What happens when we overuse antibiotics?

Antibiotics saved our lives over a century ago. Today, they remain essential: every year they prevent millions of deaths worldwide.

The problem? It’s not that they exist, but that they’re often used excessively or indiscriminately, even when they’re not needed. Every unnecessary dose destroys not only harmful bacteria but also good ones: the ones that make up our microbiota, that invisible barrier that protects us from infections, strengthens our immune system, and regulates key processes in our body.

When you kill too much: dysbiosis

Antibiotics don’t distinguish between friends and foes: they wipe out the bad and the good alike. One week of treatment can disrupt microbial communities that take months — or years — to recover… or that never fully do.

This imbalance, known as dysbiosis, is behind recurrent intestinal infections like Clostridioides difficile, chronic inflammation, liver diseases, and other conditions that end up overwhelming hospitals and health systems.

Resistance: the silent pandemic

Every cycle of misuse fuels bacteria that learn to survive. Antimicrobial resistance (AMR) already causes more than 35,000 deaths a year in Europe⁵ alone and could surpass 10 million annual deaths by 2050⁶, according to the WHO.

To put this in perspective: cancer kills around 10 million people each year today. If we don’t act, antibiotic resistance could equal that deadly impact — and indirectly worsen other health problems too.

Beyond infections: a link with cancer

More and more studies are connecting gut dysbiosis with the progression of certain cancers and the body’s response to treatments like immunotherapy. Restoring and protecting the microbiota isn’t just about preventing infections: it could be key to reinforcing our barrier against even more complex diseases.

(We’ll soon share more about how the microbiota influences cancer and what research is underway in Europe to tackle this.)

Our proposal: restore, don’t destroy

At Mikrobiomik, we believe the answer is to rebuild what gets destroyed: restoring a healthy, complete, and functional microbiota to break the cycle of infections and reduce the need for repeated treatments.

Our MBK-01 therapy, based on Full Spectrum® technology, is an oral microbiotherapy manufactured under European GMP standards. In its Phase III clinical trial, MBK-01 proved to be seven times more effective than fidaxomicin — one of the most advanced antibiotics — at preventing C. difficile recurrences, with a 100% safety profile.

More than 100 patients have already received it in Spanish hospitals through our compassionate use program, with real-world results.

Keeping antibiotics working

Antibiotics will remain essential tools in medicine, but they don’t always have to be the only option.

Our Phase III clinical trial showed that MBK-01 is non-inferior to fidaxomicin for treating Clostridioides difficile infections and up to seven times more effective at preventing recurrences⁷

Why is this so important? Because MBK-01 can replace repeated antibiotic use in specific cases like recurrent CDI, preventing the microbiota from being destroyed over and over again. This breaks the vicious cycle: less dysbiosis ➜ fewer infections ➜ less antimicrobial resistance (AMR).

In this way, we not only restore the gut barrier but also protect the effectiveness of antibiotics for when they’re truly needed.

Betting on the microbiota means betting on a more sustainable kind of medicine — one that preserves antibiotic power and protects our gut, immune, and metabolic health.

⁵ EECDC – European Centre for Disease Prevention and Control. Antimicrobial Resistance Surveillance in Europe 2022. World Health Organization. Global Action Plan on Antimicrobial Resistance, WHO, Geneva

⁶ O’Neill J. Tackling Drug-Resistant Infections Globally: Final Report and Recommendations. Review on Antimicrobial Resistance, UK Government, 2016.

⁷ Mikrobiomik. ICD-01 Clinical Study – Phase III, Clostridioides difficile Infection (CDI). EudraCT Number: 2023-509151-13-00. Disponible en: https://www.clinicaltrialsregister.eu