Tag: gut microbiota

Categories : GastrointestinalTags :

Faecal Transplants Safe in the Long Term for C. Diff Treatment

On By ModernMedia

A new study from the Mayo Clinic has provided more evidence for the safety and efficacy of faecal microbiota transplantation (FMT) in treating Clostridioides difficile infection (CDI).

Recruiting 609 patients diagnosed with CDI, 20% of whom were overweight or obese and 22.8% had inflammatory bowel disease (IBD), FMT was performed with a stool product from a common donor. At a short term follow-up, >60% of patients had diarrhoea, <33% had constipation, and 9.5% reported additional CDI episodes after one year. At long-term follow up (median 3.7 years), there 73 new diagnoses out of 477 patients, 13% had gastrointestinal problems, 10% had weight gain, and 11.8% had new unrelated infections.

However, this was marked by the appearance of additional medical conditions such as weight gain and irritable bowel syndrome, which the authors indicated should be investigated further. The study also did not use a standardised questionnaire for IBS, making those results harder to generalise, and there was no control group. However, administering questionnaires over an extended period to all participants instead of only a brief period shortly after FMT explains why there are fewer symptoms reported compared to other studies.  

A separate study with 207 patients receiving FMT showed 143 new diagnoses after the procedure, with a mean follow-up of 34 months. The researchers conducting this second study attribute the ability of FMT to reduce CDI to enhancements in CD4+ T cell and antibody-mediated immunity to C. difficile toxins such as TcdB.

“These results are important for the design of disease monitoring strategies and highlight that future study of how FMT influences pathogen specific immunity is warranted: specifically, determining if effectively restoring the TcdB specific cellular repertoire to healthy control proportions contributes to treatment success of FMT,” the researchers wrote.

These studies add to the growing body of evidence that show FMT combined with antibiotics is an effective way to treat CDI.

Source: MedPage Today

Journal information (first source): Saha S, et al. Long-term safety of fecal microbiota transplantation for recurrent Clostridioides difficile infection, Gastroenterol 2021; DOI: 10.1053/j.gastro.2021.01.010. 

Journal information (second source): Cook L, et al. Fecal microbiota transplant treatment for recurrent Clostridioides difficile infection enhances adaptive immunity to TcdB, Gastroenterol 2021; DOI: 10.1101/2020.06.05.20114876.

Categories : UncategorizedTags :

Healthy Country Childhood: The Protective “Farm Effect” on Asthma

On By ModernMedia

The presence of a diverse gut microbiome appears to exert a protective effect against asthma, which may explain the largely protective “farm effect” on asthma.

European researchers analysed faecal samples from over 700 infants raised on farms, and found a strong environmental effect. It was anticipated that nutrition would be a strong contributor to gut microbiome maturation, but there were unanticipated environmental effects such as exposure to animal sheds.

Researchers found that faecal butyrate (related to butyrate, a short-chain fatty acid), which is already known to protect against asthma in mice, had an inverse association with asthma. They ascribed this to gut bacteria such as Roseburia and Coprococcus which have the potential of producing short chain fatty acids. Children with more matured gut microbiomes had Roseburia and Coprococcus present.

“Our study provides further evidence that the gut may have an influence on the health of the lung. A mature gut microbiome with a high level of short chain fatty acids had a protective effect on the respiratory health of the children in this study. This suggests the idea of a relevant gut-lung axis in humans,” said Dr. Markus Ege, professor for clinical-respiratory epidemiology at the Dr. von Hauner Children’s Hospital. “This also means, however, that an immature gut microbiome may contribute to the development of diseases. This emphasizes the need for prevention strategies in the first year of life, when the gut microbiome is highly plastic and amenable to modification.”

Source: News-Medical.Net

Categories : Immune SystemTags :

Gut Microbiota Have Large Effects on Immune System

On By ModernMedia

For the first time, immune cells in the bloodstream have been shown to be affected by the makeup of gut microbiota.

In recent years, there has been increased interest in gut microorganisms and their influence on human health, partly as a result of improvements in the ability to study them. Much prior understanding of gut microbiota on the immune system comes from animal studies; this study was able to examine the effects in humans. This study used data from allogeneic stem cell and bone marrow transplants (BMTs), where the patient’s blood formation system is destroyed by radiation or chemotherapy and replaced with stem cells from a donor’s bone marrow. The patient is given antibiotics until the transplanted cells are able to re-establish the immune system, the gut microbiota being destroyed in the process and then re-establishing once the antibiotics are withdrawn. Over a period of ten years, a multidisciplinary team with the Memorial Sloan Kettering Cancer Center took blood and faecal samples from BMT patients.

Study author Dr Joao Xavier said, “Our study shows that we can learn a lot from stool—biological samples that literally would be flushed down the toilet. The result of collecting them is that we have a unique dataset with thousands of datapoints that we can use to ask questions about the dynamics of this relationship.”
“The parallel recoveries of the immune system and the microbiota, both of which are damaged and then restored, gives us a unique opportunity to analyse the associations between these two systems,” lead author Dr Jonas Schluter said.

A higher diversity of microbiota was shown to lower the risk of death following a BMT, and a lower diversity increased the risk of graft-versus-host disease, a potentially fatal condition where the transplanted marrow attacks the host’s body.

“Because experiments with people are often impossible, we are left with what we can observe,” Dr. Schluter noted. “But because we have so many data collected over a period of time when the immune system of patients as well as the microbiome shift dramatically, we can start to see patterns. This gives us a good start toward understanding the forces that the microbiota exerts on the rebuilding of the immune system.”

Source: Medical Xpress

Journal information: Jonas Schluter et al. The gut microbiota is associated with immune cell dynamics in humans, Nature (2020). DOI: 10.1038/s41586-020-2971-8

Categories : Diseases, Syndromes and Conditions Gastrointestinal LungTags :

Gut Microbiome is Linked to Pulmonary Disease

On By ModernMedia

A link has been shown between the gut microbiome and chronic obstructive pulmonary disease (COPD), a lung disease with an often poor prognosis.

Senior author Prof Phil Hansbro, Director of the Centenary University of Technology Sydney Centre for Inflammation, said, “It’s already known that the lung microbiome is a contributing factor in COPD. We wanted to see if the gut environment was also somehow involved–to determine whether the gut could act as a reliable indicator of COPD or if it was connected in some way to the development of the disease.”

Stool samples of COPD patients showed elevated levels of the bacteria Streptococcus and Lachnospiraceae. Additionally a unique metabolite signature was identified in individuals with COPD, created by the chemical by-products of the metabolic process.

First author Dr Kate Bowerman from the University of Queensland said, “Our research indicates that the gut of COPD patients is notably different from healthy individuals. This suggests that stool sampling and analysis could be used to non-invasively diagnose and monitor for COPD,” she said.
“The ‘gut-lung axis’ describes the common immune system of the lung and gastrointestinal tract. This means that activity in the gut can impact activity in the lung. Our COPD findings suggest that the gut microbiome should now also be considered when looking for new therapeutic targets to help treat lung disease,” Prof Hansbro said.

Source: Medical Xpress