To defend ourselves from germs and infections, the immune system of the human body serves as our shield. But to maintain this shield, people must maintain a healthy lifestyle which includes a nutritious diet.

Here are five foods you can consider eating more often so that you are well-prepared for the next time you are at risk of getting sick.

1. Yogurt

Good bacteria, known as probiotics, is said to be found in numerous yogurt products.

"While more research needs to be done, there's some evidence that some strains of probiotics can help boost the immune system and promote a healthy digestive tract," stated Elaine Magee, a nutrition expert and author.

For example, one study found yogurt consumption may help patients with inflammatory bowel disease by improving their immune response.

2. Mushrooms

Mycologist Paul Stamets explained how mushrooms are a rich source of antioxidants, providing anti-inflammatory properties. The cells that give rise to mushrooms, known as the mycelium, were said to have "uniquely amplified properties," against viruses and bacteria.

In a study from the University of Florida observed an immunity boost among people who ate shiitake mushrooms every day. 

"We're enhancing the immune system, but we're also reducing the inflammation that the immune system produces," explained lead researcher Sue Percival.

3. Chicken soup

There may be a good reason why this is the highly recommended, grandma-approved, go-to dish when you are sick. Apart from being easy to consume when your appetite is not at its best, chicken soup can provide beneficial minerals like calcium, sulphur, and magnesium.

"Chicken soup's illness-fighting ability is thought to be related to cysteine, an amino acid released from chicken during cooking. The hot liquid in soup also helps you to stay hydrated, which can help loosen any secretions," said Alissa Rumsey, a spokesperson for the Academy of Nutrition and Dietetics.

4. Nuts

The long list of health benefits never seems to end with this powerhouse snack. Brazil nuts, which contain selenium, are a great option for a boost. But nutrition experts also encourage variety when it comes to nuts.

"Vitamin E can be a powerful antioxidant that helps your body fight off infection," according to registered dietitian Kristin Kirkpatrick from the Cleveland Clinic Wellness Institute.

Almonds, peanuts, hazelnuts and sunflower seeds are all good sources of vitamin E, she added.

5. Garlic

Garlic, another great source of antioxidants, is said to have germ-fighting properties. It contains compounds that have a powerful effect on the immune system and can also aid the absorption of other minerals. 

In one study, participants who ate garlic not only had a lower risk of catching a cold but also had 70 percent shorter colds compared to the placebo group. Other studies have also suggested a possible association with reduced heart disease risk and improved mental health.