In this episode of The Histamine Well Podcast, Joanne explores biofilms: organised communities of bacteria and fungi surrounded by a protective extracellular matrix. This sticky structure can help microorganisms attach to surfaces, communicate, share resources and become more difficult for antimicrobial treatments and the immune system to reach.

Joanne explains how biofilms may contribute to persistent or recurring microbial overgrowths in the gastrointestinal tract and nasal passages. She discusses their potential role in small intestinal bacterial overgrowth (SIBO), Candida overgrowth, large bowel dysbiosis, chronic rhinosinusitis and MARCoNS.

You’ll learn what biofilms are made from—including polysaccharides, proteins, extracellular DNA, lipids and water—and why there may not be one universal “biofilm breaker.” Joanne also explains how bacterial and fungal organisms can coexist within mixed-species biofilms, creating a complex microbial ecosystem rather than a problem involving only one organism.

The episode also clarifies an important distinction between mould and mycotoxins. Living fungi such as certain Aspergillus species can form biofilms, while mycotoxins are non-living chemical metabolites and cannot create biofilms themselves.