Diet and gut microbiota: Nutrition that supports a healthy gut

Heather Campbell
 min read

Diet and gut microbiota go hand in hand, and it is vital that they complement each other for overall well-being.

Diet and gut microbiota: Nutrition that supports a healthy gutThe food we eat is broken down in our mouths, kneaded in the stomach, digested, and absorbed in the first part of the small intestine.

As a whole, everything we eat affects the intestinal microbiota, and an imbalance in our microbiota can lead to infections and diseases. A diet rich in various fibers from fruits, vegetables, and grains helps maintain or restore a dense and diverse microbiota which means better overall health.

Indeed, all the foods we eat will modulate the intestinal microbiota. Moreover, the remains of our meals arrive in the colon. Here, the microbiota completes the digestion of all the residues upon which the microbes feed.

Read on to learn the impact nutrients can have on our microbiota, and how to achieve overall health and well-being.

Diet and gut microbiota: Introduction

The contents of our plates and the undigested residues will favor the growth of germs.

When you change your diet, even for a short period, it can immediately impact the composition of your gut microbiota.

However, the return to the previous state of our body is also very fast when the initial regime is reintroduced. Therefore, this proves that the microbiota has excellent plasticity. In addition, prolonged diet changes will lead to a lasting change in the microbiota.

The intestinal microbiota can be defined as all the micro-organisms that occupy our intestines, skin, or mucous membranes. A microbiota is the set of micro-organisms found in a specific environment.

Micro-organisms consist mainly of yeasts, fungi, bacteria, and viruses.

An imbalance in our microbiota can lead to infections and diseases, hence the importance of a healthy and balanced diet.

Dietary fiber is essential for good health

For the proper functioning of our bodies, it is essential to enrich and diversify our intestinal microbiota. A diet rich in dietary fiber is essential for this.

Plant foods (fruits, vegetables, legumes, whole grains) are rich in dietary fiber. These are composed of polysaccharides and are not absorbed by the small intestine.

Fiber is resistant to digestion thanks to human digestive enzymes. They are broken down in the small intestine and the colon by fermentation and the bacterial action of the intestinal microbiota.

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Depending on the nature of the fibers, they can have different effects on the composition of the microbiota.

In fact, a diet rich in various fibers from fruits, vegetables, and grains helps maintain or restore a dense and diverse microbiota. It will respect the intestinal mucus and strengthen the intestinal barrier.

On the other hand, a fiber deficiency, associated with a depletion of the intestinal microbiota, can encourage the formation of bacteria that increase mucus digestion.

This means that in the absence of fiber, some bacteria will feed by turning to the mucus and thus weakening the intestinal barrier with a risk of bacterial translocation.

The consumption of fiber in our daily diet has an important impact on our overall health. While we all know the favorable effects of fibers on constipation, their influence on life expectancy is less known.

It appears that high fiber consumption as part of a Mediterranean diet is associated with lower mortality rates. Studies show that this diet reduces the frequency of cardiovascular accidents, cancers, and infections.

In fact, eating fiber improves the quality of the intestinal microbiota.

There are various foods rich in fiber, but the richest are:

  • Dried fruits
  • Legumes such as lentils, chickpeas, dried beans, or soybeans
  • Whole grains such as rice, pasta, bread, flour, and oats
  • Vegetables and fruits

It is recommended to consume 0.05 pounds of fiber per day from different sources.

The impact of fats on the intestinal microbiota

In general, the function of the intestinal microbiota is to transform the abundant fats ingested through eating. However, this will also cause the appearance of severe dysbiosis, which is bad for your health.

Dysbiosis of the intestinal flora, induced by high-fat diets, is characterized by a decrease in intestinal microbiota diversity.

As a result, there is an imbalance between the different bacterial populations and the reproduction of bacteria that are toxic to certain intestinal nerve fibers, promoting inflammation.

In addition, diets rich in saturated fatty acids (such as palm oil) are associated with greater weight gain than diets rich in polyunsaturated fatty acids (such as olive oil).

The effects on the gut microbiota of these two types of fat are not qualitatively very different.

However, the impact of saturated fat dysbiosis, such as high blood pressure or body fat overload, is more pronounced than those of unsaturated fat.

The protective role of omega-3 polyunsaturated fatty acids

Studies involving mice have shown the role of polyunsaturated fatty acids. Researchers use genetically modified mice (transgenic mice) to synthesize these essential fatty acids.

On a diet rich in fats and sugars, these mice maintained a more diverse colonic flora than non-genetically modified mice (wild-type mice) that were fed the same foods.

Moreover, the transgenic mice were protected against obesity and diabetes, and their intestinal barrier was of good quality and impermeable.

Transplantation of the intestinal flora from the transgenic to wild-type mice rapidly reversed the abnormalities caused by the high-fat, high-sugar diet.

In conclusion, the results of this study revealed that essential omega-3s, therefore, have a protective effect against unbalanced diets rich in fats. They also showed the protective effect linked to their action on the intestinal flora.

Foods rich in unsaturated fatty acids

These are mainly vegetable oils that contain a high proportion of unsaturated fatty acids (over 85%), such as sunflower, corn, olive, and soybean oils.

Some animal fats also contain a high proportion of monounsaturated fatty acids, such as duck (50%) and goose fat (60%).

Foods rich in saturated fatty acids

These are mainly composed of:

  • Animal fats: meat and dairy products
  • Vegetable oils: palm oil and coconut oil.

Palm oil extracted from the pulp of the oil palm fruit contains 50% saturated fat, while palm kernel oil extracted from the kernels of the oil palm fruit contains 80% saturated fat.

Animal proteins in moderation

The origin of the proteins can be of:

  • Animal origin: red and white meats, eggs, and dairy products
  • Vegetable origin: mainly legumes, nuts, seeds, and whole grains.

It is essential to know that proteins of animal origin contain all the essential amino acids, unlike proteins of plant origin.

This is why a vegetarian diet must combine several sources of vegetable proteins to provide all the essential proteins. For example, you can combine legume seeds, such as lentils, with grains like brown rice.

Proteins will have a different effect on the intestinal microbiota, depending on the quantity, the preparation, and the origin.

The fast-food diet dangerously depletes our microbiota

It’s not news that eating high-fat, high-sugar fast food every day is terrible for your health.

Research has shown that Tanzania is one of the last hunter-gatherer communities globally. This community is free of cardiovascular disease and suffers much less from malnutrition and infectious or metabolic problems.

Indeed, the microbiota of this population is considerably richer in density and diversity than that of an urban population.

Other studies have also compared the diet and microbiota of healthy children aged 1-5 years from a rural area in Burkina Faso to children of the same age group in the United States.

This research showed that the diet of Burkinabe children was high in fiber. In contrast, American children’s diet is rather unbalanced, low in fiber and high in fats, proteins, and refined sugars.

As a result, the microbiota of the Burkinabe children was much denser and more diverse than the microbiota of the American children.

These two studies show that it is important to diversify one’s diet and to avoid as much as possible processed food rich in sugars and fats.

Diet and gut microbiota: Conclusion

Our intestinal microbiota has several significant roles in maintaining good health. Not only does it intervene in the digestion of food, but it also helps our immune system function as it should.

Therefore, it is essential to take care of our intestinal microbiota because if it is unbalanced, it can affect the transit and absorption of our food and thus our immunity.

It is vital to develop good eating habits and adopt a balanced and varied diet.

Focus on the right types of foods like fruits and vegetables and high-fiber foods, and it will keep you healthy!

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About Heather Campbell

As a dietitian, my field of specialization is science-based nutritional advice but more importantly, it is my goal to share capturing and inspiring stories, examples and solutions which can help plus-size individuals overcome their specific difficulties. Read More