I love to read about our gut microbes and learn what they are capable of. They are actually amazing!
Here, I share more about the complex systems of the intestines and how diet helps the gut microbes function effectively
Our intestines contain a complex and dynamic population of microorganisms — bacteria, fungi, parasites and viruses. This community is called the ‘microbiota’. Microbial groups living in the stomach, small and large intestine are very important for human health.
Many factors affect the formation of intestinal microbiota, starting from the mother’s womb, during the delivery through the birth canal and through mother’s breast milk. Our genes and environmental factors play an important role on our gut composition. That being said, the food we consume in the first three years of our lives, is considered to be one of the strongest factors in shaping our microbiota.[1,2]
Our microbiota contains trillions of microorganisms, including at least 1000 different known bacteria species, and can weigh up to 2 kilograms in total. Although each of us has a unique microbiota, our microbes always perform the same physiological functions and has a direct impact on our health.
Some roles of the microbiota:
- Digesting some foods that the stomach and small intestines cannot digest (such as fibrous vegetables and fruits).
- Producing some of the B vitamins (aiding an important role in cell metabolism and helping the formation of new blood cells) and vitamin K (which plays a role in blood clotting, bone metabolism, and regulation of blood calcium levels).
- Helps us fight against the attacks of other microorganisms by creating a barrier effect as the gut walls contain immune cells
- Produces and secreting hormones and regulating hormone levels. For example, the happiness hormone Serotonin is produced in our intestines.[3]
In a healthy person, a delicate balance is maintained with a large number of beneficial bacteria competing against disease-causing bacteria. Considering an average lifespan, about 60 tons of food pass through our guts, hence, we are pretty exposed to disease-causing bacteria.
In addition, the abundance of microorganisms from the environment, for example in water, in the air we breath in, in the products we use daily, poses a major threat to the microbiota and intestinal integrity. In case of a highly disturbed integrity of our gut microbiota, health problems such as gastrointestinal conditions and then wider systemic conditions such as obesity and diabetes may occur.
How can our diet help the gut microbes function effectively to optimise health?
Including probiotics and prebiotics in our diet is invaluable for the balance of the gut microbiota. Probiotics are known as “health-friendly microorganisms” found in fermented foods. Although very few in number compared to our gut microbes, probiotics can grow, metabolise, and interact with resident microbes.
In times of threats to the integrity, such as the use of antibiotics, poor diet, or stress, probiotics can help support the beneficial bacteria that live with us.[4] Probiotics can also be used as a nutritional supplement in addition to food.
Examples of probiotic foods include fermented foods like kefir, yogurt with live active cultures, pickled vegetables, tempeh, sourdough bread, kombucha, kimchi, miso, and sauerkraut.[5]
Prebiotics, on the other hand, are defined as the fertilisers for the healthy gut bacteria. In other words, they are the foods that trigger the growth and activity of probiotics and beneficial bacteria in the microbiota. Prebiotics consist of complex carbohydrates (fibre and resistant starch) that our bodies cannot digest.[6]
In more detail, dietary fibre is broken down and fermented by enzymes from the microbiota inhabiting in the colon, releasing short chain fatty acids (SCFA). This results in a lower pH of the colon, limiting the growth of some harmful bacteria. Research also revealed that SCFA has many benefits on healthy, including stimulation of immune cell activity and preserving normal blood glucose and blood cholesterol levels.[7]
Some examples of prebiotics include fruits and vegetables of many colours (e.g. garlic, leek, apple, pear, banana, onion, mushroom), almonds, flaxseeds, chickpeas, lentils, red kidney beans, barley, oats and many more.
Please be aware that increasing the intake of prebiotic foods suddenly, may result in an increased gas production (flatulence) and bloating.
To promote a healthy gut, it is suggested to eat foods of all colours of the rainbow, as each colour represents a wide variety of bioactive compounds. In addition, adopting a regular routine for eating and sleeping is also important for a healthy gut. Happy gut, happy you!
References:
Suna Cenk Nutrition 