It is a well-known fact that the way our digestive tract works depends greatly on what we eat. In order for the microbes found in the human intestine to thrive and work properly, they need us to adopt a diet which is rich in certain nutrients, most notably fibers. The latest study, however, indicates that generations of low-fiber diet can affect the diversity of these microbes from one generation to the other, influencing negatively the ‘inherited’ microbiome of later generations.
The study called Starving our Microbial Self: The Deleterious Consequences of a Diet Deficient in Microbiota-Accessible Carbohydrates was headed by Erica D. Sonnenburg and Justin L. Sonnenburg who started from the assumption that the modern diet may be responsible for the recent lowered diversity in gut bacteria which has been observed in people from developed countries as opposed to that found in modern hunter-gatherers.
They conducted their study on rodents, raising mice in a germ-free environment and then feeding them human feces in order to give them human gut bacteria. They discovered that the animals fed a low-fiber diet (containing 30 percent less fiber than control diet) exhibited a dramatic decrease in gut microbe diversity. The next step was breeding the mice fed on low-fiber foods and examining their offspring. They observed a trend where the offspring lost entire groups of microbes with each following generation.
By the fourth generation of mice, they observed a new ‘plateau’ microbiota diversity which had only a quarter of the microbe species of the original generation. In addition to this, the researchers attempted to improve the situation by feeding later generations high-fiber foods. They were unsuccessful.
According to the researchers, this poses a very serious question on how the type of food we eat today can affect our offspring in the future. In the developed world, people are usually eating foods that are several times less rich in fibers, which may result in our grandchildren and subsequent generations struggling with even more gastrointestinal problems than we are now. It is also quite possible that the recent increase in number of cases of irritable bowel syndrome and other similar conditions has something to do with this.
The researchers have also pointed out that the consequences of this could turn out to be even more dramatic in the future, touching upon some research that has discovered that fat people are more likely to have lower diversity in gut microbes than their lean peers.