Should further study validate these findings, clinical laboratories managing hospital blood banks would be among the first to benefit from an abundance of universal donor blood
In a surprising outcome for microbiome research, scientists at the Technical University of Denmark (DTU) and Sweden’s Lund University discovered that the bacteria Akkermansia muciniphila, which resides in the human gut, produces enzymes that can be used to process whole blood in ways that could help produce type-O blood. This “universal” blood type can be given to patients during transfusions when other blood types are in short supply.
Receiving the wrong type of blood via a transfusion could result in a fatal reaction where the immune system launches an attack on foreign antigens. As blood bankers and clinical laboratory scientists know, the A antigens in type A blood are not compatible with the B antigens in type B blood. Type-O blood completely lacks these antigens, which explains why it can be used for individuals of any blood type.
The DTU/Lund discovery—still in its initial stages of development—could eventually give blood bankers in hospital laboratories a way to expand their supply of universal type-O blood. Although individuals with type-O blood are universal donors, often the available supply is inadequate to meet the demand.
“For the first time, the new enzyme cocktails not only remove the well-described A and B antigens, but also extended variants previously not recognized as problematic for transfusion safety,” said Maher Abou Hachem, PhD, Professor of Biotechnology and Biomedicine at DTU, one of the authors of the study, in a news release.
Discovering a way that ensures any blood type can donate blood for all blood types could increase the supply of donor blood while reducing the costs and logistics affiliated with storing four separate blood types. Additionally, the production of a universal blood type using gut microorganisms could reduce the waste associated with blood products nearing their expiration dates.
“We are close to being able to produce universal blood from group B donors, while there is still work to be done to convert the more complex group A blood,” said Maher Abou Hachem, PhD (above), Professor of Biotechnology and Biomedicine at DTU in a news release. “Our focus is now to investigate in detail if there are additional obstacles and how we can improve our enzymes to reach the ultimate goal of universal blood production,” he added. Hospital clinical laboratories that manage blood banks will be among the first to benefit from this new process once it is developed and cleared for use in patient care. (Photo copyright: Technical University of Denmark.)
Creating Universal Donor Blood
The bacterium Akkermansia muciniphila is abundant in the guts of healthy humans. It produces valuable compounds, and it is able to break down mucus in the gut and can have significant, positive effects on body weight and metabolic markers.
“What is special about the mucosa is that bacteria, which are able to live on this material, often have tailor-made enzymes to break down mucosal sugar structures, which include blood group ABO antigens. This hypothesis turned out to be correct,” Hachem noted in the DTU news release.
“Instead of doing the work ourselves and synthesizing artificial enzymes, we’ve asked the question: What looks like a red [blood] cell surface? The mucus in our gut does. So, we simply borrowed the enzymes from the bacteria that normally metabolize mucus and then applied them to the red [blood] cells,” Martin Olsson MD, PhD, professor of hematology and transfusion medicine at Lund University, told Live Science. “If you think about it, it’s quite beautiful.”
The researchers successfully identified long strings of sugar structures known as antigens that render one blood type incompatible with another. These antigens define the four blood types: A, B, AB and O. They then used a solution of gut bacteria enzymes to remove the sugar molecules present on the surface of red blood cells (RBCs).
“We biochemically evaluated 23 Akkermansiaglycosyl hydrolases and identified exoglycosidase combinations which efficiently transformed both A and B antigens and four of their carbohydrate extensions,” the study authors wrote in Nature Microbiology. “Enzymatic removal of canonical and extended ABO antigens on RBCs significantly improved compatibility with group O plasmas, compared to conversion of A or B antigens alone. Finally, structural analysis of two B-converting enzymes identified a previously unknown putative carbohydrate-binding module.”
“Universal blood will create a more efficient utilization of donor blood, and also avoid giving ABO-mismatched transfusions by mistake, which can otherwise lead to potentially fatal consequences in the recipient. When we can create ABO-universal donor blood, we will simplify the logistics of transporting and administering safe blood products, while at the same time minimizing blood waste,” Olsson said in the news release.
Future Progress
The researchers have applied for a patent for the enzymes and their method of enzyme treatment. The two educational institutions hope to make further progress on this joint project over the next three years. They eventually hope to test their theory in controlled patient trials and make it available for commercial production and clinical use.
More research and clinical studies are needed to prove the effectiveness of this discovery. Clinical laboratory professionals—particularly those who manage hospital blood banks—will want to follow DTU’s research. It could someday lead to the availability of a more abundant supply of universal donor blood for transfusions.
Further research could eventually lead to clinical laboratory biomarkers and screening tests to identify infants whose gut bacteria may predispose them to neurodevelopment disorders later in life
Microbiologists and clinical laboratory scientists working with gut bacteria will be intrigued to learn that a study conducted by scientists from Linköping University in Sweden and the Department of Microbiology and Cell Science at the University of Florida (UFL) recently found that gut microbiota (aka, gut flora) in infancy can be correlated with developing a neurodevelopmental disorder (ND) later in life.
The researchers analyzed patient records from the 20-year All Babies in Southeast Sweden (ABIS) prospective cohort study into the etiology of obesity, diabetes, and other diseases. They found that “disturbances” in the microbiomes of children during the first years of life could be linked to later ND diagnoses, according to Neuroscience News.
“We’ve found associations with some factors that affect gut bacteria, such as antibiotic treatment during the child’s first year, which is linked to an increased risk of these diseases,” stated pediatrician Johnny Ludvigsson, MD, PhD, Senior Professor, Department of Biomedical and Clinical Sciences at Linköping University, who co-led the study, in a Linköping University news release.
“Analyzing over 16,000 children from the ABIS study, researchers identified significant biomarkers in cord blood and stool samples that correlate with future diagnoses of these disorders,” Neuroscience News reported.
This study adds evidence to the growing theory that every individual’s microbiome has much to do with his/her state of health and specific health conditions.
“We can see in the study that there are clear differences in the intestinal flora already during the first year of life between those who develop autism or ADHD and those who don’t,” said pediatrician and study co-author Johnny Ludvigsson, MD, PhD (above), Senior Professor, Department of Biomedical and Clinical Sciences at Linköping University, in a news release. Clinical laboratory scientists and microbiologists who work with gut microbiota will find these observations intriguing. (Photo copyright: Linköping University.)
Analysis of the ABIS Study
To conduct their study, the researchers analyzed the health records of 16,440 children born between 1997 and 1999 who participated in the ABIS study. The subjects were a close representation of the general Swedish population and were followed from birth into their twenties.
Research showed that 1,197 of the 16,440 children (7.28%) had been diagnosed with either autism, ADHD, communication disorders, or an intellectual disability.
The researchers also surveyed the ABIS study participants concerning their lifestyles and environmental factors during childhood. They analyzed substances found in the umbilical cord blood and stool bacteria collected at age one in some of the study participants. Cord blood remains in the placenta and umbilical cord after birth and is rich in stem cells.
“The remarkable aspect of the work is that these biomarkers are found at birth in cord blood or in the child’s stool at one year of age over a decade prior to the diagnosis,” said Eric Triplett, PhD, Professor and Chair of the Department of Microbiology and Cell Science at UFL and a co-leader of the study, in the Linköping University news release.
The investigation found that children who had numerous ear infections during the first year of life were more prone to receiving a diagnosis of a neurodevelopmental disorder later in life. The scientists surmised that it was not the infections that caused the issues. Rather, it was that repeated antibiotic treatments had disturbed the balance of healthy gut bacteria.
“We’re not trying to say that antibiotics are necessarily a bad thing,” stated Angelica Ahrens, PhD, Assistant Research Scientist in the Triplett Research Group at the University of Florida and first author of the study, in a UFL blog. “But perhaps overuse can be detrimental to the microbiome, and for some children, for whatever reason, their microbiome might not recover as readily.”
Deficits in Important Bacteria
The researchers discovered that the presence of Citrobacter bacteria increased the risk of a future ND diagnosis. According to ScienceDirect, “organisms of the genus Citrobacter are gram-negative bacilli that are occasional inhabitants of the gastrointestinal tract and are responsible for disease in neonates [newborns that are four weeks or younger] and debilitated or immunocompromised patients.”
They also discovered that the absence of Coprococcus bacteria increased the risk of getting an ND as well. One of the main producers of butyrate, Coprococcus is known to support gut barrier function, suppress harmful bacteria, and contain anti-inflammatory properties.
“Coprococcus and Akkermansia muciniphila have potential protective effects,” said Ahrens in the Linköping University news release. “These bacteria were correlated with important substances in the stool, such as vitamin B and precursors to neurotransmitters which play vital roles orchestrating signaling in the brain. Overall, we saw deficits in these bacteria in children who later received a developmental neurological diagnosis.”
Environmental/Behavioral Findings of the ABIS Study
Through the analysis of toxins present in study participants’ cord blood, the researchers confirmed that risk of developing an ND increases when babies are exposed to parents who smoke. The scientists also found that breastfeeding offers a protective effect against NDs.
More research is needed to determine whether gut flora in infants can have an effect on developing NDs later in life, and it is not yet known if similar findings will be detected in other populations. Nevertheless, the findings that many biomarkers for NDs can be observed in infancy may enable scientists to create clinical laboratory screening protocols, preventative measures, and innovative treatments for neurodevelopmental disorders.
Further research and studies linking certain microbiome factors to specific health conditions will create opportunities for microbiologists and clinical laboratories as well, to perform diagnostic testing that identifies if a patient—in this case a newborn or infant—has a microbiome that will lead to immediate or later neurological health conditions.
New technology could enable genetic scientists to identify antibiotic resistant genes and help physicians choose better treatments for genetic diseases
Genomic scientists at the Icahn School of Medicine at Mount Sinai Medical Center in New York City have developed what they call a “smart tweezer” that enables researchers to isolate a single bacterium from a patient’s microbiome in preparation for genetic sequencing. Though primarily intended for research purposes, the new technology could someday be used by clinical laboratories and microbiologists to help physicians diagnose chronic disease and choose appropriate genetic therapies.
The researchers designed their new technology—called mEnrich-seq—to improve the effectiveness of research into the complex communities of microorganisms that reside in the microbiomes within the human body. The discovery “ushers in a new era of precision in microbiome research,” according to a Mount Sinai Hospital press release.
“Imagine you’re a scientist who needs to study one particular type of bacteria in a complex environment. It’s like trying to find a needle in a large haystack,” said the study’s senior author Gang Fang, PhD (above), Professor of Genetics and Genomic Sciences at Icahn School of Medicine at Mount Sinai Medical Center, in a press release. “mEnrich-seq essentially gives researchers a ‘smart tweezer’ to pick up the needle they’re interested in,” he added. Might smart tweezers one day be used to help physicians and clinical laboratories diagnose and treat genetic diseases? (Photo copyright: Icahn School of Medicine.)
Addressing a Technology Gap in Genetic Research
Any imbalance or decrease in the variety of the body’s microorganisms can lead to an increased risk of illness and disease.
In researching the microbiome, many scientists “focus on studying specific types of bacteria within a sample, rather than looking at each type of bacteria present,” the press release states. The limitation of this method is that a specific bacterium is just one part of a complicated environment that includes other bacteria, viruses, fungi and host cells, each with their own unique DNA.
“mEnrich-seq effectively distinguishes bacteria of interest from the vast background by exploiting the ‘secret codes’ written on bacterial DNA that bacteria use naturally to differentiate among each other as part of their native immune systems,” the press release notes. “This new strategy addresses a critical technology gap, as previously researchers would need to isolate specific bacterial strains from a given sample using culture media that selectively grow the specific bacterium—a time-consuming process that works for some bacteria, but not others. mEnrich-seq, in contrast, can directly recover the genome(s) of bacteria of interest from the microbiome sample without culturing.”
Isolating Hard to Culture Bacteria
To conduct their study, the Icahn researchers used mEnrich-seq to analyze urine samples taken from three patients with urinary tract infections (UTIs) to reconstruct Escherichia coli (E. Coli) genomes. They discovered their “smart tweezer” covered more than 99.97% of the genomes across all samples. This facilitated a comprehensive examination of antibiotic-resistant genes in each genome. They found mEnrich-seq had better sensitivity than standard study methods of the urine microbiome.
They also used mEnrich-seq to selectively examine the genomes of Akkermansia muciniphila (A. muciniphila), a bacterium that colonizes the intestinal tract and has been shown to have benefits for obesity and Type 2 diabetes as well as a response to cancer immunotherapies.
“Akkermansia is very hard to culture,” Fang told GenomeWeb. “It would take weeks for you to culture it, and you need special equipment, special expertise. It’s very tedious.”
mEnrich-seq was able to quickly segregate it from more than 99.7% of A. muciniphila genomes in the samples.
Combatting Antibiotic Resistance Worldwide
According to the press release, mEnrich-seq could potentially be beneficial to future microbiome research due to:
Cost-Effectiveness: It offers a more economical approach to microbiome research, particularly beneficial in large-scale studies where resources may be limited.
Broad Applicability: The method can focus on a wide range of bacteria, making it a versatile tool for both research and clinical applications.
Medical Breakthroughs: By enabling more targeted research, mEnrich-seq could accelerate the development of new diagnostic tools and treatments.
“One of the most exciting aspects of mEnrich-seq is its potential to uncover previously missed details, like antibiotic resistance genes that traditional sequencing methods couldn’t detect due to a lack of sensitivity,” Fang said in the news release. “This could be a significant step forward in combating the global issue of antibiotic resistance.”
More research and clinical trials are needed before mEnrich-seq can be used in the medical field. The Icahn researchers plan to refine their novel genetic tool to improve its efficiency and broaden its range of applications. They also intend to collaborate with physicians and other healthcare professionals to validate how it could be used in clinical environments.
Should all this come to pass, hospital infection control teams, clinical laboratories, and microbiology labs would welcome a technology that would improve their ability to detect details—such as antibiotic resistant genes—that enable a faster and more accurate diagnosis of a patient’s infection. In turn, that could contribute to better patient outcomes.
If the link between certain types of gut bacteria and improved effectiveness of certain cancer treatments can be leveraged, then medical laboratories could soon have another diagnostic tool to use in supporting physicians with cancer care
The goal of both studies was to determine whether there was a link between gut bacteria and the efficacy of cancer drugs known as PD-1 inhibitors. These drugs are used for several types of cancer, including:
Melanoma;
Lung;
Bladder; and,
Stomach cancers.
They function by freeing up the immune system to attack cancer cells.
Greater Bacterial Diversity in Gut Brings Improved Response to PD-1 Inhibitors
One of the studies, “Gut Microbiome Modulates Response to Anti–PD-1 Immunotherapy in Melanoma Patients,” found that a microbiome populated with “good” bacteria can elevate the potency of certain drug treatments. The researchers discovered that the gut bacteria in patients who responded well to PD-1 inhibitors differed from that found in patients who did not respond to the treatment.
For this study, researchers at the MD Anderson Cancer Center at the University of Texas collected oral, gut, and fecal microbiome samples and tumor biopsies from 112 patients with advanced melanoma. Clinical laboratorians took the samples before and after PD-1 treatments. They divided the patients into two groups—responders and non-responders—and profiled each microbiome using genetic sequencing.
“What we found was impressive: There were major differences both in the diversity and composition of the gut microbiome in responders versus non-responders,” Jennifer Wargo, MD, MMSc, leader of the study, told STAT. “Those who did well had greater bacterial diversity in their gut, whereas those whose tumors didn’t much shrink had fewer varieties of microbes present.”
Melanoma patients who experienced success with PD-1 therapy had a more diverse microbiome and higher concentrations of bacteria known as Ruminococcus and Faecalibacterium. Patients involved in the study who did not respond well to PD-1 therapy had the presence of another bacterium called Bacteroidales.
Jennifer Wargo, MD (above center) with her team at the MD Anderson laboratories. The researchers cautioned that clinical trials are needed before a definitive conclusion can be reached on whether altering gut bacteria can improve the effectiveness of PD-1 therapy. “If you’re changing the microbiome, depending on how you do it, it may not help you—and it might harm you,” Wargo emphasized in STAT. “Don’t try this at home.” (Photo copyright: MD Anderson.)
Antibiotics Can Reduce Effectiveness of PD-1Therapy
Researchers for this study, led by Laurence Zitvogel, MD, PhD, of the Gustave Roussy Cancer Campus in Villejuif, France, examined 249 patients who were given a PD-1 inhibitor for lung, kidney, or urinary tract cancers. A little over one fourth of these patients had recently taken antibiotics, which can strip the gut of essential bacteria necessary to treat infections.
The team found that patients who had ingested an antibiotic relapsed faster and did not live as long as patients who had not taken an antibiotic before receiving PD-1 therapy. When they analyzed variances between patients who responded well to treatment versus patients who did not, they detected the presence of Akkermansia muciniphila, a mucin-degrading bacterium, in the responders.
Personalized Treatment Based on Each Patient’s Gut Microbiome
The culmination of this type of research raises questions about how cancer medications may interact with microbiomes.
“Should we be profiling the gut microbiome in cancer patients going into immunotherapy?” asked Wargo in the STAT article. “And, should we also be limiting, or closely monitoring, the antibiotic use in these patients?
“This is all very context-specific, and multiple different factors need to be considered on how best to change the microbiome,” she continued. “When it comes to optimizing cancer therapy, treatments will have to be heavily personalized, based on what a patient’s gut microbiome looks like already.”
Diagnostic tests that could determine whether a certain drug will be beneficial for a patient would perform a critical role in healthcare decision-making. Since cancer drug treatments can cost tens of thousands of dollars or more, it would be advantageous to know which therapies would be optimal for individual patients. The hope is that in the future, clinicians, working with anatomic pathologists and clinical laboratories, will have the tools needed to ascertain if patient’s microbiomes will best work with a particular drug and if they would likely encounter any side effects.
