Stopping Food-Borne Illness
If you've ever carefully washed a cutting board after slicing raw chicken or passed on the platter of deviled eggs that's been sitting at room temperature for who knows how long, you've done your part to prevent Salmonella infection, a type of food poisoning.
Now, scientists at Arizona State University say they've found evidence that Lactobacillus reuteri, bacteria that naturally live in a healthy gut, produce a substance called "reuterin," which wards off Salmonella poisoning. The exact mechanism is unknown, but reuterin appears to help keep cells lining the intestinal walls of mammals safe from salmonella.
We know that there is a connection between the brain and the gut, which is why a stressful day can cause indigestion or anxiety can increase irritable bowel symptoms, for example. But it is newly thought that this communication may not be simply from the brain to the gut, but a two-way sharing of signals. Animal studies have shown that good bacteria help facilitate resistance to stress, particularly early in life, when bacteria are first being introduced. And the way we tolerate stress tends to persist over our lifespan, so the bacteria that the body is exposed to when we are very young may well have lifelong consequences.
A study led by a Washington University School of Medicine researcher compared the gut bacteria of twin siblings in which one twin was obese. They introduced the gut bacteria of each twin to mice, and found that the rodents gained weight or stayed lean according to which bacteria they were exposed to.
Interestingly, allowing the mice with differing bacteria to interact with each other helped obese mice return to a healthy weight—but only when that interaction was paired with a healthy diet. In other words, obese mice exposed to the "lean" promoting bacteria did not lose weight on an unhealthy, high-calorie diet.
Although much of this research is in its early stages, today's studies hint that a gut filled with "good" bacteria can have a range of health-promoting impacts, from supporting the immune system to allowing us to better cope with stress.
American Psychological Association, "That Gut Feeling," www.apa.org, accessed on December 6, 2013.
Arizona State University, "Beneficial Bacteria May Help Ward Off Infection," researchmatters.asu.edu, accessed on December 6, 2013.
International Foundation for Functional Gastrointestinal Disorders, "Antibiotics & Diarrhea," www.iffgd.org, accessed on December 6, 2013.
Jane A. Foster and Karen-Anne McVey Neufeld. "Gut-Brain Axis." Trends in Neurosciences. 2013 May;36(5):305-12.