Staying healthy takes guts

We all want to stay healthy and have a strong immune system. And since most of the immune system is located in the gut, taking good care of your digestive tract is a great first step. Keeping a healthy gut can in many ways lead to an overall better quality of life.

Read more about Gut health

What is the immune system?

The immune system is the body’s way of protecting itself from pathogens, like bacteria, viruses, fungi and parasites. Multiple tissues and cells throughout the body work together to orchestrate an effective response to infections and to keep your healthy.

How does the immune system work?

The immune system has two main parts that complement each other: the innate immune system and the acquired immune system.

The innate immune system is the body’s first line of defence. It includes the skin, the mucous membranes that line the mouth, nose and digestive track, the gut microbiota and other general barriers that keep away infections. The innate immune system also involves several types of white blood cells that detect the presence of pathogens, recruit other immune cells to attack and trigger inflammation and fever.

The role of the adaptive immune system is to create a targeted defence against specific infections. It is responsible for making antibodies that recognize and neutralise individual pathogens, or tag them for destruction. It also includes memory cells that circulate for months or years after an infection ends so that the body can respond quickly if the pathogen returns.

Your adaptive immune system develops as you age and are exposed to a variety of infections. Lots of new and potentially dangerous microbes and viruses enter the body through the digestive tract, so the gut microbiota play an important role in training the adaptive immune system not to attack beneficial microbes or the body’s own cells.

You also can experience passive immunity for a short time if you receive antibodies from an outside source. Breastmilk and antitoxin treatments both contain antibodies that provide passive immunity.

How to keep your immune system strong

The best way to keep your immune system strong is to make healthy lifestyle choices.

  • Get plenty of sleep. Lack of sleep may reduce the production of antibodies, white blood cells and immune signalling molecules called cytokines.
  • Eat a varied diet that is low in fat and rich in fruits and vegetables. A high-fibre diet nourishes the beneficial gut microbiota that provide a barrier against pathogens and help train the immune system.
  • Exercise regularly. Working out reduces the risk of upper respiratory infections, like the common cold, and boosts the production of certain types of lymphocytes that wane as people age.
  • Drink alcohol only in moderation. Heavy drinking can reduce white blood cell numbers and make macrophages less effective at ingesting pathogens.
  • Don’t use tobacco products. Cigarette smoke contains multiple chemicals that interfere with the immune system, and are known to worsen gum disease and lung infections. Smoking also increases the risk of autoimmune disorders.
  • Practice good hygiene to avoid infections, such as frequent hand washing. Also, wash produce and cook meat thoroughly to prevent food poisoning.
    Consume probiotics that have shown to be effective for gut health, which can help balance your immune response and prevent excess inflammation.

Vitamin D – a natural way to stay healthy

One important component of a healthy lifestyle is sufficient levels of vitamin D. Studies have shown that vitamin D and certain bacteria in our microbiota are dependent on each other to maintain a strong gut defence. Vitamin D is associated with increased immune health, bone health and wellbeing.1 Fatty fish like salmon is one of few natural sources of vitamin D. Our skin also produces vitamin D when exposed to sunlight. But if we do not spend enough time outside during the day, or if we live in a region where the sun’s rays are seasonally weak, we cannot produce enough vitamin D. In fact, most people do not have an optimal level of vitamin D, and dark-complexioned people as well as elderly people are at increased risk of vitamin D deficiency. By supplementation you can make sure your vitamin D levels are at an optimum.

Read more about Kids and infections


Vitamin D intake recommendations*

Small children (7 – 11 months)* 10 micrograms/day

Children and adults (1 – 70 years)** 15 micrograms/day

Adults 19 – 70 years of age* 15 micrograms/day

Pregnant women* 15 micrograms/day

People over 70 years of age* 20 micrograms/day

* Institute of Medicine US/Canada

** European Food Safety Authority


L. reuteri Protectis – the perfect match with vitamin D

The probiotic strain L. reuteri Protectis has been shown to have a positive effect on the composition of the gut microbiota and may thereby benefit the function of the immune system. In combination with immune-strengthening vitamin D, it provides protection from infections and contributes to better overall wellbeing. Our products with L. reuteri Protectis combined with vitamin D are available in different product formulations.


BioGaia Protectis D3 strengthens your immune system from the inside with a combination of a clinically proven probiotic and vitamin D.

A healthy immune system at any age

As the body ages, the immune system becomes less effective at protecting against infection.

  • The aging immune system has a harder time distinguishing between pathogens and the body’s own cells, increasing the risk of developing an autoimmune disorder.
  • Macrophages ingest bacteria and tumour cells more slowly, which may be why older individuals have higher rates of cancer.
  • T cells take longer to respond to infections that you have been exposed to previously.
  • Fewer white blood cells in the body mean that you have a harder time defending against new infections, which may slow healing.
  • Antibodies become less effective at attaching to pathogens.

As a result, keeping the immune system strong through diet, exercise, vitamin D and a healthy gut microbiota becomes even more important with age.

Don’t stress!

Stress may be an inevitable part of your everyday life, but high levels of stress can suppress your immune system. When stressed, your body produces the hormone cortisol. Initially, cortisol causes inflammation, which can help you respond to an infection. Over time, however, too much cortisol in the blood leads to chronic inflammation and increases the risk of autoimmune diseases. Stress also reduces the number of white blood cells that respond to infection, which can make it more likely that you will contract cold and flu viruses.


1. Vitamin D contributes to the normal function of the immune system. Referens: EFSA Journal 2010; 8(2):1468 
Vitamin D contributes to the normal function of the immune system in children1 and is also needed for normal growth and development of bone in children2. Referens: 1. EFSA-Q-2014-00826 2. EFSA-Q-2008-116