They are a species unto themselves and they live in us ALL.
Recently, medical science has begun to clue into the fact that the bacteria that thrives in us, is directly related to our health…
Though no one is exactly SURE who, what, when or how, the possibilities are indeed there, hinted at, and because they are? They have been pushing a whole NEW field of medical research.
[via Scientific American] Probiotics are living species (typically bacteria, though I will argue for a broader definition) [I have one - It's poo!] taken in one form or another by animals (typically though not always humans) in order to improve their health. The great hope with probiotics is that we might eat and favor a suite of living forms that make us healthier. Stores are filled with probiotics produced and purchased on the basis of this hope. The difficulty has been actually figuring out what species of bacteria might benefit us and also how, and/or why. For the most part, the answers are. A) No one is sure. B) No one is sure and C) No one is sure.
You would be forgiven for thinking that the benefits of probiotics were well known and worked out. After all, billions of dollars of probiotics are purchased each year and books offer “the wonderful new probiotics lifestyle.” Yet, a recent review of probiotics finds that for many of the ailments for which they are used, ailments that range from cancer to yeast infections, that their benefits are still unclear.
“A multicenter European based trial with 287 children aged 1-36 months from 10 countries is one of the most extensive trials investigating probiotic treatment for acute diarrhea reported (Guandalini et al., 2000). The children were experiencing moderate to severe diarrhea. The patients were randomized to be given placebo or LGG along with oral rehydration solution. The children receiving LGG had a shorter duration and decreased severity of disease along with a shorter hospital stay.”
Here, LGG is the species Lactobacillus GG. That this species helps with diarrheal cases, which are a major cause of death in infants globally, is important and interesting, but how do these bacterial species actually “work?” What scientists often assume happens is that the probiotic bacteria team up with the immune system (both by boosting it and by fighting themselves) to run the disease-causing agent (in the case of diarrhea, often a rotavirus) in the gut out of town. The problem though with this assertion is that such molecular warfare by probiotic bacteria has not been very well studied, particularly in the case of specific pathogens, rather than just broad diseases (such as diarrhea). It is hard to study humans with such pathogens and their diseases, harder still to experimentally give humans diseases only to subsequently try to cure them. That is why scientists study mice. In mice, a series of new studies has finally begun to get down to the nitty gritty of probiotic success and failure.
Then, recently, a very exciting study was published by Empara Chenoll and her colleagues at the University of Valencia in Spain. Chenoll was interested in the human pathogen, Heliobacter pylori AKA H. pylori. Though its name does not have the ring of, say, Cholera, H. pylori is bad news. It is the major cause of ulcers and a major cause of intestinal cancer in humans. If we could get rid of H. pylori, it would be good. Chenoll wondered if there were probiotic bacteria that when consumed would kill off H. pylori. Her first step was to fight H. pylori against different lineages of the bacterial species Bifidobacterium bifidum, in petri dish versions of cage matches. The good and bad bacteria were paired in a petri dish and then allowed to fight, to the death. Chenoll then picked the toughest lineage, the one that most often killed H. pylori. That lineage, which turned out to be “CECT 7366″ was the one they would introduce into mice, to save them from H. pylori, after, of course, giving them H. pylori.
When Chenoll and friends added the H. pylori and good bacteria to the mice, the rules were,
“In experimental groups A and B, … a suspension of H. pylori … was administered for three consecutive days from day 1 onwards. In group B,… a suspension … of strain CP5 was administered orally for 11 and 18 days after infection. In group A, … a placebo … was administered. On day 14, five mice from each group were killed and analyzed, and on day 21, the remaining five mice from each group were killed and analyzed.”
Or in other words, all of the mice were given H. pylori. Half of the mice were then given the probiotics, the other half weren’t. H. pylori might just win, in which case all of the mice would stay sick. Or maybe the probiotics would win, in which case the mice treated with the probiotics would get better.
In the end, what happened was what society seems to hope will happen. The mice given the probiotic bacteria got better. The probiotics killed the H. pylori (which we know because after the mice got better, the scientists, of course, killed them and checked). In the grudge match of H. pylori versus probiotics, the probiotics won, handily. And what of the weapon being used in these fights? The evidence points toward the possibility that the probiotic bacterial species, Bifidobacterium bifidum, is producing an antibiotic protein that it is using to kill the H. pylori. What is more, the probiotics, with these tiny chemical swords, appear capable of surviving the journey through a mouse stomach and into the intestines (as revealed in additional experiments) such that those of us who are like mouse (which is all of us, who are you kidding) might one day take Bifidobacterium bifidum to cure ourselves of H. pylori. Hooray. [Read More]
Although we have no idea what ALL exactly this species that lives in us, can do for us?
We now know this species can do something.
And if you think using the term ‘species’ for bacteria is a bit of stretch?
We also know this as well…
They use tools too.
What is that, if not species-like?
[via eScience News] Bacteria use various appendages to move across surfaces prior to forming multicellular bacterial biofilms. Some species display a particularly jerky form of movement known as “twitching” motility, which is made possible by hairlike structures on their surface called type IV pili, or TFP. “TFP act like Batman’s grappling hooks,” said Gerard Wong, a professor of bioengineering and of chemistry and biochemistry at the UCLA Henry Samueli School of Engineering and Applied Science and the California NanoSystems Institute (CNSI) at UCLA. “These grappling hooks can extend and bind to a surface and retract and pull the cell along.”
In a study to be published online this week in Proceedings of the National Academy of Sciences, Wong and his colleagues at UCLA Engineering identify the complex sequence of movements that make up this twitching motility in Pseudomonas aeruginosa, a biofilm-forming pathogen partly responsible for the deadly infections seen in cystic fibrosis.
During their observations, Wong and his team made a surprising discovery. Using a high-speed camera and a novel two-point tracking algorithm, they noticed that the bacteria had the unique ability to “slingshot” on surfaces.
The team found that linear translational pulls of constant velocity alternated with velocity spikes that were 20 times faster but lasted only milliseconds. This action would repeat over and over again.
“The constant velocity is due to the pulling by multiple TFP; the velocity spike is due to the release of a single TFP,” Wong said. “The release action leads to a fast slingshot motion that actually turns the bacteria efficiently by allowing it to over-steer.” [Read More]
Makes one wonder what else they are doing in our bodies that we have NO clue about…
Either to our benefit or our detriment, we HAVE a species that lives inside us…
We are a host plant to another world.
Hard, isn’t it, to be able to grasp that concept, almost, isn’t it?
But one must admit, is sure doesn’t detract from the cool of it either.