Good bacteria pack a positive punch for the gut

By Martin Leggett - 23 May 2011 16:0:0 GMT
Good bacteria pack a positive punch for the gut

For those suffering from the myriad complaints that are rolled up under the term 'Irritable Bowel Disorders', relief has often been promised through large dollops of probiotic yogurt or drinks. Now research from Tennessee's Vanderbilt University has shown that an extracted protein, from just such beneficial bacteria, really does make things easier for IBD sufferers. That could lead to more effective ways of maximizing the benefits of 'good bacteria' in our guts.

The study, published in today's Journal of Clinical Investigation, is one of the first to isolate some promising proteins from bacteria that pro-biotic yogurts contain. Our guts are natural homes for a vast panoply of bacteria - ones that usually co-exist happily there - performing a number of useful functions. But for some, as yet undiscovered, reason, people in developed countries have been increasingly prone to bowel disorders - including such nasties as ulcerative colitis and Crohn's disease.

The co-author for the study, Brent Polk of the Vanderbilt University Medical Center, had his interest piqued when a colleague, asked him ''Is there anything to this probiotic stuff?'' In order to answer that question, Polk and paper lead, Fang Yan - also from the  Medical Center - looked at a commonly advocated bacteria: Lactobacillus rhamnosus GG, or LGG.

As well as a supplement in yogurts, LGG has been used to treat IBD, diarrhea and dermatitis, with varying degrees of success. Yan and Polk wondered whether using a direct extracts of proteins from the bacterium might produce more clear-cut benefits. In order to test this, the pair extracted a specific protein, known as p40, and looked at how its application worked on models of mice guts.

Their cell-based experiments showed that the p40 protein was a potentially useful one for IBD -  because it activates the epidermal growth factor receptor (EGFR). EGFR produces a protein that promotes cell growth and survival - including the important cells lining the lower gut. It is thought that this helps to reduce the disruptive knock-on effects of inflammation.

The team then looked at whether gel bead impregnated with the p40 protein could be useful in treating colitis. It was hoped the gel would protect the protein from attack by digestive enzymes, and acids - which might reduce the benefits of the p40 protein. And the results were promising - the three mouse models they tested showed p40 did 'the trick' in reducing the symptoms of acute colitis.

Yan thinks that delivering the benefits of 'good bacteria' in this way will be much more effective overall - if somewhat less tasty. Firstly, ''even if you eat live bacteria (as in yogurt), that does not mean 100 percent of bacteria will still be alive (and active) in your body,'' she said. And then there is the issue of allergic reaction. ''In patients with immune deficiency, it could be a problem because it may induce an abnormal immune response.'' A gel-delivered extract could overcome both those issues, and provide potential respite for IBD sufferers.