Microbiota and Microbiome – The Secret of Our Body: Interview with a Dietitian

Do you know what’s hidden in your gut and how it affects your health?

In recent years, terms like microbiome and gut microbiota have been increasingly discussed. But what do they actually mean, and why should you care about them? To find out, we spoke with Lina Habjanič, an expert in dietetics and public health with experience in health promotion programs and nutritional counseling. Lina graduated in dietetics from the Faculty of Health Sciences. Her thesis focused on the connection between gut microbiota and Alzheimer’s disease.

In this interview, you’ll learn:

What a microbiome is and how it differs from gut microbiota,
How the balance of bacterial communities in the gut affects digestion, the immune system, and even cognitive functions,
Which factors can disrupt bacterial balance and how to support it naturally,
Whether probiotics and dietary supplements are always necessary,
Practical tips for maintaining a healthy gut microbiota through diet and lifestyle.

If you want to better understand how your microbiome and gut microbiota influence your health and wellbeing—and how to naturally support them through food—this interview is a perfect read.

Why has there been growing interest in microbiome and microbiota in recent years?

LINA: First, it may be helpful to define what each term actually includes. When we talk about the microbiome, we refer to the entire human habitat: all microorganisms that live in and on us, their genomes, and the environmental factors that trigger specific processes.

Each person hosts between 10 and 100 trillion microbial cells in and on their body.

The gut microbiota, within this system, represents a vast and highly important part of the microbial community in the human body. Its primary function is, of course, assisting in the digestion of food—especially noticeable when consuming high-fiber foods (like legumes), often followed by a feeling of bloating.

Maintaining a balance between beneficial and less desirable bacterial communities in the gut is essential. These probiotic bacteria help support the immune system, prevent inflammatory processes, and maintain gut health.

Personally, I think much of the interest in gut microbiota composition has been driven by the supplement industry, although over the last 10–15 years we have also seen increased investment in clinical research not just on gut microbiota but other microbiomes as well.

What do the microbiota and microbiome actually affect?

LINA: Research shows that a healthy balance of gut bacteria can help reduce chronic inflammation, which is linked to conditions such as increased body fat (in both obese and lean individuals) and the natural aging process. Both involve long-term low-grade inflammation that can affect cognitive functions. Some theories of Alzheimer’s disease prevention suggest that this inflammation negatively impacts mental functions.

There’s also a connection between gut microbiota and mental health, with links to depression, anxiety, and more.

Should we get tested to see our gut composition?

LINA: No, it’s not necessary. It’s far more important to focus on a balanced diet, as we know that, for example, in Slovenia people consume too little fiber (both soluble and insoluble). This means insufficient vegetables and fruits—whole fruits with skin, not just smoothies—and too few types of grains and legumes, while consuming a lot of processed, fatty, and sugary foods.

For healthy individuals, improving daily nutrition should be the priority. If someone has a medical condition, a multidisciplinary medical team should assess the best approach.

How can we tell if our gut microbiota is imbalanced?

LINA: Excessive bloating without a medical diagnosis is a common sign. For example, a healthy person eating a portion of bean soup should not experience severe bloating if their gut microbiota is balanced and diverse. Poor dietary habits, like high intake of processed, fatty, or sugary foods, can disrupt this balance.

What disrupts gut microbiota balance?

LINA: Poor diet, stress, medications, and other factors.

How can we naturally support a healthy microbiome and optimal digestion?

LINA: Consuming foods naturally rich in probiotics, such as kefir, fermented vegetables (traditionally sauerkraut, pickled turnips), and fermented soy, can help. These foods often contain beneficial bacteria like Lactobacillus acidophilus.

Are supplements necessary?

LINA: For healthy individuals, no. After intense antibiotic therapy, consultation may be useful. Most dietary supplements are regulated minimally—they must not harm health, but benefits are not always guaranteed.

Can diet regulate digestion?

LINA: Mainly through nutrition, physical activity, sleep, and maintaining mental wellbeing.

Does gut function change in winter, requiring extra attention?

LINA: No.