Microbes
Episodes
In this clip, Dr. Rhonda Patrick describes how vitamin C is involved in immunity.
In this clip, Dr. Rhonda Patrick explains how allergens in the environment may shape the immune system during early life.
In this clip, Dr. Rhonda Patrick describes how the body's microbiome affects immune function.
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In this clip, Dr. Rhonda Patrick describes how vitamin C is involved in immunity.
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In this clip, Dr. Rhonda Patrick explains how allergens in the environment may shape the immune system during early life.
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In this clip, Dr. Rhonda Patrick describes how the body's microbiome affects immune function.
Topic Pages
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Polyphenols
Gut microbes biotransform dietary polyphenols into bioactive metabolites while polyphenols modulate microbial composition via antimicrobial and prebiotic effects.
News & Publications
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If you’re struggling with exercise performance, your gut health might be partly to blame. The gut microbiota is critical for boosting exercise performance and regulating energy metabolism. A recent study found that mice without gut microbes, known as germ-free mice, had lower exercise capacity and used oxygen and glucose less efficiently during physical activity.
Researchers compared germ-free mice to mice with normal gut bacteria. They fed both groups a regular diet and allowed them to exercise on running wheels. They measured the animals' body composition, oxygen and carbon dioxide usage, and glucose levels to assess how the absence of gut microbes affected exercise performance and energy use.
They found that germ-free mice gained less weight, had lower fat mass, and had lower aerobic exercise capacity than mice with normal gut bacteria. Germ-free mice also exhibited reduced glucose storage and usage, impairing their capacity to fuel physical activity. Additionally, their fat tissue adapted by breaking down more fat, making them leaner and less prone to obesity, but at the cost of reduced energy availability during physical activity.
These findings suggest that the absence of gut bacteria limits the body’s ability to store and use glucose, adversely affecting exercise performance. They also highlight gut microbes' vital role in supporting metabolism and physical endurance. Learn more about gut microbes' effects on metabolism in this clip featuring Dr. Michael Snyder.
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Curcumin may act as an intervention in chronic urinary tract infection through dampening of toll-like receptors and reducing bacterial colony count pubmed.ncbi.nlm.nih.gov
Curcumin reduces urinary tract infection symptoms via interaction with toll-like receptors.
Urinary tract infections are common outpatient infections. They occur more frequently among women, and 50 to 60 percent of all women report having had at least one UTI in their lifetime. Findings from a 2017 study suggest that curcumin reduces the symptoms associated with urinary tract infections via interaction with toll-like receptors.
Toll-like receptors comprise a family of pattern recognition receptors expressed on the surfaces of immune and other cells. They are the principal inducers of innate immunity and are responsible for the activation of transcription factors that increase the expression of proinflammatory cytokines. Chronic infections of the urinary tract, which either don’t respond to treatment or keep recurring, can occur in some people.
Curcumin is a bioactive compound found in the roots of Curcuma longa, a type of tropical plant. It is responsible for the vibrant yellow color of the spice turmeric. Evidence suggests that curcumin exerts robust antioxidant, anti-inflammatory, and anticancer effects. Curcumin also exhibits antibacterial activity, but the compound is strain-specific.
The study involved rats that had chronic urinary tract infections. Half of the rats received a curcumin injection, while the other half did not. The investigators measured the animals' white blood cell counts, bacterial counts (in the bladder and urine), markers of inflammation, and expression of toll-like receptor (TLR)2 and TLR4.
They found that white blood cell counts, bacterial counts, markers of inflammation, and expression of TLR2 and TLR4 of the rats that received the curcumin injection were considerably lower than those of the rats that didn’t receive curcumin. These findings suggest that curcumin improves the symptoms of chronic urinary tract infections and reduces inflammatory responses via dampening the expression of TLR2 and TLR4.
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Fecal microbiota transplantation from young mice reverses aging effects. www.sciencedaily.com
Declines in brain function are common with age owing to metabolic and immune alterations that include changes to the gut microbiota, the community of microorganisms that inhabit the intestines. While a diverse microbial community with many species of beneficial bacteria is associated with improved nutrition and reduced inflammation, older adults (especially residents of long-term care facilities) have perturbations in microbiota composition that increase the risk for cognitive decline and frailty. Findings of a report released this month show that fecal microbiota transplantation from young to aged mice reverses age-associated cognitive impairment.
Fecal microbiota transplantation is a therapy in which microbes are isolated from the stool of a donor, processed, filtered, and administered to a recipient by nasogastric tube or enema. Previous research demonstrates the efficacy of fecal microbiota transplantation in treating infection with Clostridium difficile, a hospital-acquired infection that is difficult to treat with antibiotics, and a growing list of other diseases such as inflammatory bowel disease, metabolic syndrome, neurodevelopmental disorders (e.g., autism), and autoimmune diseases. Fecal microbiota transplantation improves health partially by increasing microbiota alpha diversity, meaning the number of species in an individual’s microbiota, also called “richess.” A microbiota with high richness is more likely to contain key beneficial species, such as those that produce neuroprotective short chain fatty acids.
Given the wide range of diseases associated with gastrointestinal microbiota composition, its effects on aging are an area of intense interest. Prior investigations have demonstrated that transfer of the fecal microbiota from aged mice to young mice alters immunity, neurogenesis, and cognition; however, the consequence of fecal transplantation from young mice to aged mice is unknown.
The investigators performed their experiment using young and aged male mice. They assigned aged mice to receive a fecal microbiota transplant from either a young mouse (the experimental group) or aged mouse (the control group). For further comparison, the researchers also assigned a group of young mice to receive a fecal microbiota transplant from another young mouse. Mice received the fecal microbiota transplant treatments once per day for three days, then twice weekly for four weeks. The mice completed a battery of tests to assess cognitive function. The researchers collected fecal samples in order to sequence the DNA of the microbiota and blood samples in order to measure hormones, cytokines, and other immune markers before and after the four weeks of treatment. Finally, they analyzed changes to gene expression and metabolism in the hippocampus, the brain region most-associated with age-related cognitive decline.
At baseline, young and aged mice had distinctly different microbiota composition. Following four weeks of microbiota transplantation, young mice, aged mice receiving a young transplant, and aged mice receiving an aged transplant all had similar microbiota composition. Aged mice tended to have more over-reactive T cells, dendritic cells, and macrophages, especially in the lymph nodes that line the intestines. Aged mice also showed enlargement of microglia (the predominant immune cells in the brain), a common feature of neurodegenerative diseases. Microbiota transplantation from young mice reversed these age-related effects on brain and peripheral immunity. Amino acid metabolism in the hippocampus, which is necessary for neurotransmission and cognition, was impaired in aged mice, but restored following microbiota transplantation from young mice. Finally, the improved hippocampal metabolism in aged mice that received a young microbiota transplant translated to increased learning and long-term memory and reduced anxiety-related behaviors compared to aged mice receiving an aged microbiota transplant.
These results reveal the potential benefits of fecal microbiota transplantation from young donors as a therapy to promote healthy aging.
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Medieval remedy kills biofilm-forming pathogens. www.nature.com
Antibiotic-resistant bacterial infections are a growing threat, as researchers estimate a high probability of them killing an estimated 10 million people per year by 2050. Of particular concern are infections with bacteria that form biofilms, which require 100 - 1,000 times more antibiotics than other bacteria, and being significantly more likely to become multidrug resistant. A team of researchers recently uncovered a surprisingly effective treatment - one that dates back as far as 1,000 years.
Biofilms are like cities for microbes - large deposits containing high concentrations of multiple microorganisms that work in coordination to produce and share resources. These microorganisms produce a variety of polymer substances that form an extracellular matrix that has a sticky texture and protects the inside layers of the biofilm from the external environment, including antibiotic treatments. Before the discovery of antibiotics in the 20th century, remedies such as Bald’s eyesalve (a combination of onion or leek, garlic, wine, and bile salts) were used to treat infection. Given recent evidence of its efficacy in killing Staphylcoccus aureus biofilms, and the current lack of success in creating novel antibiotics, researchers are now turning to the question of whether ancient remedies may guide the development of new treatments.
The researchers prepared the Bald’s eyesalve according to instructions from a 10th century Anglo-Saxon leechbook - an Old English medical text. The ingredients were mixed and left to brew for nine days. Then the researchers prepared cultures of non-biofilm bacteria and mature biofilms of eight strains of bacteria that commonly cause chronic wound infections. The biofilms were deposited in a synthetic soft-tissue wound model made to mimic bodily infection. The researchers then measured the number of live bacteria remaining after 24 hours of exposure to Bald’s eyesalve. They found that the medieval treatment eradicated six of the eight non-biofilm cultures, while the two species that were not eradicated, (Staphylococcus aureus and Staphylococcus maltophilia), were exponentially reduced. The treatment’s success was similar in treating biofilm-producing cultures, with five of eight of them being exponentially reduced. There was, however, no consistent killing of biofilms containing Pseudomonas aeruginosa, Escherichia cloacae, or Staphylococcus maltophilia.
Having documented the effectiveness of the remedy in a variety of bacterial strains, the researchers then repeated their experiment with various preparations of the salve that omitted one ingredient at a time, in order to determine whether any one of them was responsible for any antimicrobial effects. They found that garlic, which contains the antimicrobial compound allicin, was independently effective in killing non-biofilm cultures. However, all four ingredients were necessary to produce the anti-biofilm effects.
These results indicate that ancient remedies containing multiple coordinating ingredients may have a crucial role in the fight against antibiotic resistance.