Saturday, January 30, 2010

Microbes and Us

Microbes and us from Aurametrix, Live on Vokle, February 12, 2010 

an improved version of my last diagram :Image:...Image via Wikipedia

Who's the True You? A human or a habitat for microbial communities?

Immediately after birth, every macroscopic creature is colonized by myriads of micro-critters that outnumber cells comprising the host.

Guts, ears, nose, skin, mouth, vagina, all environmentally exposed surfaces are home to thousands of species of bacteria, protists, algae, fungi (including yeast, molds, etc) and viruses. The types of microbes vary systematically across body habitats and time, as well as geographical location. Each finger tip is likely to have a distinct set of residents, so are left and right palms. If you are a woman, the number of populating you species is even larger.

Known as microbiota, the trillions of bacteria and other microorganisms could be our little friends. Some of them, dubbed probiotics, help to metabolize calories , provide nutrients, even shape immune responses during health and disease. A common gut bacteria called Bacteroides fragilis alleviates inflammation by restoring a balance of immune cells. It was shown to prevent inflammatory bowel disease in mice. Other bacteria shown to be protective in inflammatory bowel disease includes Lactobacillus casei, Lactobacillus plantarum, Lactobacillus salivarius, Lactobacillus acidophilus, Lactobacillus delbrueckii subspecies bulgaricus, Lactobacillus rhamnosus GG, Bifidobacterium longum, Bifidobacterium breve, Bifidobacterium infantis, Escherichia coli Nissle 1917, Streptococcus salivarius subspecies thermophilus, Bacteriodes thetaiotaomicron, Faecalibacterium prausnitzii, etc.

Many other diseases called autoimmune strike when the immune system gets out of balance. Perhaps some microorganisms could protect us not only from IBD but also from disorders such as asthma, type-1 diabetes, or multiple sclerosis (incidence of which increased more than 3 times in the past years).

Humans are much more similar to one another at the level of the genome than the microbiome. Microbial ratios change with an individual's weight, travels, medications, stress, diet. For early men, changes in bacterial ratios favoring increased fat/energy storage was beneficial - as the periods when food was plentiful would be always followed by times when food is scarce. For a modern man, this is a potential health hazard rather than an advantage.

The most abundant bacterial groups detected by molecular screening are Bacteroides (relatively stable population profile) and the bacteria belonging to the Clostridium coccoides group and the Clostridium leptum group (see this article on the Normal Bacterial Flora of Humans).
A lower proportion of gram-positive anaerobes related to Faecalibacterium prausnitzii, Ruminococcus flavefaciens-Ruminococcus bromii, Eubacterium rectale-Clostridium coccoides, and Eubacterium cylindroides. The most widely promoted prebiotics inulin and fructooligosaccharides (neither is absorbed in the upper gastrointestinal tract) have been suggested to increase the number of bifidobacteria. Dahlia inulin was shown to cause a pronounced increase in the number of bacteria related to R. flavefaciens-R. bromii and E. cylindroides.

Other findings suggest that heavier individuals may have a different makeup of gut bugs than thin ones. The gut microbiota of obese mice has been shown to have significantly more of one main type of bacteria called Firmicutes and fewer of another kind called Bacteroidetes (both types populate human guts as well); in normal mice, the distribution is the opposite.
Whether you call them thongs, flip-flops or jandals, the simple rubber sandals could be a breeding ground for bacteria too. They allow easy access to oxygen, skin cells and oils, dirt and moisture. Eighty per cent of the population already have Staphylococcus aureus - found on sandals after being work for 4 days - on their skin, in their nose and armpits, yet this microbe aureus could make you pretty sick if it gets into a cut and into your blood, and if your immune system is not robust.
Some of bad bacteria can be even found in bottled water or in Fast Food Soda Fountains (see this article published in International Journal of Food Microbiology). 48% of soda fountains at fast food restaurants contain coliform bacteria. More than 11% of the beverages analyzed contained Escherichia coli and over 17% contained Chryseobacterium meningosepticum. Other opportunistic pathogenic microorganisms isolated from the beverages included species of Klebsiella, Staphylococcus, Stenotrophomonas, Candida, and Serratia.

Bacterial phylotypes Clostridium cocleatum, Clostridium thermosuccinogenes, Coprobacillus catenaformis, Ruminococcus bromii-like, Ruminococcus torques and R. torques were detected in similar amounts in IBS-C and IBS-D patients. C. thermosuccinogenes, however, was quantified in significantly different quantities depending on constipation or diarrhea-predominant cases. Bacteria similar to R. torques was more prevalent in IBS-D patients' intestinal microbiota than in that of control subjects. a R. bromii-like phylotype was associated with IBS-C patients. These findings further emphasized the possible contribution of the gastrointestinal microbiota in IBS. For IBD, novel invasive species of Escherichia coli possibly replacing some Clostridiales were found in inflamed mucosa. The number of E.coli correlated with the severity of Crohn's disease involving the ileum.

Differences in microbiota may depend on genetics, metabolism, environmental exposures during childhood, state of health. Selective increase in novel invasive species of E.coli seems to be involved in the etiopathogenesis to Crohn's disease involving the ileum (different species are implicated in UC). Other bacterial species specific to Crohn's are B. ovatus and B. vulgatus.
Myalgic Encephalomyelitis/Encephalopathy/Chronic Fatique Syndrome may be another condition caused by microbes. People with Cystic Fibrosis, for example, have more microbes enriched in aromatic amino acid metabolism in their airways. Note that this disease causes a distinct acidic breath - the more severe the condition is in an individual, the more acidic his breath becomes. The microbes were especially sensitive to amino-acid starvation indicating that therapeutic measures may be more effective if used to change the respiratory environment, as opposed to shifting the taxonomic composition of resident microbiota.

Altered breath resulting from changed micrflora is a known phenomenon and it can be detected not only by complex mass spec machines, but also by devices used in QA testing of foods (e.g. Cyranose pick up the scent of penzane, isoprene acetone, and benzene in the breath of lung cancer patients) and car air quality sensors to study human "fermentome". Hydrogen Sulfide Urine Test was developed (Kenny de Meirleir's work on testing was never published in a Peer Reviewed Journal) and is available for at-home use. Some people, however, prefer to use their nose instead of spending money for testing kits. Candida overgrowth usually is not associated with excess hydrogen sulfide. Biomed diagnostics offers inexpensive tests for Candida species.
Their InTrayTM ColorexTM Screen also detects E.coli, Proteus mirabilis, Enterococcus sp., Klebsiella pneumnaiae, Staphylococcus aureus bacteria and Dermatophytes fungi. Many tests are available for urinary tract infections and various metabolites in urine. See also ongoing clinical trials on chemicals in human breath for diagnostics of diseases. The science of Grossology has only just scratched the surface of all the possibilities.

So, even seemingly innocent gut bacteria may be affecting many aspects of health and behavior. One day we may be even allowed to say: I’m sorry, sir, my microbes made me do it.

Even though the vast majority of our microbes are good for us or can be even used for diagnostics of the processes in our bodies, some are there to get us, contributing to skin diseases, body odor, malabsorption, gastrointestinal problems, ear infections and more.

Almost anything we touch or wear could be a breeding ground for bacteria. Remember the heavily reblogged and retwitted statement: "Wearing headphones for just an hour will increase the bacteria in your ear by 700 times"? Well, not exactly 700 times, 11 times and these are mostly our own bacteria that liked heat and humidity created in the ears and started to multiply more actively, but pretty much anything you stick in your ears - stethoscopes, hearing aids, audiological gear - comes out covered in microbes.

Parade beads could be be contaminated with bacteria too. Gasparilla beads, were shown to be covered with several types of bacteria includinf E. coli and salmonella.

Even cigarettes - besides their harmful toxic chemicals - host a bacterial bonanza —hundreds of different germs, including those responsible for many human illnesses, according to a new study. For example, Campylobacter, which can cause food poisoning and Guillain-Barre Syndrome; Clostridium, which causes food poisoning and pneumonias; Corynebacterium, also associated with pneumonias and other diseases; E. coli; Klebsiella, Pseudomonas aeruginosa and Stenotrophomonas maltophilia, all of which are associated not only with pneumonia but also with urinary tract infections; and a number of Staphylococcus species that underlie the most common and serious hospital-associated infections.

Anoter source of pathogens is undercooked and spoiled food. Take pork, for example. Five out of 90 samples of retail pork in Lousiana tested positive for MRSA — an antibiotic-resistant staph infection — thanks to antibiotics piglet's ears. MRSA (pronounced “mersa”) stands for methicillin-resistant Staphylococcus aureus whose new strain ST398 is on the rise.

And of course, people could also pass microbes to each other: Epstein-Barr virus (EBV) (causing mononucleosis - infamously known as the kissing disease), Herpes Simplex Virus-1 (causing cold sores) bacterium Streptococcus (causing various infections such as gum disease and strep throat), H.pylori, Candida or other yeast species, Hepatitis B Virus and cytomegalovirus (CMV) are spread via oral transmission from microbe-containing saliva.

How can we control populations of microbes colonizing us? Besides drugs wiping out entire populations - assuming they are not resistant to these drugs, food could help in cultivation efforts too. Example: vinegar. It was shown to reduce counts of not-so-benefitial bacteria. Diluted solutions of various household sanitizers (apple cider vinegar, white vinegar, bleach, and a reconstituted lemon juice product) were tested for their effectiveness in reducing counts of inoculated Escherichia coli and naturally present aerobic, mesophilic bacteria on lettuce. Of the sanitizers tested, 35% white vinegar (1.9% acetic acid) was the most effective in reducing E. coli and other aerobic microbes.

Aurametrix is developing decision support systems to help you evaluate health risks, decide on preventative measures, estimate cost/benefits of performing diagnostic tests, determine your nutrition needs and life style adjustments. Better solutions for a healthier world.

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