Hot pepper oil may inhibit Salmonella in poultry.

Adding capsaicin, the spicy component of peppers, to the diet of neonatal broiler chicks appears to increase their resistance to Salmonella, according to scientists at Virginia Polytechnic and State University (Department of Animal and Poultry Sciences, College of Agriculture and Life Sciences, 3020 Litton-Reaves Hall, Blacksburg, VA 24061).

Researchers wondered why people like spicy foods even though they often cause watery eyes and other ill effects. Some believe that hot foods and spices provide protection against disease.

The scientists quickly made the jump from humans to poultry, and hypothesized that a diet that included some form of hot peppers might protect broilers and other commercial poultry from intestinal disease. Their research began by purchasing 1,530 commercial meat chicks, dividing them into three groups and feeding each group a standard corn and soybean meal-based diet for 42 days. Investigators fed the plain feed to the first group, but added 5 parts per million (ppm) of pure capsaicin to the feed of the second group, and 20 ppm to the third group's feed.

They then administered S. enteritidis to the chicks at 21, 28 and 42 days of age. They found that both the low and the high level of capsaicin increased resistance to the Salmonella without adversely affecting feed consumption, weight gain or the taste of the chicken when cooked. What they saw from their initial microscopic evaluation is that the capsaicin appears to cause a very mild inflammation in the chickens' intestines.

One theory researchers are investigating is that the presence of the capsaicin-induced inflammation might make it more difficult for the Salmonella to bind to the intestinal cells and, from there, to branch out to invade the blood, liver and spleen. It may be that the capsaicin acts on the intestine to recruit immune cells, which then fight off the Salmonella.

Researchers evaluated any observable effects of capsaicin directly on Salmonella in laboratory conditions, the effects of capsaicin on the intestinal environment and the most economical scheme of feeding capsaicin to commercial poultry. Salmonella typically results in little to no observable illness in chickens, but it is a disease of concern to the industry due to its ability to cause human illness. In a poultry house, it is spread from bird to bird or through the feeders and water. From there, it may move into the processing plant, where it can cross-contaminate other birds.

The poultry seem to have no objections to the taste or sting of the capsaicin. Researchers believe that chickens and other birds may have evolved so that their taste receptors adapted to allow them to eat the colorful pods. If scientists can prove that feeding capsaicin to birds does reduce Salmonella in a commercial poultry-production situation, then they would have a non-antibiotic way of reducing foodborne pathogens. Consumers look for antibiotic-free products, and this may provide the answer.

Further information. Audrey McElroy; phone: [phone]; fax: [phone]; email: [e-mail].