Diet and health : the role of the intestinal microbiota in metabolic diseases
Balance in the microbiotas – the collections of microorganisms (bacteria, yeasts, fungi, viruses) that live in the human body – is essential for good health. The Biocodex Microbiota Institute, an expert in research and distribution of advances in the field, regularly releases themed dossiers on its website www.biocodexmicrobiotainstitute.com.
The themed dossier « Diet and health : the role of the intestinal microbiota in metabolic diseases » published in July reports on the latest advances on the role of microbiotas on metabolism (the collection of chemical and biological reactions that happen within the body). Recent publications underline the connection between the intestinal microbiota and diet and certain diseases like diabetes (types 1 and 2); they also hint at potential therapeutic benefits based on the use of probiotics and probiotics.
DIETS ARE GOOD, REGARDLESS OF OUR MICROBIOTA
FALSE. The positive effects of a balanced diet don’t affect everyone equally. The problem lies with our intestinal microbiotas: no two are completely alike, even in twins. Depending on what bacteria make up the majority, the effects of regulating diet can vary depending on the intestinal flora. Our dietary habits also play a role. Some microbiotas have been shown to be more resistant to changes in food. Eventually we will be able to account for all of these parameters (dietary habits, personal composition, and intestinal flora resilience) and be able to tailor any diet to any individual.
ALL FATS ARE BAD FOR YOUR HEALTH
FALSE. All fats are not created equal. There are two types of fatty acids: saturated and unsaturated. Saturated fatty acids (butter, palm oil, fatty meats, etc.) are indeed bad for your health, if they are consumed in excess. They are associated with a drop in bacterial diversity, weight gain, and cardiovascular diseases. Unsaturated fatty acids, however, are generally beneficial. For example, the omega-9s present in olive oil restore bacterial diversity. Omega-3s and omega-6s in fatty fish and canola oil are essential for the body, but should be consumed in moderation.
EATING FIBER PREVENTS BACTERIAL INFECTIONS
TRUE. Fiber – sugars present in cereals, tubers, nuts, grains, fruits, and vegetables – are digested by bacteria in the digestive microbiota. Without fiber to ferment to extract energy, the bacteria instead eat away at the protective mucus that covers our intestinal cells, exposing them to bacterial invasion. Furthermore, fiber helps control blood sugar levels. The moral of the story: to keep your microbiota healthy, don’t eat too much fat – but choose the right ones – and don’t forget your fiber!
INSULIN RESISTANCE IS THE ONLY THING THAT CAUSES TYPE 2 DIABETES
FALSE. Diabetes is indeed related to sugar – but not sugar alone. Bacteria also play a role. People with type 2 diabetes have a microbiota less rich in bacteria that can digest slow sugars than healthy people do. Moreover, other bacteria cause chronic liver inflammation through accumulated fats (“NASH,” Nonalcoholic Steatohepatitis).
FECAL TRANSPLANT IS A POTENTIAL THERAPY FOR TYPE 2 DIABETES
TRUE. The first conclusive tests have shown that transplanting fecal microbiota from a healthy donor to a sick recipient improves the latter’s insulin sensitivity and increases the quantity of butyrate-producing bacteria, which is beneficial for metabolism. Although the technique is very old (it was already being used 1700 years ago in China), the road has been long to get around the psychological barriers.
COMBINING PREBIOTICS AND PROBIOTICS HAS NO EFFECT ON “FATTY LIVER” DISEASE
FALSE. In some patients, adding fructooligosaccharides (prebiotics) to probiotics reduces inflammation and fatty particles in the liver, lowers weight and body fat, and improves insulin sensitivity. These positive results were confirmed by a drop in fat in the liver in Hong Kong patients treated with a combination of lactobacilli and bifidobacteria for six months.
EXPERT’S POINT OF VIEW
Professor Rémy Burcelin directs a laboratory specializing in the study of the mechanisms behind the communication between the brain, gut, and the rest of the body at the Institute for Metabolic and Cardiovascular Diseases (Inserm Unit/University of Toulouse III Paul-Sabatier). According to the professor, the intestinal microbiota is a major discovery of the 21st century, and probiotics – which act on our flora – are a particular cause for hope. “It’s still too early to consider probiotics as an independent therapy [but] interesting strategies [are currently being developed] to improve tolerance and the effectiveness of treatments”, he said.