gut microbiome

December 19, 2022 News by Steve Bryson, PhD

Lcn-2 Protein Marks Intestinal Inflammation in MS, Study Shows

People with relapsing-remitting multiple sclerosis (RRMS) have elevated levels of the lipocalin 2 (Lcn-2) protein in their stool samples, a marker for intestinal inflammation, compared with healthy controls, a study demonstrated. Among patients, findings also demonstrated those with high fecal Lcn-2 had changes in their gut microbiome, the collection…

February 2, 2022 News by Lindsey Shapiro, PhD

How Eating Meat Affects MS via Gut Microbiome, Immune Cells Detailed

A relationship between meat consumption and how it affects gut bacteria, immune cell profiles, and metabolism was identified in people with relapsing-remitting multiple sclerosis (RRMS) participating in a small study. Specifically, a diet rich in meat was associated with a decrease in Bacteriodes thetaiotaomicron, a common gut bacteria that works…

July 18, 2018 News by Iqra Mumal, MSc

Non-fermentable Fiber Diet Helped Prevent MS in Mice

A diet that incorporates non-fermentable fiber — a common component of a vegetarian diet — during early life can help prevent the onset of autoimmune diseases such as multiple sclerosis (MS), a new study shows. The study, “Dietary non-fermentable fiber prevents autoimmune neurological disease by changing gut metabolic and…

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.”

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."

July 14, 2017 News by Patricia Inacio, PhD

High Levels of Pro-Inflammatory Immune Cells in Intestines May Promote MS Activity, Study Reports

People with multiple sclerosis have high levels of pro-inflammatory TH17 immune cells in their intestines that correlate with change in the micro-organism mix in their gut and the levels of their disease activity, a study reports. Researchers said the findings suggest that diet, probiotics and therapies that regulate TH17 cells could help treat MS. Probiotics are supplements containing beneficial bacteria. The study, “High frequency of intestinal TH17 cells correlates with microbiota alterations and disease activity in multiple sclerosis,” was published in the journal Science. Research has shown that TH17 cells, also known as T helper 17 cells, play a role in the development of MS. In fact, they were the first harmful immune T-cells to infiltrate the central nervous system, according to studies in animals Where TH17 cells become activated has been unclear, however. Studies in mice suggested it was mainly in the small intestine. Research has also indicated that their activation increases the potential for a person to develop an autoimmune brain disease like multiple sclerosis. An autoimmune disease occurs when the immune system, which defends the body against disease, decides that a person's healthy cells are foreign, and attacks those cells. Researchers decided to see if the findings in mouse models of MS applied to people with the disease. They discovered a link between higher levels of TH17 cells in MS patients' intestines and autoimmune brain problems. They also found a correlation between higher levels of TH17 cells and changes in patients' gut microbiome. The team then identified which bacteria were changing in the gut. Patients with increased levels of TH17 cells and higher disease activity had a higher ratio of Firmicutes to Bacteroidetes bacteria and more Streptococcus strains in their gut, particularly Streptococcus mitis and Streptococcus oralis. Previous studies have shown that these species promote TH17 cell differentiation in humans. Cell differentiation involves a cell transforming from one cell type to another — usually a more specialized type. This dramatically changes a cell's size, shape, metabolic — or fuel-burning — activity, and responsiveness to signals. Some studies have suggested a link between T-cell differentiation and brain autoimmune diseases. “On the basis of our findings, we speculate that, under certain conditions, or because of still unknown virulence factors, these Streptococcus strains can colonize the small intestine and favor TH17 cell differentiation in the human gut mucosa [linings],” researchers wrote. In addition to more Streptococcus bacteria, the team detected lower levels of Prevotella bacteria in MS patients with disease activity than in healthy controls or patients with no disease activity. This decrease may also promote TH17 cell differentiation because “Prevotella is capable of producing the anti-inflammatory metabolite propionate that limits intestinal TH17 cell expansion in mice," the researchers wrote. Overall, the team concluded that “our data demonstrate that brain autoimmunity is associated with specific microbiota modifications and excessive TH17 cell expansion in the human intestine.” The findings suggest that regulating TH17 cell expansion, along with changes in diet aimed at regulating intestinal linings, could be ways to help treat MS.

 

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