Cholesterol: the best way to reduce it by taking care of your intestinal health
The intestinal microbiota, which groups hundreds of different bacterial communities, evolved in the early days of our species as part of a fundamental symbiosis. they get a place to live and a plentiful food supply and, in return, provide services to their host. They began by helping to digest food; over time, their contribution to the overall health of the body has become much larger and more complex.
Over the past two decades, these microorganisms have been the subject of intensive research throughout the world. They produce molecules called metabolites that, in addition to participating in digestion, also perform metabolic, immune, and other equally basic functions for life.
And one of the most important facts unraveled by science is that this relationship can be perverted: if the microbiota is damaged, by the excess of fats and inflammatory foods that the so-called ‘western diet’ entails or by the abuse of antibiotics, the risk of suffering metabolic, cardiovascular, neurological and oncological diseases increases. Specifically, they are related to hypertension and atherosclerosis, the stiffness of the arteries that increases the risk of heart attacks.
With this fact in mind, researchers are trying to find ways to remodel the microbiome, reversing the damage and restoring good health. A project at Scripps Research (USA) proposes a method by which small molecules can be introduced that would kill harmful bacteria or prevent their growth, without affecting beneficial microorganisms.
“Our approach uses small molecules called cyclic peptides, and is inspired by nature itself,” explains one of the authors, Dr. Luke Leman of Scripps Research Department of Chemistry. “Our cells naturally use a diverse collection of molecules including antimicrobial peptides to regulate microbial populations.
According to his work, published in Nature Biotechnology, these laboratory-created peptides were given to mice that had been fed a high-fat diet, and suffered from high cholesterol levels as well as incipient atherosclerosis. The action of the molecules on their intestinal microbiota radically stopped the accumulation of fat deposits on the walls of their arteries that led to heart disease.
In laboratory cultures, the researchers had identified the two peptides that significantly reduced the growth of undesirable intestinal bacteria, balancing the microbiota at levels more like those of mice that had received a healthy diet. For the animals that had consumed ‘Western’ style fats, they found “dramatic” reductions in cholesterol compared to the untreated mice, 36% at two weeks. After 10 weeks, atherosclerotic plaques in their arteries had been reduced by 40%.
As observed, these cyclic peptides seem to interact with the outer membranes of some of the bacteria, preventing or hindering their growth. In addition, these molecules pass through the gastrointestinal tract without entering the bloodstream; the mice took them with water, and did not suffer any adverse effect. The team’s next challenge is to test them on mice with diabetes, another metabolic disease closely associated with the microbiome and which reaches epidemic levels in industrialized societies.
And vice-versa, too.
Treating cholesterol, on the other hand, leads to an improvement in the intestinal microbiota when one of the most common medications for hypercholesterolemia, statins are used. This is described in a new study led by the University of Gothenburg (Sweden) and published in the journal Nature.
They have done so on the basis of the MetaCardis project (Metagenomics in Cardiometabolic Diseases), which gathers information on more than 2,000 European Union citizens who suffer from metabolic and heart diseases to varying degrees. The aim of this macro-study is to determine the extent to which the microbiome has an impact on heart disease.
The intestinal microbiota, the authors recall, is divided into several major groups called enterotypes. One of these, labelled Bact2, has fewer bacteria in quantity and composition. And it lacks those that have anti-inflammatory effects, such as the Faecalibacterium, which contribute to strengthening the immune system.
The Bact2 enterotype is more common in patients suffering from irritable bowel syndrome (IBS), multiple sclerosis and depression. In the current study, researchers also detected its prevalence in patients with obesity (18%) compared to the general population (4%).
However, patients who were treated with statins saw the amount of Bact2 in their microbe decrease, to the point of normalization. The authors conclude that their observations represent a further step on the road to developing drugs that modulate and optimise the bacterial populations of our intestines.
