Did you know that your body is a host to bacteria? The human microbiome consists of trillions of bacteria who call your body home. The majority of these are located in your gut (gastrointestinal tract). It’s a mutually beneficial relationship-they rely on us and we rely on them. In fact, the role gut bacteria play in health is something we are constantly learning about.
The levels of good and bad bacteria in the gut are constantly changing due to changes in our diet and lifestyle, and this starts from a young age. Babies are born with a sterile gut, which becomes inhabited on different types of bacteria based on what they consume. The effect of diet on bacteria continues into adulthood. Research as shown that changing dietary intake can change the bacteria in our gut in as little as two weeks, and these changes can have positive or negative effects.
Bacteria in the gut have a number of beneficial functions. By sticking to our gut cells, they physically prevent pathogenic (disease causing) bacteria from colonising (growing). They also secrete proteins which prevent colonisation. Gut bacteria also produce nutrients such as vitamin K, biotin and vitamin B12, which all play a role in the maintenance of good health.
Research is now hinting that our microbiome has a much larger effect than previously thought on health. Some studies have shown a link between certain types of bacteria and obesity. Small studies in mice have found transplanting bacteria from lean individuals into obese mice could help prevent weight gain, but only when the mice were being fed a healthy diet, high in fruit and vegetables. While animal studies can never be used as proof that similar mechanisms occur in humans, they do provide guidance to help future, larger studies in humans.
Given the beneficial effects of gut bacteria, it makes sense to try to support them. One of the easiest ways to support your gut bacteria is to eat prebiotics. Prebiotics are fibers found food such as apples, bananas, garlic, pulses, leeks, tomatoes and oats. Resistant starches are another prebiotic which have a similar effect. They can be found in unripe bananas, pulses, undercooked or reheated potato potatoes and potato products.
Prebiotics pass through the gastrointestinal tract undigested, until they reach the colon. Here, they act as food for our gut bacteria. The bacteria in the gut ferment these fibers and produce short chain fatty acids, which in turn provide energy to the cells lining the gut. These fatty acids help us too, as they create an environment which is unsuitable for pathogenic bacteria.
Another way to help your body is to actually eat healthy bacteria, or probiotics. These are found in fermented foods such as sauerkraut, kimchi and kombucha, along with commercially prepared probiotic supplements. Check out this article for food sources of probiotics, and this menu for ways to use them. If you wish to take a probiotic supplement, as your registered dietitian for advice-many probiotics are not scientifically proven to have any effect, so make sure you get guidance on picking the right one.
For more tips on using probiotics click here. Enjoy!