Microbiome and nutrition

Microbiome and Nutrition is a complex interplay where gut microorganisms metabolize nutrients, using diet as the primary factor.

For a more in-depth review, see the complete guide to proper nutrition — a key manual from the expert team at Sport Zona.

What it is

The microbiome represents the collection of all microorganisms (bacteria, viruses, fungi, and archaea) that inhabit the human body. The community of microorganisms in the gastrointestinal tract, known as the gut microbiome, is the most numerous and functionally significant. This complex ecosystem is incredibly diverse, with the number of microbial cells in each individual potentially exceeding the number of human cells, and their genetic material being hundreds of times greater than the human genome. The gut microbiome plays a central role in metabolic processes, immune function, and even neurological health.

The relationship between the microbiome and nutrition is bidirectional and dynamic. The diet we consume is the primary factor shaping the composition, diversity, and functions of the gut microbiome. Nutrients – especially fiber, protein, and fats – serve as dietary substrates for various microbial species. In turn, the metabolic activity of these microorganisms influences how the body absorbs nutrients, producing compounds that can be beneficial (like short-chain fatty acids) or harmful. This constant dialogue between diet and microbiome is fundamental to overall health and athletic performance.

How it works

The mechanism of action of the microbiome in the context of nutrition is based on the processing of nutrients that are not fully absorbed by the human body. Bacteria in the gut ferment complex carbohydrates (fiber), synthesize vitamins (such as some B vitamins and vitamin K), metabolize bile acids, and produce short-chain fatty acids (SCFAs) like acetate, propionate, and butyrate. These SCFAs are vital energy sources for the cells of the intestinal lining and have systemic effects on metabolism and immunity. For example, butyrate improves the integrity of the intestinal barrier and has anti-inflammatory properties.

Furthermore, the microbiome influences nutrient absorption, regulates appetite and energy balance through the production of hormones and neurotransmitters, and modulates the immune system. Here are some key mechanisms:

• Fermentation of indigestible carbohydrates.
• Synthesis of vitamins and essential amino acids.
• Production of short-chain fatty acids (SCFAs).
• Influence on intestinal permeability and immune function.

Why it's important for athletes

For athletes, optimal microbiome function is essential for achieving peak performance and rapid recovery. A healthy gut microbiome supports the absorption of macro- and micronutrients, which is critical for energy metabolism and muscle recovery after intense training. For example, adequate dietary fiber intake (recommended 25-38 grams per day for adults) is associated with higher microbiome diversity and increased SCFA production, which can improve cellular energy efficiency and have anti-inflammatory effects, relevant for reducing muscle soreness and fatigue.

Microbiome imbalance (dysbiosis) can lead to gastrointestinal problems during physical activity, which are common in athletes, especially those involved in endurance sports. Moreover, the microbiome influences the immune system – 70-80% of immune cells are located in the gut. A strong immune system is key for athletes to protect themselves from infections and maintain their training regimen. Studies also show links between the gut microbiome and improved cognitive function, which is important for concentration and decision-making during competitions. Optimizing diet, in line with recommendations for athletes (e.g., 1.4-2.0 g/kg body weight of protein for muscle growth), can indirectly support a healthy microbiome.

Related concepts

• Prebiotics — This term describes indigestible food ingredients that nourish beneficial bacteria in the gut microbiome.
• Probiotics — This term refers to live microorganisms that, when consumed in adequate amounts, contribute to improving the gut microbiome and health.
• Postbiotics — This term encompasses metabolic products resulting from the fermentation of prebiotics by probiotics, serving as end products of microbiome activity.
• Anabolism — A healthy microbiome can indirectly influence anabolic processes through optimal nutrient absorption and reduced inflammation, supporting recovery and muscle growth.