Your Lifestyle May Constitute a Hazard to Your Gut Microbiota
Researchers at University of Trento have found that the Westernization process in some countries is reducing the number of bacteria in the gut that aid digestion. They came to this conclusion after assessing bacteria samples from a mummy, which is over 5,000 years old.
Findings from the study were published recently in the journal Cell Host & Microbes.
The gut microbiome features trillions of microorganisms. Bacteria accounts for a major proportion of these microbes, helping with digestion and absorption of nutrients. They boost immunity and protection against pathogens and viruses.
Depletion of gut bacteria is becoming increasingly common in Western countries. The current study involving Otzi the Iceman highlights lifestyle as possibly being responsible for this.
Otzi was an individual believed to have lived about 5,300 years ago. He was discovered in the ice of the Otztal Alps at the border between Italy and Austria in 1991.
Analysis of bacteria samples from the Iceman confirmed findings that Western diets and lifestyle has reduced gut bacteria. University of Trento researchers had carried out genome analyses of the intestinal microbiome of more than 6,500 people across continents.
Harmful effects of westernization
It could be argued that industrialization has helped to improve the living standards of more people. However, this study suggests that it has had a massive, undesirable effect on gut microbiota.
The industrialization process has led to more people eating unhealthy, junk foods. The diets of many persons are low in fibers and high in fats.
Also, more individuals are maintaining a less-active, sedentary lifestyle – especially in urban areas. There is extensive use of medical products, including antibiotics, and adoption of new hygiene habits as well.
On the surface, the aim with these changes is to make human lives safer or easier. They are, however, capable of disrupting the fine balance of gut microbiota.
In previous studies at the University of Trento, researchers had observed a link between changes in gut bacteria and increasing incidence of certain disorders, including obesity and autoimmune disease, in Western countries.
Scientists found in the current research that there is a fall in certain types of bacteria in Western microbiome.
In this study, researchers at Eurac Research in Bolzano sequenced the DNA of the Iceman. They identified the set of bacteria the mummy had.
Their colleagues at the University of Trento examined the intestinal microbiome of over 6,500 persons from all continents. They compared the bacteria found in Otzi to those present in populations that are not used to Western diets, hygiene habits, and lifestyle. These non-Westernized populations were particularly from Tanzania and Ghana.
The scientists, who focused mainly on the microbe Prevotella copri, were surprised by what they found in their analyses.
When present in the human intestine, P. copri is typically highest in number. Researchers say equivalent of about 3 in every 10 Western individuals have it.
In the current research, it was found that the P. copri species does not have just a single type. It actually has four somewhat similar, but different clades. Non-Westernized people almost always have at least three of these clades. However, the story is different for Westernized individuals.
Nicola Segata, a study coordinator, revealed that people who maintain Western lifestyle and habits typically have only one clade.
“We postulated that the complex process of Westernization had a considerable impact on the gradual disappearance of this bacterium,” he said.
Segata noted that analysis by Frank Maixner of Eurac Research’s Institute for Mummy Studies showed the Iceman had three of four clades. All four clades were also in samples of stool fossils from Mexico that are over a thousand years old.
Adrian Tett of the University of Trento said the team found that the “ancient” samples were “genetically delineated with the human species and before the initial human migrations out of the African continent.”
Researchers do not know the full biomedical effects of microbiome changes for now. The human body has remained virtually unchanged, genetically, for centuries while the microbiome has continued to evolve.