Sources: nobody expects you, dear reader, to get down and dirty with the scientific literature. Each paper will normally present only one study indicating that bacterial strain X is associated with condition Y in either mice or humans, occasionally both. If you take the materials and methods on trust [and you shouldn't!], you can get the key factlet from the PubMed abstract. Or you can read Giulia Enders book: Gut: The Inside Story of Our Body's Most Underrated Organ; [originally Darm mit Charme. Alles über ein unterschätztes Organ] which I reviewed a tuthree weeks ago. I was all set to present an ExecSummary of that book when one of the WexSciCaf lurkers pointed me at The Psychobiotic Revolution by Anderson, Cryan and Dinan. Scott Anderson is a US-based science journalist, while John Cryan and Ted Dinan are academics from UCC in the Independent Republic of Cork.
In the airy arm-wavy world of popular science books you have to polish your crap-detector before you invest time and money in 'facts' therein presented. Here, I'll share some of the interesting intel which I gleaned from my reading.
The money is in probiotics but you and I don't want to spend our hard-earned dollars on products of dubious efficacy and doubtful quality control. Dinan & Cryan cite one study where the contents of 13 probiotic supplements were compared to what it said on the tin. Only 4/13 had a table of contents than actually matched the contents. Probiotics are food supplements and have a far lower administrative and licencing bar to leap than drugs which are classified as medicine. But the thrify should follow the prebiotics route: these are the dietary changes that can encourage the growth of good bacteria: try ginger, garlic, carrots, apples for starters. Actually, keep it simple and follow Michael Pollan [multiprev]: Eat food; not too much; mostly plants. Un-food is anything that comes in a packet with more than 6 indredients.
There has been a bit of interest recently in the few cases of auto-brewery syndrome. This occurs when a colony of bakers' yeast Saccharomyces cerevisiae, against the odds and its normal environment, sets up shop in some person's intestine. There it scarfs up any passing sugar and anaerobically converts it to ethanol and carbon dioxide. The CO2 causes a certain increase in fartiness but the alcohol crosses the intestinal epithelium and starts to intoxicate. I don't think you'd have a leg to stand on [you'd be legless, arf arf] in court if you got arrested for driving under the influence.
Now before I forget, I'll note some of the major players in the gut flora: some good and some bad; all just tryimng to make a living. There may be 1,000 different species of microbe donw in the dark, but 99% of them fit into 4 different Phyla [major groups of bacteria]
- Bifidobacterium longum, B. breve; B. dentium [richer in infant guts]
- Proprionobacterium shermanii [bubbles in Emmenthal]
- Clostridium difficile, C. botulinum [botox]
- Bacillus cereus [re-heated rice poisoning]
- Lactobacillus spp. LABs good guys
- Bacteroides thetaiotaomicron [prev]; B. fragilis; B. plebeus [freq in Japan]
- alpha: Rickettsia prowazekii; Brucella abortus [prev Alice Evans]
- beta: Neisseria gonorrhoeae, [the clap] N. meningitidis [meningitis]
- gamma: Escherichia coli and other enterics incl Salmonella; Pseudomonas aerogenosa
- epsilon: Campylobacter jejuni [food poisoning] Helicobacter pylori [ulcers]