Physiological Psychology in Practice: Understanding the Gut–Brain Impact on Mental Health

Physiological Psychology in Practice: Understanding the Gut–Brain Impact on Mental Health

Lisa Marie Bobby, PhD, LMFT, BCC

Dr. Lisa Marie Bobby is a licensed psychologist, licensed marriage and family therapist, board-certified coach, AAMFT clinical supervisor, host of the Love, Happiness, and Success Podcast and founder of Growing Self.

As therapists, we spend our lives helping people understand their thoughts, emotions, and relationships. But there’s another layer influencing how our clients think, feel, and behave—one that lives beneath the surface of the psyche.

Our clients’ physiology, from their gut microbiome to their stress hormones to the media they consume every day, can have just as much impact on their mental health as the stories they tell in therapy. Understanding this psychological and physiological connection isn’t optional anymore—it’s part of being an effective, holistic clinician in today’s world.

In this episode of Love, Happiness, and Success for Therapists, I sat down with Dr. Tatyana El-Kour, a psychologist and nutritionist who specializes in media psychology. She’s doing fascinating work at the intersection of physiological psychology, nutrition, and technology—helping us see how the mind, body, and digital world are in constant conversation.

Together, we unpacked the emerging science around the gut–brain axis and mental health, and how the “Three Ps” framework—plate, physiology, and platform—can help us understand our clients in a deeper, more integrated way.

You can continue developing these integrative skills through our Growth Collective for Therapists, where ongoing education meets real-world application.

Understanding the Gut–Brain Axis

The gut–brain axis is the communication system that connects our digestive tract to our brain. This bidirectional relationship means that gut health can affect mood, cognition, and emotional regulation—and vice versa.

Research on the gut-brain axis and mental health shows that the microbiome’s influence reaches deep into our emotional world. Studies like Gao et al. (2023) and Appleton (2018) reinforce the link between digestion and mood regulation, giving therapists new insight into clients’ experiences of anxiety and depression.

Dr. Tatyana explains that what our clients eat directly shapes their gut microbiome, which influences neurotransmitters like serotonin and dopamine. Highly processed foods and unstable blood sugar can trigger inflammatory responses that lead to irritability, cravings, and even depressive symptoms.

In other words, mental health isn’t just in the mind—it’s also in the microbes.

The Three Ps: Plate, Physiology, and Platform

Dr. Tatyana’s “Three Ps” framework is a simple, science-backed way to explore how different systems interact in our clients’ lives:

• Plate: What we eat shapes how we feel. Food choices affect gut health, which in turn affects brain chemistry. Even small nutritional shifts—like adding more fiber or reducing ultra-processed foods—can stabilize mood and energy. Learn more about nutrition-informed therapy in our article on metabolic psychiatry.
  
• Physiology: The body’s stress response, sleep patterns, and hormonal rhythms all influence the brain–gut impact on mental health. Poor sleep, chronic stress, and low vagal tone can create inflammatory states that mimic psychological distress. For more on supporting clients holistically, see habits of highly effective therapists.
  
• Platform: Our clients’ media environments affect their physiological state too. Algorithm-driven content loops can heighten anxiety, fuel cravings, and reinforce negative thinking. Helping clients audit their “digital diet” can be as important as addressing their food diet.
  
  
  

Circuit Breakers for the Gut–Brain Loop

When clients feel anxious, irritable, or depleted, we can help them look for small “circuit breakers” across these three areas. Scope-appropriate changes—like starting the day with protein and fiber, practicing three minutes of vagal breathing, or limiting doomscrolling before bed—can make a meaningful difference.

Dr. Tatyana calls this approach breaking the loop: interrupting the reinforcing cycle between stress, physiology, and digital consumption that can trap clients in emotional dysregulation.
For more practical insights, explore our pieces on ongoing assessment in therapy and when therapy isn’t working for a client.