Tag: IBD

Traditional Japanese Herbal Medicine Found to Alleviate Colitis

Gut microbiome. Credit: Darryl Leja, NIH

A Japanese study published in Frontiers in Immunology shows that a traditional herbal mix called daikenchuto reduced the severity of colitis in lab mice by preventing the loss of important gut bacteria and by raisin levels of anti-inflammatory immune cells in the colon.

Colitis is a chronic inflammation of the colon, characterised by an imbalance in gut bacteria and an abnormal immune response. Its prevalence has doubled over the last 20 years and although there are many treatments, they are only partially effective. This has led some researchers to take a closer look at traditional Asian herbal medicines.

Daikenchuto (DKT) is a formula containing specific amounts of ginger, pepper, ginseng, and maltose, and is one of 148 herbal medicines called Kampo, which have been developed in Japan and are often prescribed by doctors to treat a variety of illnesses. Numerous studies conducted in Japan and the United States have provided clinical evidence of DKT’s effect on colonic transit and postoperative ileus.

DKT was shown by previous research to have possible use in colitis treatment, but molecular level evidence has been lacking. Researchers at the RIKEN Center for Integrative Medical Sciences (IMS) in Japan conducted a detailed examination of its effects on a mouse model of colitis.

Colitis was induced in mice using dextran sodium sulfate, which is toxic to the cells that line the colon. When these mice were given DKT, their body weights remained normal, and they had lower clinical scores for colitis. Additional analysis revealed much less damage to the cells lining the colon. Having thus shown that DKT does indeed help protect against colitis, the researchers proceeded to analyze the gut microbiome of the mice and expression levels of anti-inflammatory immune cells.

Colitis is associated with an imbalance in gut microbiota, and analysis showed that a family of lactic acid bacteria were depleted in the colitic mice of this study. Also depleted was one of their metabolites, a short-chain fatty acid called propionate. Treating the model mice with DKT restored much of these missing bacteria – particularly Lactobacillus – and levels of propionate were normal.

Colitis is also associated with an abnormal immune response that causes the characteristic intestinal inflammation. When the team looked at innate intestinal immune cells, they found that levels ILC3 cells were lower in the untreated colitic mice than in the DKT-treated colonic mice, and that mice engineered to lack ILC3 suffered more and could not benefit from DKT treatment. This means that ILC3s are critical for protecting against colitis and that DKT works by interacting with them. Lastly, qPCR analysis indicated that these important immune cells had receptors for propionate, called GPR43, on their surface.

Daikenchuto is commonly prescribed to prevent and treat gastrointestinal diseases, as well as for reducing intestinal obstruction after colorectal cancer surgery,” said Naoko Satoh-Takayama. “Here we have shown that it can also alleviate intestinal diseases like colitis by rebalancing Lactobacillus levels in the gut microbiome. This likely helps reduce inflammatory immune responses by promoting the activity of type 3 innate lymphoid cells.”

Source: RIKEN

Caesarean Delivery may Increase Risk of Developing Crohn’s Disease

Photo by Christian Bowen on Unsplash

A population-based study analysing over one million individuals suggests that babies born via caesarean section delivery may face a higher risk of developing Crohn’s disease later in life. The findings, published in Acta Obstetricia et Gynecologica Scandinavica, add to a growing body of evidence on long-term impacts of caesarean section delivery. 

More and more people are being delivered by caesarean section, and there is interest in understanding possible long-term health consequences of this mode of delivery. One possible route is through a lack of the early exposure of the infant to colonising bacteria via a vaginal delivery. Previous studies suggest that infants delivered by CS are at increased risks of disorders involving the immune system, such as asthma and allergies, type 1 diabetes, celiac disease, obesity, immune deficiencies, and leukaemia and other malignancies affecting young people.

In this study, all full-term individuals registered in the Medical Birth Register in Sweden between 1990 and 2000 were followed until 2017. Among 1 102 468 individuals, of whom 11.6% were delivered by caesarean section and 88.4% were vaginally delivered, caesarean section was associated with a 14% higher risk of developing Crohn’s disease after adjusting for confounding factors. No associations between delivery mode and appendicitis, ulcerative colitis, cholecystitis, or diverticulosis were found.

“Our study is the largest in this field, showing new interesting associations between caesarean section and increased risk later in life for Crohn’s disease. We hypothesise that the underlying mechanism could be the gut microbiome, but further studies will have to confirm this,” said senior author Anna Löf Granström, of the Karolinska Institute.

Source: Wiley

IBD and Depression is a Two-way Street

Photo by Andrea Piacquadio on Pexels

While irritable bowel disease (IBD) and depression are known to occur together, scientists report a clinical overlap of these conditions in the Journal of Gastroenterology and Hepatology, implying the existence of a two-way relationship. Patients diagnosed with IBD were nine times as likely to develop depression than the general population. Their siblings who did not suffer from IBD were almost two times as likely to develop depression.

Conversely, patients with depression were two times as likely to develop IBD, and their siblings without depression were more than one and a half times as likely to develop IBD.

“This research reveals a clinical overlap between both conditions, and is the first study to investigate the two-way association between IBD and depression in siblings,” said Bing Zhang, MD, a gastroenterologist with Keck Medicine and co-lead author of the study.

The researchers drew on the data of more than 20 million people from Taiwan’s National Health Insurance Research Database. For 11 years, they tracked patients with either IBD or depression and their siblings without either condition, comparing onset of depression or IBD with a control group of people without either condition, but with similar age, sex and socioeconomic status.

Zhang hypothesises that many factors may contribute to the bidirectional nature of the disorders, including environmental stressors, the gut microbiome and genetics.

“The finding that people with IBD are more prone to depression makes sense because IBD causes constant gastrointestinal symptoms that can be very disruptive to a patient’s life,” he said. “And the elevated depression risk among siblings of IBD patients may reflect caregiver fatigue if the siblings have a role in caring for the patient.”

What surprised researchers was that patients with depression were prone to IBD. Zhang speculates that this discovery may have to do with what is known as the gut-brain axis, a scientifically established connection between the gastrointestinal system and the central nervous system, which consists of the spinal cord and the brain.

For example, he said, inflammation of the brain, which plays a role in depression, may be linked to the inflammation of the gastrointestinal tract, a hallmark of IBD.

The researchers are not sure why siblings of patients with depression are more likely to be diagnosed with IBD. Zhang surmises that there may be a shared genetic susceptibility for either disease that presents differently in family members.

Zhang hopes that the study findings will encourage health care professionals to take both family history and the relationship between gastrointestinal and mood disorders into consideration when evaluating or treating patients with either IBD or depression.

Through more research and better understanding of the gut-brain axis, he envisions leveraging the newfound connection between the conditions to improve the prevention, diagnosis and treatment of IBD and mental disorders.

Source: University of Southern California – Health Sciences

Gut Inflammation and Mental Health Link

Image by Falkurian Design on Unsplash

Using mouse models, scientists have discovered a link between gut inflammation and mental comorbidities. In response to gut inflammation like that caused by inflammatory bowel disease (IBD), they observed that the vascular barrier in the brain choroid plexus closes, clamping down access to the brain. The findings were published in Science.

Though this gut-brain vascular axis deregulation is likely a protective mechanism for the brain against inflammation, the findings suggest it may also result in the various cognitive and psychiatric symptoms that are occasionally associated with IBD.

Usually associated with intestinal inflammation, IBD can also cause a wide variety of symptoms in other organs. There is a robust link between anxiety and IBD; up to 40% of patients with IBD also present with psychiatric symptoms such as anxiety or depression. While the gut-brain axis is thought to be involved in driving these symptoms, no other related mechanisms are currently known.

Using a mouse model of intestinal inflammation, Sara Carloni and colleagues identified a potential pathogenic link between IBD and its associated mental comorbidities. According to the findings, the gut vascular barrier becomes more permeable due to the inflammatory process, which allows inflammation to spread beyond the intestines.

In response to this spread, the vascular barrier in the choroid plexus of the brain shuts down, which helps to protect the brain from inflammation. However, in doing so, the process also potentially impairs communications between organs and may hinder brain function.

In a mouse model of genetically driven closure of choroid plexus endothelial cells, Carloni and colleagues observed a deficit in short-term memory and anxiety-like behaviour. Thus, the mental deficits observed alongside IBD may result from deregulation of the gut-brain vascular axis, the authors said. This finding could be used for the development of therapeutic targets in treating some behavioural disorders.

Source: News-Medical.Net

Jump-starting Macrophages to Help with IBD Tissue Repair

A novel method which prompts immune cells to aid the repair of damaged intestinal tissues has been developed by researchers at KU Leuven and Seoul National University.

This new approach promises new treatments for inflammatory bowel disease (IBD), including ulcerative colitis and Crohn’s disease. Normally, the immune system defends against pathogens that enter the body. In conditions like IBD, the immune system instead attacks tissues that line the gut, creating ulcers. Some 3.9 million women and 3.0 million women suffer from IBD worldwide.

The origin of IBD is not known, so treatments typically dampen immune response, but at the same time this also obstructs the normal repair of damaged intestinal tissue by other parts of the immune system. Macrophages, for example, consume foreign bodies, clean out debris and direct other steps in inflammatory or repair response through released substances. 

Lead author Professor Gianluca Matteoli, an immunologist at the Translational Research Center for Gastrointestinal Disorders (TARGID) KU Leuven, explained the motivation behind the research. “Our idea is that the migration of macrophages to the damaged tissue in IBD is essential to stimulate its recovery.”

Examining macrophages in the intestines of a handful of people with IBD, the researchers found that a sub-group of cells responding to prostaglandin E2 (PGE2). Prostaglandins are messenger molecules involved in homeostatic functions and mediate pathogenic mechanisms, such as the inflammatory response, and are also involved in tissue repair.

“If the patients had acute disease, they had a lower amount of these beneficial cells, and if they went into remission, then amounts of macrophages went up. This suggests that they are part of the reparative process,” said Professor Gianluca Matteoli, immunologist, Translational Research Center for Gastrointestinal Disorders (TARGID), KU Leuven

In mice with ulcerative colitis (one the main forms of IBD), there were fewer macrophages responsive to prostaglandin than in healthy mice. However, when PGE2 levels were increased, those macrophages still responsive released a substance that stimulated tissue repair. When the researchers knocked out the PGE2 receptors on the macrophages, the level of tissue repair dropped.

Getting the macrophages to absorb a liposome containing a substance to trigger the repair stimulation agent restored the macrophages’ repairing effect. Liposomes are bubbles made of two layers of lipids enclosing an aqueous cavity, often used to hold substances for drug delivery.

“We already knew that prostaglandins were important for inducing proliferation of tissue cells, but this study shows that they are also important for controlling the inflammatory effect, so moving the body from the acute stage where inflammation dominates to the reparative stage,” Professor Matteoli said.

New treatments could involve liposomes being used to prompt macrophages into boosting tissue repair, a well-established experimental tool but which would require considerable work for this new application.

“This is one of the first times it has been used to produce a beneficial, therapeutic effect,” said Professor Seok. 

The next step is to closely examine human macrophages at different stages of IBD. “We want to identify other factors that trip the switch that turns macrophages from inflammatory cells to non-inflammatory cells,” said Professor Matteoli. “Then, using the liposome technology that Professor Seok has developed, these could be used to target the macrophages and so produce very precise drugs.”

Source: News-Medical.Net