Treating Colitis by Targeting the Brain? A Complex Question

The idea of treating inflammatory colitis by directly targeting the brain, specifically the insular cortex, is gaining momentum. however, experts urge caution, highlighting the meaningful differences between human and laboratory animal microbiomes.

“It is challenging to say, because there are great differences between the human gastrointestinal microbiota and laboratory animals,” explains Janet Cunningham, a psychiatrist at the University of Uppsala. “The mice in the labos are all identical, with an identical diet, and have a very, very similar microbiota. In humans, there is a lot of variability of the microbiota between individuals.”

This variability presents a considerable challenge to translating research findings from animal models to human treatments.The controlled habitat of laboratory animal studies doesn’t accurately reflect the diverse range of factors influencing the human gut microbiome, such as genetics, diet, environment, and lifestyle.

Despite these challenges, there is evidence that the brain plays a role in inflammatory colitis. Cunningham notes that “neurological ‘signatures’ in the brain have been observed” in some patients with severe allergies that cause the condition. Moreover,stress can exacerbate colitis symptoms,suggesting a bidirectional relationship between the brain and the gut.”And when these patients are stressed, and therefore their brain is altered, the colitis is more severe.”

The “Transfer of the Blues”: Evidence for the Gut-Brain Axis

Research into the gut-brain axis has gained significant momentum in recent years, fueled by studies like the groundbreaking British study in 2016, humorously titled “The Transfer of the Blues.” This research demonstrated that depression could be transmitted from one mouse to another via fecal transplant, highlighting the profound influence of the gut microbiome on mental health.

Understanding the Gut-Brain Axis: Inflammation, Bacteria, and the Vagus nerve

The gut-brain axis theory centers on the complex interplay between inflammation, bacteria, and the nervous system. The presence of certain bacteria in excess can trigger the immune system, leading to inflammation. This inflammation, in turn, can influence the brain, perhaps manifesting as neurological symptoms.

the vagus nerve also plays a crucial role. As a major component of the autonomic nervous system,it regulates involuntary functions such as breathing,digestion,and heart rate. Researchers believe that the vagus nerve acts as a direct communication pathway between the gut and the brain, transmitting signals that influence both physical and mental well-being.

Future Treatments: Medicines,Diet,and Meditation

the exploration of the gut-brain axis opens new avenues for treating a wide range of conditions. “Will we succeed in developing new drugs against gastrointestinal disorders by targeting the brain, or against psychiatric diseases by targeting the belly? This is very possible,” says Cunningham.

Though, pharmaceutical interventions may not be the only solution. Cunningham suggests that “it is indeed just as likely that we manage to deal with Psychiatric diseases with food, thus by modifying the microbiota, or that one manages to treat gastrointestinal diseases by psychotherapy or meditation.”

This holistic approach acknowledges the interconnectedness of the body and mind. Diet,psychotherapy,and meditation can all influence the gut microbiome and,consequently,brain function and mental health.

The Impact of Gastrointestinal Disorders on psychiatric Patients

Cunningham’s research has shed light on the significant impact of gastrointestinal disorders on psychiatric patients. Her 2020 study in the journal
BMC psychiatry
revealed that gastrointestinal issues in these patients were not solely attributable to medication. Furthermore, the study found a strong correlation between the severity of gastrointestinal symptoms and the degree of depression or anxiety experienced by the patients.

Serotonin, melatonin, and the Gut

Serotonin, frequently enough referred to as the “feel-good” neurotransmitter, is not only produced in the brain but also in the gut. This has significant implications for the treatment of depression, as many antidepressant drugs target serotonin pathways.

“There are other molecules targeting psychiatric drugs which are not only secreted in the brain, but also in the intestines,” Cunningham notes. conversely, drugs like Ozempic, initially developed for obesity, have shown potential benefits in treating dependencies, indicating their impact on the brain.

Melatonin, a hormone primarily known for regulating sleep, is also present in the intestines, suggesting that it might affect the intestinal barrier. “We have made a list of all the melatonin receptors in the body and there are many in the belly,” says Cunningham.

given melatonin’s presence in both the brain and the gut, questions arise about the potential impact of melatonin supplementation on intestinal health. “Studies show that it could be positive,” Cunningham states, suggesting that melatonin may offer benefits beyond promoting sleep.

Anxiety and Depression in IBS Patients