In this episode of Need to Know Nuggets, host Ahmet Baysal is joined by returning guest Ilkem Kaya to explore a surprising truth about human identity: biologically speaking, most of you isn’t actually you.

Only a small fraction of the cells in your body are human. The rest belong to trillions of microbes that live in and on you—shaping your digestion, immune system, brain chemistry, and even your mood. Drawing on research from institutions like Harvard, UCLA, MIT, and the NIH, this episode unpacks what the human microbiome really is, how it works, and why it may be one of the most important frontiers in modern medicine.

From the gut–brain axis and psychobiotics to fecal transplants, cancer therapy, and personalized nutrition, this conversation reveals how deeply our health depends on the invisible ecosystem inside us. You’ll also learn what everyday choices—diet, stress, antibiotics, and environment—do to your microbiome, and how to support it for long-term well-being.

If you’ve ever wondered what it truly means to be human, this episode will change how you think about your body, your mind, and the life living within you.