The microplastics you eat fill the intestine with bad bacteria

The contamination of ecosystems by microplastics It is one of the main problems environmental that the current waste management model faces. By its difficult control, due to its scope and the consequences it has for the health of the planet.

Now, a group of Spanish scientists has gone a step further to also define what is the specific damage it causes to human health. Specifically, what effects does it have after settling in the intestines along with the foods and drinks consumed in the usual diet.

Although practically invisible, since they have a size less than 5 millimeters, An incalculable quantity of spheres, fragments or fibers composed of this resistant material are present everywhere. Mainly in the waters (rivers, seas and oceans), but also in the animal species that populate it and the lands that are irrigated with them.

They have even been detected in the penguins of the Antarctica. Which is the worst of omens. But if we try to find them in our immediate environment, we find a sad exponent of contamination by this elusive waste: the sea. Mediterranean coast.

This is one of the areas in the world with the greatest accumulation of plastics. The studies carried out to date estimate that it contains 84.800 microplastics per km2 in its surface waters, about 300 per kilogram of marine sediment, and 59 per kilogram of beach sand.

Up to 5 grams each day

What consequences does this very close reality have? Another one that is much more so. To find them you don't have to look beyond, but yourself. After all, everything that is thrown into Nature and that it is not capable of degrading, returns to our body. Thus, Science has calculated that every week we ingest between 0,1 and 5 grams of microplastics through food and drinks.

Studies on the toxicity of these nanowaste In humans they are not abundant, but it is a booming field of research due to the interest it arouses. The last one that has been published in this sense has a Spanish signature and has managed to determine what effects it has on digestive health when they lodge in the intestine.

The key lies in the microbiota, that set of bacteria found in the intestine and that are directly related, not only to digestive health, but to many other aspects of the body's well-being.

The study carried out by a group of researchers from CSIC, and published in the magazine Scientific Reports, demonstrates that the ingestion of PET microplastics (associated with the food chain) decreases the abundance of bacteria known for their positive effects on health and increases the presence of other microbial groups related to a pathogenic activity.

Bacterial imbalance

"Given the possible chronic exposure to these particles through our diet, the results obtained suggest that their continued intake could alter intestinal balance and, therefore, health," he explains. Victoria moreno, researcher at the Food Sciences Research Institute (CIAL) of the CSIC.

The work of Spanish researchers is very relevant because it is doubly pioneering. It is the first to evaluate the impact of microplastic ingestion on the human digestive tract and intestinal microbiota and, on the other hand, it has never before been directly observed how this material evolves once it is lodged inside us.

Upon reaching the colon, it has been seen that it has a different biological structure from the original. "All these observed mechanisms and factors, which are just beginning to be studied, will contribute to finding out if microplastics They can remain in the human body and potentially accumulate in some organs and tissues."concludes the researcher. Thus, defends Moreno, it is necessary to know the destination of these materials that reach our body and the consequences in the short, medium and long term.

The interest in studying these effects on human health (in addition to that of ecosystems) is currently among the objectives of the European Union, which finances the PlasticFatE program in which this work is part of.

An emerging discipline

The study of the microbiota, its composition, the role it 'good' bacteria play, the consequences of the population becoming unbalanced and the 'bad' bacteria gaining ground, is a relatively new discipline that is becoming increasingly relevant in Medicine. Sari Arponen, doctor in Biomedical Sciences and internist, is one of the most prominent specialists in our country in this field and has studied the consequences of imbalance that ingested microplastic may cause.

The role of the billions of bacteria that populate our intestine is essential for life as they digest food and produce, among other substances, vitamins. They are so relevant that when you lack some of these bacteria or have too many you can get sick.

Diseases related to the microbiota

Many aspects of physical well-being depend on the balance of this population of microscopic 'bugs', each with its role. "Its alteration is omnipresent in a multitude of diseases," says the aforementioned specialist. These can range from dermatitis to cardiovascular failure, including stress or obesity.

The CSIC itself, for example, is one of the Spanish research institutes that is involved in demonstrating the relationship of these intestinal bacteria with depressive processes, since they are related to the manufacture of neurotransmitters as relevant to this disease as dopamine and serotonin.

But apart from these ailments, the list of other illnesses that a poor microbiota can influence is not short: allergies, bad mood, fatigue, headaches, constipation (and the opposite, diarrhea), joint pain, intestinal inflammation, gas and even dermatitis.