The Big MACs: Microbiota-accessible Carbohydrates

Do you think big MACs are just burgers? In this article, we explain what they are and how they can help keep us healthy.

By big MAC, we’re not talking about the famous hamburger, we mean microbiota-accessible carbohydrates. It has been hypothesized that they are the main nutrient for the microbiota and several researches have associated them with greater microbial variety and better overall health.

What are big MACs?

Big MACs (or microbiota-accessible carbohydrates) are non-digestible polysaccharides that the microbiota feeds on. Most of them meet the definition of soluble fiber.

The term “fiber” refers to that part of the carbon hydrates which, being edible, resists the processes of digestion and absorption. In other words, that part able to reach the large intestine intact, whose microbiota will have the possibility to ferment it.

Unfortunately, not all fibers are fermentable, meaning not all are microbiota-accessible. The aforementioned property, namely that of being fermentable, is attributable only to the soluble fiber, i.e. able to retain water, swell and form viscous gels in the intestine.

Conversely, insoluble fiber cannot be fermented or it can ferment very slowly. However, while it lacks this property, it is still advantageous for other reasons. Its main feature lies in its ability to clean up the intestine, detaching waste from its walls.

Why do big MACs need to be fermentable?

The fermentability of carbohydrates is important as it is the only way that the microbiota has to access them and thus be able to feed. Without this characteristic the virtuous microorganisms could not survive and multiply and the pathogens would become stronger.

Furthermore, this fermentation is a fundamental process for the microbiota to create substances such as short-chain fatty acids, which exert positive effects from a nutritional, trophic, metabolic, immune and anti-inflammatory point of view.

What are the benefits of microbiota-accessible carbohydrates?

The benefits of big MACs are all associated with a healthy microbiota, and among them stand out:

• Intestinal benefits. Healthy microorganisms are able to improve and stabilize the integrity of the intestinal barrier, as well as improve intestinal transit.

• Anti-inflammatory effects. The microbiota is able to produce substances with a high anti-inflammatory power, in particular, among these, butyric acid stands out for its importance. We must remember that chronic cellular inflammation is the first step towards Alzheimer’s, cancers, diabetes mellitus, cardiovascular disease, premature aging and obesity, for example.

• Trophic effects. The fermentation of big MACs is essential for the microbiota to offer us nutrients such as short-chain fatty acids and vitamins such as K, B12, biotin and folic acid.

• Immunomodulating properties. A healthy microbiota is able to stimulate the immune response of the intestine, enhancing the action of some elements of the body’s natural defense, such as: IgA antibodies, macrophages, Natural Killer cells, T cells, interferons and interleukins. In addition, it synthesizes components with antimicrobial action.

• Neuropsychiatric properties. A healthy gut microbiota and a poorly permeable gut are crucial for maintaining good mental health.

What foods are rich in big MAC?

In the context of the big MACs we are faced with: starch-resistant, beta-glucans, fructo-oligosaccharides and inulin, mucilage and pectin. Below, we explain in which foods they are found:

• Resistant starch. It is mainly found in rice, potatoes and oats that have been cooked and then left to cool. In addition, it is particularly present in sweet potatoes, chestnuts, peas, lentils, bananas and buckwheat.

• Betaglucans. They are present in algae, oats and mushrooms and, in addition to the impact they have on the microbiota, they stand out for their incredible ability to regulate the immune system.

• Fructooligosaccharides and inulin. The foods richest in this type of fiber are garlic, onion, asparagus and bananas.

• Mucilage. It is found mainly in agar-agar, plantain and chia seeds, as well as in tomato and flax.

• Pectin. The foods richest in pectin are blueberries, currants, lemons, tangerines, apples, quinces, oranges and grapes.

In conclusion, to keep the microbiota healthy and to enjoy a state of total well-being, not only must we have an adequate quantity and variety of healthy microorganisms, but we must also take care of them. And the big MACs specialize in this.