IN SICKNESS AND HEALTH: OUR MARRIAGE WITH THE HUMAN MICROBIOME
Infections, obesity, depression — all these might be linked to your microbiota, the microorganisms that live inside your body. And it may be up to them to cause you trouble, or save to you.
Our bodies are surrounded by microorganisms that inhabit our tissues and organs: We call them microbiota as a whole. The totality of the genes belonging to the microbiota is called the microbiome, and it includes genes that code for proteins that we humans cannot produce.
Its unique metabolic influences make the microbiome indispensable for us. For instance, the gut microbiota processes certain molecules that we humans cannot. This allows us to have a wider diet and a more efficient digestion. Some bacteria living in our gut can produce E, K and B-group vitamins, which we cannot synthesize ourselves. The gut microbiota also plays role in protecting the intestinal barrier, thus preventing inflammatory diseases. Likewise, microorganisms inhabiting the vagina protect it from pathogens that may cause infectious diseases.
But the human microbiota as a whole is not an army of microorganisms defending their host either: We also harbour some potential pathogens in our microbiota. In a healthy individual, these are kept under control by the mutualistic (beneficial) microorganisms. When the balance is lost however, be it by use of antibiotics or by type of diet, they may become dominant and cause diseases.
According to the scientific studies, many inflammatory bowel diseases such as Crohn’s disease and ulcerative colitis are related to a lack of balance in the microbiome composition. But the gut microbiome’s effects on our health are much broader: Scientists are now exploring the influence of the gut microbiome in obesity, diabetes, autism, and even anxiety and depression. An unhappy gut microbiome may also be the cause of sleep problems, recent research suggests. Additionally, there are studies discussing the gut microbiome’s role in chemotherapy regulation.
Microorganisms in other parts of the body can also influence our medical condition. The dominant type of bacteria in the vagina will determine the efficacy of HIV drugs in women. A species of skin bacteria on the other hand, produces a chemical that could protect individuals from skin cancer.
The benefits, dangers and medical uses of the human microbiome are hard to grasp as of yet. We are by no means done with the ‘microbial expedition’ in the human body. But there is enough evidence to be confident that they will only become more relevant in the field of medicine.
