UNDERSTANDING PREBIOTICS AND PROBIOTICS
Probiotics have been getting so much press over the past years, but what are they? And what about prebiotics? Let’s shed some light and understand what they are, and how they can affect our health.
The gut is home to a variety of microorganisms, divided into colonies and collectively called microbiome. These symbiotic microorganisms cohabitate our body and contribute to health by being involved in various mechanisms. Firstly, when the number of symbiotic colonies is high, there is not enough space for other microbes, inhibiting the proliferation of pathogens. Secondly, a thriving microbiome, lowers the gut PH making the environment perfectly suitable for friendly microbes but inhospitable for pathogens. Thirdly, by maintaining a strong gut lining (thanks to the short chain fatty acids by-products of the microbiome metabolism), the microbiome promotes a balanced immune response. Some bacteria also make vitamin K important for blood clotting, and others can also improve Calcium absorption in the distal intestine, supporting strong bones. The gut microbiome has a two-way communication system with the rest of the body, therefore influencing its functions. This mechanism is still studied by researchers and not fully understood yet.
Let me explain in more detail the composition of the microbiome. We have 4 main phyla (Firmicutes, Actinobacteria, Bacteroidetes and Proteobacteria), each composed by different genus (like Bifidobacterium and Lactobacillus), species (like Boulardii and Acidophilus) and strains (a number). To put it simply, think about a school: the genus is the type of school, the specie is the class, and the strain is one child in that class. Every child has a role and interacts with other children. In the same way, each strain interacts with the others to maintain overall health.
Albeit we do not know the ideal composition and balance of the microbiome, we recognise that it must have variety to sustain health. When the microbiome is out of balance, pathogens can take over, causing disease. Our diet greatly influences its composition, the consumption of prebiotic and probiotic foods is beneficial, while stress and sugar are harmful.
Probiotics are microorganisms (yeast and bacteria) that help to promote healthy gut microbiome by increasing the number of beneficial colonies. As explained earlier, the gut is formed by a variety of microorganisms, but sometimes the symbiotic ones are lower in number compared to pathogens. This is called dysbiosis, a disruption of the microbiome balance that can lead to malabsorption, maldigestion and overall poor health. Increasing the number of beneficial strains could then improve digestion and absorption of nutrients, as well as enhance positive outcomes in conditions like IBS, acne, eczema and many more.
The most common misconception is that a probiotic with multiple strains is better than one with a single strain, but this is not always the case. If your goal is to give a boost to your microbiome, then, a multi-strain probiotic can work well, while research shows that with particular health conditions fewer strains could be more beneficial (this is the case for IBS, acne and eczema, to name a few).
Probiotics can be found naturally in fermented foods like sauerkraut, kimchi, miso, natto, tempeh, yogurt, kefir, fermented pickles and kombucha. They can be also taken as supplements; the majority now can be stored at room temperature without compromising the effectiveness.
Supplements can vary widely, each having specific strengths (number of microbes, or CFU) and strains (type of microbe). They can be taken either with food or on empty stomach, but I would choose a microencapsulated brand to ensure that microbes reach the gut alive.
Side effects are not common, but can include gas, bloating and overall digestive issues. They usually stop after few weeks, when the body gets used to them, but if you experience them for longer, talk to your doctor. Some individuals are more at risk of experiencing serious side effects, like the immunocompromised. Ask for medical advice if this is your case.
PREbiotics, on the other hand, are a type of fibre that have the important role of feeding the microbiome. This indigestible fibre is consumed by the microbiome, which turn it into short chain fatty acids that are responsible to maintain healthy gut lining. This is a particularly important role because when the gut lining integrity is disrupted, we are more prone to allergies and intolerances, due to food particles crossing the gut barrier. Another benefit of increasing prebiotics in the diet includes lowering the colonic PH, making the environment less hospitable for pathogens.
An interesting 2013 study (Osborn & Sinn) revealed the beneficial effects of prebiotics in children with eczema, probably thanks to their effect on the immune system. Another 2019 study found that prebiotics, and particularly inulin, can have a positive effect on individuals with IBD due to the protective effects on the gut lining.
There are many common foods that are high in prebiotics such as garlic, Jerusalem artichokes, onions, leeks, asparagus, apples, chicory, dandelion root, barley, almonds, and oats.
In supplements, prebiotics are often found in the same formulation as probiotics, under the name of fructooligosaccharides, inulin or galactooligosaccharides. It is best to consume prebiotic rich foods daily to feed the microbiome and keep it strong against opportunistic pathogens.
Although prebiotics do not typically cause side effects, they are not usually suitable for individuals suffering from IBS, as they can make the condition worse. Other side effects include gas, bloating and digestive discomfort.
The bottom line is that ideally you should include both pre and probiotics through foods in your diet to maintain a healthy microbiome, with a variety of colourful fruit and vegetables. If you do not currently consume any, start to introduce them slowly, in small portions, to avoid possible side effects like gas and bloating.
If you decide to take a supplement, in most cases I would choose one that contains pre and probiotics, to increase its beneficial effects. Remember also to pay attention to your stress level and sugar consumption, as they can contribute to dysbiosis.
If you have an underline health condition, speak to your healthcare practitioner before changing your diet.
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