Lack of sleep will not affect my immune defence

FALSE! Poor sleeping habits and stress are things that may put our microbiota out of balance, which means that we are more susceptible to infections.

My immune system is not connected to my gut

FALSE! There are several mechanisms which link our gut health with our immune system. Simply put, most of our immune system is located in the gut and a well-balanced gut and microbiota are very important for our health.

Antibiotics help my immune system fight disease

FALSE! Antibiotics kill all types of bacteria, both the pathogens that cause the infection, and good bacteria that are necessary for our immune defence. This puts the immune system out of balance, putting us at an increased risk of infections directly after finishing the course. Sometimes it is necessary to take antibiotics, but we should only do so when absolutely necessary. After taking antibiotics it is always a good idea to take measures to support our gut bacteria and thereby also the immune system.

Babies and small children do not have a developed immune system. Therefore, it is important to keep them in a sterile environment

FALSE! An excessively sterile environment may prevent the normal development of the immune system. A baby establishes its gut bacteria and intestinal microbiota starting from birth and during the first three years of life. If kept in a too sterile environment, a baby will miss out on important bacteria that build up the babies’ microbiota. These bacteria train the immune system and provide a barrier against infections. Thus, it is important to be exposed to harmless bacteria during the first three years of life.

Supplementing with vitamin D is only important for small children and the elderly

FALSE! If we don’t eat enough fatty fish like salmon, don’t spend time outside during the day or if we live in a region with long winters and lack of sunshine, we cannot produce enough vitamin D. In fact, most people do not get enough vitamin D. Dark-complexioned people as well as elderly are at increased risk of vitamin D deficiency.

Bacteria are bad for my immune system

FALSE! Actually, our bacteria are the first line of defence against bad bacteria, called pathogens. The good bacteria are educating the immune system, making it ready to fight unwelcome invaders, like pathogens and toxins.

Using hand sanitizer all the time will help me fight off colds and diseases

FALSE! Obsessive hygiene, including using germ-killing soaps and showering several times a day, deplete the good bacteria that are important for our immune defence. Also, hand sanitizers have a drying effect, which may actually make our skin become more sensitive and vulnerable.

Athletes are less likely to get sick from common infections

FALSE! While light and moderate amounts of exercise can lower stress levels and keep the immune system healthy, overdoing it at the gym can have the opposite effect. High-performance athletes actually have a higher risk of infection than the average person.

Antibiotics can treat colds and the flu

FALSE! The common cold and the flu are caused by viruses, which are unaffected by antibiotics. You should only take antibiotics if your doctor determines that you have a serious bacterial infection. Antibiotics kill good bacteria as well as bad, and can hurt your healthy microbiota, putting you at risk for other infections.

Stress keeps your immune system active to help defend you from infections

MOSTLY FALSE! In response to stress, your body produces the hormone cortisol, which triggers inflammation that can help fight infections in the short term. Over time however, having too much cortisol leads to chronic inflammation, which increases the risk of autoimmune diseases. Stress also reduces white blood cells, which can make it more likely that you will catch cold and flu viruses.

You should feed a cold but starve a fever

FALSE! Regardless of the type of respiratory infection you have, it’s important to drink lots of water and provide your body with healthy foods to keep your immune system and your gut microbiota strong.