Rheumatoid arthritis linked with gut bacteria imbalance

From New Atlas

Impressive new research led by a team from University College London is suggesting bacterial imbalances in the gut microbiome may play a major role in the development of rheumatoid arthritis. The preclinical study found damage to the gut lining directly correlates with joint inflammation and arthritis severity.

For some time now researchers have reported consistent links between gut microbiome abnormalities and rheumatoid arthritis, and increasing populations of certain types of bad bacteria have frequently been associated with arthritis severity.

But exactly how bacteria in the gut could influence joint inflammation has so far been unclear. A number of mechanisms have been hypothesized, from gut bacteria modulating the development of the specific inflammatory cells responsible for arthritis, to particular bacterial metabolites contributing to disease severity. This new study investigated a different causal hypothesis, focusing on the links between arthritis severity and a bacteria-induced weakening of the gut wall.

“We wanted to know what was happening in the gut and whether changes to the intestinal lining – which usually acts as a barrier to protect the body from bacteria – are a feature of the disease and contribute to its development,” explains co-lead author Claudia Mauri.

The new study showed mice bred to have a genetic predisposition to gut permeability also developed signs of severe arthritis. A different mouse model, engineered to develop collagen-induced arthritis, was then found to display reduced joint swelling when gut permeability was improved.

Looking at human patients the researchers found those suffering from rheumatoid arthritis had higher blood levels of lipopolysaccharide (LPS), LPS binding protein (LBP), and intestinal fatty acid binding protein. All these molecules are known biomarkers of intestinal damage, and LBP levels in particular were found to correlate with acute disease severity.

“Researchers at University College London have shown that, in arthritis, there is profound damage to the gut lining, which fails to work properly as a barrier, as well as an accumulation in the gut of white blood cells that cause inflammation,” the authors write in the newly published study. “The authors show that, in arthritis, bacteria cross the prohibited border of the intestinal lining and that repairing gut permeability defects with specific drugs inhibits joint inflammation.”

The research cannot completely explain the chain of mechanisms that link this weakening of the gut lining with arthritis. So although modulating the degree of gut permeability was found to directly relate to joint inflammation there are still missing links in that relationship yet to be described.

Mauri does say, however, these finding do indicate the gut could be a useful therapeutic target. She particularly speculates that improving gut permeability may be an effective new treatment model.

“Our findings suggest that the intestinal lining is a therapeutic target,” says Mauri. “Importantly, we found that using existing drugs that restore the gut-barrier integrity i.e., prevent the gut from becoming leaky or inhibit inflammatory cells from moving to and from to the gut, could reduce the severity of arthritis in pre-clinical models.”

The new study was published in the journal Med.

Source: University College London

 

Peanuts, herbs and spices--good for your gut

From ZME Science

Imagine a busy city on a weekday morning, with sidewalks packed with people rushing to get to work. Now, imagine this at a microscopic level and you’ll understand what the microbiome looks like inside our bodies. It has trillions of microorganisms of thousands of different species, including not just bacteria but also fungi, parasites, and viruses.

These “bugs” coexist peacefully in a healthy body, in fact recent research is showing that they influence a great deal of bodily processes. They’re also largely influenced by what we eat. Processed and fried food can damage the gut equilibrium, while vegetables and fruits help maintain it. Now, researchers found that adding a daily teaspoon of herbs and spices and an ounce of peanuts to the diet can also have a positive impact on your gut.

“Research has shown that people who have a lot of different microbes have better health, and a better diet, than those who don’t have much bacterial diversity,” Penny Kris-Etherton, a professor of Nutritional Sciences at Penn University, and one of the researchers behind the two new studies on microbiome health, said in a statement.

In their first study, Kris-Etherton and her colleagues compared the effects of snacking 28 grams (one ounce) of peanuts per day versus a higher carbohydrate snack (like cheese bits or pretzels for instance). At the end of six weeks, those who ate peanuts had an increased abundance of Ruminococcaceae — a bacterium linked to healthier liver metabolism.

A total of 50 participants completed the study, with the researchers assessing fecal bacterial diversity. Nuts (including tree nuts, peanuts, and nut butter) are usually recommended as part of healthy dietary patterns. Peanuts are the most consumed nut in the US. But this was the first study to look at their effect on microbiota composition.

In the herbs and spices study, the researchers analyzed the impact of adding blends of herbs and spices (such as ginger, cinnamon, cumin, turmeric, rosemary, oregano, basil, and thyme) to the diets of participants at risk of cardiovascular disease. Herbs and spices have been previously associated with a healthy gut, but not actually investigated.

The researchers looked at three doses — about 1/8 teaspoon per day, a little more than 3/4 teaspoon per day, and about 1 1/2 teaspoon per day. By the end of the four-week experiment, participants had an increase in gut bacteria diversity, including an increase in Ruminococcaceae, especially those eating the highest doses of herbs and spices.

“It’s such a simple thing that people can do,” said Kris-Etherton in a statement. “Everyone could benefit by adding herbs and spices. It’s also a way of decreasing sodium in your diet but flavoring foods in a way that makes them palatable and, in fact, delicious! Taste is really a top criterion for why people choose the foods they do.”

Scientists are still learning about the connection between gut microbiota and a range of health factors, from blood pressure to weight. A lot more research is still needed, said Kris-Etherton. In the meantime, we can all start looking at our diets and think of ways to make changes. It’s never too late to start eating a healthier diet.

The two studies were published in the Journal of Nutrition and the Journal of Clinica Nutrition.

If you do eat peanut butter, make sure it hasn't been 'stabilised', i.e., hydrogenated.
There should be oil separated out in the peanut butter.
If there isn't, the unsaturated fatty acids in the peanut butter have been turned
into trans fats, which are bad for you.

 

The gut biome and living long and healthily

 The Guardian ran a fascinating article on the gut biome that we, all unknowing, carry around inside us, and which is crucial to our health.   Bacteria, fungi and archaea in your gut defend you against disease, and there appear to be specific organisms which help you lose weight, produce the essential fatty acids your brain needs, reduce allergies and inflammation.  

The history of industrial civilisation is that we have 'dominion' over nature, and therefore, we can do what we like.  At a macro scale, the extreme weather over the last few years has demonstrated the falsity of that particular conceit.  Our discovery of the critical rôle our gut biome plays in our health is busy reinforcing that message. 

Centenarians per 100,000 population
Source: New Scientist

This article from New Atlas discusses how a healthy biome leads to very long life spans.

The relationship between lifespan and the bacteria living inside our gut is perhaps one of the stranger corners of scientific research right now. A new study published in the journal Nature, investigating the microbiomes of centenarians, offers clues to how gut bacteria may engender healthy aging.

The research looked at fecal samples from 160 centenarians in Japan. The cohort had an average age of 107 and the majority were free of chronic diseases such as cancer or diabetes. The results were compared to an elderly cohort, aged in their mid-80s, and a young cohort aged between 20 and 50.

In general the researchers detected a number of bacterial species specifically enriched in the centenarian group compared to the two controls. The bacteria found in higher levels in the centenarians were known to play a major role in the production of secondary bile acids.

Bile acids are vital elements for effective digestion and metabolism. Primary bile acids are synthesized in the liver while secondary bile acids are generated by bacteria in our gut.

The main finding from this new research is the hypothesis that these centenarians potentially remain relatively healthy into extreme old age by maintaining a diverse microbiome modulated by high volumes of these secondary bile acids. The study particularly focused on one secondary bile acid called isoalloLCA.

The researchers conducted mice studies and found directly feeding the animals isoalloLCA stifled the growth of a number of pathogenic gut bacteria species known to play a role in inflammation. This indicates isoalloLCA, and other secondary bile acids, may play a key role in keeping gut bacterial populations in healthy equilibrium.

“The ecological interaction between the host and different processes in bacteria really suggests the potential of these gut bugs for health maintenance,” says Damian Plichta, co-first author on the new research.

The findings follow on from other centenarian microbiome studies indicating healthy aging can be linked with certain gut bacteria profiles. Kim Barrett, a researcher from UC San Diego who did not work on this new study, says it is early days for this kind of research with studies still only revealing correlations, but these new findings certainly offer a plausible causal mechanism worthy of further investigation.

“…bile acids are emerging as a new class of “enterohormones” beyond their classic role in fat digestion and absorption,” notes Barrett. “It is certainly conceivable that manipulating concentrations of specific bile acids, whether microbially or by giving them directly, could exert health benefits.”

As one of the secondary bile acids detected in the study was found to inhibit the growth of a specific type of antibiotic resistant bacteria, one of the more immediate outcomes from this study is further investigations into how bile acids could be manipulated to treat related antibiotic-resistant bacterial diseases. Ramnik Xavier, co-corresponding author on the study, says this preliminary work also offers other researchers a starting point to investigate specific molecules to engender healthy aging.

“A unique cohort, international collaboration, computational analysis, and experimental microbiology all enabled this discovery that the gut microbiome holds the keys to healthy aging,” says Xavier. “Our collaborative work shows that future studies focusing on microbial enzymes and metabolites can potentially help us identify starting points for therapeutics.”

The new study was published in the journal Nature.