You’ve probably heard people talk about ‘good’ and ‘bad’ bacteria and that we want more ‘good’ bacteria to have a positive effect on our health. You’ve seen those ‘gut-friendly’ yoghurts drinks that are (or claim to be) full of ‘friendly’ bacteria and perhaps you're already taking little capsules of probiotics as a daily supplement, in a quest for better health.
But do you know what they are, what they’re actually doing or if you even need them?
It's a balance of 'good' versus 'bad'
Your gut ‘microbiome’ comprises tens of trillions of microorganisms – more than there are cells in your body, in fact. It's a parallel universe of up to around 1000 different species - mostly bacteria - and most of them live in the large intestine (the colon).
They play a crucial role in helping to break down food, make vitamins, regulate your immune system and prevent the growth of harmful pathogens. And there are 'good' and 'bad'. ‘Good’ bacteria have a positive impact on your health and whilst the ‘bad’ bacteria can exist at low levels without causing any harm, it’s the ratio of good to bad that is the key. An imbalance – referred to as ‘dysbiosis’ – can have implications, not only for your digestion but also for your health in general, so we want the right kinds of bacteria in the right places.
The composition of the gut microbiome is unique for each of us and variations may be associated with a number of health conditions, including inflammatory bowel disease, obesity, diabetes as well as cancer and neurodegenerative diseases. As a result there has been increased research over the last 10-15 years to better understand the gut microbiota, its role in health and in developing strategies to maintain or modify it for therapeutic purposes.
Oh, and by the way, your microbiome is not limited to your gut, although that is how we most commonly associate it. You also have microbiomes in other parts of the body, such as the skin, mouth, eyes, lungs and reproductive tract.
Probiotic foods are foods that naturally contain live microorganisms like bacteria or yeasts. They are often referred to as "functional foods" as they provide nutritional benefits beyond basic nutritional needs. Think of these as providing your body with additional friendly bacteria.
Some of the most common probiotic foods include:
Yoghurt is made by fermenting milk with live bacterial cultures, typically Lactobacillus bulgaricus and Streptococcus thermophilus. Some also contain additional probiotic strains, such as Lactobacillus acidophilus and Bifidobacterium lactis.
Kefir is a milk drink that is fermented using live kefir grains. Kefir grains are small clusters of bacteria and yeasts and they resemble cottage cheese or chopped cauliflower.
It is more tangy and less creamy than yoghurt and is fermented for longer so contains more strains of bacteria and more in total, as well as other beneficial compounds, such as vitamins and minerals.
Kombucha is a fizzy tea drink fermented with a live culture of bacteria and yeast called a ‘scoby’. The culture feeds off the sugars present in the sweetened tea and releases carbon dioxide, giving the drink its fizz. It’s full of healthy probiotics as well as other vitamins and minerals, depending on the base ingredients used. However, it does contain added sugar – it has to for the fermentation to work – so it should be consumed in moderation.
Sauerkraut is a fermented cabbage dish popular in Europe. It is made by combining finely shredded cabbage with salt to form a brine, then allowing it to ferment for several days or weeks. The fermentation process produces lactic acid, which gives sauerkraut its distinctive sour taste and also serves as a natural preservative.
Kimchi is a spicy Korean dish that is made by fermenting napa cabbage (Chinese leaf) with carrot and daikon and a mixture of spices and seasonings. It is rich in probiotics and may also contain other beneficial compounds, such as antioxidants and anti-inflammatory compounds.
Miso is a Japanese condiment that is made by fermenting soya beans with a type of fungus called Aspergillus oryzae, or koji. Miso is typically used as a seasoning in soups and other dishes and is rich in probiotics and other beneficial compounds, such as antioxidants and vitamins. You can buy miso from most supermarkets, most commonly as a soup, ready to drink and as a paste, to use in cooking.
What about ‘those’ probiotic drinks?
I’m sure you have seen those popular and heavily advertised drinks, like Actimel and Yakult, on the supermarket shelves. Unfortunately, like many mass-produced foods, they usually have added ‘extras’ to make them more palatable or give them a longer shelf life. Added sugars, or even sweeteners are a no-no when it comes to gut health. And actually many of these popular drinks do not contain enough bacteria to have much of an impact or those bacteria do not survive the harsh digestive environment in the gut.
Should you take probiotic supplements?
So if those mass-produced little drinks are no good you might be wondering whether you should take a probiotic supplement instead?
Maybe - but it really depends.
You cannot supplement your way out of a bad diet or poor lifestyle habits, but specific supplements can provide targeted support and get you back on an even keel. If you have ongoing digestive problems then it’s important to investigate your symptoms further, to understand what might be going on. I can help with that
Since everyone is different and we all have a unique microbiome, truly targeted support can look at finding specific strains of bacteria to support certain conditions (some strains are great for supporting low mood, others are helpful for hormone balance, and so on). These are often not the kinds of products you can find without professional recommendation.
That said, some of the key beneficial bacteria that can help include lactobacillus (acidophilus and rhamnosus) and the bifidobacteria group (breve, longum, lactis).
Bottom line, what will most benefit you very much depends on your specific symptoms or conditions.
What about prebiotics?
Prebiotics are a type of dietary fibre that cannot be digested in the small intestine, but instead reaches the large intestine where it serves as a food source for the beneficial gut bacteria. So while probiotics provide additional bacteria, prebiotics feed the bacteria that are already there and help promote the growth and activity of specific types of bacteria that are considered beneficial for health.
Some common types of prebiotics include inulin, fructooligosaccharides (FOS) and galactooligosaccharides (GOS). These prebiotic fibres are found naturally in many plant-based foods, such as bananas, oats, onions, garlic, leeks, asparagus, artichokes and whole grains.
Cruciferous vegetables are also very helpful for your digestion, as well as your liver function. They contain compounds called glucosinolates, which are fermented by bacteria in the digestive tract. This produces other bioactive compounds that have been shown to inhibit the growth of cancer. Glucosinolates are also anti-inflammatory.
Cruciferous veggies include bok choy, broccoli, Brussels sprouts, cabbage, cauliflower, kale and spring greens.
Prebiotics have been shown to have a variety of health benefits, including improving digestion, boosting the immune system, reducing inflammation, and improving the absorption of certain nutrients. Additionally, research suggests that prebiotics may help reduce the risk of certain health conditions, such as type 2 diabetes, heart disease and colorectal cancer.
Should everyone be eating pre- and probiotic foods?
It is important to note that while prebiotics and probiotics are beneficial for health, they can also cause digestive discomfort in some people, particularly when consumed in high amounts.
If you have never tried fermented foods or drinks before then my advice is to introduce them slowly to allow your digestion to adjust – too much too quickly could cause or exacerbate gas or bloating. Anyone on immunosuppressants should check with their health provider first and those with a histamine intolerance should avoid them altogether as these foods tend to be high in histamine.
Additionally anyone with symptoms of IBS should approach some of these foods with care. A common cause of these symptoms can be the migration of bacteria to the small intestine - where they shouldn’t be. Large intestine, yes; small intestine, no.
When your body is in a fasted state (i.e. between meals and overnight) it carries out a sweep of all indigestible substances from the stomach down to the colon. This is the Migrating Motor Complex at work. There is a variety of reasons that might cause this process not to happen and that can result in bacteria in the small intestine feasting on these prebiotic foods, causing gas, bloating and discomfort. As with fermented foods, if you’re not currently eating your 7-portions-a-day of veggies then it is best to increase slowly.
Good health starts in the gut
Improving your gut health can bring benefits to your whole body. If you are dealing with on going digestive discomfort always seek advice from a health professional. The problem could be caused by any part of the digestive process - anywhere from the mouth to ... well, the other end. Low salivary enzymes, low or excess stomach acid, insufficient digestive enzymes, or it could be due to the foods you are eating (or not eating).
As a nutrition practitioner, regardless of what you actually come to me about, I will always take a good look at your digestion first. Getting things on the right track here can be key to resolving a lot of other symptoms.