Scientists have been learning more about the specific microbes that compose the human gut microbiome, which is a vast community of microorganisms that calls the human gastrointestinal (GI) tract home. These microbes perform many crucial and beneficial functions, like helping us digest food and absorb nutrients. And they can also have a significant influence on many aspects of human health and well being. The gut microbiome presents an excellent opportunity to improve human health, if we can harness the power of beneficial microbes.
A new research study reported in Science has identified a bacterium called Lactiplantibacillus plantarum that colonizes a specific region of the GI tract. This work may help pave the way towards engineered and healthier microbiomes. It has also highlighted the heterogeneous nature of the microbiome, not only from one person to another, but also within the same individual. Certain microbial communities tend to live in certain zones of the gut, where they have specific functions and specialties.
Delivering beneficial probiotics to the gut is unfortunately not as simple as just ingesting the right microbes. Different characteristics influence the microbes that live in certain places, such as oxygen levels, pH levels, other microbial species that may be present, and physiological conditions like stomach acids or bile salts, for some examples.
“We’re talking about an incredibly complex system of interconnected microbial communities, and each species needs to get to the right place where it can thrive and contribute to host health,” explained corresponding study author Will Ludington of Carnegie Science. “Researchers have been trying to figure out how each bacterial species is directed to the right location and how colonization by harmful or less than ideal species is minimized.”
Beneficial microbes have to get to the right places so they are able to establish a community, noted co-first study author Karina Gutiérrez-García, also of Carnegie Science. “We worked to reveal the mechanisms that enable this to happen.”
Bacteria carry proteins in their cell walls called adhesins, which help bacterial cells stick to various surfaces. The researchers actually observed the Lactiplantibacillus plantarum microbe in fruit fly guts, as one bacterial cell took up residence there.
The L. plantarum taken from wild fruit fly guts could easily attach to host tissue, but L. plantarum bacteria that had been isolated from the guts of other animals could only form transient attachments. Then the researchers identified the genes that allowed fruit fly L. plantarum to colonize certain places.
With that information, other bacterial species could be engineered to specifically build colonies in certain parts of the human gut, noted co-first study author Kevin Aumiller, also of Carnegie Science.
Sources: Carnegie Science, Science
