Tag Archive for: probiotics

gut bacteria

Understanding gut bacteria: forces for good (and sometimes evil)

gut bacteria

In a paper published Sept. 11, 2019, in PLOS ONE, a multi-institutional research team led by George Washington University (GW) faculty found 157 different types of organisms (eight phyla, 18 classes, 23 orders, 38 families, 59 genera and 109 species) living inside the guts of healthy volunteers.

Back in 2015, an interdisciplinary group of research scientists made their case during a business pitch competition: They want to create a subscription-based service, much like 23andMe, through which people could send in samples for detailed analyses. The researchers would crunch that big data fast, using a speedy algorithm, and would send the consumer a detailed report.

But rather than ancestry testing via cheek swab, the team sought to determine the plethora of diverse bacterial species that reside inside an individual’s gut in their ultimate aim to improve public health.

Hiroki Morizono, Ph.D., a member of that team, contributed detailed knowledge of Bacteroides, a key organism amid the diverse array of bacterial species that co-exist with humans, living inside our guts. These symbiotic bacteria convert the food we eat into elements that ensure their well-being as well as ours.

“Trillions of bacteria live in the gut. Bacteroides is one of the major bacterial species,” says Morizono, a principal investigator in the Center for Genetic Medicine Research at Children’s National in Washington, D.C. “In our guts they are usually good citizens. But if they enter our bloodstream, they turn evil; they’re in the wrong place. If you have a bacteroides infection, the mortality rate is 19%, and they resist most antibiotic treatments.”

The starting point for their project – as well as step one for better characterizing the relationship between gut bacteria and human disease – is taking an accurate census count of bacteria residing there.

In a paper published Sept. 11, 2019, in PLOS ONE, a multi-institutional research team led by George Washington University (GW) faculty did just that, finding 157 different types of organisms (eight phyla, 18 classes, 23 orders, 38 families, 59 genera and 109 species) living inside the guts of healthy volunteers.

The study participants were recruited through flyers on the GW Foggy Bottom campus and via emails.  They jotted down what they ate and drank daily, including the brand, type and portion size. They complemented that food journal by providing fecal samples from which DNA was extracted. Fifty fecal metagenomics samples randomly selected from the Human Microbiome Project Phase I research were used for comparison purposes.

“The gut microbiome inherently is really, really cool. In the process of gathering this data, we are building a knowledge base. In this paper, we’re saying that by looking at healthy people, we should be able to establish a baseline about what a normal, healthy gut microbiome should look like and how things may change under different conditions,” Morizono adds.

And they picked a really, really cool name for their bacteria abundance profile: GutFeelingKB.

“KB is knowledge base. Our idea, it’s a gut feeling. It’s a bad joke,” he admits. “Drosophila researchers have the best names for their genes. No other biology group can compete. We, at least, tried.”

Next, the team will continue to collect samples to build out their bacteria baseline, associate it with clinical data, and then will start looking at the health implications for patients.

“One thing we could use this for is to understand how the bacterial population in the gut changes after antibiotic treatment. It’s like watching a forest regrow after a massive fire,” he says. “With probiotics, can we do things to encourage the right bacteria to grow?”

In addition to Morizono, study co-authors include Lead Author Charles H. King, and co-authors Hiral Desai, Allison C. Sylvetsky, Jonathan LoTempio, Shant Ayanyan, Jill Carrie, Keith A. Crandall, Brian C. Fochtman, Lusine Gasparyan, Naila Gulzar, Najy Issa, Lopa Mishra, Shuyun Rao, Yao Ren, Vahan Simonyan, Krista Smith and Senior Author, Raja Mazumder, all of George Washington University; Paul Howell and Sharanjit VedBrat, of KamTek Inc.; Konstantinos Krampis, of City University of New York; Joseph R. Pisegna, of VA Greater Los Angeles Healthcare System; and Michael D. Yao, of Washington DC VA Medical Center.

Financial support for research described in this post was provided by the National Science Foundation under award number 1546491 and the National Institutes of Health National Center for Advancing Translational Sciences under award number UL1TR000075.

Staphylococcus

How our bladder’s microbiota affect health

Staphylococcus

The presence of bacteria such as Staphylococcus in the urine is linked to the incidence and severity of urge urinary incontinence as well as treatment success.

About half of the cells in our bodies aren’t really “ours” at all. They’re the microbiota: The vast array of microorganisms that live in our gut, skin, oral cavity and other places. Decades ago, researchers thought that these organisms simply happened to colonize these areas, playing only a tangential role in health, for example, helping to break down food in the intestines or causing cavities. More recent work has revealed the incredibly complex role they play in diseases ranging from diabetes and schizophrenia.

The bladder is no exception. Just a single decade ago, the bladder was thought to be a sterile environment. But that view has shifted radically, with more sensitive cultivation methods and precise 16S rRNA gene-sequencing techniques revealing a significant bladder microbiome that could have an enormous impact on pediatric urologic diseases. These findings have opened brand new fields of research aimed at clarifying the role that the bladder’s microbiome plays in common urological diseases that affect children, according to a review article published online Feb. 22, 2018, by Current Urology Reports.

“There is a growing appreciation for the role of diverse bacteria in contributing to improved health as well as triggering disease processes or exacerbating illness,” says Michael H. Hsieh, M.D., Ph.D., director of the Clinic for Adolescent and Adult Pediatric Onset Urology (CAPITUL) at Children’s National Health System and study senior author. “Already, we know that probiotics and dietary modifications have the potential to play powerful roles in preventing urinary diseases that commonly occur among pediatric patients,” Dr. Hsieh says. This underscores the importance of conducting even more studies to improve our understanding and to identify new therapies for health conditions that resist current treatment options.”

The review conducted by Dr. Hsieh and co-authors highlights the effects of the microbiome on a number of urologic diseases that affect children, including:

  • Urinary tract infection A number of studies point to the association between decreased microbial diversity and the incidence of what is commonly called urinary tract infection (UTI) or “dysbiosis.” This relationship suggests that using probiotics to replace or supplement antibiotics could favorably alter the urinary microbiome. Future research will focus on the pathophysiological role of the microbiome to determine whether it can be manipulated to prevent or treat UTIs.
  • Urge urinary incontinence While data vary by study, the presence of bacteria in the urine, especially certain bacterial species – such as Gardnerella, Staphylococcus, Streptococcus, Actinomyces, Aerococcus, Corynebacterium and Oligella – are linked to the incidence and severity of urge urinary incontinence (UUI) as well as treatment success. Most studies find an association between greater genitourinary biodiversity and reduced incidence and lessened severity of UUI as well as improved treatment response. Future research will focus on further clarifying this relationship.
  • Urolithiasis Calcium oxalate stones, the most common type of kidney stone, have a microbiome that differs from the urinary microbiome leading researchers to question whether the stone’s own bacterial makeup could help to predict recurrence of future kidney stones. What’s more, Oxalobacter formigenes, a gram-negative bacterium, lowers oxalate levels in the blood and are associated with a 70 percent reduction in the risk of kidney stones forming. In an experimental model, fecal transplants with the full microbiome represented had a pronounced and persistent effect on oxalate production. Patients who receive some antibiotics often have reduced rates of formigenes colonization. However, the bacteria are resistant to amoxicillin, augmentin, ceftriaxone and vancomycin, which could point to preferential use of these antibiotics to stave off disease and ward off kidney stone formation.

Additional authors include Daniel Gerber, study lead author, The Georgetown University School of Medicine and Health Sciences; and Catherine Forster, M.D., study co-author, Children’s National.