What each person eats can have significant impact on the presence of microorganisms living within the gastrointestinal tract. The microorganisms hosted in the colon are specifically known as gut microbiota, and they play a deeply important role in health given their involvement in several processes like:  

• Food Digestion 
• Nutrient Absorption
• Strengthening of Immune System
• Protection Against Harmful Microorganisms
• Cognitive Functions, Mood, and Behavior (Gut-Brain Axis)

Microbiota’s Role

The structure gut microbiota has changes from person to person and can be modified during life due to different factors. Nonetheless, its function is always the same: Provide the intestine with enzymes, proteins, and short-chain fatty acids that favor immune response, stimulate vitamin synthesis, and improve neurotransmitter production.

Any alteration to a diet has an impact on the microbiota and, consequently, may be related to the onset of diseases resulting from inflammatory processes.

Microbiota Creates Beneficial Substances

Gut microbiota plays a critical role in the synthesis of bioactive compounds–which are essential to health–such as polyphenols found in foods like fruits, vegetables, legumes, whole grains, dried fruit, tea, coffee, cacao, etc.

The largest part of these polyphenols is attached to dietary fiber. When they arrive at the large intestine, they are exposed to microbial activity. Then, fiber is slowly degraded by the microbiota liberating polyphenols and their metabolites (short-chain fatty acids)–this has a prebiotic effect which benefits the colon as well as other organs and tissues.

Some microorganisms found in the microbiota can produce vitamins–vitamin K and some B complex vitamins, for example. A proper diet provides the nutrients needed for these microorganisms to produce said vitamins and other relevant compounds.

Everything in Balance, Including the Microbiota

The kind and amount of microorganisms making up the gut microbiota may vary due to biological and environmental circumstances. The key is keeping a larger number of beneficial microorganisms compared to those which may cause infections and diseases. A good strategy to achieve this is the intake of foods rich in fiber–present in fruits, vegetables, legumes, and whole grains.

Some complex carbohydrates found in plant-origin foods (known as dietary fiber) may act as prebiotics and bring energy to some beneficial microbial populations fostering their growth and diversity.

Microbiota ferments non-digestible dietary fiber and produces short-chain fatty acids such as acetate, propionate, and butyrate–substances that keep a healthy intestinal environment, reduce bloating, strengthen intestinal barrier, and boost health.

The presence and diversity of beneficial microorganisms can be increased by consuming probiotics–living microorganisms that have a positive impact on health and can be found in dairy products and fermented vegetables such as yogurt, kefir, sour cabbage, sour pickles, to name a few.

The balance and health of our microbiota can also have an effect on metabolism regulation, nutrient absorption, and appetite control. When there is an imbalance or dysbiosis in the microorganisms making up the gut microbiota, inflammatory processes related to chronic diseases arise; that is the case of conditions such as obesity, type 2 diabetes, cardiovascular diseases, and gastrointestinal disorders.

A Healthy Microbiota From the Start

Eating habits are adopted in the early stages of life, so it is highly likely the variety of microorganisms living in a person’s gut microbiota is already stablished by the time they reach adulthood.

What someone eats throughout their life favors a larger growth of certain microorganisms compared to others, modifying the composition and activity of their microbiota. A monotonous diet with scarce variety and a low fiber intake will result in a higher presence of health issues and not only at a gastrointestinal level.

However, eating habits can always be improved or changed by following a proper diet which includes fermented and rich-in-fiber foods–options that contain beneficial bacteria like lactobacillus and bifidobacteria, among others.

Connection Between the Intestines and the Brain

Gut microbiota is part of a complex bidirectional communication axis with the nervous systems (enteric, autonomic, central, and neuroendocrine and immune) called “the gut-brain axis”.

Communication between these two systems could be affected by a person’s lifestyle which, in turn, determines someone’s health and risk of developing disorders related to eating habits and behavior. Factors such as eating habits, age, sex, among others, may influence communication and performance of the intestines, brain, liver, pancreas, and fatty tissue.  

Antibiotics and Lifestyle Impact the Microbiota

Gut microbiota can be negatively impacted by the use of antibiotics, since they modify its diversity and abundance. 

Other factors which might alter the microbiota are:

• An unhealthy diet low in fiber.
• Chronic stress, which can impact the balance among bacteria hosted in the intestine and damage intestinal function.
• Gastrointestinal diseases in which dysbiosis temporarily disturb the composition of microbiota. In some cases, this alteration could persist even to the point of surpassing an infectious process. 

To regain balance of the gut microbiota, the use of supplements with probiotics is advised along with an adequate diet–always with the help of healthcare or nutrition specialists. 

Microbiota, as Personal as Your Diet

A customized nutrition plan is recommended so as to guarantee the specific requirements as well as the health and nutritional needs of a person are being met. This aiming at having a positive impact and getting a balanced and healthy gut microbiota by fostering healthy long-term eating habits according to the needs, likes, and dietary objectives each person has.

When it comes to gut microbiota, a tailored nutrition plan can be used to influence the composition of microorganism species in the intestines encouraging the growth of good bacteria by eating specific foods with bioactive compounds such as antioxidants and prebiotics.

There are still great challenges and limitations in the research field to fully understand the complexity of the interactions between diet, gut microbiota, and overall health.

Fostering and preserving diversity of the microbiota is a recent clinical objective to improve health and prevent diseases; this can be done with a healthy diet (high in fiber, diverse, and varied) paired with a lifestyle including physical activity, rest, healthy eating habits, and a proper management of stress.

References

Alimentos funcionales. (2006, 8 junio). Consejo Europeo de Información sobre la Alimentación (EUFIC). https://www.eufic.org/es/produccion-de-alimentos/articulo/alimentos-funcionales/

Alvarez, J., Real, J. M. F., Guarner, F., Gueimonde, M., Rodríguez, J. M., De Pipaón, M. S., & Sanz, Y. (2021). Microbiota intestinal y salud. Gastroenterología y Hepatología, 44(7), 519-535. https://doi.org/10.1016/j.gastrohep.2021.01.009

Carretero, R., & Morillo Glez. de Villaumbrosía, I. (2022, 16 febrero). Polifenoles y microbiota: una sinergia clave para la salud. Instituto de Microecología. https://microecologia.es/polifenoles-y-microbiota/

Dar forma al microbioma intestinal a través de una nutrición personalizada. (2023, 31 julio). Consejo Europeo de Información sobre la Alimentación (EUFIC). https://www.eufic.org/es/vida-sana/articulo/dar-forma-al-microbioma-intestinal-a-traves-de-una-nutricion-personalizada/

Hablemos sobre la microbiota. (2018, 31 mayo). Hablemos claro. https://hablemosclaro.org/hablemos-sobre-la-microbiota/

Herrera Mejía, J. (2020, 2 diciembre). ¿Por qué es importante la microbiota para mantener tu salud intestinal? Hablemos claro. https://hablemosclaro.org/por-que-es-importante-la-microbiota-para-mantener-tu-salud-intestinal/

Icaza-Chávez, M. (2013). Microbiota intestinal en la salud y la enfermedad. Revista de Gastroenterología de México, 78(4), 240-248. https://doi.org/10.1016/j.rgmx.2013.04.004

Infobae. (2017, 1 febrero). Científicos argentinos vinculan el exceso de grasa y azúcares con la aparición del Alzheimer. Infobae. https://www.infobae.com/salud/ciencia/2017/01/31/cientificos-argentinos-vinculan-el-exceso-de-grasa-y-azucares-con-la-aparicion-del-alzheimer/

Rajilic-Stojanovic, M. (2019, 27 febrero). Conceptos generales sobre la microbiota. Hablemos claro. https://hablemosclaro.org/conceptos-generales-sobre-la-microbiota/

Saulnier, D. M., Ringel, Y., Heyman, M. B., Foster, J. A., Berčík, P., Shulman, R. J., Versalovic, J., Verdú, E. F., Dinan, T. G., Hecht, G., & Guarner, F. (2013a). The intestinal microbiome, probiotics and prebiotics in neurogastroenterology. Gut microbes, 4(1), 17-27. https://doi.org/10.4161/gmic.22973

Saulnier, D. M., Ringel, Y., Heyman, M. B., Foster, J. A., Berčík, P., Shulman, R. J., Versalovic, J., Verdú, E. F., Dinan, T. G., Hecht, G., & Guarner, F. (2013b). The intestinal microbiome, probiotics and prebiotics in neurogastroenterology. Gut microbes, 4(1), 17-27. https://doi.org/10.4161/gmic.22973