Kindle Notes & Highlights
Read between
April 9 - April 14, 2025
There is something almost obnoxious in the way the organ barges its way into our social world, drawing attention to the fleshy fact of the body and its most shame-inducing functions. Even the medical term for gastric noises – borborygmus – has an unappealing bilious ring to it.
Long fascinated by the complex relationship between mind and body, Darwin wagered that his patient’s unsettled mental state might produce gastric distress, trapping her in a dreadful cycle in which negative feelings upset the stomach, whose vocal protests then provoked even greater anxiety.
Scientists have found that the gut communicates with the brain through several key routes in the body: the immune system, the vagus nerve that controls heart rate and digestion, tryptophan metabolism, which is associated with ageing and inflammation, and the enteric nervous system that governs gastrointestinal behaviour.
Where biomedicine views these processes as largely neutral functions of the body, Rumbles argues that they are in fact bound up with understandings of gender, race and class.
Over the last few decades there has been a marked increase in the number of people recorded as suffering from chronic digestive problems.
Asked to explain these figures, experts have pointed to the possible influence of various factors from the overprescription of antibiotics and the use of personal sanitary products that kill all bacteria – good and bad – on the skin, to environmental toxins and the overconsumption of processed foods. The debilitating symptoms of conditions like IBS are, according to some, one result of the developed world’s attachment to extreme hygiene and detachment from the so-called ‘natural’ world.
The gut’s gurglings appear to speak directly to the concerns of the present: to the increasing incidence of chronic illness and worries about processed foods, to anxiety, depression, and the hope that the solution to highly complex problems might lie in simply eating better.
Throughout the Middle Ages, for instance, the Latin venter was used to describe both the gut and the womb, so that the belly was both digestive and procreative; well into the nineteenth century physicians debated whether digestion was a mechanical or chemical process; and as we have already seen, what body parts are thought to constitute ‘the gut’ changes from context to context.
When, for instance, we learn that the concept of childhood has changed dramatically over the last four hundred years, from the pre-industrial world where the transition to adulthood began at age six to the modern day where the right to be considered a child until sixteen is enshrined in law, then something that might have seemed immutable suddenly reveals itself to be contingent.
Much of our current enthusiasm for the organ has been generated by emerging insights from the world of science into the role it might play in shaping our emotional lives.
Interpreting emotions as historical constructs rather than universal constants, scholars working in this field have explored how our embodied experiences are shaped by social pressures, cultural influences, intellectual fashions, religious practices and political whims.
With this in mind it is perhaps not surprising that our relationship to the organ has so often been characterised as a struggle for control.
We have not one, but two brains.
His major discovery was the myenteric plexus or Auerbach’s plexus, a group of cells that direct the movements of the gastrointestinal tract, which include neurons like those found in the brain.
Neurologists have been tracing the path of the vagus nerve that runs from brain to bowel and elsewhere biologists mapping the microbiome have discovered that bacteria living in the intestines help to regulate the production of the biochemicals responsible for stimulating neuronal growth.
This result demonstrated that the bowel possessed, what Bayliss and Starling described as, its own ‘local nervous mechanism’.24 In other words, the gut could act independently of the brain.
Around the same time, over at Trinity College, Cambridge, the physiologist John Newport Langley was using nicotine to map out the autonomic nervous system (ANS), responsible for regulating heart rate, blood pressure, respiration, sexual arousal and digestion, when he discovered something unexpected.25 Surveying the thousands of ganglia that line the stomach, small and large intestines, pancreas and gallbladder, he observed that these seemed to function unassisted.
Writing in the 1900 edition of Schäfer’s Textbook of Physiology, Langley was the first to describe the ‘enteric nervous system’ (ENS).26 This intricate neuronal network was, he argued, not simply a subdivision of the ANS, rather the gastrointestinal tract appeared to be a wholly autonomous kingdom buried deep within the viscera.
The efforts of this group of scientists, working independently of each other throughout the nineteenth century and into the early decades of the twentieth, laid the ground for the modern fascination with what Michael Gershon has described as the ‘second brain’.28 Gershon made a claim for the existence of this so-called second brain based on the self-governance of the gut, and the fact that it is a ‘site of neural integration and processing’ that ‘can elect not to do the bidding of the brain or spinal cord’.
Unlike most other parts of the body, which would cease to function if their links to the central nervous system were severed, the peristaltic reflex – responsible for the wave-like muscle contractions that move food through the digestive tract – can operate independently.
By the seventeenth century, however, this vision of a kind of dispersed intelligence was waning in the face of the new anatomical discoveries being made by scientists like Thomas Willis. Often credited as the founder of modern neuroscience, Willis spent his career examining the brain in ever more minute detail, mapping its vast neural networks and complex muscle structures, and eventually publishing his findings in a 1664 treatise titled Cerebri anatome.
Though Willis drew on the work of physicians like Galen – as Professor of Natural Philosophy at the University of Oxford he would have also been required to instruct his students in classical thought – his account of the brain differed in one key respect. While the Ancient Greeks and even early Christians imagined animals to possess something like a soul, Willis and many of his contemporaries viewed it as the exclusive preserve of human beings.
Philosophers like Willis and Descartes proposed that only human brains contained a soul and all that it connoted – emotion, intelligence, immortality – and by doing so they not only refuted the notion that the belly might think, but also restricted the privilege of thought itself to man.
Milk, according to Kissane, was a source of particular concern: he writes that ‘demonology literature is full of stories of women (and it was mostly women) who could magically “steal” milk, spoil it, make it impossible to churn or cause the milking animal to “dry up”’.65 Part of what the discourse around so-called ‘milk magic’ reveals is anxieties over the power that women were able to exercise over consumption. Having been charged with managing the kitchen, tending the garden and looking after any animals, wives and daughters effectively controlled what was drunk and eaten in the home.
Midwives were charged with possessing devilish knowledge of herbs and natural remedies, with replacing children with otherworldly changelings and, most often, with bringing about miscarriage and stillbirth.
Possessing intimate knowledge of the mysteries of procreation, fertility and birth, their seeming power over matters of life and death, in a patriarchal society not generally amenable to displays of female mastery, exposed them to charges of malfeasance.
In her study of divine and demonic possession in the Middle Ages, historian Nancy Caciola draws attention to the overlaps between womb and gut in this period. The Latin term venter was used to refer to the womb, the stomach or the digestive tract, and Caciola suggests that this overlapping definition indicates a ‘pre-existing cultural assimilation between these organs and their processes’.68
Faced with the devious misrule of the possessed, ungovernable, irretractable, irritable gut, throughout history we have turned to diet to wrest back control of our mental and physical wellbeing.
From the medieval anatomists who used food to restore the balance of the body and the early Islamic philosopher Avicenna who observed that ‘mental excitement or emotion’ hinders digestion, from Jewish holy days like Yom Kippur in which fasting helps the devout to enter the right state of mind to atone, to the fifteenth-century monks who used fermented milk to quell anger and the private physicians who urged their patients to forgo rich meals in favour of even temperament, dietary advice often addressed itself to the emotions as well as to the stomach.
Without becoming tangled in complexities here – perhaps those with better mental health feel able to eat better; how do medications used to treat psychiatric conditions alter appetite?; and where might class, gender or environment factor into this? – it is enough to note that what is consistently pressed upon us by healthcare professionals, diet gurus and cutting-edge science is the need to achieve some kind of healthy balance.
The key to good health was to keep the humours in balance by adjusting environmental factors and modifying diet.
Digestion was, according to this ancient theory, one of the most important processes in the body, as it involved not only the assimilation of food but also the production of spirits and humours.
Despite being couched in the language of contemporary science – disrupted neural transmitters and the parasympathetic nervous system – this research concerns itself with a centuries-old problem: what if the brain and the digestive system were not only in communication with each other, but in direct competition?
For Galen, a pioneer in fields like anatomy, physiology, pharmacology and neurology, civilisation begins with the intestine.
This rather dubious-sounding procedure is based on the science of bacteriotherapy, an emerging understanding of the body that elevates the microbiome, the vast ecosystem of yeasts, fungi, viruses and protozoans that inhabit our gut, as a key player in the health of both body and mind.
That the procedure is hailed, in some quarters, as a cure for everything from ulcerative colitis and Crohn’s disease to multiple sclerosis, diabetes and even depression speaks to the power of the microbiome as a new way of imagining and organising knowledge about the body.
While today scientists tend to view the gut–mind relationship as a fundamentally friendly one, sometimes set off course by miscommunication, doctors working at the beginning of the twentieth century took a much dimmer view of this alliance.
Having studied the diets of communities around the world who were known for their exceptional longevity, Metchnikoff found that most featured the daily consumption of some kind of soured milk preparation and from this correlation concluded that lactic acid must have some part to play in securing a long life.
Only by flooding the system with the good microbes found in yogurt was it possible to slow this decay because, as research undertaken by the great French chemist Louis Pasteur had already demonstrated, lactic acid stalled bacterial growth.
The interior of the bowel is lined by a single layer of cells, known as the mucosal barrier, a border wall erected to prevent potentially harmful germs from passing into the bloodstream.
For Michel Foucault, a French historian of ideas known for his theorisation of the way bodies are shaped by societal forces, time is a ‘technology of power’ that has been wielded to discipline and control populations. Think of the strictly timetabled school day or the tyranny of the office time card, ways of structuring time that – according to Foucault – also force the functions of the body into patterns or rhythms.233
Here mechanisms of ingestion, absorption and expulsion track meaning between individual, collective and political bodies in ways that register the corporeal impact of power and organised defiance.
Though fables like ‘The Belly and Its Members’ have enlisted the stomach in support of top-down paternalism, the cultural history of the belly also reveals more disruptive potentials. The maintenance of the dominant social order has, as explored in Chapter Three, often involved the careful regulation of the body’s baser functions, especially those associated with consumption, digestion and defecation.
Considered from the vantage point of political institutions, diet arguably enacts a kind of coercion, a means of disciplining not only the gut but also the populace.
