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Showing 270 results for "gut"

July 12, 2018 News by Ana Pena PhD

Missouri Trial to Examine if Fasting Alters Gut Microbiome and Immune System of RRMS Patients in Helpful Ways

A 12-week clinical study is recruiting people with relapsing-remitting multiple sclerosis (RRMS) to evaluate if intermittent fasting can improve their immune response, metabolism, and gut microbiome — the bacterial community that inhabits the gastrointestinal tract. Its findings may also hint at whether such a diet might ease MS symptoms or alter discourse course and, if used in conjunction with other treatments, boost their efficacy. Conducted by researchers at Washington University in St. Louis, Missouri, the trial is supported by their findings in an earlier mouse study.  Results showed that fasting worked to ease MS-like symptoms in a mouse model of the disease, the research team reported. Specifically, EAE mice fed every other day were less prone to symptoms that included difficulty in walking, limb weakness, and paralysis than mice allowed to eat freely.  A fasting diet also enriched bacterial diversity in the mice guts, and shifted immune cell populations there toward a lower inflammatory response. When gut bacteria were transferred from fasting mice to nonfasting mice, the later also were seen to be better protected against MS-like movement problems, supporting the influence of the gut microbiome on MS symptoms. Several diets have been proposed to help ease disease progression in MS patients, but solid scientific evidence is lacking to support any one diet over another, leaving the issue much to an individual’s choice. “The fact is that diet may indeed help with MS symptoms, but the studies haven’t been done,” Laura Piccio, MD, an associate professor of neurology at WUSTL and the study's lead author, said in a WUSTL news release written by Tamara Bhandari. Taking place at the Missouri university, the trial is expected to enroll 60 RRMS patients. Half will be randomly assigned to eat a standard Western-style diet seven days a week, and the other half to Western-style diet five days a week, with two days set aside for fasting (consuming a maximum of 500 calories each day). On fasting days, patients can only drink water or calorie-free beverages and eat fresh, steamed or roasted non-starchy vegetables All will undergo a neurological assessment, and provide blood and stool samples in the study's beginning, at mid-point or week six, and at its end (week 12). Those using MS medications will continue on their prescribed treatment regimens throughout the study. More information, including enrollment information, is available here. Piccio noted that a pilot study on diet in 16 MS patients showed that limiting calories every other day for two weeks led to immune and gut microbiome changes that resembled those observed in the mice study she helped to lead. Its researchers concluded that intermittent fasting had the potential to positively manipulate the immune response in MS patients by changing their gut microbiome. The gut microbiome plays a central role in digestion, and in producing vitamins and amino acids (the building blocks of proteins). But a growing body of evidence indicates that it also determines how our immune systems develops and matures. Indeed, an increasing number of studies link irregularities in the gut microbiome with MS. “There are several possible ways fasting can affect inflammation and the immune response,” Piccio said. “One is by changing hormone levels. We found that levels of the anti-inflammatory hormone corticosterone were nearly twice as high in the fasting mice. But it also could act through the gut microbiome.” The new trial will allow the team to analyze more deeply the effects of a fasting diet — and perhaps gather evidence for a larger study investigating if skipping meals can ease MS symptoms. Its goal is to find out "whether people on limited fasts undergo changes to their metabolism, immune response and microbiome similar to what we see in the mouse,” Piccio said. “I don’t think any physician working with this disease thinks you can cure MS with diet alone,” she added, “but we may be able to use it as an add-on to current treatments to help people feel better.”

October 16, 2017 News by Ana Belo van Wijk, PhD

One More Small Piece of the Puzzle on the Role of Gut Micro-organisms in MS

Researchers found a significant increase in some types of gut bacteria and lower levels of an anti-inflammatory factor in untreated multiple sclerosis twins. The study offered working evidence that components of gut microbiota contribute to autoimmune diseases like MS. Researchers published their article in the journal Proceedings of the National Academy of Sciences.It was titled "Gut microbiota from multiple sclerosis patients enables spontaneous autoimmune encephalomyelitis in mice." Our gut contains millions of good bacteria, fungi, bacteria-like archaea, and viruses that we can't live without. Although there are 300 to 1,000 species of bacteria in our gut, most of our intestines is populated with 30 or 40 species. Recent increases in knowledge and technical advancements have made it possible for scientists to measure the equilibrium between different species in the gut, and analyze their influence on our health. One discovery was a link between the balance of bacteria in the intestines and autoimmune diseases like MS. A team of researchers decided to see if differences in gut microbiota play a role in MS progression and perhaps its onset. They analyzed the feces of 34 identical twins, one of each who had MS and one of each who didn't. They used twins to try to reduce genetic and environmental differences' influence on the onset of the disease. All of those with MS were Caucasian and had grown up with their healthy twin to adulthood. Researchers analyzed the type and abundance of microorganisms in the feces of both the MS-affected and healthy twins. They found no differences in species or amount of bacteria between siblings. What they did find was a significant increase in some types of bacteria, such as Akkermansia, in untreated twins with MS. The team transplanted fecal samples from MS-affected and healthy twins into a mice model of MS called experimental autoimmune encephalomyelitis. These animals have an inflammatory myelin-destroying disease of the central nervous system that is comparable to human MS. Myelin is a protective coating around neurons whose loss is associated with MS. MS twin-derived gut microbiota caused a significantly higher amount of mice to develop a relapsing–remitting autoimmunity similar to MS than healthy twin-derived microbiota. When researchers measured the microbial profiles of the mice's feces, they found significant differences in amounts of bacteria. The most important difference was in Sutterella, an organism that helps protect against inflammation. Sutturella levels were significantly reduced in the feces of mice transplanted with MS twin-derived microbiota compared with feces from healthy twins. The team also measured the mice's immune cells and the proteins they release. They discovered that immune cells in mice with MS-twin feces transplants produced less of the anti-inflammatory factor IL-10 than immune cells from mice colonized with healthy-twin samples. IL-10, or interleukin 10, is an important immune protein. When researchers transplanted the feces of healthy twins into the mice, then gave them an antibody that blocks the function of IL-10, they also became sick. This indicated that IL-10 may temper autoimmunity in the central nervous system. The team then measured the twins' immune blood components. They found that the healthy twin had higher quantities of IL-10 than the MS-affected one. This is a complex issue in which very subtle differences of type and amount of bacteria in the gut can have considerable consequences, they added.  

August 23, 2017 News by Alice Melão, MSc

Researchers Identify Nerve Pathway Linking Brain Inflammation, Gut Dysfunction in MS

Chronic stress and inflammation in the brain can cause multi-organ dysfunction including severe gut failure, mediated by a newly identified nerve pathway in animal models of multiple sclerosis, a Japanese study shows. MS is an autoimmune disease caused by CD4+ T-cells that cross the blood-brain barrier protecting the central nervous system. This inflames and stresses the brain and spinal cord. In previous studies, a team led by professor Masaaki Murakami of Japan's Hokkaido University showed that these cells could cross the blood-brain barrier in specific sites. These entrance sites depend on brain regional activation, which was found to be triggered by specific nerve interactions — a mechanism the team called gateway reflexes. In collaboration with other Japanese researchers and a team from Germany, the project aimed to address the potential correlation among chronic stress, brain inflammation and organ failures in MS. Using mice with MS-like disease — the experimental autoimmune encephalomyelitis model — researchers found that animals that had autoreactive CD4+ T-cells and which were exposed to stressful conditions developed severe symptoms such as gastrointestinal failure, or even death. Detailed analysis of the animals' brains showed that in stressed mice, CD4+ T-cells accumulated in two specific sites in the center of the brain around blood vessels. This event would cause inflammation around those vessels, and activation of a nerve pathway that is commonly turned off. This switch led to gut dysfunction, bleeding and failure. "These results demonstrate a direct link between brain micro-inflammation and fatal gastrointestinal diseases via the establishment of a new neural pathway under stress," Murakami, the study's senior author, said in a news release. Researchers were able to prevent gut symptoms by inhibiting inflammation in the brain or blocking the nerve pathway responsible for driving the signals from the brain to the gastrointestinal tract. "Micro-inflammation in the brain is also seen in Alzheimer's disease and Parkinson's disease," Murakamai concluded. "So it's of particular interest to investigate possible connections between brain micro-inflammations and organ dysfunctions, including those within the brain itself, in those patients."

August 14, 2017 News by Patricia Inacio, PhD

Human Gut Microbes May Help Suppress MS, New Research Suggests

A bacteria present in the gut, called Prevotella histicola, prevented multiple sclerosis from developing in a preclinical mouse model, found researchers at the Mayo Clinic in Rochester, Minnesota, along with colleagues at the University of Iowa. Current research suggests that alterations to the gut microbiome residing in human intestines may potentially trigger inflammatory diseases such as MS. In an attempt to identify which gut resident bacteria are capable of modulating immune responses, researchers studied cultured small pieces of intestine tissue extracted from biopsies of patients with celiac disease. The team then isolated three bacteria strains and found that one of species — P. histicola — had the capacity to suppress MS in a preclinical animal model of the disease. “This is an early discovery but an avenue that bears further study," Dr. Joseph Murray, a Mayo Clinic gastroenterologist and the study's lead author, said in a press release. "If we can use the microbes already in the human body to treat human disease beyond the gut itself, we may be onto a new era of medicine. We are talking about bugs as drugs." By investigating how P. histicola modulated immune responses to suppress MS, researchers found that bacteria decreased the expression of two pro-inflammatory cytokines – interferon-gamma and interleukin (IL)-17. Overall results show that P. histicola has immune modulatory activity and can suppress abnormal immune responses, which ultimately prevent autoimmunity. This supports the idea that maintaining a healthy microbial community within our intestines is a potential therapeutic strategy for MS. "Our work is a classic example of a bedside-to-bench and potentially back to bedside study. Recent MS microbiome studies have shown the lack of Prevotella genus in patients with the disease and an increase when patients were treated with disease-modifying drugs," said Ashutosh Mangalam, the study's first author and an assistant professor of pathology at University of Iowa's Carver College of Medicine. "And it's not just for MS, because this may have a similar modulating effect on other nervous system and autoimmune diseases."

May 17, 2017 Columns by Judy Lynn

Taming Grumpy Gut

Many people with MS experience symptoms related to digestion. According to the Pittsburgh Institute for MS Care and Research, “Nearly two-thirds of MS patients have at least one GI symptom that persists for 6 months or more.” Some of the most common problems are dysphagia (trouble swallowing), heartburn, nausea,…