In 2023, our understanding of microorganisms that live inside thehuman intestine – the so-called gut microbiota – will lead to new ideas for medicine. We now know that gut microbes promote development and support our immune system. They do this by producing large quantities of three types of short-chain fatty acid molecules: acetic acid, propionic acid and butyric (or butanoic) acid. The latter promotes the activity of immune cells known as T lymphocytes. These cells specialize in ‘turning off’ other immune cells, a key function to prevent the immune system from harming the body. The other short-chain fatty acids also affect immune cells and those lining the intestines, processes we don’t currently have a deep understanding of.
The potential of the microbiota
Simplifying, a high level of fatty acid molecules can “calm down” the immune system, creating a “anti-inflammatory” environment not only locally in the intestine but also in the rest of the body. This function plays an important role in many contexts, including the management or prevention of allergies.
Since allergies are caused by unwanted immune reactions against elements that are mistakenly considered harmful, helping to dampen these immune responses or to encourage the body to develop this ability could prove to be useful for the prevention of allergies.
Some evidence suggests that the gut microbiota does just that, helping the immune system develop to avoid allergies. In the intestines of mice fed a high-fiber diet, for example, production of high levels of short-chain fatty acids was found, which are associated with less likely to develop asthma in animals. Even a small-scale study of young children found that allergy sufferers had lower levels of short-chain fatty acids in their stools. These observations however represent at the moment only correlations.
The role of technological development
In 2023, our knowledge of gut microbes will deepen thanks to the technology development. First, the instrumentation in the labs will be used to rapidly sequence large amounts of genetic material. Second, new hardware and software has been developed that will allow us to screen for different microbial gene sequences, look for patterns in the data, and correlate the results with other factors, such as a person’s diet or health status. For big data science, attempts to understand the human microbiome have become a priority.
I probiotics – foods or supplements to which live bacteria are added – represent a possibility on the front of the manipulation of the microbiome. They’ve been shown to ease symptoms of an ongoing illness, such as irritable bowel syndrome, and perhaps even help ward off side effects from taking antibiotics. However, health authorities in Europe and the United States have not yet approved the use of probiotics as a drug.
Today we have to deal with a major scientific problem: the immense variability in the composition of each individual’s intestinal microbes does not allow us to precisely establish what a “healthy” microbe is. One aspect that seems relevant would be the presence of a group of different bacteria (none of which are obviously dangerous). Beyond this, however, we still know little. When we have more certainties, we will be able to design and produce cocktail of healthy microbes to be administered as drugs.
This article originally appeared on Wired UK.