Scientists investigate crop-made prebiotics that bolster gut bacteria.

Ongoing studies by USDA-ARS scientists suggest that making prebiotics from carbohydrates, using a new enzymatic process, may expand markets for corn and other commodity crops.

As you may know, prebiotics are complex carbohydrates, such as inulin and short-chain sugars and oligosaccharides, that pass undigested from the lower intestine to the colon. There, the carbohydrates are consumed by Bifidobacterium and other beneficial bacteria that release vitamins, minerals and nutrients that might not otherwise be available to their human or animal hosts. The bacteria may also change the colon environment so that the existence of such pathogens as Salmonella is curtailed.

In this case, ARS chemists found that an enzyme-based process for making alternan--a promising bulking agent--also yields oligosaccharides that stimulate the growth of Bifidobacterium bacteria.

In Europe and Asia, consumers seeking to improve their gastrointestinal health can purchase prebiotic products specifically formulated to bolster populations of these and other bacterial gut colonists. The U.S. market for prebiotics is comparatively young, but it is growing. The fermentation studies at ARS' National Center for Agricultural Utilization Research eventually could offer U.S. prebiotic makers a way to mass-produce the oligosaccharides from a domestic commodity: carbohydrate-rich corn, soybean, beet and cane crops. Scientists at the USDA-ARS Eastern Regional Research Center in Wyndmoor, PA, have similar aspirations--but for pectin from citrus peels and other crop byproducts.

Early lab results indicate the oligosaccharides nourish several beneficial strains of Bifidobacterium, but not pathogens such as Salmonella, Escherichia coli and Clostridium. In April, the ARS researchers applied for patent protection covering the synthesis and potential use of some of the prebiotics as food additives for both people and livestock animals.

The research comes at a time when 10 million Americans annually require hospital care for gastrointestinal problems ranging from constipation and diarrhea to ulcers, irritable bowel syndrome and colon cancer. Prebiotics might be able to fortify beneficial bacteria in the gut and help relieve some of these problems.

Further information. Gregory Cote, USDA-ARS National Center for Agricultural Utilization Research, Room 3104, 1815 N. University St., Peoria, IL, 61604; phone: [phone]; fax: [phone]; email: [e-mail].