When the son of the American surgeon Bayard Holmes developed schizophrenia, Holmes devoted his life to researching the disease. In 1916, impressed by the new germ theory that stated many diseases were caused by an overgrowth of bacteria, he tried to cure his son by opening his abdomen and going through the appendix to wash out his intestine. Sadly, his son died after four days from complications of the surgery.

But the concept of intestinal bacteria causing disease did not die with young Holmes. Between 1900 and 1940, the theory of focal sepsis was frequently invoked to justify a variety of surgical procedures. Patients had their paranasal sinuses explored; sphenoidotomy was proposed as a cure for criminal behavior; some people had their teeth extracted and colons removed to treat “focal sepsis”. In The Doctor’s Dilemma, George Bernard Shaw had Cutler Walpole discover a new noxious organ, the nuciform sac, full of decaying matter, undigested food, and poisonous ptomaines, a cause of all diseases so that its removal should be made compulsory. Only five percent of the general population, including Walpole himself, were fortunate to have been born without a nuciform sac and did not need the operation.

Less aggressive ideas and studies couched in learned language have since focused on the so-called human distal gut microbiome and the bidirectional gut-brain axis. The concept of bacterial overgrowth causing disease was resuscitated in 2006, followed in 2007 by a human microbiome project, and in 2014 by a further study of the gut-brain axis relationship. Fecal content from schizophrenic patients, when transplanted into germ-free mice, was shown to alter their behavior. Schizophrenic patients were treated with probiotics to restore the balance of the gut microbiome, had their genetic background studied, and their bowel bacteria manipulated. Specific gut microbial metabolites in schizophrenia patients were shown to be correlated with the severity of their symptoms. Other studies reported an association between specific gut bacteria, inflammation, metabolic dysfunction, and altered neurotransmitter signaling. Gut dysbiosis was invoked as causing occult inflammation and metabolic dysfunction, and pro-inflammatory cytokines were investigated. Altered neurotransmitter signaling was studied, as were the neural, endocrine, and immune pathways of the bidirectional gut-brain axis. Many scientists have argued that much larger and better-funded studies would be required to successfully manipulate the gut microbiome.

What has not been done recently is to revisit the works of Jonathan Swift and the experience of Lemuel Gulliver at the Academy of Lagado in the country of Balnibarbi. Many environmentally friendly studies had been carried out there, such as extracting sunbeams out of cucumbers, turning spiders into silkworms, plowing fields with hogs, transforming ice into gunpowder, and constructing houses by beginning at the roof and working downwards in order to produce cheap energy. The gut-brain axis was to be studied by reducing human excrement to its original food components and separating it into several fractions, removing the bile, the smell, and the saliva. In one project, all persons were to be cured by the same prescription. Physicians were to feel their senators’ pulse after a day’s debate and then have their apothecaries treat them with the same medicines, but when political parties disagreed violently, they would saw off the occipital lobes of the members of one party and exchange them for equal parts of the brains of the other, producing moderation and agreement and putting an end to acrimony and gridlock.

Clearly, there is no end to innovations; new ideas come and go, what is new today will be old tomorrow, and what was old yesterday will be new someday in the future. The world will always have great scientists with great ideas, all devoted to improving the lot of human existence and alleviating suffering. In the process, they will often embark on intellectual and scientific journeys that lead to nowhere.