Improving the gut microbiome is the key to maintaining one's overall health and well-being. However, the composition of the microbiome depends mainly on what a person eats, a new study has found.

The gut microbiota consists of a community of trillions of microorganisms that lives in the human gut. Earlier studies have shown that the abundance of certain microorganisms is associated with certain conditions such as inflammatory bowel diseases, obesity and diabetes and even psychological disorders.

The microbiota is seeded during birth, and the composition is later determined by several other internal and external factors including diet, genetics, medication, exercise and defense molecules.

The defensins are the largest group of antimicrobial peptides that function as the first line of defense against infections. They are produced by all body surfaces, including the skin, the lungs and the gastrointestinal tract. Apart from fighting infections, defensins are also essential in shaping the microbiota composition in the small intestine.

However, the role of defensins on microbiota in comparison to the diet was not researched so far, prompting the research team from Umeå University, Sweden to take up the study.

The study, which was published in the journal Microbiology Spectrum, evaluated the microbiota composition of normal healthy mice to mice that could not produce functional defensins in the gut. Both the groups were then fed either a healthy diet or a low-fiber Western-style diet.

The research team determined that although several factors shape the adult microbiota, the diet has more impact than defensins, the intestinal defense molecules produced by the body.

"When we analyzed the microbiota composition inside the gut and at the gut wall of two different regions in the small intestine, we were surprised — and slightly disappointed — that defensins had only a very minor effect on shaping the overall microbiota composition," study co-author Björn Schröder, the principal investigator in Laboratory for Molecular Infection Medicine Sweden in Umeå University, said in a news release.

The research team said the role of defensins remains significant for its protective role against metabolic complications from the "Western diet."

"To our surprise, we also found that the combination of eating a Western-style diet and lacking functional defensins led to increased fasting blood glucose values, which indicated that defensins may help to protect against metabolic disorders when eating an unhealthy diet," Schröder added.

"While the effect of defensins in shaping the adult microbiota composition is rather minor when compared to diet, defensins still have a very important role in protecting us against microbial infections; and our research highlights their protective role against the metabolic complications that can arise after the intake of a high-fat and high-sugar Western-style diet," study co-author Fabiola Puértolas Balint, a doctoral student who works in Schröder's research group, explained in the news release.

healthy diet
Although several factors shape the adult microbiota, the diet has more impact. pixabay

Need To Improve Your Gut Microbiota? What You Eat Influences More Than Intestinal Defense Molecules