Can probiotics improve your IBS symptoms?
The 5 best probiotic foods for a healthy gut
Probiotic foods contain a large number of 'good bacteria'. This type of bacteria is believed to play a key role in the health and function of your gut. For this reason, many people experiencing persistent and uncomfortable digestive problems - such as bloating, gas, or diarrhoea - are incorporating probiotic foods into their diets. Which foods contain the most probiotics, and what does current research say?
What are probiotic foods?
In recent years, you may have become accustomed to seeing the word 'probiotic' plastered on yoghurt pots, cereal bars, and fermented drink labels in the supermarket. These products claim to boost the number of probiotics in your gut, which in turn is thought to keep it healthy.
We all naturally have probiotics, regardless of whether we add them in our diet consciously through probiotic foods or supplements. These probiotics are tiny creatures that live in the digestive system. They go by several different names - to scientists they are known as microbes; to the public they are often called 'beneficial' or 'good' bacteria.
Probiotics for gut health
Having a healthy number of probiotics can support your gut health and help to protect you from digestive discomfort and problems. A healthy gut can have far-reaching benefits and could help to protect against or improve several health conditions.
High probiotic levels may:
- Make it easier to digest food and absorb important vitamins and minerals.
- Ease your symptoms if you have irritable bowel syndrome (IBS).
- Reduce common digestive problems such as diarrhoea, bloating, gas, and constipation.
- Reduce lactose intolerance symptoms.
- Improve symptoms linked to ulcerative colitis and Crohn's disease.
- Help to keep harmful substances out of your body by strengthening the intestinal barrier of your gut.
- Strengthen your immune system which helps to protect you from illness.
- Benefit pregnant women and reduce pregnancy complications.
- Protect you from infections, including the common cold and urinary tract infections.
- Lower your risk of type 2 diabetes.
- In babies, help with the development of the digestive and immune system.
Despite the promising results of many studies, research into probiotics for gut health and overall health often reveals mixed results and in many areas is limited. If you have a digestive health concern, seek the advice of your pharmacist or doctor. They may suggest treatments that have been proven to work in more thorough scientific clinical trials.
What foods contain probiotics?
Fermented foods are naturally high in probiotics. This is because fermentation involves growing live and active cultures (live bacteria). These natural probiotic foods are healthy and safe to eat, whether you are concerned about your gut health or not.
What are the best probiotic foods?
The following probiotic foods have shown promising health benefits in some people.
Plain yoghurt which hasn’t been sweetened is rich in probiotics. It is also one of the most easy-to-find fermented probiotic foods, as natural yoghurt generally isn't limited to large supermarkets or speciality stores.
Yoghurt is made through fermenting milk. The probiotics in this milk consume the naturally occurring milk sugars, turning it into lactic acid. This process may sound peculiar, but this is what gives plain yoghurt the creaminess and slightly sour taste that many of us enjoy.
Probiotic foods need to be consumed on a regular basis, and to contain enough probiotics, for us to see noticeable health benefits. Because of this, some yoghurts also have added probiotics for gut health and overall health. Studies suggest consuming around 10 billion CFU (colony forming units) per day. This is the measure of good bacteria in probiotic foods and probiotic supplement products. However, it's important to note that not everyone will feel the benefits of probiotics, regardless of how much they consume.
In recent years, you may have noticed kefir products appearing in the dairy section of your local supermarket. This is a drink made from fermented milk, kefir grains, yeast, and friendly bacteria.
Kefir is one of the most widely researched fermented probiotic foods. There has been at least one high-quality randomised controlled trial that showed promising results for kefir's ability to destroy harmful gut bacteria and help symptoms of lactose intolerance.
Some experts believe that probiotic foods such as kefir may also be useful in cancer prevention and treatment. Studies indicate that kefir can block some cancer cells, including breast cancer, lung cancer, and colorectal cancer. Research into this area is ongoing.
Sauerkraut is cabbage that has been fermented by lactic acid bacteria, giving it a distinct sour taste. Originating in Germany, it is often used as a side dish, and has a long shelf-life. The fermentation of this probiotic food has been studied for many years.
As well as helping to resolve problems of the gut, such as constipation, it is also thought that the good bacteria in sauerkraut may be useful in the protection against cancer, obesity, and high cholesterol, amongst other health issues.
Another popular probiotic food made from fermented cabbage is kimchi, this time originating from Korea. Compared to sauerkraut, kimchi is fermented with many more ingredients - including other vegetables and seasonings - which gives it an even more complex micro-ecosystem of live bacteria strains.
As Kimchi is also a good source of probiotic lactic acid bacteria, evidence suggests that this probiotic food has the same potential health benefits as sauerkraut and many other pickled vegetables (including helping to protect against high blood pressure and obesity).
Kombucha is a fermented tea drink that's available in many UK stores and supermarkets. Fermentation begins when sugar and several probiotic bacteria strains are added to green or black tea and then left for a week or longer. Kombucha contains a diverse range of good bacteria, including lactic acid, acetic acid, fungi, and yeasts.
Yet, while these probiotic properties are promising, direct evidence supporting kombucha's benefits for human health is lacking. Most experts agree that more robust research is needed.
Do probiotics work?
On the one hand, many studies suggest that fermented foods provide a range of health benefits. As most also contain antioxidants, anti-inflammatory, and immune-supporting properties, these benefits extend beyond probiotics and gut health.
However, it can't be ignored that some studies have not found a link between fermented probiotic foods and health benefits. Generally speaking, experts agree that more research is needed in the form of high-quality clinical human trials.
Are probiotics safe?
As it stands, the choice to try food sources rich in probiotics is entirely yours. These foods are generally considered safe to consume on a regular basis and few reports of negative outcomes can be found.
Are all pickled food types probiotics?
It's easy to mistake pickled foods for fermented foods, but there is a key difference when it comes to what's good for your gut. In fact, most pickled foods don't contain beneficial probiotics for gut health.
Pickling: uses an acid such as brine (salty water) or vinegar to preserve food. It is this acid that gives these foods their sour taste. Only foods pickled with salts, and not vinegar, contain probiotics.
Fermenting: always involves a chemical reaction between a food's sugars and bacteria. It is this reaction that results in the sour flavour.
What about unfermented foods?
These days, there are many unfermented food products on the market that have had probiotics added to them. According to the National Institutes of Health (NIH), whether these manufactured probiotic foods can truly count as probiotics comes down to how many micro-organisms they contain, whether they survive digestion, and whether the bacteria strain they contain has health benefits.
Common manufactured probiotic foods include some:
- Milk drinks.
- Cereal bars.
Tips for buying and consuming fermented probiotic foods
To ensure a product contains active probiotics:
- To help tell the difference between pickled and fermented foods you can check where the product is stored in your supermarket. You will likely find fermented foods in the refrigerated section.
- Look for the words "naturally fermented" on the label.
- When buying yoghurt, check it has not been heat treated as this can kill good bacteria.
- Check for high sugar, sweetener, or preservative content, as this can upset the stomach when consumed in large amounts and can cancel out probiotic benefits.
- Avoid products that have been pasteurised as this process kills beneficial bacteria.
- When opening a jar of fermented vegetables, bubbles in the liquid indicate live probiotics.
- If adding fermented foods to hot food, mix them in immediately before serving or add them as a topping, as high heat can kill the bacteria.