3 published verifications about brain brain ×
“The gut-brain axis is a real biological communication system between the gastrointestinal tract and the brain.”
The core claim is well supported by mainstream biomedical literature. The gut-brain axis refers to real, bidirectional communication between the gastrointestinal tract and the brain via neural, hormonal, immune, and microbial pathways. What remains unsettled are some specific mechanisms and clinical implications, not the existence of gut-brain communication itself.
“Pathogenic flora activates pro-inflammatory cytokines, which affect the brain and increase automatic negative reactions.”
Evidence from numerous peer-reviewed reviews and experimental studies supports a pathway in which pathogenic or dysbiotic gut bacteria activate immune cells to release pro-inflammatory cytokines; these cytokines can penetrate the brain, promote neuroinflammation, and are associated with heightened anxiety-, depression-, and threat-related responses. Most data come from animal work and human correlational studies, and effects are clearest in dysbiosis or chronic stress, so universality and direct causation in healthy individuals remain uncertain.
“Humans use only 10 percent of their brain capacity.”
This is one of the most persistent myths about the brain, but it is definitively false. Modern brain imaging (fMRI, PET scans) shows that humans routinely use all parts of their brain — not just 10%. Even during rest, widespread neural networks remain active. Harvard Health calls the claim "100% fiction," and MIT's McGovern Institute confirms we use our entire brain every day. The brain consumes roughly 20% of the body's energy, which would be biologically wasteful if 90% were unused.