- Scientists recently learned how fermented foods increase our immunity.
- Fermented foods provide protection against colds, improve the intestinal microbiome, and can alleviate IBS.
- If it's new to healthy bacteria, slowly introduce fermented foods.
Study: Fermented foods boost immunity
Foods that have gone through the fermentation process offer health benefits, but we didn't understand the exact mechanism behind this. Now part of this puzzle has been uncovered by new research into how fermented foods positively affect our immune cells.
The study, which was carried out at the University of Leipzig in Germany, found that there are receptors on human cells that recognize the bacteria in fermented foods and strengthen the immune system. It is specifically the lactic acid bacteria present in fermented foods that produce a metabolite, D-phenyllactic acid, which binds to a receptor on the surface of human cells and triggers an immune response.
Interestingly, only humans and monkeys have been found to have this particular receptor on cells – it's our third receptor while most animals only have two – and researchers suspect that it evolved as a form of evolutionary protection. It would allow our ancestors to eat foods such as pieces of fruit or vegetables that are lying on the ground and may have decayed.
Fermentation is an ancient, natural process
Fermentation occurs naturally in food when certain bacteria, such as yeast, begin to convert carbohydrates into acids or alcohol. Although we have been conditioned to view bacteria in our food as harmful, it is just the opposite, as fermentation acts as a preservative and adds nutrients to the food.
The fermentation process not only changes the composition of a food, but also the taste. Fermented foods tend to have a strong taste. Some examples of fermented foods are sauerkraut, miso, kombucha, yogurt, kefir, and kimchi.
Fermented foods and beneficial health effects
As current research finds, fermented foods can boost the immune system. A 2010 study at the Food Science Institute in Kanagawa, Japan showed that regular consumption of fermented yogurt was linked to a lower risk of developing colds in the elderly.
One of the benefits of fermentation is that it encourages the growth of probiotics in food, which can encourage the formation of larger colonies of beneficial bacteria in the gut and contribute to stronger immunity. As Jon Barron has said several times, "A well-maintained gut biome accounts for more than 80 percent of your immune function." To learn more about why we all need adequate dietary probiotics and / or a good quality natural supplement, see "Do you need to take probiotics?".
In addition, a thriving population of good bacteria in the gut contributes to better digestive health. That means everyone should experience more regular bowel movements and less gas and constipation. People with irritable bowel syndrome (IBS) could benefit even further, as a 2018 study at the University of Copenhagen in Denmark found that symptoms of IBS were less severe when patients consumed sauerkraut on a daily basis.
Slowly introduce fermented foods into your diet
If you are not used to eating fermented foods other than the occasional yogurt, gradually add these to your diet. While they are very safe to consume, the initial introduction of these bacteria – especially when combined with fiber like in kimchi – can lead to an increase in gas or gas in some people.
However, don't let that stop you from consuming more fermented foods. Take it slowly and introduce new fermented foods in smaller quantities. And remember that while fermented foods are inherently healthy, if you buy them packaged at a supermarket, other ingredients may not be as healthy. For example, flavored yogurts can be high in sugar. Just as you would with anything you buy, read these nutrition labels carefully.