Selling fiber and bacteria

I watch the Simpsons. I consider it essential viewing for the maintenance of sanity. Apparently an awful lot of people with either IBS or "normal" constipation do too, judging by the marketing wizards' placement of advertisements for probiotics and/or soluble fiber in the central ad slot. Drives me up the wall. So how effective are these interventions in improving bowel function?

Well, probiotics appear to be very strain related but can have benefits in some situations. Dr Hunter is a gastroeneterologist at Addenbrooks in Cambridge. Taking a combination of bifidobacteria and lactobacillus that looks remarkably like yogurt minimises anaerobic overgrowth when you are on an antibiotic for helicobacter. Fair enough. I ferment my cream with these bugs.

But the role of probiotics in IBS "has not been clearly defined". Probably depends on who funded the study. Certainly lactobacillus plantarum 299v is not too hot.

Lactobacillus casei strain Shirota is pretty interesting according to the company which sells it. Lovely graphics on the homepage BTW. How much did the web site cost? I guess nothing compared to their TV advertising budget.

But are they needed anyway? Two interventions which do work are compared, by Dr Hunter again, here:

Metronidazole (an antibiotic aimed at anaerobic lower bowel bacteria) is pretty good, reducing peak gas production from 671ml/min to 422ml/min. Obviously no one wants to take metronidazole long term in view of its serious interaction with alcohol and its occasional neurological toxicity. But it makes a fairly convincing case that the problem is a bacterial problem. What do bacteria eat that humans cannot digest? Fiber.

So the other intervention is a no-fiber diet. Peak gas production dropped from 564ml/min to 205ml/min. This looks to be very effective and very interesting.

Both improved symptoms. As fiber is of no use to humans and it appears to feed the bacteria that cause IBS, including good old klebsiella, you have to wonder where the medical fascination with fiber comes from...

We all know where fiber ends up, why suffer the gut problems it causes as it gets there?

Peter