There are trillions of microbes in the human gastrointestinal tract, each of which expresses its own genome, and carries out a variety of biochemical processes. Gut microbes can generate a variety of molecules that can have a significant impact on human health, such as vitamins, specially modified bile acids, and short-chain fatty acids (SCFAs).
SCFAs have fewer than six carbon atoms, and are found in a few major forms, including acetate, propionate, and butyrate. When we eat fibers that are tough to digest, gut microbes metabolize them instead, and generate SCFAs. Many links have been found between butyrate and human health; it is thought to have roles in the maintainence of epithelial barriers, prevention of gut inflammation in the gut and colorectal cancer, and oxidative stress relief.
Low levels of microbes that generate butyrate have also been associated with health conditions such as inflammatory bowel disease, gut inflammation, and colorectal cancer. Thus, butyrate-producing bacteria are thought to be beneficial to human health. Species of butyrate-producing microbes include Anaerobutyricum, Butyrivibrio, Coprococcus, and Subdoligranulum.
Now, a new study has analyzed data from two large groups of European patients: one cohort from the Netherlands one from Finland, and determined that for every ten percent increase in the level of gut bacteria that generate butyrate, there were 14 and 25 percent reductions in the risk of an individual's hospitalization for any infection, respectively. These findings will be officially presented in late April at the European Congress of Clinical Microbiology and Infectious Diseases (ECCMID 2024).
In this study, the researchers focused on butyrate-producing bacteria because patients with infections often have low levels of these microbes. These bacteria can be identified with genetic sequencing that identifies the microbial species present in patient stool samples, a common technique for assessing the composition of the gut microbiome.
Like many other gut microbes, butyrate-producing bacteria tend to grow in conditions that are free of oxygen, or that only have very low oxygen levels, which can make them much harder to successfully add to the gut. But researchers are looking for ways to boost a healthy microbiome.
Sources: Frontiers in Microbiology, European Society of Clinical Microbiology and Infectious Diseases