Microbiome Bites Feb 13th: Whole Grains are Good, Antibiotics Can be Bad and Figuring-out the Microbiome in Crohn's Disease

Whole grains are good for the microbiome

1. Whole Grains are Good for the Microbiome and Immunity

Whole grain consumption has been linked to reduced risk of heart disease, type 2 diabetes and some cancers. Scientists have long speculated that the reason is due to whole grains reducing inflammation. To address the speculation a research team analyzed the results of an eight-week randomized, controlled trial with 81 patients to understand the effects of a diet rich in while grains on immune and inflammatory responses, gut microbiota, and stool frequency in healthy adults. The diets of the participants were tightly controlled so that any effects observed in the study would be specific to the whole grains.

To determine how whole grains affect the gut microbiome, the team measured the bacteria present and concentration of short-chain fatty acids in the participants stool. Those who ate the whole-grain diet had an increase in Lachnospira, a species of bacteria that produces short-chain fatty acids. Additionally, those who ate whole grains had a decrease in the inflammation-causing bacteria Enterbacteriaceae.

The researchers caution that the effects observed were modest, possibly because all of the study’s participants were healthy. This may also make it harder to generalize the results to those with dysbiosis or of high inflammatory status.

The study is published in the American Journal of Clinical Nutrition and you can read it here.

2. Antibiotics Might Kill Gut Bacteria that Protect Newborn Lungs

A new research study in mice suggests that exposure to antibiotics in the womb could permanently weaken the immune system and make lung disease more likely. The study, published in the journal Science Translational Medicine, suggests that antibiotics can harm infant mice by killing important gut bacteria.

The researchers identified chemicals released by the bacteria that tell newborn lungs when to make immune cells, how many to make, and when to use them. Temporarily disrupting the gut flora was enough to make the young mice more likely contract pneumonia and die.

Excessive use of antibiotics in early life might explain why some people with no obvious genetic risk develop asthma or other lung diseases later on in life. You can find the study here.

3. A Gut Microbiome Signature for Crohn's Disease

Crohn’s disease (CD) and Ulcerative colitis (UC) are the two main forms Inflammatory Bowel Disease (IBD). Diagnosis of the diseases is particularly difficult because they have overlapping and distinct symptoms - one may be misdiagnosed as the other.

Crohn’s disease and ulcerative colitis were amongst the first diseases associated with a disrupted gut microbiome. However, scientists don’t really know what’s wrong with the gut microbiomes of these patients, only that they’re not normal. Now a team of European scientists has carried out a deep analysis of the microbiomes of more than 2000 CD and UC patients to try and address this problem. In the study, published in the journal Gut, the scientists show that disruption of the gut microbiome is greater in Crohn’s than UC. The variety of bacteria present is greatly reduced, the types of bacteria making up the microbiome are different and less stable. Additionally smoking, and the specific location of the disease (within the gut) affect the type of bacteria present.

The scientists believe that looking for these specific microbiome features in potential CD or UC patients will help doctors make the correct diagnosis and provide the right treatment for the patients. You can find the study here