Dr. Katrina Coulter on Gut Health, Antibiotics, and How to Feed Your Microbiome Right

Antibiotics save lives—but they can also harm your gut. In this episode, Dr. Kerry Reller sits down with infectious disease expert Dr. Katrina Coulter to explore how antibiotics, food, and lifestyle impact your microbiome, and what you can do to protect it.

Key Takeaways:

• The microbiome is your body’s hidden defense system.
  It’s made up of trillions of bacteria, fungi, and viruses that help regulate immunity, digestion, inflammation, and even mood.

• Antibiotics disrupt your gut—even when necessary.
  While lifesaving, antibiotics can wipe out beneficial bacteria, with effects lasting months to years. The goal: use them wisely and recover strategically.

• Fiber is your gut’s favorite food.
  Most Americans fall far short of the recommended 25–35g of fiber per day. More fiber = stronger, more diverse gut flora.

• Fermented foods help replant the garden.
  Yogurt, sauerkraut, kombucha, kimchi, and other fermented foods provide live bacteria that support gut diversity.

• Ultra-processed foods do major damage.
  Additives, preservatives, and sugar can reduce microbial diversity and contribute to inflammation and chronic disease.

• Movement and sleep matter too.
  Regular physical activity and good sleep improve gut health and help regulate digestion and mood.

• Always ask before accepting antibiotics.
  Don’t be afraid to question prescriptions. If you’re unsure whether an infection is bacterial or viral, discuss it with your doctor.

Conclusion:

Your gut health is the foundation of your overall wellness—from immunity to mental clarity. Antibiotics aren’t the enemy, but they should be used with intention. Dr. Katrina Coulter offers practical, evidence-based advice to help you nourish and protect your microbiome through food, movement, and awareness. Whether you're recovering from an infection or simply want to feel your best, this episode is packed with tools you can use right now.

About Our Guest:

Dr. Katrina Coulter is a board-certified infectious disease physician who has spent over a decade treating patients in hospital and clinic settings. She now focuses on microbiome health, gut function, and lifestyle strategies to prevent infections and support immune balance. Dr. Coulter offers coaching and educational content via her website katrinacoultermd.com and her YouTube channel, where she teaches how to live in harmony with your microbiome.