in knowing the effects of the various strains.
In addition, there are also specific situations, either due to intolerances or some pathology, that may contraindicate the consumption of probiotics.
Choosing a good probiotic supplement
It is very difficult to generalize, however, there are some points that we should always keep in mind before buying a probiotic.
Evaluate which strains it contains. Depending on the situation of each person, some strains will be more useful than others. In fact, in certain cases, some strains could be counterproductive.
Minimum quantity of bacteria greater than 1 billion. We must bear in mind that colonizing the intestine is not an easy task, especially if we consider that they must survive the gastric juices when ingested, so we need a probiotic that has a very large number of bacteria so that at least some manage to survive.
No sweeteners. Recently, several probiotics in liquid format have become fashionable (mainly due to very aggressive marketing campaigns). Although I have nothing against this format (as long as it is achieved that they colonize the intestine…) and that, in fact, it can help many people with swallowing problems, they usually present a common problem: sweeteners. We must bear in mind that if liquid probiotics had a very unpleasant taste, few people would consume them, so many manufacturers decide to add sweeteners. This, in my opinion is a contradiction, because on the one hand we are providing bacteria theoretically with the aim of “improving” our microbiota, but on the other hand, they are loaded with sweeteners, which there are quite solid suspicions that they could harm it.
Fermented foods
There are many fermented foods that contain bacteria or yeasts that can be beneficial to our health. However, their benefits go far beyond the direct benefit that these bacteria produce. During the fermentation process certain substances such as lactic acid are produced, which are of great interest to health, in addition, some compounds become more bioavailable and the amount of toxins or antinutrients of certain foods is reduced. Some interesting examples would be the following:
Kefir: Its characteristic strain is Lactobacillus kefiri. Studies have shown that it is capable of reducing inflammation markers, producing an increase in hemoglobin in people with Crohn’s disease, in some cases it has been able to improve lactose intolerance, and in animals, an increase in “beneficial” bacteria at the expense of potentially pathological ones in their microbiota. Milk kefir has more scientific evidence than water kefir.
Yogurt: It has Lactobacillus bulgaris and Streptococcus thermophilus as the most characteristic strains. It is possible that its regular consumption contributes to maintaining a healthy intestinal flora, however, it is not enough in case it is already altered.
Kombucha: It is a fermented drink based on tea (green or black) and sugar. Depending on its production, the bacteria present will vary. It exerts a symbiotic effect, that is, a prebiotic and probiotic effect. There is a shortage of clinical studies in humans, however, in vitro and animal studies suggest that it could exert antimicrobial effects, improve blood glucose, offer protection against oxidative stress, and produce an improvement in renal and hepatic function in diabetic rats.
Sauerkraut: Fermented cabbage with salt. In it, several microorganisms such as Lactobacillus rhamnosus, Lactobacillus plantarum, Lactobacillus casei have been found… However, its effects do not seem to come directly from the probiotic effect, and as I said before, the benefits of fermented foods go far beyond their probiotic effect.
Tempeh: It is a preparation of boiled and fermented soybeans with the Rhizopus oligoporus fungus. Thanks to fermentation, certain antinutrients are eliminated, so minerals will be better absorbed.
Contraindications
There are certain situations in which the use of probiotics may be discouraged, such as, for example, in SIBO (not always), states of immunodeficiency, pregnancy and lactation or in very young children, among others. In addition, the sustained use of supplements over time is discouraged.
Prebiotics
So far, I have talked about providing potentially beneficial bacterial strains, but how do we make these develop correctly to maintain a balanced microbiota?
This is where prebiotics come into play. These are non-digestible compounds that, when metabolized by intestinal bacteria, have a positive impact on beneficial intestinal microbiota, thus achieving an improvement in the person’s health.
Not all fiber has prebiotic effects, for example, insoluble fiber is poorly fermentable by intestinal bacteria (with the exception of resistant starch), so it will not have a prebiotic effect. On the other hand, soluble fiber, which is highly fermentable, will be a good food for beneficial bacteria.
Main types of prebiotics
Fructooligosaccharides: These are natural oligosaccharides (soluble fiber) found in various fruits and plants such as onions, leeks, bananas, artichokes, chicory root… even in wheat.
Inulin: It is a fructan (polysaccharide) especially present in the roots of certain plants such as chicory or dandelion.
Galactooligosaccharides: These are oligosaccharides composed of galactose and glucose. They are found in milk and soybeans. The oligosaccharides present in human milk are extremely important for the health of the newborn, as they cannot be digested by him, but they can be fermented by his intestinal bacteria, which can condition the baby’s health for the rest of his life.
Resistant starch: There are up to four types of resistant starch, but I will focus on type 3, called ‘retrograde resistant starch’, as it seems the most interesting. Why? Well, because it can be obtained at home thanks to temperature management: by cooking foods such as potatoes, sweet potatoes, rice or oats (among others), and then leaving them in the refrigerator for 24 hours, they undergo a series of changes that make the starch present in these no longer digestible and reach the large intestine where it is fermented by the intestinal flora. Once cooled, it can be reheated for consumption (no more than 80 - 130ºC).
Benefits derived from consuption of prebiotics
Consuming prebiotics, either in the form of food or supplements, can have great health benefits, below I indicate the main ones that have been pointed out in scientific studies.
Regulating the strains of intestinal bacteria. Not all bacteria are capable of ‘feeding’ on prebiotics, in addition, the change in pH that occurs in the colon after bacterial fermentation (producing lactic acid and short-chain fatty acids), favors the proliferation of certain strains to the detriment of others, such as potentially pathogenic Bacteroides.
They contribute to better absorption of minerals and synthesis of B group vitamins.
They favor the proper functioning of the immune system.
They contribute to regulate intestinal transit.
They dicrease low-grade inflammation.
Studies indicate that they can collaborate in the prevention of colon cancer.
The fermentation of fiber by intestinal bacteria produces, among others, short-chain fatty acids: acetate, propionate, and butyrate, the latter considered the main source of energy for the cells lining the colon wall, in addition, it helps to maintain intestinal integrity (thus reducing the permeability of the large intestine), among other benefits.
Conclusions
Each person is unique and so is their intestinal flora, so before supplementing with a probiotic it is necessary to evaluate their personal needs, their context. Each probiotic has its own characteristics, knowing them is key.
In certain situation the use of probiotics especially in supplement form, may be contraindicated.
The benefits of fermented foods go far beyond probiotic effects, being a very interesting option to consider to add in our diet.
It is as important to provide prebiotics in the diet as probiotics. It would make no sense to provide beneficial strains if they cannot develop properly.
If you want me to help you find your natural balance, do not hesitate to book an acupuncture and naturopathy appointment with me.
I remind you that this information is only for informational purposes and that I am not a medical doctor :)
Studies used in this blog entry
Cai, J., Zhao, C., Du, Y., Zhang, Y., Zhao, M., & Zhao, Q. (2018). Comparative efficacy and tolerability of probiotics for antibiotic‐associated diarrhea: Systematic review with network meta‐analysis. United European Gastroenterology Journal, 6(2), 169–180. https://doi.org/10.1177/2050640617736987
Dimidi, E., Cox, S. R., Rossi, M., & Whelan, K. (2019). Fermented Foods: Definitions and Characteristics, Impact on the Gut Microbiota and Effects on GastrointestinalHealth and Disease. Nutrients, 11(8), 26. https://doi.org/10.3390/nu11081806
Kozyrovska, N. O., Reva, O. M., Goginyan, V. B., & de Vera, J.-P. (2012). Kombucha microbiome as a probiotic: a view from the perspective of post-genomics and synthetic ecology. Biopolymers and Cell, 28(2), 103–113. https://doi.org/10.7124/bc.000034
Holscher, H. D. (2017). Dietary fiber and prebiotics and the gastrointestinal microbiota. Gut Microbes, 8(2), 172–184. https://doi.org/10.1080/19490976.2017.1290756
Fleming, D., Kesey, J., Rumbaugh, K., & Dissanaike, S. (2017). Comparing the Survivability of Lactobacillus Species in Various Probiotic Delivery Vehicles. Journal of Parenteral and Enteral Nutrition, 41(8), 1411–1413. https://doi.org/10.1177/0148607116672266
Yilmaz, I., Dolar, M. E., & Ozpinar, H. (2020). Effect of administering kefir on the changes in fecal microbiota and symptoms of inflammatory bowel disease: A randomized controlled trial. The Turkish Journal of Gastroenterology, 30(3), 242–253. https://doi.org/10.5152/tjg.2018.18227
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