Nausea, indigestion, stomach pain. These are all the unpleasant symptoms of chronic gastritis, which can be caused by infection with Helicobacter pylori bacteria. H.pylori infection is hard to treat, in part because it can form biofilms – near-impenetrable barriers of bacteria. Researchers try to better understand the genetics of how this happens by growing normal H.pylori (pictured) and mutants on epithelial cells in a plastic dish, as captured using scanning electron microscopy. Mutants were selected that couldn’t form biofilms. The underlying genetic defects pinpointed genes involved in a variety of processes. This revealed the importance of these processes in H.pylori biofilm formation, specifically the reshaping of projections called flagella, acetone metabolism and the activity of enzymes called hydrogenases. H.pylori, therefore, appears to change its metabolism and its flagella when forming biofilms. These insights may help in the development of treatments to break down these notorious bacterial barriers.
Written by Lux Fatimathas
Image from work by Skander Hathroubi, Shuai Hu & Karen M. Ottemann
Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA, USA
Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
Published in npj biofilms and microbiomes, November 2020
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Technology shows how microbes in the body respond to exercise. That helps scientists understand why those microbes keep athletes healthy.
Exercise does more than make us hot and thirsty. It can have big effects on the trillions of microbes that live in our gut. Each one-celled organism is tiny. Together, their huge community, known as the gut microbiome (My-kroh-BY-oam), can weigh up to 2 kilograms (4.4 pounds). Its microbes can offer mighty benefits. They help digest food to extract the energy our bodies need. They help fight infections. They may even affect our mood. Technology can now gauge the activity of these microbes — and how it changes with exercise.
Sweat tech alerts athletes when to rehydrate — and with what
Lucy Mailing is a nutritional scientist. She earned her PhD at the University of Illinois Urbana-Champaign. There, she was part of a team that studied how exercise affects the gut microbiome.
The researchers recruited 32 men and women who were fairly inactive. For six weeks, each recruit exercised three days a week. They worked out on a treadmill or bike, starting at 30 minutes per day. Over the weeks, they gradually increased the workouts to 60 minutes.
Scientists Say: Microbiome
The researchers wanted to see how becoming active might affect someone’s gut microbes. And to find out, they didn’t have to open anyone up. They just had to wait for a share of the microbes to come out — in poop. Each recruit collected some of their feces before the study began. They did it again right after the six weeks of exercise ended. Six weeks after that, they collected one last sample of poop.
During the workout weeks, the recruits did not change what they ate — except for three days before each poop collection. For those days only, each of the recruits followed a menu designed just for them. It included only foods and drinks from their usual diet.
Scientists Say: Fatty acid
Collecting poop is yucky. Receiving and processing it is, too. But working through this yuckiness yielded new insights. For instance, the recruits’ microbes made more short-chain fatty acids (SCFAs) that are good for health. One of these was butyrate [BYOO-tur-ayt]. Studies have shown it can protect against certain cancers, fight inflammation and regulate genes that promote health. It may even enhance sleep. Our gut bacteria make such SCFAs from the fiber found in nuts, grains and many vegetables.
By the end of the study, the recruits had more SCFA-producing microbes than at the start. This was especially true in lean people. And those with more of these bacteria lost more body fat during the six weeks of exercise. Their fitness also improved more quickly.
But once people stopped exercising, their gut microbiomes went back to what they had been before the study. This shows that “regular exercise changed the composition and activity of the gut microbes,” Mailing says. And the benefits of exercise in these people had likely been helped along by those microbes, she adds.
Her team shared its findings in the April 2018 Medicine & Science in Sports & Exercise.
Scientists have isolated a molecule that may be under-produced in the gut, a discovery that may lead to treatments for the neurodegenerative condition.
Two studies - one in mice and the other in human subjects - offer the first definitive evidence that exercise alone can change the composition of microbes in the gut. The studies were designed to isolate exercise-induced changes from other factors - such as diet or antibiotic use - that might alter the intestinal microbiota.
Two studies - one in mice and the other in human subjects - offer the first definitive evidence that exercise alone can change the composition of microbes in the gut. The studies were designed to isolate exercise-induced changes from other factors - such as diet or antibiotic use - that might alter the intestinal microbiota.
In the first study, scientists transplanted fecal material from exercised and sedentary mice into the colons of sedentary germ-free mice, which had been raised in a sterile facility and had no microbiota of their own. In the second study, the team tracked changes in the composition of gut microbiota in human participants as they transitioned from a sedentary lifestyle to a more active one - and back again.
"These are the first studies to show that exercise can have an effect on your gut independent of diet or other factors," said Jeffrey Woods, a University of Illinois professor of kinesiology and community health who led the research with former doctoral student Jacob Allen, now a postdoctoral researcher at Nationwide Children's Hospital in Columbus, Ohio. The work with mice was conducted at the U. of I. and with scientists at the Mayo Clinic in Rochester, Minnesota, who develop and maintain the germ-free mice. The work in humans was conducted at Illinois.
Jacob M. Allen et al, Exercise Alters Gut Microbiota Composition and Function in Lean and Obese Humans, Medicine & Science in Sports & Exercise (2017). DOI: 10.1249/MSS.0000000000001495
J. M. Allen et al. Exercise training-induced modification of the gut microbiota persists after microbiota colonization and attenuates the response to chemically-induced colitis in gnotobiotic mice, Gut Microbes (2017). DOI: 10.1080/19490976.2017.1372077
Jacob Allen, left, Jeffrey Woods and their colleagues found that exercise alters the microbial composition of the gut in potentially beneficial ways. Credit: L. Brian Stauffer
Gut Microbes Combine to Cause Colon Cancer, Study Suggests
by Gina Kolata / NY Times
Two types of bacteria commonly found in the gut work together to fuel the growth of colon tumors, researchers reported on Thursday.
Their study, published in the journal Science, describes what may be a hidden cause of colon cancer, the third most common cancer in the United States. The research also adds to growing evidence that gut bacteria modify the body’s immune system in unexpected and sometimes deadly ways.
The findings suggest that certain preventive strategies may be effective in the future, like looking for the bacteria in the colons of people getting colonoscopies.
If the microbes are present, the patients might warrant more frequent screening; eventually people at high risk for colon cancer may be vaccinated against at least one of the bacterial strains.
“I can’t guarantee you these bacteria will be the holy grail of colon cancer, but they should be high on the list” of possible culprits, said Christian Jobin, a professor of medicine at the University of Florida who studies bacteria in the gastrointestinal tract.
Giving fecal transplants to kids with autism helped their stomach symptoms and behavioral symptoms — even two years after the poop trade.
MADISON, Wis. — Autism can make it hard for children to communicate with others and to deal comfortably with the world around them. But that’s not all. Often these kids may suffer stomach problems. One new treatment for these tummy troubles sounds gross: Give the kids microbes isolated from other people’s poop. A new study found it helped rid their stomach distress. The new gut bugs also improved behaviors linked with autism. Best of all: The benefits appear to last at least two years after the treatment ends.
Explainer: What is autism?
Autism is a word that describes a group of disorders that happen as the brain develops. Scientists are not entirely sure what causes it, although the genes passed down from parents may play a role. (Despite some rumors to the contrary, vaccines do not cause autism.) About one in every 68 kids in the United States has been diagnosed with some form of autism. The symptoms can vary in type and severity. That’s why doctors now refer to autism disorders as falling within a broad spectrum.
Most people associate autism with certain behaviors, such as hyperactivity, repetitive actions and irritability. But some patients also have stomach problems. These can include diarrhea, stomach pain or constipation. The new findings appear to strengthen the link between tummy troubles and autism.
Scientists refer to all of the bacteria, viruses and other microbes that live in the intestines as the gut’s microbiome (My-kroh-BY-ohm). The new data now provide more evidence that the microbiome can affect behavior.
Michael Hylin is a neuroscientist — someone who studies the brain — at Southern Illinois University in Carbondale. These data are “a long way from saying there’s a cure for autism.” Still, says Hylin, who was not involved in the work, “I think it’s a promising approach. It’s one that’s worthwhile.”
The scientists linked poop with autism because kids with the disorder tend to have fewer types of microbes living in their guts than do other kids. Harvesting gut microbes from human poop (gross as it may sound) has been used for years to treat a range of other health problems. So scientists wondered whether giving kids a healthier mix of gut germs might make their bellies feel better.
And it did.
Scientists reported success from their two-year trial on July 10, 2018, here, at the Beneficial Microbes Conference.
Gut bacteria can chemically change the drugs people swallow. ID-ing a patient’s microbes might one day help doctors prescribe the most effective drugs.
To prescribe the best medicine, it might help if a doctor knows which bacteria live in a patient’s gut. That’s the finding of a new study.
The bugs within us
Reports had shown that some gut microbes can alter the drugs that people swallow. That might affect how well those drugs work. But researchers weren’t sure how big a problem this was. Now, a study suggests that gut bacteria can modify many drugs. And that means the genes in those microbes may predict how those drugs would work in that patient.
Maria Zimmermann-Kogadeeva is a computational biologist at Yale University in New Haven, Conn. She and her colleagues shared their new finding June 3 in Nature.
“Knowing how the gut microbes … affect a drug is hugely useful,” says Matthew Redinbo. He did not take part in the new research. But as a biochemist at the University of North Carolina at Chapel Hill, he understands that such effects could help drug companies develop more effective drugs. It could also help doctors choose the best treatment for a particular patient.
Researchers chose 76 types of bacteria that can live in the human gut. Then they tested if — and how — those bacteria changed the molecular structure of 271 drugs. From hormones to anti-virus drugs, each medicine had been designed to be taken by mouth.
The scientists put the bacteria into test tubes holding nutrients and drug solutions. After 12 hours, about two in every three of the drugs had been changed by at least one strain of bacteria. Each of these strains could modify between 11 and 95 different drugs.
Scientists Say: Microbiome
“That is huge,” says Nichole Klatt. The microbiome is the sum of all of the microbes living in the body. Klatt is a microbiome researcher at the University of Miami in Florida. She, too, was not involved in the new study. Still, she notes, knowing which microbes affect which drugs isn’t enough. Future studies should look into exactly how bacteria make these changes, she says. Studies might also explore the impacts those altered drugs would have on the human body.
