How do you prevent your reusable water bottles from becoming real bacteria nests?

Pollution, plastic overconsumption, microplastics found in mineral water bottles, rising prices… There are many reasons why we buy a water bottle. Whether in the corner of a desk, in our backpack or in the car, reusable bottles are popular. But do these eco-responsible objects only have benefits? How do you prevent them from becoming a real breeding ground for bacteria with daily use? This is the question we asked Marc-André Selosse, biologist and professor at the National Museum of Natural History in Paris (Ile-de-France). West France answers you.

Where do bacteria come from?

First of all, it is important to remember that most bacteria are not dangerous to health. “There are microbes that are vital to the functioning of our digestive tract and immune system, and they pass through our diet,” says Marc-Andre Selosse.

But how do these bacteria come from? When we drink from a gourd, we unknowingly leave some saliva and bits of skin from our lips that stick to the inside, allowing bacteria to grow. The solution: Use water in a glass. However, the professor wants to reassure: It is more of a risk to taste than to health, the bacteria that develop are not necessarily pathogenic to humans. »

Be careful if, for example, you keep coffee or syrup in your bottle. “Sweetened drinks have more molecules that can help microbes grow, and it can make it a little less healthy,” adds the teacher.

Also read: PODCAST. Are water bottles really more environmentally friendly than plastic bottles?

How to properly wash your water bottle?

Although your water bottle is not a health hazard, it is still important to clean it regularly to remove biofilms, these layers of microorganisms that stick to a surface. To do this, it is recommended to polish your bottle with a cotton swab, with water and a little soap. This brushing should be done every two to four weeks, except with sugary drinks where it is necessary to brush your reusable bottle more often.

However, this delay can be increased if your water is filled with limestone. “If you realize that limescale marks are forming during drying, as these are good hookups for microbes, don’t hesitate to rinse with white vinegar for a long time before brushing”, says the biologist.

It is also not recommended to put your bottle in the dishwasher, as the water will not enter properly. “In other words, rinse your bottle every day and let it dry to prevent the development of germs. And brush it every now and then. »

Choosing the right material

Today, there are many reusable bottles of different brands on the market. They can be plastic, glass, aluminum or stainless steel. Their composition is a significant criterion.

This is why Marc-André Selosse forbids it plastic water bottles because they can release microplastics which themselves release molecules that are harmful to the body. Aluminum is also not recommended since“it releases aluminum lesions that are not good for health”. To avoid these compounds, stainless steel or glass water bottles are recommended instead.

“No matter how much we have to clean our objects lying around, we clean the water bottle from time to time and that’s it”, continues the biologist. And to finish: “The real problem is taste, not health. So by cleaning too often, we are depriving ourselves of the microbes that are useful to us. »