Do bacteria also live in our urine? Yin and Yang of the urinary tract

The human body is the perfect place for bacteria to live. We can say that in our body there are at least as many of them as human cells: about 39 trillion. Seems like a lot, right? These high numbers make us think that the micro-organisms that inhabit us play an important role.

The set of bacteria – the microbiota – that lives in certain parts of the body, such as the intestines, has been extensively studied. Its composition and role in health and disease are well known.

However, what can we say about the urine microbiota, which is still completely unknown? Researchers from the University of Granada, Almeria and the Virgen de las Nieves University Hospital wanted to answer the question by analyzing the information available in this new research area.

The Urinary Microbiome: The Great Unknown

For a long time it was believed that the urine of healthy people is sterile and that all the bacteria it contains can cause urinary tract infections. The idea was supported by the use of bacterial culture methods, which allow only a very limited number of microorganisms to be grown.

But the era of genomics, the Human Microbiome Project, and the development of new mass sequencing tools have made it possible to identify the microbial community in the urinary tract of healthy people as well.

Thus, we know that this ecosystem differs by sex: most genera of bacteria in women lactobacilliwhereas the much less studied male urine microbiota is dominated by childbirth corynebacteria And streptococcus.

Other factors, such as age and hormone levels, also cause changes. As we get older there is a decline lactobacilli And Gardnerella and genres like mobilunkus, oligella And Porphyromonas.

In addition, many types of urinary tract also live in the vagina and intestines. Therefore, changes in these two bacterial communities lead to changes in the urinary microbiota.

Its role in urinary tract diseases

Traditionally, urinary tract infections have been associated with isolated pathogenic bacteria such as coli. However, new research has revealed multiple origins; that is, it is due to the deterioration of the microbiota rather than the invasion of a specific pathogen. In general, the reduction lactobacilli – the predominant sex in healthy people – seems to increase the incidence of urinary tract infections.

Certain changes in the urinary microbiota are also associated with other pathologies such as urothelial carcinoma and prostate cancer. An increase in the number of bacteria that secrete substances involved in inflammatory processes can contribute to the development of these diseases.

In addition, mechanical problems such as urinary incontinence can be caused by changes in the bacterial community in question. Decreased bacterial counts in healthy individuals increase the population of pathogens, which release molecules that promote bladder muscle contraction, among other mechanisms.

These are just some of the diseases associated with the state of the urine microbiota. Thus, the data obtained underline the importance of taking them into account in the prevention, diagnosis and treatment of these diseases.

New research area for new treatments

Today, most urinary tract infections are treated with broad-spectrum antibiotics. However, the growing emergence of bacteria resistant to these drugs points to the importance of better identification of the responsible pathogens. We are talking about improving the action of drugs and preventing the destruction of microbial communities present in the human body.

Another solution is to develop new treatments beyond antibiotics. Among them are probiotics, which have attracted increased interest in recent years. Intravaginal or oral administration of some strains lactobacilliHow L. crunchy And L. acidophilusallowed colonization of the urinary microbiota in the long term and reduced the incidence of infections.

Other therapies based on current knowledge of the urinary microbiota include transplantation of the fecal microbiota and the use of bacteriophages, viruses that infect and destroy bacteria. In both cases, it was possible to reduce the prevalence of urinary tract infections and the number of pathogens, including those with widespread resistance to antibiotics.

Diet to maintain a healthy microbiota

But before we reach this point, we can also contribute to the health and stability of the microscopic population that colonizes the urinary tract through our habits. And, as with other microbiota, diet plays an important role here. Thus, moderate consumption of foods containing blueberries or blueberry juice and fermented foods rich in probiotics can help maintain bacterial balance and suppress pathogenic bacteria.

Although it is still far from fully understood, the urinary microbiome may be the key that will allow us to develop new preventive, diagnostic and therapeutic strategies for diseases that affect the urinary system.

Virginia Perez Carrasco, FPU Research Fellow, University of Granada; José Antonio Garcia Salcedo, Principal Investigator in Biomedicine, University of Almeria; Jose Gutierrez-Fernandez, Professor of Medical Microbiology, University, University of Granadaand Miguel Soriano Rodriguez, university professor. Department of Agronomy, University of Almeria

This article was originally published on The Conversation. Read the original.