When it comes to your immunity, the gut has been found to have an important part to play. Maintaining good gut health can give your body’s immune system a boost, and prebiotics and probiotics both have a role to play in this.
The role of the gut in immunity
Most of us know that keeping our gut healthy is important, and this involves maintaining a healthy gut microbiota.
Researchers have discovered and recognised that the body’s other organ systems can be influenced by the gut environment and it’s now becoming realised that poor gut health could cause many diseases and conditions like lung disease or depression.
Our immune systems form the primary link between the gut bacteria and the way in which they influence our well-being. At one time it was believed that the uterus was bacteria-free, however, it’s now been found that bacteria can be detected in the placenta, ensuring that babies are exposed to bacteria from before birth. We’re all born with an underdeveloped immune system and therefore rely on the antibodies provided by our mothers at first, but our immune cells then learn the best ways of protecting our bodies from illnesses once all the material antibodies have worn away. Bacteria in the gut is essential in this education process.
Research has shown that gut bacteria maintains balance in our immune systems. During our lives, we’re exposed continually to new things inside the gut, the lungs and the nose through our environment and the food that we consume. Things like food additives, the non-pathogenic microorganisms found in dirt or dust, and pollen in the air we breathe all enter our bodies. Luckily, when our immune systems are healthy, they can handle these invaders easily.
For those with an impaired immune system, inflammatory responses are triggered each time a new food is tried or each time a new substance is encountered. The immune system is required to maintain the right balance between tolerance and reaction. This tolerance is known as oral tolerance. It can be established by maintaining diverse gut flora with lots of different fungi, microorganisms and bacteria to teach the immune system’s cells which invaders are bad and which can be safely overlooked.
The bacterial balance in the gut influences our immune system’s balance. If the balance is off, the immune system may adopt an increased inflammatory state that goes on to affect the other systems in the body, increasing the chances of developing a range of diseases including Type I and II diabetes, depression and obesity.
Although most bacteria are beneficial, there are some that cause diseases to progress. Bacteria also adjusts to its current environment. This means that, when good bacteria become removed because of medication or dietary changes, some opportunistic pathogens move in to fill up the gap that remains. This, of course, leads to further problems, more inflammation and health concerns.
It isn’t easy to permanently change the gut flora once it has been established. Once it has been disturbed, it usually returns to its normal state in a short space of time. So, for example, if you go abroad on vacation and eat different foods, your gut will return to normal on your return home.
However, imbalanced gut flora can loop in negative cycles, reinforcing harmful functions. It is a lack of bacterial diversity that causes a skewed microbiota – maintaining diversity means that your gut can bounce back more rapidly from any unhealthy dietary fluctuations and is more capable of withstanding outside intruders. As a result, your immune system will be better regulated and considerably more tolerant of change. As a result, you will be more resistant to disease and illnesses.
What are prebiotics and how can they help?
Prebiotics are food components that are known to improve the supply of food for the microorganisms that live inside our gastrointestinal tracts. They are capable of giving the beneficial bacteria in our guts the nourishment they need and, therefore, the best possible chance of growing and flourishing. It’s possible to boost the level of prebiotics in your body naturally by eating more vegetables and fruits.
How can prebiotics be added to the diet?
There are a number of foods that are known to be beneficial prebiotics. These include:
- Chicory root – popular thanks to its coffee-like taste, chicory root is a valuable source of prebiotics. Almost half of the fibre in chicory root comes from inulin, a prebiotic fibre. This nourishes the bacteria in the gut, improves your digestion and relieves your constipation. It also helps to boost the production of bile in the body which, in turn, improves the digestion of fat. Not only that, but chicory root contains a lot of antioxidant compounds known to protect your liver from oxidative damage.
- Dandelion greens – these greens are ideal for inclusion in a salad and they are an excellent source of fibre, containing as much as 4g of fibre in each 100g serving. Much of that fibre is derived from inulin which reduces constipation, increases the amount of good bacteria in your gut and boosts your immune system. Dandelion greens have diuretic, antioxidant, anti-inflammatory, cholesterol-lowering, and anti-cancer effects that can help you to stay healthy and well.
- Jerusalem artichokes – sometimes called the Earth Apple, the Jerusalem artichoke offers a host of health benefits. It supplies around 2g of dietary fibre in every 100g and 76 percent of this fibre is derived from inulin. This food increases the good bacteria in your good, strengthens your immune system and even prevents specific metabolic disorders. Not only that, but it is high in potassium and thiamine, both of which aid the nervous system, promoting good muscle function.
- Garlic – this tasty herb has been linked with many health benefits. Around 11 percent of its fibre content is derived from inulin, with 6 percent coming from a naturally occurring sweet probiotic known as fructo-oligosaccharides. Garlic is a prebiotic that promotes Bifidobacteria growth inside the gut. These beneficial bacteria also help to prevent disease promoting bacteria from growing. Garlic also reduces the chance of developing heart disease thanks to its antimicrobial, anti-cancer and antioxidant effects.
- Onions – these vegetables are versatile and tasty, but they also offer a host of health benefits, with inulin accounting for 10 percent of their fiber content and fructooligosaccharides making up another 6 percent.
As a result, the gut flora is strengthened while fat breakdown is aided, and the immune system boosted by increasing the production of nitric oxide in the cells. Furthermore, onions have a high level of quercetin, the flavonoid that gives this vegetable its anti-cancer and antioxidant properties.
- Leeks – coming from the same vegetable family as garlic and onions, leeks offer similar benefits for your health. They contain as much as 16 percent inulin fibre and this helps to promote the growth of healthy bacteria in the gut while also helping to break down fat. Also, leeks have a high amount of flavonoids which help to support the body’s natural response to oxidative stress.
- Asparagus – this popular vegetable represents another excellent prebiotic source, with around 2 to 3 grams of inulin content in every 100-gram serving. Asparagus promotes the growth of friendly bacteria inside the gut and is associated with the prevention of some cancers. By combining antioxidants and fibre, asparagus offers anti-inflammatory benefits.
- Bananas – these popular fruits are rich in fibre, minerals and vitamins while also containing a small amount of inulin. Unripe bananas contain large amounts of resistant starch and this has a prebiotic effect that increases the number of healthy bacteria in the gut while reducing bloating.
- Barley – this cereal grain contains 3 to 8 grams of beta-glucan in every 100-gram serving. This prebiotic fibre promotes friendly bacteria growth inside your digestive tract. It also lowers your LDL and total cholesterol and blood sugar while also being rich in selenium to boost thyroid function, provides antioxidant benefits and improves immunity.
- Oats – healthy whole oat is a grain with prebiotic benefits. Oats contain a large amount of beta-glucan fiber together with some resistant starch. The beta-glucan found in oats is associated with healthier gut bacteria as well as improved blood sugar control, lower levels of LDL cholesterol and a reduced risk of cancer. Oats also offer anti-inflammatory and antioxidant protection for the body thanks to the phenolic acid they contain.
- Apples – not only are apples delicious but pectin makes up around half of the total fibre content of an apple. As we’ve already pointed out, pectin offers benefits to your immune system. Its prebiotic advantages include its ability to increase butyrate – the short-chain fatty acid which feeds good bacteria in the gut while decreasing the number of bad bacteria.
Apples also contain a high level of polyphenol antioxidants, and when pectin and polyphenols are combined, fat metabolism and digestive health are improved. Not only that, but apples have anti-inflammatory and antioxidant properties that help to reduce the chances of developing illnesses and diseases.
Konjac root – sometimes called elephant yam, is a tuber that can sometimes be used as a supplement to offer health benefits. It contains 40 percent glucomannan fibre which is an extremely viscous dietary fibre. Glucomannan fibre in konjac promotes good bacteria growth inside the colon, relieving constipation and boosting your immunity. It also reduces your blood cholesterol levels and helps to promote weight loss while also improving how your body metabolises carbohydrates.
- Cocoa – cocoa beans aren’t just delicious, they’re also very healthy. When cocoa beans break down inside the colon, nitric oxide is produced, and this offers benefits to your cardiovascular system. Cocoa is one of the best sources of flavanols which has a number of powerful prebiotic benefits, helping to boost the growth of good gut bacteria while benefiting your heart health.
- Burdock Root – popular in Japan, burdock root offers many health benefits, containing around 4 grams of fibre in every 100-gram serving, with most of this fibre being from inulin and FOS. The FOS and inulin in burdock root have prebiotic properties, inhibiting the growth of the bad bacteria in your intestines while improving immune function and promoting healthy bowel movements. Burdock root also offers anti-inflammatory and antioxidant properties while lowering your blood sugar levels.
- Flaxseeds – these seeds are very healthy and an excellent source of prebiotics. Containing around 20-40 percent soluble fibre from mucilage gums and 60-80 percent insoluble fiber from lignin and cellulose, the fibre found in flaxseeds boosts the number of good bacteria in your gut, promoting healthy bowel movements and reducing the amount of fat in your diet that you absorb and digest. Also, since flaxseeds contain phenolic antioxidants, they offer antioxidant and anti-cancer properties while helping to regulate your blood sugar level.
- Yacon root – similar to sweet potato, yacon root is packed with fibre, especially prebiotic FOS (fructooligosaccharides) and inulin. The inulin found in yacon root improves healthy gut bacteria, reducing constipation, enhancing your immunity, improving the absorption of minerals in the body and helping to regulate fats in the blood. Also, yacon root contains phenolic compounds that boost its antioxidant properties.
- Jicama root – this root is high in fibre but low in calories. It contains a lot of inulin, a prebiotic fibre that helps to boost your digestive health, enhance your sensitivity to inulin and lower your blood sugar level. It is also in vitamin C that stimulates your immune system to combat diseases.
Wheat bran – this outer layer of whole wheat grain is a great prebiotic source that contains a special kind of fibre made up of AXOS (arabinoxylan oligosaccharides). AXOS fibre makes up as much as 64-69 percent of the fibre content of wheat bran and allows it to boost the levels of good Bifidobacteria inside the gut. Not only that, but wheat bran reduces digestive problems like abdominal pain, cramping and flatulence. Grains that are rich in AXOS also offer anti-cancer and antioxidant properties.
- Seaweed – although seaweed isn’t eaten often, it’s a powerful prebiotic to add to your diet. Around 50 to 85 percent of the fiber content of seaweed is derived from the water-soluble fiber. This enhances good gut bacteria growth while preventing bad bacteria from growing. It also boosts your immune function, reducing your chances of developing colon cancer. Also, seaweed is rich in the antioxidants that have been associated with strokes and heart attack prevention.
Probiotics and the gut
Prebiotics are key to good gut health, but probiotics are equally important. There are some misunderstandings about the difference between prebiotics and probiotics. Some people even think that they are the same thing. However, this isn’t the case at all. Probiotics are very different from prebiotics, but they are no less vital to good gut health and a strong immune system.
What Are Probiotics?
Probiotics are live yeasts and bacteria that offer many health benefits, especially for the digestive system. Usually, we think of bacteria as being bad for you and causing diseases. However, the human body is actually full of different bacteria. While some bacteria are bad, others are good and can help to keep the gut healthy and functioning properly.
Probiotics can be found in certain foods such as yogurt as well as in certain supplements. They are often recommended by doctors to aid in the relief of digestive disturbances.
Probiotics work to keep us healthy by:
- Replacing the good bacteria inside the body that are lost through taking antibiotics.
- Balancing the bad and good bacteria levels so your body can continue to function in the way that it should.
Many bacterial types are kinds of probiotic. All offer different benefits. However, the majority are covered by two main groups:
- Lactobacillus – this probiotic is the most common. You find it in fermented foods and yogurt. Different strains help to treat diarrhoea and may be helpful for people who are unable to digest the sugar in milk known as lactose.
- Bifidobacterium – this probiotic can also be found in some types of dairy product. It helps to reduce the symptoms associated with IBS (irritable bowel syndrome) and some other conditions.
Saccharomyces Boulardii is a yeast that can be found in probiotics. It helps combat digestive problems and diarrhea.
How can Probiotics Improve Immunity?
It’s known that probiotics can boost your immune system, inhibiting harmful gut bacterial growth in your body. Not only that, but some probiotics promote your body’s natural antibody production. They may even boost the immune cells such as T lymphocytes, natural killer cells and IgA-producing cells.
Reviews have found that if you take probiotics, you’re less likely to suffer from respiratory infections, and any you do develop will last for less time. The probiotic known as Lactobacillus Crispatus has also been proven to reduce the chances of developing a urinary tract infection by as much as 50 percent.
How can I include more probiotics in my diet?
Although there are a number of different types and classes of probiotics, some common ones include:
- Saccharomyces Boulardii
Sometimes, food manufacturers call probiotics “active cultures” or “live cultures”. They are all the same thing. Many fermented foods contain probiotics. This essentially means that the bacteria inside those foods are still alive. Often, the process of producing food destroys any living bacteria in them. When products are left on a store shelf without being refrigerated, it may be unable to contain active and live probiotics.
Some dairy products that are known to contain probiotics include:
- Kefir (a probiotic milk drink)
- Aged cheeses like mozzarella, gouda, and cheddar
- Traditional uncultured buttermilk
However, there are some foods that aren’t dairy but still contain probiotics. These include:
- Sour, fresh dill pickles
- Kombucha (a fermented tea)
- Non-dairy yogurt
- Natto (made from fermented soybean)
- Water or brine-cured olives
Many different probiotic foods are available, and this means that you have plenty of options when it comes to including them in your daily diet. There is sure to be something to suit your individual tastes, whether you prefer sweet or savoury foods.
Some ways of adding probiotics to your healthy diet include:
- Having a breakfast made up of probiotic yogurt along with nuts, flax seeds and berries.
- Making a stir fry that uses tempeh instead of meat. Make sure to add tempeh right at the end of the cooking process since excessive heat may destroy its active cultures.
- Adding miso into soup.
- Drinking beverages that are rich in probiotics like kombucha or kefir as a snack in the mid-morning.
- Serving sauerkraut alongside your main meal as a side dish.
Remember though that certain foods like yogurt often contain extra sugars, so try to choose ones that contain minimal sugars, artificial sweeteners, and artificial flavourings to ensure the best possible health.
Also, not every type of fermented food contains live cultures.
Some fermented foods that don’t contain probiotics include:
- Soya sauce
- Sourdough bread
That is because these foods have undergone additional processing that causes the live cultures to be made inactive. Processes like filtering, pasteurisation and baking kill the live cultures so they offer no health benefits.